48 results on '"Serwanga J"'
Search Results
2. Examining oral pre-exposure prophylaxis (PrEP) literacy among participants in an HIV vaccine trial preparedness cohort study
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Chimukuche, RS, Kawuma, R, Mahapa, N, Mkhwanazi, S, Singh, N, Siva, S, Ruzagira, E, Seeley, J, Gray, G, Gaffoor, Z, Morar, N, Sithole, T, Woeber, K, Hwengwere, E, Chidawanyika, RS, Khanyile, P, Jani, I, Viegas, E, Remane, I, Bule, O, Nhacule, E, Ramgi, P, Chissumba, R, Namalango, E, Manganhe, Y, Massingue, C, Capitine, I, Ribeiro, J, Maganga, L, William, W, Kapesa, E, Danstan, E, Pamba, D, Kway, MMA, Kisinda, A, Njovu, L, Sudi, L, Kunambi, R, Aboud, S, Munseri, P, Lyamuya, E, Msafiri, F, Joachim, A, Tarimo, E, Nagu, DFT, Buma, D, Bakari, M, Kaleebu, P, Kibengo, FM, Kakande, A, Serwanga, J, Holmes, CH, Kansiime, S, Kusemererwa, S, Masawi, S, Basajja, V, Vudriko, T, Hughes, P, Nabukenya, S, Mutonyi, G, Nakiboneka, R, Mugaba, S, Weber, J, Kingsley, C, Miller, T, McCormack, S, Crook, A, Dunn, D, Bern, H, Sy, A, Brodnicki, L, Joseph, S, Wenden, C, Chinyenze, K, Musau, J, Matsoso, M, Amondi, M, Chetty, P, Gumbe, A, Pantaleo, G, Ding, S, Nilsson, C, Kroidl, A, Fox, J, Doncel, G, Matthews, A, Rooney, J, Lee, C, and Robb, M more...
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AIDS Vaccines ,Cohort Studies ,Literacy ,Anti-HIV Agents ,Health Policy ,Humans ,Pre-Exposure Prophylaxis ,HIV Infections - Abstract
Background PrEP literacy is influenced by many factors including the types of information available and how it is interpreted. The level of PrEP literacy may influence acceptability and uptake. Methods We conducted 25 in-depth interviews in a HIV vaccine trial preparedness cohort study. We explored what participants knew about PrEP, sources of PrEP knowledge and how much they know about PrEP. We used the framework approach to generate themes for analysis guided by the Social Ecological Model and examined levels of PrEP literacy using the individual and interpersonal constructs of the SEM. Results We found that PrEP awareness is strongly influenced by external factors such as social media and how much participants know about HIV treatment and prevention in the local community. However, while participants highlighted the importance of the internet/social media as a source of information about PrEP they talked of low PrEP literacy in their communities. Participants indicated that their own knowledge came as a result of joining the HIV vaccine trial preparedness study. However, some expressed doubts about the effectiveness of the drug and worried about side effects. Participants commented that at the community level PrEP was associated with being sexually active, because it was used to prevent the sexual transmission of HIV. As a result, some participants commented that one could feel judged by the health workers for asking for PrEP at health facilities in the community. Conclusion The information collected in this study provided an understanding of the different layers of influence around individuals that are important to address to improve PrEP acceptability and uptake. Our findings can inform strategies to address the barriers to PrEP uptake, particularly at structural and community levels. Trial registration https://clinicaltrials.gov/ct2/show/NCT04066881 more...
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- 2022
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Catalog
3. Group M consensus Gag and Nef peptides are as efficient at detecting clade A1 and D cross-subtype T-cell functions as subtype-specific consensus peptides
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Mugaba, S., Nakiboneka, R., Nanyonjo, M., Bugembe-Lule, D., Kaddu, I., Nanteza, B., Tweyongyere, R., Kaleebu, P., and Serwanga, J.
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- 2014
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4. Immunogenicity of a Recombinant Human Immunodeficiency Virus (HlV)-Canarypox Vaccine in HlV-Seronegative Ugandan Volunteers: Results of the HIV Network for Prevention Trials 007 Vaccine Study
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HIV Network for Prevention Trials, Cao, H., Kaleebu, P., Hom, D., Flores, J., Agrawal, D., Jones, N., Serwanga, J., Okello, M., Walker, C., Sheppard, H., El-Habib, R., Klein, M., Mbidde, E., Mugyenyi, P., Walker, B., Ellner, J., and Mugerwa, R. more...
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- 2003
5. HLA-restricted peptide-specific IFNγ responses in HIV-infected and exposed but seronegative (ESN) individuals
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Gotch, F., Rowland, S., Serwanga, J., Imami, N., and Kebba, A.
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- 2003
6. Immunogenicity of a recombinant human immunodeficiency virus (HIV)--canarypox vaccine in HTV-seronegative Ugandan volunteers: results of the HIV network for prevention trials 007 vaccine study. (Major Article)
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Cao, H., Kaleebu, P., Hom, D., Flores, J., Agrawal, D., Jones, N., Serwanga, J., Okello, M., Walker, C., Sheppard, H., El-Habib, R., Klein, M., Mbidde, E., Mugyenyi, P., Walker, B., Ellner, J., and Mugerwa, r. more...
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Africa -- Health aspects ,Communicable diseases -- Research ,AIDS vaccines -- Usage ,AIDS vaccines -- Evaluation ,AIDS vaccines -- Research ,HIV antigens -- Physiological aspects ,AIDS (Disease) -- Prevention ,HIV (Viruses) -- Physiological aspects ,HIV (Viruses) -- Genetic aspects ,Vaccines industry -- Research ,Immunogenetics -- Research ,Health - Published
- 2003
7. Abstracts of the Eighth EDCTP Forum, 6-9 November 2016.
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Makanga, M, Beattie, P, Breugelmans, G, Nyirenda, T, Bockarie, M, Tanner, M, Volmink, J, Hankins, C, Walzl, G, Chegou, N, Malherbe, S, Hatherill, M, Scriba, TJ, Zak, DE, Barry, CE, Kaufmann, SHE, Noor, A, Strub-Wourgaft, N, Phillips, P, Munguambe, K, Ravinetto, R, Tinto, H, Diro, E, Mahendrahata, Y, Okebe, J, Rijal, S, Garcia, C, Sundar, S, Ndayisaba, G, Sopheak, T, Ngoduc, T, Van Loen, H, Jacobs, J, D'Alessandro, U, Boelaert, M, Buvé, A, Kamalo, P, Manda-Taylor, L, Rennie, S, Mokgatla, B, Bahati, Ijsselmuiden, C, Afolabi, M, Mcgrath, N, Kampmann, B, Imoukhuede, E, Alexander, N, Larson, H, Chandramohan, D, Bojang, K, Kasaro, MP, Muluka, B, Kaunda, K, Morse, J, Westfall, A, Kapata, N, Kruuner, A, Henostroza, G, Reid, S, Alabi, A, Foguim, F, Sankarganesh, J, Bruske, E, Mfoumbi, A, Mevyann, C, Adegnika, A, Lell, B, Kranzer, K, Kremsner, P, Grobusch, M, Sabiiti, W, Ntinginya, N, Kuchaka, D, Azam, K, Kampira, E, Mtafya, B, Bowness, R, Bhatt, N, Davies, G, Kibiki, G, Gillespie, S, Lejon, V, Ilboudo, H, Mumba, D, Camara, M, Kaba, D, Lumbala, C, Fèvre, E, Jamonneau, V, Bucheton, B, Büscher, P, Chisenga, C, Sinkala, E, Chilengi, R, Chitundu, H, Zyambo, Z, Wandeler, G, Vinikoor, M, Emilie, D, Camara, O, Mathurin, K, Guiguigbaza-Kossigan, D, Philippe, B, Regassa, F, Hassane, S, Bienvenu, SM, Fabrice, C, Ouédraogo, E, Kouakou, L, Owusu, M, Mensah, E, Enimil, A, Mutocheluh, M, Ndongo, FA, Tejiokem, MC, Texier, G, Penda, C, Ndiang, S, Ndongo, J-A, Guemkam, G, Sofeu, CL, Afumbom, K, Faye, A, Msellati, P, Warszawski, J, Vos, A, Devillé, W, Barth, R, Klipstein-Grobusch, K, Tempelman, H, Venter, F, Coutinho, R, Grobbee, D, Ssemwanga, D, Lyagoba, F, Magambo, B, Kapaata, A, Kirangwa, J, Nannyonjo, M, Nassolo, F, Nsubuga, R, Yebra, G, Brown, A, Kaleebu, P, Nylén, H, Habtewold, A, Makonnen, E, Yimer, G, Burhenne, J, Diczfalusy, U, Aklillu, E, Steele, D, Walker, R, Simuyandi, M, Beres, L, Bosomprah, S, Ansumana, R, Taitt, C, Lamin, JM, Jacobsen, KH, Mulvaney, SP, Leski, T, Bangura, U, Stenger, D, De Vries, S, Zinsou, FJ, Honkpehedji, J, Dejon, JC, Loembe, MM, Bache, B, Pakker, N, Van Leeuwen, R, Hounkpatin, AB, Yazdanbakhsh, M, Bethony, J, Hotez, P, Diemert, D, Bache, BE, Fernandes, JF, Obiang, RM, Kabwende, AL, Grobusch, MP, Krishna, S, Kremsner, PG, Todagbe, AS, Nambozi, M, Kabuya, J-B, Hachizovu, S, Mwakazanga, D, Kasongo, W, Buyze, J, Mulenga, M, Geertruyden, J-P, Gitaka, J, Chan, C, Kongere, J, Kagaya, W, Kaneko, A, Kabore, N, Barry, N, Kabre, Z, Werme, K, Fofana, A, Compaore, D, Nikiema, F, Some, F, Djimde, A, Zongo, I, Ouedraogo, B, Kone, A, Sagara, I, Björkman, A, Gil, JP, Nchinda, G, Bopda, A, Nji, N, Ambada, G, Ngu, L, Tchadji, J, Sake, C, Magagoum, S, Njambe, GD, Lisom, A, Park, CG, Tait, D, Sibusiso, H, Manda, O, Croucher, K, Van Der Westhuizen, A, Mshanga, I, Levin, J, Nanvubya, A, Kibengo, F, Jaoko, W, Pala, P, Perreau, M, Namuniina, A, Kitandwe, P, Tapia, G, Serwanga, J, Yates, N, Fast, P, Mayer, B, Montefiori, D, Tomaras, G, Robb, M, Lee, C, Wagner, R, Sanders, E, Kilembe, W, Kiwanuka, N, Gilmour, J, Kuipers, H, Vooij, D, Chinyenze, K, Priddy, F, Ding, S, Hanke, T, Pantaleo, G, Ngasala, B, Jovel, I, Malmberg, M, Mmbando, B, Premji, Z, Mårtensson, A, Mwaiswelo, R, Agbor, L, Apinjoh, T, Mwanza, S, Chileshe, J, Joshi, S, Malunga, P, Manyando, C, Laufer, M, Dara, A, Niangaly, A, Sinha, I, Brodin, D, Fofana, B, Dama, S, Dembele, D, Sidibe, B, Diallo, N, Thera, M, Wright, K, Gil, J, Doumbo, O, Baraka, V, Nabasumba, C, Francis, F, Lutumba, P, Mavoko, H, Alifrangis, M, Van Geertruyden, J-P, Sissoko, S, Sangaré, C, Toure, S, Sanogo, K, Diakite, H, Doumbia, D, Haidara, K, Julé, A, Ashurst, H, Merson, L, Olliaro, P, Marsh, V, Lang, T, Guérin, P, Awuondo, K, Njenga, D, Nyakarungu, E, Titus, P, Sutamihardja, A, Lowe, B, Ogutu, B, Billingsley, P, Soulama, I, Kaboré, M, Coulibaly, A, Ouattara, M, Sanon, S, Diarra, A, Bougouma, E, Ouedraogo, A, Sombie, B, Kargougou, D, Ouattara, D, Issa, N, Tiono, A, Sirima, S, Chaponda, M, Dabira, E, Dao, F, Dara, N, Coulibaly, M, Tolo, A, Maiga, H, Ouologuem, N, Niangaly, H, Botchway, F, Wilson, N, Dickinson-Copeland, CM, Adjei, AA, Wilson, M, Stiles, JK, Hamid, MA, Awad-Elgeid, M, Nasr, A, Netongo, P, Kamdem, S, Velavan, T, Lasry, E, Diarra, M, Bamadio, A, Traore, A, Coumare, S, Soma, B, Dicko, Y, Sangare, B, Tembely, A, Traore, D, Haidara, A, Dicko, A, Diawara, E, Beavogui, A, Camara, D, Sylla, M, Yattara, M, Sow, A, Camara, GC, Diallo, S, Mombo-Ngoma, G, Remppis, J, Sievers, M, Manego, RZ, Endamne, L, Hutchinson, D, Held, J, Supan, C, Salazar, CLO, Bonkian, LN, Nahum, A, Sié, A, Abdulla, S, Cantalloube, C, Djeriou, E, Bouyou-Akotet, M, Mordmüller, B, Siribie, M, Sirima, SB, Ouattara, SM, Coulibaly, S, Kabore, JM, Amidou, D, Tekete, M, Traore, O, Haefeli, W, Borrmann, S, Kaboré, N, Kabré, Z, Nikèma, F, Compaoré, D, Somé, F, Djimdé, A, Ouédraogo, J, Chalwe, V, Miller, J, Diakité, H, Greco, B, Spangenberg, T, Kourany-Lefoll, E, Oeuvray, C, Mulry, J, Tyagarajan, K, Magsaam, B, Barnes, K, Hodel, EM, Humphreys, G, Pace, C, Banda, CG, Denti, P, Allen, E, Lalloo, D, Mwapasa, V, Terlouw, A, Mwesigwa, J, Achan, J, Jawara, M, Ditanna, G, Worwui, A, Affara, M, Koukouikila-Koussounda, F, Kombo, M, Vouvoungui, C, Ntoumi, F, Etoka-Beka, MK, Deibert, J, Poulain, P, Kobawila, S, Gueye, NG, Seda, B, Kwambai, T, Jangu, P, Samuels, A, Kuile, FT, Kariuki, S, Barry, A, Bousema, T, Okech, B, Egwang, T, Corran, P, Riley, E, Ezennia, I, Ekwunife, O, Muleba, M, Stevenson, J, Mbata, K, Coetzee, M, Norris, D, Moneke-Anyanwoke, N, Momodou, J, Clarke, E, Scott, S, Tijani, A, Djimde, M, Vaillant, M, Samouda, H, Mensah, V, Roetynck, S, Kanteh, E, Bowyer, G, Ndaw, A, Oko, F, Bliss, C, Jagne, YJ, Cortese, R, Nicosia, A, Roberts, R, D'Alessio, F, Leroy, O, Faye, B, Cisse, B, Gerry, S, Viebig, N, Lawrie, A, Ewer, K, Hill, A, Nebie, I, Tiono, AB, Sanou, G, Konate, AT, Yaro, BJ, Sodiomon, S, Honkpehedji, Y, Agobe, JCD, Zinsou, F, Mengue, J, Richie, T, Hoffman, S, Nouatin, O, Ngoa, UA, Edoa, JR, Homoet, A, Engelhon, JE, Massinga-Louembe, M, Esen, M, Theisen, M, Sim, KL, Luty, AJ, Moutairou, K, Dinko, B, King, E, Targett, G, Sutherland, C, Likhovole, C, Ouma, C, Vulule, J, Musau, S, Khayumbi, J, Okumu, A, Murithi, W, Otu, J, Gehre, F, Zingue, D, Kudzawu, S, Forson, A, Mane, M, Rabna, P, Diarra, B, Kayede, S, Adebiyi, E, Kehinde, A, Onyejepu, N, Onubogu, C, Idigbe, E, Ba, A, Diallo, A, Mboup, S, Disse, K, Kadanga, G, Dagnra, Y, Baldeh, I, Corrah, T, De Jong, B, Antonio, M, Musanabaganwa, C, Musabyimana, JP, Karita, E, Diop, B, Nambajimana, A, Dushimiyimana, V, Karame, P, Russell, J, Ndoli, J, Hategekimana, T, Sendegeya, A, Condo, J, Binagwaho, A, Okonko, I, Okerentugba, P, Opaleye, O, Awujo, E, Frank-Peterside, N, Moyo, S, Kotokwe, K, Mohammed, T, Boleo, C, Mupfumi, L, Chishala, S, Gaseitsiwe, S, Tsalaile, L, Bussmann, H, Makhema, J, Baum, M, Marlink, R, Engelbretch, S, Essex, M, Novitsky, V, Saka, E, Kalipalire, Z, Bhairavabhotla, R, Midiani, D, Sherman, J, Mgode, G, Cox, C, Bwana, D, Mtui, L, Magesa, D, Kahwa, A, Mfinanga, G, Mulder, C, Borain, N, Petersen, L, Du Plessis, J, Theron, G, Holm-Hansen, C, Tekwu, EM, Sidze, LK, Assam, JPA, Eyangoh, S, Niemann, S, Beng, VP, Frank, M, Atiadeve, S, Hilmann, D, Awoniyi, D, Baumann, R, Kriel, B, Jacobs, R, Kidd, M, Loxton, A, Kaempfer, S, Singh, M, Mwanza, W, Milimo, D, Moyo, M, Kasese, N, Cheeba-Lengwe, M, Munkondya, S, Ayles, H, De Haas, P, Muyoyeta, M, Namuganga, AR, Kizza, HM, Mendy, A, Tientcheu, L, Ayorinde, A, Coker, E, Egere, U, Coussens, A, Naude, C, Chaplin, G, Noursadeghi, M, Martineau, A, Jablonski, N, Wilkinson, R, Ouedraogo, HG, Matteelli, A, Regazzi, M, Tarnagda, G, Villani, P, Sulis, G, Diagbouga, S, Roggi, A, Giorgetti, F, Kouanda, S, Bidias, A, Ndjonka, D, Olemba, C, Souleymanou, A, Mukonzo, J, Kuteesa, R, Ogwal-Okeng, J, Gustafsson, LL, Owen, J, Bassi, P, Gashau, W, Olaf, K, Dodoo, A, Okonkwo, P, Kanki, P, Maruapula, D, Seraise, B, Einkauf, K, Reilly, A, Rowley, C, Musonda, R, Framhein, A, Mpagama, S, Semvua, H, Maboko, L, Hoelscher, M, Heinrich, N, Mulenga, L, Kaayunga, C, Davies, M-A, Egger, M, Musukuma, K, Dambe, R, Usadi, B, Ngari, M, Thitiri, J, Mwalekwa, L, Fegan, G, Berkley, J, Nsagha, D, Munamunungu, V, Bolton, C, Siyunda, A, Shilimi, J, Bucciardini, R, Fragola, V, Abegaz, T, Lucattini, S, Halifom, A, Tadesse, E, Berhe, M, Pugliese, K, De Castro, P, Terlizzi, R, Fucili, L, Di Gregorio, M, Mirra, M, Zegeye, T, Binelli, A, Vella, S, Abraham, L, Godefay, H, Rakotoarivelo, R, Raberahona, M, Randriamampionona, N, Andriamihaja, R, Rasamoelina, T, Cornet, M, De Dieu Randria, MJ, Benet, T, Vanhems, P, Andrianarivelo, MR, Chirwa, U, Michelo, C, Hamoonga, R, Wandiga, S, Oduor, P, Agaya, J, Sharma, A, Cavanaugh, S, Cain, K, Mukisa, J, Mupere, E, Worodria, W, Ngom, JT, Koro, F, Godwe, C, Adande, C, Ateugieu, R, Onana, T, Ngono, A, Kamdem, Y, Ngo-Niobe, S, Etoa, F-X, Kanengoni, M, Ruzario, S, Ndebele, P, Shana, M, Tarumbiswa, F, Musesengwa, R, Gutsire, R, Fisher, K, Thyagarajan, B, Akanbi, O, Binuyo, M, Ssengooba, W, Respeito, D, Mambuque, E, Blanco, S, Mandomando, I, Cobelens, F, Garcia-Basteiro, A, Tamene, A, Topp, S, Mwamba, C, Padian, N, Sikazwe, I, Geng, E, Holmes, C, Sikombe, K, Hantuba, Czaicki, N, Simbeza, S, Somwe, P, Umulisa, M, Ilo, J, Kestelyn, E, Uwineza, M, Agaba, S, Delvaux, T, Wijgert, J, Gethi, D, Odeny, L, Tamandjou, C, Kaindjee-Tjituka, F, Brandt, L, Cotton, M, Nel, E, Preiser, W, Andersson, M, Adepoju, A, Magana, M, Etsetowaghan, A, Chilikwazi, M, Sutcliffe, C, Thuma, P, Sinywimaanzi, K, Matakala, H, Munachoonga, P, Moss, W, Masenza, IS, Geisenberger, O, Agrea, P, Rwegoshora, F, Mahiga, H, Olomi, W, Kroidl, A, Kayode, G, Amoakoh-Coleman, M, Ansah, E, Uthman, O, Fokam, J, Santoro, M-M, Musolo, C, Chimbiri, I, Chikwenga, G, Deula, R, Massari, R, Lungu, A, Perno, C-F, Ndzengue, G, Loveline, N, Lissom, A, Flaurent, T, Sosso, S, Essomba, C, Kpeli, G, Otchere, I, Lamelas, A, Buultjens, A, Bulach, D, Baines, S, Seemann, T, Giulieri, S, Nakobu, Z, Aboagye, S, Owusu-Mireku, E, Danso, E, Hauser, J, Hinic, V, Pluschke, G, Stinear, T, Yeboah-Manu, D, Elshayeb, A, Siddig, ME, Ahmed, AA, Hussien, AE, Kabwe, M, Tembo, J, Chilukutu, L, Chilufya, M, Ngulube, F, Lukwesa, C, Enne, V, Wexner, H, Mwananyanda, L, Hamer, D, Sinyangwe, S, Ahmed, Y, Klein, N, Maeurer, M, Zumla, A, Bates, M, Beyala, L, Etienne, G, Anthony, N, Benjamin, A, Ateudjieu, J, Chibwe, B, Ojok, D, Tarr, CA, Perez, GM, Omeonga, S, Kibungu, F, Meyer, A, Lansana, P, Mayor, A, Onyango, P, Van Loggerenberg, F, Furtado, T, Boggs, L, Segrt, A, Dochez, C, Burnett, R, Mphahlele, MJ, Miiro, G, Mbidde, E, Peshu, N, Kivaya, E, Ngowi, B, Kavishe, R, Maowia, M, Sandstrom, E, Ayuo, E, Mmbaga, B, Leisegang, C, Thorpe, M, Batchilly, E, N'Guessan, J-P, Kanteh, D, Søfteland, S, Sebitloane, M, Vwalika, B, Taylor, M, Galappaththi-Arachchige, H, Holmen, S, Gundersen, SG, Ndhlovu, P, Kjetland, EF, Kombe, F, Toohey, J, Pienaar, E, Kredo, T, Cham, PM, Abubakar, I, Dondeh, BL, Vischer, N, Pfeiffer, C, Burri, C, Musukwa, K, Zürcher, S, Mwandu, T, Bauer, S, Adriko, M, Mwaura, P, Omolloh, K, Jones, C, Malecela, M, Hamidu, BA, Jenner, TE, Asiedu, LJ, Osei-Atweneboana, M, Afeke, I, Addo, P, Newman, M, Durnez, L, Eddyani, M, Ammisah, N, Abas, M, Quartey, M, Ablordey, A, Akinwale, O, Adeneye, A, Ezeugwu, S, Olukosi, Y, Adewale, B, Sulyman, M, Mafe, M, Okwuzu, J, Gyang, P, Nwafor, T, Henry, U, Musa, B, Ujah, I, Agobé, JCD, Grau-Pujol, B, Sacoor, C, Nhabomba, A, Casellas, A, Quintó, L, Subirà, C, Giné, R, Valentín, A, Muñoz, J, Nikiema, M, Ky-Ba, A, Comapore, KAM, Sangare, L, Oluremi, A, Michel, M, Camara, Y, Sanneh, B, Cuamba, I, Gutiérrez, J, Lázaro, C, Mejia, R, Adedeji, A, Folorunsho, S, Demehin, P, Akinsanya, B, Cowley, G, Da Silva, ET, Nabicassa, M, De Barros, PDP, Blif, MM, Bailey, R, Last, A, Mahendradhata, Y, Gotuzzo, E, De Nys, K, Casteels, M, Nona, SK, Lumeka, K, Todagbe, A, Djima, MM, Ukpong, M, Sagay, A, Khamofu, H, Torpey, K, Afiadigwe, E, Anenih, J, Ezechi, O, Nweneka, C, Idoko, J, Muhumuza, S, Katahoire, A, Nuwaha, F, Olsen, A, Okeyo, S, Omollo, R, Kimutai, R, Ochieng, M, Egondi, T, Moonga, C, Chileshe, C, Magwende, G, Anumudu, C, Onile, O, Oladele, V, Adebayo, A, Awobode, H, Oyeyemi, O, Odaibo, A, Kabuye, E, Lutalo, T, Njua-Yafi, C, Nkuo-Akenji, T, Anchang-Kimbi, J, Mugri, R, Chi, H, Tata, R, Njumkeng, C, Dodoo, D, Achidi, E, Fernandes, J, Bache, EB, Matakala, K, Searle, K, Greenman, M, Rainwater-Lovett, K, Makanga, M, Beattie, P, Breugelmans, G, Nyirenda, T, Bockarie, M, Tanner, M, Volmink, J, Hankins, C, Walzl, G, Chegou, N, Malherbe, S, Hatherill, M, Scriba, TJ, Zak, DE, Barry, CE, Kaufmann, SHE, Noor, A, Strub-Wourgaft, N, Phillips, P, Munguambe, K, Ravinetto, R, Tinto, H, Diro, E, Mahendrahata, Y, Okebe, J, Rijal, S, Garcia, C, Sundar, S, Ndayisaba, G, Sopheak, T, Ngoduc, T, Van Loen, H, Jacobs, J, D'Alessandro, U, Boelaert, M, Buvé, A, Kamalo, P, Manda-Taylor, L, Rennie, S, Mokgatla, B, Bahati, Ijsselmuiden, C, Afolabi, M, Mcgrath, N, Kampmann, B, Imoukhuede, E, Alexander, N, Larson, H, Chandramohan, D, Bojang, K, Kasaro, MP, Muluka, B, Kaunda, K, Morse, J, Westfall, A, Kapata, N, Kruuner, A, Henostroza, G, Reid, S, Alabi, A, Foguim, F, Sankarganesh, J, Bruske, E, Mfoumbi, A, Mevyann, C, Adegnika, A, Lell, B, Kranzer, K, Kremsner, P, Grobusch, M, Sabiiti, W, Ntinginya, N, Kuchaka, D, Azam, K, Kampira, E, Mtafya, B, Bowness, R, Bhatt, N, Davies, G, Kibiki, G, Gillespie, S, Lejon, V, Ilboudo, H, Mumba, D, Camara, M, Kaba, D, Lumbala, C, Fèvre, E, Jamonneau, V, Bucheton, B, Büscher, P, Chisenga, C, Sinkala, E, Chilengi, R, Chitundu, H, Zyambo, Z, Wandeler, G, Vinikoor, M, Emilie, D, Camara, O, Mathurin, K, Guiguigbaza-Kossigan, D, Philippe, B, Regassa, F, Hassane, S, Bienvenu, SM, Fabrice, C, Ouédraogo, E, Kouakou, L, Owusu, M, Mensah, E, Enimil, A, Mutocheluh, M, Ndongo, FA, Tejiokem, MC, Texier, G, Penda, C, Ndiang, S, Ndongo, J-A, Guemkam, G, Sofeu, CL, Afumbom, K, Faye, A, Msellati, P, Warszawski, J, Vos, A, Devillé, W, Barth, R, Klipstein-Grobusch, K, Tempelman, H, Venter, F, Coutinho, R, Grobbee, D, Ssemwanga, D, Lyagoba, F, Magambo, B, Kapaata, A, Kirangwa, J, Nannyonjo, M, Nassolo, F, Nsubuga, R, Yebra, G, Brown, A, Kaleebu, P, Nylén, H, Habtewold, A, Makonnen, E, Yimer, G, Burhenne, J, Diczfalusy, U, Aklillu, E, Steele, D, Walker, R, Simuyandi, M, Beres, L, Bosomprah, S, Ansumana, R, Taitt, C, Lamin, JM, Jacobsen, KH, Mulvaney, SP, Leski, T, Bangura, U, Stenger, D, De Vries, S, Zinsou, FJ, Honkpehedji, J, Dejon, JC, Loembe, MM, Bache, B, Pakker, N, Van Leeuwen, R, Hounkpatin, AB, Yazdanbakhsh, M, Bethony, J, Hotez, P, Diemert, D, Bache, BE, Fernandes, JF, Obiang, RM, Kabwende, AL, Grobusch, MP, Krishna, S, Kremsner, PG, Todagbe, AS, Nambozi, M, Kabuya, J-B, Hachizovu, S, Mwakazanga, D, Kasongo, W, Buyze, J, Mulenga, M, Geertruyden, J-P, Gitaka, J, Chan, C, Kongere, J, Kagaya, W, Kaneko, A, Kabore, N, Barry, N, Kabre, Z, Werme, K, Fofana, A, Compaore, D, Nikiema, F, Some, F, Djimde, A, Zongo, I, Ouedraogo, B, Kone, A, Sagara, I, Björkman, A, Gil, JP, Nchinda, G, Bopda, A, Nji, N, Ambada, G, Ngu, L, Tchadji, J, Sake, C, Magagoum, S, Njambe, GD, Lisom, A, Park, CG, Tait, D, Sibusiso, H, Manda, O, Croucher, K, Van Der Westhuizen, A, Mshanga, I, Levin, J, Nanvubya, A, Kibengo, F, Jaoko, W, Pala, P, Perreau, M, Namuniina, A, Kitandwe, P, Tapia, G, Serwanga, J, Yates, N, Fast, P, Mayer, B, Montefiori, D, Tomaras, G, Robb, M, Lee, C, Wagner, R, Sanders, E, Kilembe, W, Kiwanuka, N, Gilmour, J, Kuipers, H, Vooij, D, Chinyenze, K, Priddy, F, Ding, S, Hanke, T, Pantaleo, G, Ngasala, B, Jovel, I, Malmberg, M, Mmbando, B, Premji, Z, Mårtensson, A, Mwaiswelo, R, Agbor, L, Apinjoh, T, Mwanza, S, Chileshe, J, Joshi, S, Malunga, P, Manyando, C, Laufer, M, Dara, A, Niangaly, A, Sinha, I, Brodin, D, Fofana, B, Dama, S, Dembele, D, Sidibe, B, Diallo, N, Thera, M, Wright, K, Gil, J, Doumbo, O, Baraka, V, Nabasumba, C, Francis, F, Lutumba, P, Mavoko, H, Alifrangis, M, Van Geertruyden, J-P, Sissoko, S, Sangaré, C, Toure, S, Sanogo, K, Diakite, H, Doumbia, D, Haidara, K, Julé, A, Ashurst, H, Merson, L, Olliaro, P, Marsh, V, Lang, T, Guérin, P, Awuondo, K, Njenga, D, Nyakarungu, E, Titus, P, Sutamihardja, A, Lowe, B, Ogutu, B, Billingsley, P, Soulama, I, Kaboré, M, Coulibaly, A, Ouattara, M, Sanon, S, Diarra, A, Bougouma, E, Ouedraogo, A, Sombie, B, Kargougou, D, Ouattara, D, Issa, N, Tiono, A, Sirima, S, Chaponda, M, Dabira, E, Dao, F, Dara, N, Coulibaly, M, Tolo, A, Maiga, H, Ouologuem, N, Niangaly, H, Botchway, F, Wilson, N, Dickinson-Copeland, CM, Adjei, AA, Wilson, M, Stiles, JK, Hamid, MA, Awad-Elgeid, M, Nasr, A, Netongo, P, Kamdem, S, Velavan, T, Lasry, E, Diarra, M, Bamadio, A, Traore, A, Coumare, S, Soma, B, Dicko, Y, Sangare, B, Tembely, A, Traore, D, Haidara, A, Dicko, A, Diawara, E, Beavogui, A, Camara, D, Sylla, M, Yattara, M, Sow, A, Camara, GC, Diallo, S, Mombo-Ngoma, G, Remppis, J, Sievers, M, Manego, RZ, Endamne, L, Hutchinson, D, Held, J, Supan, C, Salazar, CLO, Bonkian, LN, Nahum, A, Sié, A, Abdulla, S, Cantalloube, C, Djeriou, E, Bouyou-Akotet, M, Mordmüller, B, Siribie, M, Sirima, SB, Ouattara, SM, Coulibaly, S, Kabore, JM, Amidou, D, Tekete, M, Traore, O, Haefeli, W, Borrmann, S, Kaboré, N, Kabré, Z, Nikèma, F, Compaoré, D, Somé, F, Djimdé, A, Ouédraogo, J, Chalwe, V, Miller, J, Diakité, H, Greco, B, Spangenberg, T, Kourany-Lefoll, E, Oeuvray, C, Mulry, J, Tyagarajan, K, Magsaam, B, Barnes, K, Hodel, EM, Humphreys, G, Pace, C, Banda, CG, Denti, P, Allen, E, Lalloo, D, Mwapasa, V, Terlouw, A, Mwesigwa, J, Achan, J, Jawara, M, Ditanna, G, Worwui, A, Affara, M, Koukouikila-Koussounda, F, Kombo, M, Vouvoungui, C, Ntoumi, F, Etoka-Beka, MK, Deibert, J, Poulain, P, Kobawila, S, Gueye, NG, Seda, B, Kwambai, T, Jangu, P, Samuels, A, Kuile, FT, Kariuki, S, Barry, A, Bousema, T, Okech, B, Egwang, T, Corran, P, Riley, E, Ezennia, I, Ekwunife, O, Muleba, M, Stevenson, J, Mbata, K, Coetzee, M, Norris, D, Moneke-Anyanwoke, N, Momodou, J, Clarke, E, Scott, S, Tijani, A, Djimde, M, Vaillant, M, Samouda, H, Mensah, V, Roetynck, S, Kanteh, E, Bowyer, G, Ndaw, A, Oko, F, Bliss, C, Jagne, YJ, Cortese, R, Nicosia, A, Roberts, R, D'Alessio, F, Leroy, O, Faye, B, Cisse, B, Gerry, S, Viebig, N, Lawrie, A, Ewer, K, Hill, A, Nebie, I, Tiono, AB, Sanou, G, Konate, AT, Yaro, BJ, Sodiomon, S, Honkpehedji, Y, Agobe, JCD, Zinsou, F, Mengue, J, Richie, T, Hoffman, S, Nouatin, O, Ngoa, UA, Edoa, JR, Homoet, A, Engelhon, JE, Massinga-Louembe, M, Esen, M, Theisen, M, Sim, KL, Luty, AJ, Moutairou, K, Dinko, B, King, E, Targett, G, Sutherland, C, Likhovole, C, Ouma, C, Vulule, J, Musau, S, Khayumbi, J, Okumu, A, Murithi, W, Otu, J, Gehre, F, Zingue, D, Kudzawu, S, Forson, A, Mane, M, Rabna, P, Diarra, B, Kayede, S, Adebiyi, E, Kehinde, A, Onyejepu, N, Onubogu, C, Idigbe, E, Ba, A, Diallo, A, Mboup, S, Disse, K, Kadanga, G, Dagnra, Y, Baldeh, I, Corrah, T, De Jong, B, Antonio, M, Musanabaganwa, C, Musabyimana, JP, Karita, E, Diop, B, Nambajimana, A, Dushimiyimana, V, Karame, P, Russell, J, Ndoli, J, Hategekimana, T, Sendegeya, A, Condo, J, Binagwaho, A, Okonko, I, Okerentugba, P, Opaleye, O, Awujo, E, Frank-Peterside, N, Moyo, S, Kotokwe, K, Mohammed, T, Boleo, C, Mupfumi, L, Chishala, S, Gaseitsiwe, S, Tsalaile, L, Bussmann, H, Makhema, J, Baum, M, Marlink, R, Engelbretch, S, Essex, M, Novitsky, V, Saka, E, Kalipalire, Z, Bhairavabhotla, R, Midiani, D, Sherman, J, Mgode, G, Cox, C, Bwana, D, Mtui, L, Magesa, D, Kahwa, A, Mfinanga, G, Mulder, C, Borain, N, Petersen, L, Du Plessis, J, Theron, G, Holm-Hansen, C, Tekwu, EM, Sidze, LK, Assam, JPA, Eyangoh, S, Niemann, S, Beng, VP, Frank, M, Atiadeve, S, Hilmann, D, Awoniyi, D, Baumann, R, Kriel, B, Jacobs, R, Kidd, M, Loxton, A, Kaempfer, S, Singh, M, Mwanza, W, Milimo, D, Moyo, M, Kasese, N, Cheeba-Lengwe, M, Munkondya, S, Ayles, H, De Haas, P, Muyoyeta, M, Namuganga, AR, Kizza, HM, Mendy, A, Tientcheu, L, Ayorinde, A, Coker, E, Egere, U, Coussens, A, Naude, C, Chaplin, G, Noursadeghi, M, Martineau, A, Jablonski, N, Wilkinson, R, Ouedraogo, HG, Matteelli, A, Regazzi, M, Tarnagda, G, Villani, P, Sulis, G, Diagbouga, S, Roggi, A, Giorgetti, F, Kouanda, S, Bidias, A, Ndjonka, D, Olemba, C, Souleymanou, A, Mukonzo, J, Kuteesa, R, Ogwal-Okeng, J, Gustafsson, LL, Owen, J, Bassi, P, Gashau, W, Olaf, K, Dodoo, A, Okonkwo, P, Kanki, P, Maruapula, D, Seraise, B, Einkauf, K, Reilly, A, Rowley, C, Musonda, R, Framhein, A, Mpagama, S, Semvua, H, Maboko, L, Hoelscher, M, Heinrich, N, Mulenga, L, Kaayunga, C, Davies, M-A, Egger, M, Musukuma, K, Dambe, R, Usadi, B, Ngari, M, Thitiri, J, Mwalekwa, L, Fegan, G, Berkley, J, Nsagha, D, Munamunungu, V, Bolton, C, Siyunda, A, Shilimi, J, Bucciardini, R, Fragola, V, Abegaz, T, Lucattini, S, Halifom, A, Tadesse, E, Berhe, M, Pugliese, K, De Castro, P, Terlizzi, R, Fucili, L, Di Gregorio, M, Mirra, M, Zegeye, T, Binelli, A, Vella, S, Abraham, L, Godefay, H, Rakotoarivelo, R, Raberahona, M, Randriamampionona, N, Andriamihaja, R, Rasamoelina, T, Cornet, M, De Dieu Randria, MJ, Benet, T, Vanhems, P, Andrianarivelo, MR, Chirwa, U, Michelo, C, Hamoonga, R, Wandiga, S, Oduor, P, Agaya, J, Sharma, A, Cavanaugh, S, Cain, K, Mukisa, J, Mupere, E, Worodria, W, Ngom, JT, Koro, F, Godwe, C, Adande, C, Ateugieu, R, Onana, T, Ngono, A, Kamdem, Y, Ngo-Niobe, S, Etoa, F-X, Kanengoni, M, Ruzario, S, Ndebele, P, Shana, M, Tarumbiswa, F, Musesengwa, R, Gutsire, R, Fisher, K, Thyagarajan, B, Akanbi, O, Binuyo, M, Ssengooba, W, Respeito, D, Mambuque, E, Blanco, S, Mandomando, I, Cobelens, F, Garcia-Basteiro, A, Tamene, A, Topp, S, Mwamba, C, Padian, N, Sikazwe, I, Geng, E, Holmes, C, Sikombe, K, Hantuba, Czaicki, N, Simbeza, S, Somwe, P, Umulisa, M, Ilo, J, Kestelyn, E, Uwineza, M, Agaba, S, Delvaux, T, Wijgert, J, Gethi, D, Odeny, L, Tamandjou, C, Kaindjee-Tjituka, F, Brandt, L, Cotton, M, Nel, E, Preiser, W, Andersson, M, Adepoju, A, Magana, M, Etsetowaghan, A, Chilikwazi, M, Sutcliffe, C, Thuma, P, Sinywimaanzi, K, Matakala, H, Munachoonga, P, Moss, W, Masenza, IS, Geisenberger, O, Agrea, P, Rwegoshora, F, Mahiga, H, Olomi, W, Kroidl, A, Kayode, G, Amoakoh-Coleman, M, Ansah, E, Uthman, O, Fokam, J, Santoro, M-M, Musolo, C, Chimbiri, I, Chikwenga, G, Deula, R, Massari, R, Lungu, A, Perno, C-F, Ndzengue, G, Loveline, N, Lissom, A, Flaurent, T, Sosso, S, Essomba, C, Kpeli, G, Otchere, I, Lamelas, A, Buultjens, A, Bulach, D, Baines, S, Seemann, T, Giulieri, S, Nakobu, Z, Aboagye, S, Owusu-Mireku, E, Danso, E, Hauser, J, Hinic, V, Pluschke, G, Stinear, T, Yeboah-Manu, D, Elshayeb, A, Siddig, ME, Ahmed, AA, Hussien, AE, Kabwe, M, Tembo, J, Chilukutu, L, Chilufya, M, Ngulube, F, Lukwesa, C, Enne, V, Wexner, H, Mwananyanda, L, Hamer, D, Sinyangwe, S, Ahmed, Y, Klein, N, Maeurer, M, Zumla, A, Bates, M, Beyala, L, Etienne, G, Anthony, N, Benjamin, A, Ateudjieu, J, Chibwe, B, Ojok, D, Tarr, CA, Perez, GM, Omeonga, S, Kibungu, F, Meyer, A, Lansana, P, Mayor, A, Onyango, P, Van Loggerenberg, F, Furtado, T, Boggs, L, Segrt, A, Dochez, C, Burnett, R, Mphahlele, MJ, Miiro, G, Mbidde, E, Peshu, N, Kivaya, E, Ngowi, B, Kavishe, R, Maowia, M, Sandstrom, E, Ayuo, E, Mmbaga, B, Leisegang, C, Thorpe, M, Batchilly, E, N'Guessan, J-P, Kanteh, D, Søfteland, S, Sebitloane, M, Vwalika, B, Taylor, M, Galappaththi-Arachchige, H, Holmen, S, Gundersen, SG, Ndhlovu, P, Kjetland, EF, Kombe, F, Toohey, J, Pienaar, E, Kredo, T, Cham, PM, Abubakar, I, Dondeh, BL, Vischer, N, Pfeiffer, C, Burri, C, Musukwa, K, Zürcher, S, Mwandu, T, Bauer, S, Adriko, M, Mwaura, P, Omolloh, K, Jones, C, Malecela, M, Hamidu, BA, Jenner, TE, Asiedu, LJ, Osei-Atweneboana, M, Afeke, I, Addo, P, Newman, M, Durnez, L, Eddyani, M, Ammisah, N, Abas, M, Quartey, M, Ablordey, A, Akinwale, O, Adeneye, A, Ezeugwu, S, Olukosi, Y, Adewale, B, Sulyman, M, Mafe, M, Okwuzu, J, Gyang, P, Nwafor, T, Henry, U, Musa, B, Ujah, I, Agobé, JCD, Grau-Pujol, B, Sacoor, C, Nhabomba, A, Casellas, A, Quintó, L, Subirà, C, Giné, R, Valentín, A, Muñoz, J, Nikiema, M, Ky-Ba, A, Comapore, KAM, Sangare, L, Oluremi, A, Michel, M, Camara, Y, Sanneh, B, Cuamba, I, Gutiérrez, J, Lázaro, C, Mejia, R, Adedeji, A, Folorunsho, S, Demehin, P, Akinsanya, B, Cowley, G, Da Silva, ET, Nabicassa, M, De Barros, PDP, Blif, MM, Bailey, R, Last, A, Mahendradhata, Y, Gotuzzo, E, De Nys, K, Casteels, M, Nona, SK, Lumeka, K, Todagbe, A, Djima, MM, Ukpong, M, Sagay, A, Khamofu, H, Torpey, K, Afiadigwe, E, Anenih, J, Ezechi, O, Nweneka, C, Idoko, J, Muhumuza, S, Katahoire, A, Nuwaha, F, Olsen, A, Okeyo, S, Omollo, R, Kimutai, R, Ochieng, M, Egondi, T, Moonga, C, Chileshe, C, Magwende, G, Anumudu, C, Onile, O, Oladele, V, Adebayo, A, Awobode, H, Oyeyemi, O, Odaibo, A, Kabuye, E, Lutalo, T, Njua-Yafi, C, Nkuo-Akenji, T, Anchang-Kimbi, J, Mugri, R, Chi, H, Tata, R, Njumkeng, C, Dodoo, D, Achidi, E, Fernandes, J, Bache, EB, Matakala, K, Searle, K, Greenman, M, and Rainwater-Lovett, K more...
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- 2017
8. Interferon-gamma Responses to HIV-1 Clade A and D Peptides in Ugandan Serodiscordant Couples - the CHAVI 002 Protocol
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Pala, P, Pimego, E, Senkaali, D, Auma, B, Mugaba, S, Nakiboneka, R, Serwanga, J, Watera, C, Goonetilleke, N, Haynes, B, Mcmichael, A, and Kaleebu, P
- Published
- 2008
9. Adenovirus-Based Vaccines: Comparison of Vectors from Three Species of Adenoviridae
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Chen, H., primary, Xiang, Z. Q., additional, Li, Y., additional, Kurupati, R. K., additional, Jia, B., additional, Bian, A., additional, Zhou, D. M., additional, Hutnick, N., additional, Yuan, S., additional, Gray, C., additional, Serwanga, J., additional, Auma, B., additional, Kaleebu, P., additional, Zhou, X., additional, Betts, M. R., additional, and Ertl, H. C. J., additional more...
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- 2010
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10. P20-10. Differences in patterns of Gag-induced immunogenetic pressure occur between clades A and D chronic HIV-1 infection in a Ugandan population
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Serwanga, J, primary, Ndembi, N, additional, Nanteza, B, additional, Mugaba, S, additional, Pimego, E, additional, Pala, P, additional, Auma, B, additional, Lyagoba, F, additional, and Kaleebu, P, additional more...
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- 2009
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11. WITHDRAWN: Rapid decline in CD38 T cell activation in HIV infected Ugandans taking antiretroviral therapy – towards that of healthy european controls
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Gazzard, B., Lutwama, F., Mayanja, H., Shihab, H., Serwanga, J., Wanyama, J., McAdam, K., John, L., Spacek, L., Eller, M., Kamya, M., Kelleher, P., and Quinn, T.
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- 2006
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12. P16-03. Persistence of robust cross-reactive group M consensus T-cell responses in a chronic HIV-1 clade A1 and D-infected Ugandan population
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Ndembi NN, Katongole EM, Nanteza BB, Lyagoba FF, Pimego EE, Mugaba S, Serwanga JJ, and Kaleebu PP
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Immunologic diseases. Allergy ,RC581-607 - Published
- 2009
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13. Study protocol for promoting respectful maternity care initiative to assess, measure and design interventions to reduce disrespect and abuse during childbirth in Kenya
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Warren Charlotte, Njuki Rebecca, Abuya Timothy, Ndwiga Charity, Maingi Grace, Serwanga Jane, Mbehero Faith, Muteti Louisa, Njeru Anne, Karanja Joseph, Olenja Joyce, Gitonga Lucy, Rakuom Chris, and Bellows Ben more...
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Disrespect and abuse ,Skilled birth attendant ,Childbirth ,Implementation research ,Kenya ,Gynecology and obstetrics ,RG1-991 - Abstract
Abstract Background Increases in the proportion of facility-based deliveries have been marginal in many low-income countries in the African region. Preliminary clinical and anthropological evidence suggests that one major factor inhibiting pregnant women from delivering at facility is disrespectful and abusive treatment by health care providers in maternity units. Despite acknowledgement of this behavior by policy makers, program staff, civil society groups and community members, the problem appears to be widespread but prevalence is not well documented. Formative research will be undertaken to test the reliability and validity of a disrespect and abuse (D&A) construct and to then measure the prevalence of disrespect and abuse suffered by clinic clients and the general population. Methods/design A quasi-experimental design will be followed with surveys at twelve health facilities in four districts and one large maternity hospital in Nairobi and areas before and after the introduction of disrespect and abuse (D&A) interventions. The design is aimed to control for potential time dependent confounding on observed factors. Discussion This study seeks to conduct implementation research aimed at designing, testing, and evaluating an approach to significantly reduce disrespectful and abusive (D&A) care of women during labor and delivery in facilities. Specifically the proposed study aims to: (i) determine the manifestations, types and prevalence of D&A in childbirth (ii) develop and validate tools for assessing D&A (iii) identify and explore the potential drivers of D&A (iv) design, implement, monitor and evaluate the impact of one or more interventions to reduce D&A and (v) document and assess the dynamics of implementing interventions to reduce D&A and generate lessons for replication at scale. more...
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- 2013
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14. Gene expression of tight junctions in foreskin is not affected by HIV pre-exposure prophylaxis.
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Webb EL, Petkov S, Yun H, Else L, Lebina L, Serwanga J, Pillay AAP, Seiphetlo TB, Mugaba S, Namubiru P, Odoch G, Opoka D, Ssemata AS, Kaleebu P, Khoo S, Martinson N, Fox J, Gray CM, Herrera C, and Chiodi F more...
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- Humans, Male, Adolescent, HIV-1, Uganda, Young Adult, Adult, Tenofovir administration & dosage, Circumcision, Male, South Africa, Pre-Exposure Prophylaxis methods, Foreskin metabolism, HIV Infections prevention & control, Tight Junctions metabolism, Anti-HIV Agents administration & dosage
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Introduction: Tight junctions (TJs) serve as permeability filters between the internal and external cellular environment. A large number of proteins have been identified to be localized at the TJs. Due to limitations in tissue collection, TJs in the male genital tract have been understudied., Methods: We analysed the transcriptomics of 132 TJ genes in foreskin tissue of men requesting voluntary medical male circumcision (VMMC) and enrolled in the Combined HIV Adolescent Prevention Study (CHAPS) trial conducted in South Africa and Uganda (NCT03986970). The trial evaluated the dose requirements for event-driven HIV pre-exposure prophylaxis (PrEP) with emtricitabine-tenofovir (FTC-TDF) or emtricitabine-tenofovir alafenamide (FTC-TAF) during insertive sex. A total of 144 participants were randomized to either control arm or one of 8 PrEP arms (n=16/arm), receiving oral FTC-TDF or FTC-TAF over one or two days. Following in vivo oral PrEP dosing and VMMC, the expression level of three important TJ proteins (CLDN-1, OCN and ZO-1) was measured ex vivo in foreskin tissue by Western blot. The expression of cytokine genes implicated in TJ regulation was determined. Non-parametric Kruskal-Wallis tests were used to compare TJ gene expression and protein levels by type of PrEP received, and Spearman's correlation coefficients were calculated to assess whether TJ gene expression levels were related to cytokine gene levels or to PrEP drug concentrations and their active intracellularly phosphorylated metabolites., Results: A high level of expression in foreskin tissue was found for 118 (of 132) TJ genes analysed; this finding contributed to create a map of TJ components within the male genital tract. Importantly, PrEP regimens tested in the CHAPS trial did not affect the expression of TJ genes and the analysed proteins in the foreskin; thus, further supporting the safety of this prevention strategy against HIV-1 transmission during insertive sex. Additionally, we identified the level of several cytokines' genes to be correlated to TJ gene expression: among them, IL-18, IL-33 and VEGF., Discussion: TJs can limit viral entry into target cells; to affect this biological function viruses can reduce the expression of TJ proteins. Our study, on the expression and regulation of TJs in the foreskin, contribute important knowledge for PrEP safety and further design of HIV-1 prophylaxis., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The author(s) declared that they were an editorial board member of Frontiers, at the time of submission. This had no impact on the peer review process and the final decision., (Copyright © 2024 Webb, Petkov, Yun, Else, Lebina, Serwanga, Pillay, Seiphetlo, Mugaba, Namubiru, Odoch, Opoka, Ssemata, Kaleebu, Khoo, Martinson, Fox, Gray, Herrera and Chiodi.) more...
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- 2024
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15. Persistent and robust antibody responses to ChAdOx1-S Oxford-AstraZeneca (ChAdOx1-S, Covishield) SARS-CoV-2 vaccine observed in Ugandans across varied baseline immune profiles.
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Serwanga J, Oluka GK, Baine C, Ankunda V, Sembera J, Kato L, Katende JS, Odoch G, Auma BO, Gombe B, Musenero M, and Kaleebu P
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- Adult, Female, Humans, Male, Middle Aged, Young Adult, Antibody Formation immunology, East African People, Immunoglobulin A blood, Immunoglobulin A immunology, Immunoglobulin M blood, Immunoglobulin M immunology, Spike Glycoprotein, Coronavirus immunology, Vaccination, Antibodies, Viral blood, Antibodies, Viral immunology, ChAdOx1 nCoV-19 administration & dosage, ChAdOx1 nCoV-19 immunology, COVID-19 immunology, COVID-19 prevention & control, Immunoglobulin G blood, Immunoglobulin G immunology
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Understanding SARS-CoV-2 vaccine-induced antibody responses in varied antigenic and serological prior exposures can guide optimal vaccination strategies for enhanced immunogenicity. We evaluated spike (S)-directed IgG, IgM, and IgA antibody optical densities (ODs) and concentrations to the two-dose ChAdOx1-S Oxford-AstraZeneca (ChAdOx1-S, Covishield) SARS-CoV-2 vaccine in 67 Ugandans, categorised by prior infection and baseline S-IgG histories: uninfected and S-IgG-negative (n = 12); previously infected yet S-IgG-negative (n = 17); and previously infected with S-IgG-positive status (n = 38). Antibody dynamics were compared across eight timepoints from baseline till nine months. S-IgG antibodies remained consistently potent across all groups. Individuals with prior infections maintained robust S-IgG levels, underscoring the endurance of hybrid immunity. In contrast, those without prior exposure experienced an initial surge in S-IgG after the primary dose but no subsequent significant increase post-boost. However, they reached levels parallel to the previously exposed groups. S-IgM levels remained moderate, while S-IgA persisted in individuals with prior antigen exposure. ChAdOx1-S, Covishield vaccine elicited robust and sustained antibody responses in recipients, irrespective of their initial immune profiles. Hybrid immunity showed higher responses, aligning with global observations. Early post-vaccination antibody levels could predict long-term immunity, particularly in individuals without virus exposure. These findings can inform vaccine strategies and pandemic management., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Serwanga et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.) more...
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- 2024
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16. The single-dose Janssen Ad26.COV2.S COVID-19 vaccine elicited robust and persistent anti-spike IgG antibody responses in a 12-month Ugandan cohort.
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Serwanga J, Kato L, Oluka GK, Ankunda V, Sembera J, Baine C, Kitabye I, Namuyanja A, Opio S, Katende JS, Ejou P, and Kaleebu P
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- Adolescent, Adult, Female, Humans, Male, Middle Aged, Young Adult, Ad26COVS1 immunology, Cohort Studies, Coronavirus Nucleocapsid Proteins immunology, Immunoglobulin M blood, Immunoglobulin M immunology, Uganda, Antibodies, Viral blood, Antibodies, Viral immunology, COVID-19 immunology, COVID-19 Vaccines immunology, Immunoglobulin G blood, Immunoglobulin G immunology, SARS-CoV-2 immunology, Spike Glycoprotein, Coronavirus immunology
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Introduction: The study investigation examined the immune response to the Janssen Ad26.COV2.S COVID-19 vaccine within a Ugandan cohort, specifically targeting antibodies directed against spike (S) and nucleocapsid (N) proteins. We aimed to examine the durability and robustness of the induced antibody response while also assessing occurrences of breakthrough infections and previous anti-Spike seropositivity to SARS-CoV-2., Methods: The study included 319 specimens collected over 12 months from 60 vaccinees aged 18 to 64. Binding antibodies were quantified using a validated ELISA method to measure SARS-CoV-2-specific IgG, IgM, and IgA levels against the S and N proteins., Results: The results showed that baseline seropositivity for S-IgG was high at 67%, increasing to 98% by day 14 and consistently stayed above 95% for up to 12 months. However, S-IgM responses remained suboptimal. A raised S-IgA seropositivity rate was seen that doubled from 40% at baseline to 86% just two weeks following the initial vaccine dose, indicating sustained and robust peripheral immunity. An increase in N-IgG levels at nine months post-vaccination suggested breakthrough infections in eight cases. Baseline cross-reactivity influenced spike-directed antibody responses, with individuals harbouring S-IgG antibodies showing notably higher responses., Discussion: Robust and long lasting vaccine and infection-induced immune responses were observed, with significant implications for regions where administering subsequent doses poses logistical challenges., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Serwanga, Kato, Oluka, Ankunda, Sembera, Baine, Kitabye, Namuyanja, Opio, Katende, Ejou, The COVID-19 Immunoprofiling Team and Kaleebu.) more...
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- 2024
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17. The subdued post-boost spike-directed secondary IgG antibody response in Ugandan recipients of the Pfizer-BioNTech BNT162b2 vaccine has implications for local vaccination policies.
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Ankunda V, Katende JS, Oluka GK, Sembera J, Baine C, Odoch G, Ejou P, Kato L, Kaleebu P, and Serwanga J
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- Humans, BNT162 Vaccine, Antibody Formation, COVID-19 Vaccines, Uganda, Vaccination, Antibodies, Viral, Policy, Immunoglobulin M, Immunoglobulin G, Vaccines
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Introduction: This study aimed to delineate longitudinal antibody responses to the Pfizer-BioNTech BNT162b2 COVID-19 vaccine within the Ugandan subset of the Sub-Saharan African (SSA) demographic, filling a significant gap in global datasets., Methods: We enrolled 48 participants and collected 320 specimens over 12 months after the primary vaccination dose. A validated enzyme-linked immunosorbent assay (ELISA) was used to quantify SARS-CoV-2-specific IgG, IgM, and IgA antibody concentrations (ng/ml) and optical densities (ODs). Statistical analyses included box plots, diverging bar graphs, and the Wilcoxon test with Bonferroni correction., Results: We noted a robust S-IgG response within 14 days of the primary vaccine dose, which was consistent with global data. There was no significant surge in S-IgG levels after the booster dose, contrasting trends in other global populations. The S-IgM response was transient and predominantly below established thresholds for this population, which reflects its typical early emergence and rapid decline. S-IgA levels rose after the initial dose then decreased after six months, aligning with the temporal patterns of mucosal immunity. Eleven breakthrough infections were noted, and all were asymptomatic, regardless of the participants' initial S-IgG serostatus, which suggests a protective effect from vaccination., Discussion: The Pfizer-BioNTech BNT162b2 COVID-19 vaccine elicited strong S-IgG responses in the SSA demographic. The antibody dynamics distinctly differed from global data highlighting the significance of region-specific research and the necessity for customised vaccination strategies., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Ankunda, Katende, Oluka, Sembera, Baine, Odoch, Ejou, Kato, and The COVID-19 Immunoprofiling Team, Kaleebu and Serwanga.) more...
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- 2024
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18. Sustained S-IgG and S-IgA antibodies to Moderna's mRNA-1273 vaccine in a Sub-Saharan African cohort suggests need for booster timing reconsiderations.
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Serwanga J, Ankunda V, Katende JS, Baine C, Oluka GK, Odoch G, Nantambi H, Mugaba S, Namuyanja A, Ssali I, Ejou P, Kato L, Musenero M, and Kaleebu P
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- Humans, 2019-nCoV Vaccine mRNA-1273, Antibodies, Viral, Immunoglobulin G, Immunoglobulin M, mRNA Vaccines, Immunoglobulin A
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Introduction: This study sought to elucidate the long-term antibody responses to the Moderna mRNA-1273 COVID-19 vaccine within a Ugandan cohort, aiming to contribute to the sparse data on m-RNA vaccine immunogenicity in Sub-Saharan Africa., Methods: We tracked the development and persistence of the elicited antibodies in 19 participants aged 18 to 67, who received two doses of the mRNA-1273 vaccine. A validated enzyme-linked immunosorbent assay (ELISA) was used to quantify SARS-CoV-2-specific IgG, IgM, and IgA antibodies against the spike (S) and nucleoproteins (N). The study's temporal scope extended from the baseline to one year, capturing immediate and long-term immune responses. Statistical analyses were performed using the Wilcoxon test to evaluate changes in antibody levels across predetermined intervals with the Hochberg correction for multiple comparisons., Results: Our results showed a significant initial rise in spike-directed IgG (S-IgG) and spike-directed IgA (S-IgA) levels, which remained elevated for the duration of the study. The S-IgG concentrations peaked 14 days afterboosting, while spike-directed IgM (S-IgM) levels were transient, aligning with their early response role. Notably, post-booster antibody concentrations did not significantly change. Prior S-IgG status influenced the post-priming S-IgA dynamics, with baseline S-IgG positive individuals maintaining higher S-IgA responses, a difference that did not reach statistical difference post-boost. Three instances of breakthrough infections: two among participants who exhibited baseline seropositivity for S-IgG, and one in a participant initially seronegative for S-IgG., Discussion: In conclusion, the mRNA-1273 vaccine elicited robust and persistent S-IgG and S-IgA antibody responses, particularly after the first dose, indicating potential for long-term immunity. Prior viral exposure enhances post-vaccination S-IgA responses compared to naive individuals, which aligned with the prior-naïve, post-boost. The stable antibody levels observed post-booster dose, remaining high over an extended period, with no significant secondary rise, and no difference by baseline exposure, suggest that initial vaccination may sufficiently prime the immune system for prolonged protection in this population, allowing for potential to delay booster schedules as antibody responses remained high at the time of boosting. This finding calls for a reassessment of the booster dose scheduling in this demographic., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Serwanga, Ankunda, Katende, Baine, Oluka, Odoch, Nantambi, Mugaba, Namuyanja, Ssali, Ejou, Kato, The COVID-19 Immunoprofiling Team, Musenero and Kaleebu.) more...
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- 2024
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19. An Optimised Indirect ELISA Protocol for Detection and Quantification of Anti-viral Antibodies in Human Plasma or Serum: A Case Study Using SARS-CoV-2.
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Baine C, Sembera J, Kevin Oluka G, Katende JS, Ankunda V, and Serwanga J
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Advanced immunoassays are crucial in assessing antibody responses, serving immune surveillance goals, characterising immunological responses to evolving viral variants, and guiding subsequent vaccination initiatives. This protocol outlines an indirect ELISA protocol to detect and quantify virus-specific antibodies in plasma or serum after exposure to viral antigens. The assay enables the measurement of IgG, IgA, and IgM antibodies specific to the virus of interest, providing qualitative and quantitative optical densities and concentration data. Although this protocol refers to SARS-CoV-2, its methodology is versatile and can be modified to assess antibody responses for various viral infections and to evaluate vaccine trial outcomes. Key features • This protocol builds upon previously described methodology [1] explicitly tailored for SARS-CoV-2 and broadens its applicability to other viral infections. • The protocol outlines establishing antibody responses to SARS-CoV-2 infections by determining optical densities and concentrations from blood plasma or serum., Competing Interests: Competing interestsThe authors declare that this protocol was developed in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (©Copyright : © 2023 The Authors; This is an open access article under the CC BY-NC license.) more...
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- 2023
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20. Sustained spike-specific IgG antibodies following CoronaVac (Sinovac) vaccination in sub-Saharan Africa, but increased breakthrough infections in baseline spike-naive individuals.
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Sembera J, Baine C, Ankunda V, Katende JS, Oluka GK, Akoli CH, Kato L, Odoch G, Ejou P, Opio S, Musenero M, Kaleebu P, and Serwanga J
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- Humans, Breakthrough Infections, Vaccination, Immunoglobulin G, Immunoglobulin M, Africa South of the Sahara epidemiology, Immunoglobulin A, COVID-19 Vaccines, Blood Group Antigens
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Introduction: This study investigated the antibody responses to the inactivated COVID-19 vaccine, CoronaVac (Sinovac Biotech) in the African population to provide valuable insights into long-term immunity and breakthrough infections against SARS-CoV-2 in individuals with varying prior IgG seropositivity., Methods: Real-life cohorts were used to longitudinally track antibody levels against the SARS-CoV-2 spike and nucleoprotein in 60 participants over 12 months to examine the levels of multiple antibody isotypes (S-IgG, S-IgM, S-IgA, N-IgG, and N-IgM)., Results: Throughout the 12 months, we observed consistently high and stable seropositivity rates for spike-IgG antibodies, spike-IgM antibodies showed a decline in frequencies over time, and spike-IgA levels remained moderate and stable. Vaccinated individuals previously positive for spike-IgG antibodies demonstrated strong and persistent seropositivity, while those initially negative experienced a gradual and delayed increase in seropositivity rates. The fold change analysis of S- and N- antibody responses demonstrated a consistently stable and comparable profile over time, indicating that vaccine-induced antibody responses remain constant and lack significant fluctuations beyond the initial boost. The study emphasized that individuals lacking previous IgG positivity showed reduced vaccine-induced spike-IgG antibodies and were more susceptible to breakthrough infections, highlighting their higher vulnerability. All cases of breakthrough infections were asymptomatic, indicating the conferred protection to the vaccinated individuals., Discussion: The findings corroborated earlier studies on the effectiveness of the CoronaVac vaccine and emphasized the significance of accounting for pre-existing seropositivity in vaccine assessments. This study effectively demonstrated durable antibody responses against SARS-CoV-2 in the African population following the CoronaVac vaccination, providing crucial insights for informing vaccination strategies and safeguarding vulnerable populations. Continuous surveillance is imperative for tracking breakthrough infections and monitoring waning immunity. The insights gained offer crucial direction for public health strategies and enhance comprehension of vaccine effectiveness in sub-Saharan Africa. Further research should explore functional outcomes, cellular immune responses, and the vaccine's effectiveness against different variants to enhance our understanding and optimize vaccine strategies., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Sembera, Baine, Ankunda, Katende, Oluka, Akoli, Kato, Odoch, Ejou, Opio, Musenero, The COVID-19 Immunoprofiling Team, Kaleebu and Serwanga.) more...
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- 2023
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21. Bacterial microbiome and host inflammatory gene expression in foreskin tissue.
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Maust BS, Petkov S, Herrera C, Feng C, Brown BP, Lebina L, Opoka D, Ssemata A, Pillay N, Serwanga J, Seatlholo P, Namubiru P, Odoch G, Mugaba S, Seiphetlo T, Gray CM, Kaleebu P, Webb EL, Martinson N, Chiodi F, Fox J, and Jaspan HB more...
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The penile epithelial microbiome remains underexplored. We sequenced human RNA and a segment of the bacterial 16S rRNA gene from the foreskin tissue of 144 adolescents from South Africa and Uganda collected during penile circumcision after receipt of 1-2 doses of placebo, emtricitabine + tenofovir disoproxil fumarate, or emtricitabine + tenofovir alafenamide to investigate the microbiome of foreskin tissue and its potential changes with antiretroviral use. We identified a large number of anaerobic species, including Corynebacterium acnes, which was detected more frequently in participants from South Africa than Uganda. Bacterial populations did not differ by treatment received, and no differentially abundant taxa were identified between placebo versus active drug recipients. The relative abundance of specific bacterial taxa was negatively correlated with expression of genes downstream of the innate immune response to bacteria and regulation of inflammation. Our results show no difference in the tissue microbiome of the foreskin with short-course antiretroviral use but that bacterial taxa were largely inversely correlated with inflammatory gene expression, consistent with commensal colonization., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2023 The Authors.) more...
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- 2023
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22. Spike protein is a key target for stronger and more persistent T-cell responses-a study of mild and asymptomatic SARS-CoV-2 infection.
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Ssali I, Mugaba S, Watelo AK, Bemanzi J, Katende JS, Oluka GK, Ankunda V, Baine C, Kato L, Onyachi N, Muwanga M, Jjuuko M, Kayiwa J, Nsereko C, Auma BO, Weiskopf D, Sette A, Lutalo T, Musenero M, Kaleebu P, and Serwanga J more...
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- Humans, Longitudinal Studies, Spike Glycoprotein, Coronavirus, SARS-CoV-2, CD8-Positive T-Lymphocytes, Interferon-gamma, Antibodies, Viral, COVID-19
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Objectives: Understanding the immune response in very mild and asymptomatic COVID-19 is crucial for developing effective vaccines and immunotherapies, yet remains poorly characterized. This longitudinal study examined the evolution of interferon (IFN)-γ responses to SARS-CoV-2 peptides in 109 asymptomatic or mildly symptomatic Ugandan COVID-19 patients across 365 days and explored their association with antibody generation., Methods: T-cell responses to spike-containing clusters of differentiation (CD4)-S and CD8 nCoV-A (CD8-A) megapools, and the non-spike CD4-R and CD8 nCoV-B (CD8-B) megapools, were assessed and correlated with demographic and temporal variables., Results: SARS-CoV-2-specific IFN-γ responses were consistently detected in all peptide pools and time points, with the spike-targeted response exhibiting higher potency and durability than the non-spike responses. Throughout the entire 365-day infection timeline, a robust positive correlation was observed between CD4 T-cell responses to the spike-derived peptides and anti-spike immunoglobulin G antibody levels, underscoring their interdependent dynamics in the immune response against SARS-CoV-2; in contrast, CD8 T-cell responses exhibited no such correlation, highlighting their distinctive, autonomous role in defense. No meaningful variations in complete blood count parameters were observed between individuals with COVID-19 infection and those without, indicating clinical insignificance., Conclusions: This study highlights the dominant role of spike-directed T-cell responses in mild and asymptomatic disease and provides crucial longitudinal data from Sub-Saharan African settings. The findings provide valuable insights into the dynamics of T-cell responses and their potential significance in developing effective strategies for combating COVID-19., Competing Interests: Declarations of competing interest The authors have no competing interests to declare., (Copyright © 2023 The Authors. Published by Elsevier Ltd.. All rights reserved.) more...
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- 2023
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23. A randomized clinical trial of on-demand oral pre-exposure prophylaxis does not modulate lymphoid/myeloid HIV target cell density in the foreskin.
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Rametse CL, Webb EL, Herrera C, Alinde B, Besethi A, Motaung B, Mbangiwa T, Leach L, Sebaa S, Pillay AAP, Seiphetlo TB, Malhangu B, Petkov S, Else L, Mugaba S, Namubiru P, Odoch G, Opoka D, Serwanga J, Ssemata AS, Kaleebu P, Khoo S, Lebina L, Martinson N, Chiodi F, Fox J, and Gray CM more...
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- Male, Humans, Foreskin, Claudin-1, Emtricitabine therapeutic use, Anti-HIV Agents therapeutic use, HIV Infections prevention & control, HIV Infections drug therapy, Pre-Exposure Prophylaxis
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Objectives: As topical pre-exposure prophylaxis (PrEP) has been shown to cause immune modulation in rectal or cervical tissue, our aim was to examine the impact of oral PrEP on lymphoid and myeloid changes in the foreskin in response to dosing and timing of drug administration., Design: HIV-negative male individuals ( n = 144) were recruited in South Africa and Uganda into an open-label randomized controlled trial in a 1 : 1 : 1 : 1 : 1 : 1 : 1 : 1 : 1 ratio to control arm (with no PrEP) or one of eight arms receiving emtricitabine-tenofovir disoproxil fumarate (F/TDF) or emtricitabine-tenofovir alafenamide (F/TAF) at one of two different doses, 5 or 21 h before undergoing voluntary medical male circumcision (VMMC)., Methods: After dorsal-slit circumcision, foreskin tissue sections were embedded into Optimal Cutting Temperature media and analysed, blinded to trial allocation, to determine numbers of CD4 + CCR5 + , CD1a + cells and claudin-1 expression. Cell densities were correlated with tissue-bound drug metabolites and p24 production after ex-vivo foreskin challenge with HIV-1 bal ., Results: There was no significant difference in CD4 + CCR5 + or CD1a + cell numbers in foreskins between treatment arms compared with the control arm. Claudin-1 expression was 34% higher ( P = 0.003) in foreskin tissue from participants receiving PrEP relative to controls, but was no longer statistically significant after controlling for multiple comparisons. There was neither correlation of CD4 + CCR5 + , CD1a + cell numbers, or claudin-1 expression with tissue-bound drug metabolites, nor with p24 production after ex-vivo viral challenge., Conclusion: Oral doses and timing of on-demand PrEP and in-situ drug metabolite levels in tissue have no effect on numbers or anatomical location of lymphoid or myeloid HIV target cells in foreskin tissue., (Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.) more...
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- 2023
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24. A phase I COVID-19 vaccine trial among SARS-CoV-2 seronegative and seropositive individuals in Uganda utilizing a self-amplifying RNA vaccine platform: Screening and enrollment experiences.
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Kitonsa J, Kamacooko O, Ruzagira E, Nambaziira F, Abaasa A, Serwanga J, Gombe B, Lunkuse J, Naluyinda H, Tukamwesiga N, Namata T, Kigozi A, Kafeero P, Basajja V, Joseph S, Pierce BF, Shattock R, and Kaleebu P more...
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- Humans, Adolescent, Young Adult, Adult, Middle Aged, COVID-19 Vaccines, Uganda, RNA, Viral, Antibodies, Viral, Immunogenicity, Vaccine, SARS-CoV-2, COVID-19 prevention & control
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We report the screening and enrollment process for a phase I vaccine trial in Masaka, Uganda that investigated the safety and immunogenicity of a self-amplifying SARS-CoV-2 RNA vaccine amongst individuals with and without antibodies to SARS-CoV-2. Participant screening and enrollment were conducted between December 2021 and April 2022. Individuals were eligible if they were aged between 18 and 45 years, healthy, and never vaccinated against COVID-19. SARS-CoV-2 antibody status was determined using two point-of-care rapid tests, i.e. Multi G (MGFT3) and Standard Q (Standard Q COVID-19 IgM/IgG Plus). Data were entered and managed in OpenClinica. Analyses were performed and presented descriptively. A total of 212 individuals were screened and 43(20.3%) enrolled. The most common reasons for exclusion were ≥ grade 1 laboratory abnormalities (39, 18.4%), followed by discordant SARS-CoV-2 antibody results (23, 10.9%). While the first 38 participants were quickly enrolled over a period of 9 weeks, it took another 9 weeks to enroll the remaining five, as antibody negative participants became scarce during the surge of the Omicron variant. The SARS-CoV-2 antibody positivity rate was determined to be 60.8% and 84.4% in each half of the 18 months of screening respectively. The mean age (±Standard Deviation, SD) of screened and enrolled participants was 27.7 (±8.1) and 30.2 (±8.3) years respectively. We demonstrated that it is feasible to successfully screen and enroll participants for COVID-19 vaccine trials in Uganda in the time of a pandemic. Our experiences may be useful for investigators planning to undertake similar work in Africa. more...
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- 2023
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25. Dose finding study for on-demand HIV pre-exposure prophylaxis for insertive sex in sub-Saharan Africa: results from the CHAPS open label randomised controlled trial.
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Herrera C, Serwanga J, Else L, Limakatso L, Opoka D, Ssemata AS, Pillay AD, Namubiru P, Seiphetlo TB, Odoch G, Mugaba S, Seatlholo P, Alieu A, Penchala SD, Muhumuza R, Alinde B, Petkov S, O'Hagan K, Callebaut C, Seeley J, Weiss H, Khoo S, Chiodi F, Gray CM, Kaleebu P, Webb EL, Martinson N, and Fox J more...
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- Male, Humans, Leukocytes, Mononuclear, Emtricitabine, Africa South of the Sahara, HIV Infections prevention & control, HIV Infections drug therapy, Anti-HIV Agents therapeutic use, Pre-Exposure Prophylaxis
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Background: The efficacy of on-demand HIV pre-exposure prophylaxis (PrEP) for men in sub-Saharan Africa has not been evaluated, and the on-demand PrEP dosing requirement for insertive sex remains unknown., Methods: HIV-negative males 13-24 years, requesting voluntary medical male circumcision (VMMC), were enrolled into an open-label randomised controlled trial (NCT03986970), and randomised 1:1:1:1:1:1:1:1:1 to control arm or one of eight arms receiving emtricitabine-tenofovir disoproxil fumarate (F/TDF) or emtricitabine-tenofovir alafenamide (F/TAF) over one or two days, and circumcised 5 or 21 h thereafter. The primary outcome was foreskin p24 concentrations following ex vivo HIV-1
BaL challenge. Secondary outcomes included peripheral blood mononuclear cell (PBMC) p24 concentration, and drug concentrations in foreskin tissue, PBMCs, plasma and foreskin CD4+/CD4-cells. In the control arm, post-exposure prophylaxis (PEP) activity of non-formulated tenofovir-emtricitabine (TFV-FTC) or TAF-FTC was assessed with ex vivo dosing 1, 24, 48 or 72 h post-HIV-1 challenge., Findings: 144 participants were analysed. PrEP with F/TDF or F/TAF prevented ex vivo infection of foreskins and PBMCs both 5 and 21 h after PrEP dosing. There was no difference between F/TDF and F/TAF (p24day15 geometric mean ratio 1.06, 95% confidence interval: 0.65-1.74). Additional ex vivo dosing did not further increase inhibition. In the control arm, PEP ex vivo dosing was effective up to 48 post-exposure diminishing thereafter, with TAF-FTC showing prolonged protection compared to TFV-FTC. Participants receiving F/TAF had higher TFV-DP concentrations in foreskin tissue and PBMCs compared with F/TDF, irrespective of dose and sampling interval; but F/TAF did not confer preferential TFV-DP distribution into foreskin HIV target cells. FTC-TP concentrations with both drug regimens were equivalent and ∼1 log higher than TFV-DP in foreskin., Interpretation: A double dose of either F/TDF or F/TAF given once either 5 or 21 h before ex vivo HIV-challenge provided protection across foreskin tissue. Further clinical evaluation of pre-coital PrEP for insertive sex is warranted., Funding: EDCTP2, Gilead Sciences, Vetenskapsrådet., Competing Interests: Declaration of interests CH has received research grants from EDCTP, Vetenskapsrådet and Gilead Sciences. LE has received research grants from EDCTP, and Gilead Sciences. LL has received research grants from EDCTP, Gilead Sciences, Roche Diagnostic, DO has received research grants from EDCTP, AS has received research grants from EDCTP, AP has received research grants from EDCTP, PN has received research grants from EDCTP, PS has received research grants from EDCTP, DS has received research grants from EDCTP, RM has received research grants from EDCTP, BA has received research grants from EDCTP, SP has received research grants from EDCTP, CC is an employee of Gilead Sciences, JS has received research grants from EDCTP, HW has received research grants from EDCTP, SK has received research funding, speaker honoraria and consulting fees from EDCTP, Gilead Sciences, ViiV, Merck, GSK, and Ridgeback. FC has received research grants from EDCTP and Vetenskapsrådet. ELW has received grants from EDCTP, MRC, and NIH. CG has received research grants from EDCTP. PK has received research grants from EDCTP. EW has received research grants from EDCTP, NIH and MRC. NM has received research grants from EDCTP, and Gilead Sciences and provided unpaid advice and leadership in the DSMB and Setshaba boards. CC is a full-time employee of Gilead Sciences. All other authors declare no competing interests aside from the research grant received for this study by EDCTP., (Copyright © 2023 The Authors. Published by Elsevier B.V. All rights reserved.) more...- Published
- 2023
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26. Seroprevalence and durability of antibody responses to AstraZeneca vaccination in Ugandans with prior mild or asymptomatic COVID-19: implications for vaccine policy.
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Serwanga J, Baine C, Mugaba S, Ankunda V, Auma BO, Oluka GK, Kato L, Kitabye I, Sembera J, Odoch G, Ejou P, Nalumansi A, Gombe B, Musenero M, and Kaleebu P
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- Humans, Antibody Formation, COVID-19 Vaccines, Seroepidemiologic Studies, Uganda, Vaccination, Immunoglobulin A, Nucleoproteins, Immunoglobulin G, Immunoglobulin M, COVID-19 epidemiology, Vaccines
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Introduction: The duration and timing of immunity conferred by COVID-19 vaccination in sub-Saharan Africa are crucial for guiding pandemic policy interventions, but systematic data for this region is scarce. This study investigated the antibody response after AstraZeneca vaccination in COVID-19 convalescent Ugandans., Methods: We recruited 86 participants with a previous rt-PCR-confirmed mild or asymptomatic COVID-19 infection and measured the prevalence and levels of spike-directed IgG, IgM, and IgA antibodies at baseline, 14 and 28 days after the first dose (priming), 14 days after the second dose (boosting), and at six- and nine-months post-priming. We also measured the prevalence and levels of nucleoprotein-directed antibodies to assess breakthrough infections., Results: Within two weeks of priming, vaccination substantially increased the prevalence and concentrations of spike-directed antibodies (p < 0.0001, Wilcoxon signed rank test), with 97.0% and 66% of vaccinated individuals possessing S-IgG and S-IgA antibodies before administering the booster dose. S-IgM prevalence changed marginally after the initial vaccination and barely after the booster, consistent with an already primed immune system. However, we also observed a rise in nucleoprotein seroprevalence, indicative of breakthroughs six months after the initial vaccination., Discussion: Our results suggest that vaccination of COVID-19 convalescent individuals with the AstraZeneca vaccine induces a robust and differential spike-directed antibody response. The data highlights the value of vaccination as an effective method for inducing immunity in previously infected individuals and the importance of administering two doses to maintain protective immunity. Monitoring anti-spike IgG and IgA when assessing vaccine-induced antibody responses is suggested for this population; assessing S-IgM will underestimate the response. The AstraZeneca vaccine is a valuable tool in the fight against COVID-19. Further research is needed to determine the durability of vaccine-induced immunity and the potential need for booster doses., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Serwanga, Baine, Mugaba, Ankunda, Auma, Oluka, Kato, Kitabye, Sembera, Odoch, Ejou, Nalumansi, Gombe, Musenero, Kaleebu and the COVID-19 Immunoprofiling Team.) more...
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- 2023
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27. Pre-pandemic SARS-CoV-2-specific IFN-γ and antibody responses were low in Ugandan samples and significantly reduced in HIV-positive specimens.
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Nantambi H, Sembera J, Ankunda V, Ssali I, Kalyebi AW, Oluka GK, Kato L, Ubaldo B, Kibengo F, Katende JS, Gombe B, Baine C, Odoch G, Mugaba S, Sande OJ, Kaleebu P, and Serwanga J
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- Humans, Pandemics, SARS-CoV-2, Antibody Formation, Uganda epidemiology, Antibodies, Viral, Enzyme-Linked Immunospot Assay, COVID-19 epidemiology, HIV Seropositivity
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Introduction: We investigated whether prior SARS-CoV-2-specific IFN-γ and antibody responses in Ugandan COVID-19 pre-pandemic specimens aligned to this population's low disease severity., Methods: We used nucleoprotein (N), spike (S), NTD, RBD, envelope, membrane, SD1/2-directed IFN-γ ELISpots, and an S- and N-IgG antibody ELISA to screen for SARS-CoV-2-specific cross-reactivity., Results: HCoV-OC43-, HCoV-229E-, and SARS-CoV-2-specific IFN-γ occurred in 23, 15, and 17 of 104 specimens, respectively. Cross-reactive IgG was more common against the nucleoprotein (7/110, 15.5%; p = 0.0016, Fishers' Exact) than the spike (3/110, 2.72%). Specimens lacking anti-HuCoV antibodies had higher rates of pre-epidemic SARS-CoV-2-specific IFN-γ cross-reactivity (p-value = 0.00001, Fishers' exact test), suggesting that exposure to additional factors not examined here might play a role. SARS-CoV-2-specific cross-reactive antibodies were significantly less common in HIV-positive specimens (p=0.017; Fishers' Exact test). Correlations between SARS-CoV-2- and HuCoV-specific IFN-γ responses were consistently weak in both HIV negative and positive specimens., Discussion: These findings support the existence of pre-epidemic SARS-CoV-2-specific cellular and humoral cross-reactivity in this population. The data do not establish that these virus-specific IFN-γ and antibody responses are entirely specific to SARS-CoV-2. Inability of the antibodies to neutralise SARS-CoV-2 implies that prior exposure did not result in immunity. Correlations between SARS-CoV-2 and HuCoV-specific responses were consistently weak, suggesting that additional variables likely contributed to the pre-epidemic cross-reactivity patterns. The data suggests that surveillance efforts based on the nucleoprotein might overestimate the exposure to SARS-CoV-2 compared to inclusion of additional targets, like the spike protein. This study, while limited in scope, suggests that HIV-positive people are less likely than HIV-negative people to produce protective antibodies against SARS-CoV-2., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Nantambi, Sembera, Ankunda, Ssali, Kalyebi, Oluka, Kato, Ubaldo, Kibengo, Katende, Gombe, Baine, Odoch, Mugaba, Sande, The COVID-19 Immunoprofiling Team, Kaleebu and Serwanga.) more...
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- 2023
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28. Rapid, early, and potent Spike-directed IgG, IgM, and IgA distinguish asymptomatic from mildly symptomatic COVID-19 in Uganda, with IgG persisting for 28 months.
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Serwanga J, Ankunda V, Sembera J, Kato L, Oluka GK, Baine C, Odoch G, Kayiwa J, Auma BO, Jjuuko M, Nsereko C, Cotten M, Onyachi N, Muwanga M, Lutalo T, Fox J, Musenero M, and Kaleebu P
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- Male, Female, Humans, SARS-CoV-2, Uganda epidemiology, Antibodies, Viral, Immunoglobulin G, Immunoglobulin M, Immunoglobulin A, COVID-19 diagnosis
- Abstract
Introduction: Understanding how spike (S)-, nucleoprotein (N)-, and RBD-directed antibody responses evolved in mild and asymptomatic COVID-19 in Africa and their interactions with SARS-CoV-2 might inform development of targeted treatments and vaccines., Methods: Here, we used a validated indirect in-house ELISA to characterise development and persistence of S- and N-directed IgG, IgM, and IgA antibody responses for 2430 SARS-CoV-2 rt-PCR-diagnosed Ugandan specimens from 320 mild and asymptomatic COVID-19 cases, 50 uninfected contacts, and 54 uninfected non-contacts collected weekly for one month, then monthly for 28 months., Results: During acute infection, asymptomatic patients mounted a faster and more robust spike-directed IgG, IgM, and IgA response than those with mild symptoms (Wilcoxon rank test, p-values 0.046, 0.053, and 0.057); this was more pronounced in males than females. Spike IgG antibodies peaked between 25 and 37 days (86.46; IQR 29.47-242.56 BAU/ml), were significantly higher and more durable than N- and RBD IgG antibodies and lasted for 28 months. Anti-spike seroconversion rates consistently exceeded RBD and nucleoprotein rates. Spike- and RBD-directed IgG antibodies were positively correlated until 14 months (Spearman's rank correlation test, p-values 0.0001 to 0.05), although RBD diminished faster. Significant anti-spike immunity persisted without RBD. 64% and 59% of PCR-negative, non-infected non-contacts and suspects, exhibited baseline SARS-CoV-2 N-IgM serological cross-reactivity, suggesting undetected exposure or abortive infection. N-IgG levels waned after 787 days, while N-IgM levels remained undetectable throughout., Discussion: Lower N-IgG seroconversion rates and the absence of N-IgM indicate that these markers substantially underestimate the prior exposure rates. Our findings provide insights into the development of S-directed antibody responses in mild and asymptomatic infections, with varying degrees of symptoms eliciting distinct immune responses, suggesting distinct pathogenic pathways. These longer-lasting data inform vaccine design, boosting strategies, and surveillance efforts in this and comparable settings., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Serwanga, Ankunda, Sembera, Kato, Oluka, Baine, Odoch, Kayiwa, Auma, Jjuuko, Nsereko, Cotten, Onyachi, Muwanga, Lutalo, Fox, Musenero, Kaleebu and The COVID-19 Immunoprofiling Team.) more...
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- 2023
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29. Optimisation and Validation of a conventional ELISA and cut-offs for detecting and quantifying anti-SARS-CoV-2 Spike, RBD, and Nucleoprotein IgG, IgM, and IgA antibodies in Uganda.
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Oluka GK, Namubiru P, Kato L, Ankunda V, Gombe B, Cotten M, Musenero M, Kaleebu P, Fox J, and Serwanga J
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- Humans, Uganda, Immunoglobulin A, Antibodies, Viral, Immunoglobulin G, Enzyme-Linked Immunosorbent Assay, Immunoglobulin M, SARS-CoV-2, COVID-19 diagnosis
- Abstract
There is an urgent need for better immunoassays to measure antibody responses as part of immune-surveillance activities and to profile immunological responses to emerging SARS-CoV-2 variants. We optimised and validated an in-house conventional ELISA to identify and quantify SARS-CoV-2 spike- (S-), receptor binding domain- (RBD-), and nucleoprotein- (N-) directed IgG, IgM, and IgA binding antibodies in the Ugandan population and similar settings. Pre- and post-pandemic specimens were used to compare the utility of mean ± 2SD, mean ± 3SD, 4-fold above blanks, bootstrapping, and receiver operating characteristic (ROC) analyses in determining optimal cut-off optical densities at 450 nm (OD) for discriminating between antibody positives and negatives. "Limits of detection" (LOD) and "limits of quantitation" (LOQ) were validated alongside the assay's uniformity, accuracy, inter-assay and inter-operator precision, and parallelism. With spike-directed sensitivity and specificity of 95.33 and 94.15%, respectively, and nucleoprotein sensitivity and specificity of 82.69 and 79.71%, ROC was chosen as the best method for determining cutoffs. Accuracy measurements were within the expected CV range of 25%. Serum and plasma OD values were highly correlated (r = 0.93, p=0.0001). ROC-derived cut-offs for S-, RBD-, and N-directed IgG, IgM, and IgA were 0.432, 0.356, 0.201 (S), 0.214, 0.350, 0.303 (RBD), and 0.395, 0.229, 0.188 (N). The sensitivity and specificity of the S-IgG cut-off were equivalent to the WHO 20/B770-02 S-IgG reference standard at 100% level. Spike negative IgG, IgM, and IgA ODs corresponded to median antibody concentrations of 1.49, 3.16, and 0 BAU/mL, respectively, consistent with WHO low titre estimates. Anti-spike IgG, IgM, and IgA cut-offs were equivalent to 18.94, 20.06, and 55.08 BAU/mL. For the first time, we provide validated parameters and cut-off criteria for the in-house detection of subclinical SARS-CoV-2 infection and vaccine-elicited binding antibodies in the context of Sub-Saharan Africa and populations with comparable risk factors., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Oluka, Namubiru, Kato, Ankunda, Gombe, Cotten, The COVID-19 Immunoprofiling Team, Musenero, Kaleebu, Fox and Serwanga.) more...
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- 2023
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30. Assessment of a diverse panel of transmitted/founder HIV-1 infectious molecular clones in a luciferase based CD8 T-cell mediated viral inhibition assay.
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Fernandez N, Hayes P, Makinde J, Hare J, King D, Xu R, Rehawi O, Mezzell AT, Kato L, Mugaba S, Serwanga J, Chemweno J, Nduati E, Price MA, Osier F, Ochsenbauer C, Yue L, Hunter E, and Gilmour J
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- Humans, CD8-Positive T-Lymphocytes, Luciferases, Clone Cells, HIV-1, HIV Infections
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Introduction: Immunological protection against human immunodeficiency virus-1 (HIV-1) infection is likely to require both humoral and cell-mediated immune responses, the latter involving cytotoxic CD8 T-cells. Characterisation of CD8 T-cell mediated direct anti-viral activity would provide understanding of potential correlates of immune protection and identification of critical epitopes associated with HIV-1 control., Methods: The present report describes a functional viral inhibition assay (VIA) to assess CD8 T-cell-mediated inhibition of replication of a large and diverse panel of 45 HIV-1 infectious molecular clones (IMC) engineered with a Renilla reniformis luciferase reporter gene (LucR), referred to as IMC-LucR. HIV-1 IMC replication in CD4 T-cells and CD8 T-cell mediated inhibition was characterised in both ART naive subjects living with HIV-1 covering a broad human leukocyte antigen (HLA) distribution and compared with uninfected subjects., Results & Discussion: CD4 and CD8 T-cell lines were established from subjects vaccinated with a candidate HIV-1 vaccine and provided standard positive controls for both assay quality control and facilitating training and technology transfer. The assay was successfully established across 3 clinical research centres in Kenya, Uganda and the United Kingdom and shown to be reproducible. This IMC-LucR VIA enables characterisation of functional CD8 T-cell responses providing a tool for rational T-cell immunogen design of HIV-1 vaccine candidates and evaluation of vaccine-induced T-cell responses in HIV-1 clinical trials., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Fernandez, Hayes, Makinde, Hare, King, Xu, Rehawi, Mezzell, Kato, Mugaba, Serwanga, Chemweno, Nduati, Price, Osier, Ochsenbauer, Yue, Hunter, Gilmour and The IAVI protocol C investigators.) more...
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- 2022
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31. Short-term oral pre-exposure prophylaxis against HIV-1 modulates the transcriptome of foreskin tissue in young men in Africa.
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Petkov S, Herrera C, Else L, Lebina L, Opoka D, Seiphetlo TB, Pillay AA, Mugaba S, Namubiru P, Odoch G, Ssemata AS, Serwanga J, Kaleebu P, Webb EL, Khoo S, Martinson N, Gray CM, Fox J, and Chiodi F
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- Male, Humans, Homosexuality, Male, South Africa, Methyltransferases, Ion Channels, DEAD-box RNA Helicases, Pre-Exposure Prophylaxis, HIV-1 genetics, Sexual and Gender Minorities
- Abstract
Whilst short-term oral pre-exposure prophylaxis (PrEP) with antiretroviral drugs in men who have sex with men has shown protection against HIV-1 infection, the impact of this regimen on the in vivo foreskin transcriptome is unknown. We collected foreskin tissue after voluntary medical male circumcision from 144 young men (72 from Uganda and 72 from South Africa) randomized to one to two doses of either oral tenofovir (TFV) disoproxil fumarate (FTC-TDF) or tenofovir alafenamide (FTC-TAF) or no drug (untreated controls). This novel approach allowed us to examine the impact of short-term oral PrEP on transcriptome of the male genital tract. A single dose of FTC-TDF did not affect the foreskin transcriptome in relation to control arm, however one dose of FTC-TAF induced upregulation of four genes AKAP8 , KIAA0141 , HSCB and METTL17 . Following two doses of either FTC-TDF or FTC-TAF, there was an increase in 34 differentially expressed genes for FTC-TDF and 15 for FTC-TAF, with nine DEGs in common: KIAA0141 , SAFB2 , CACTIN , FXR2 , AKAP8 , HSCB , CLNS1A , DDX27 and DCAF15 . Functional analysis of differentially expressed genes revealed modulation of biological processes related to mitochondrial stress (KIAA0141, HSCB and METTL17) , anti-viral and anti-inflammatory pathways ( CACTIN and AKAP8) . Our results show that short-course on-demand oral PrEP in men modulates genes in foreskin tissue which are likely unfavorable to HIV acquisition and replication. We also describe an upregulated expression of genes involved in diverse mitochondria biology which may potentially result in worsened mitochondria-related. These results warrant further studies to assess the role of short-course and prolonged oral PrEP on biological processes of the foreskin mucosa., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Petkov, Herrera, Else, Lebina, Opoka, Seiphetlo, Pillay, Mugaba, Namubiru, Odoch, Ssemata, Serwanga, Kaleebu, Webb, Khoo, Martinson, Gray, Fox and Chiodi.) more...
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- 2022
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32. Optimization and validation of an ELISA assay for the determination of antibody responses to CN54gp140 and AIDSVAX BE for use in the Phase IIb PrEPVacc vaccine trial.
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Gombe B, Streatfield C, Leal L, Opio S, Joseph S, Weber J, Hare J, Kaleebu P, and Serwanga J
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- Humans, Antibody Formation, Double-Blind Method, Enzyme-Linked Immunosorbent Assay, AIDS Vaccines, HIV Infections, HIV-1
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PrEPVacc is an international, multi-centre, double-blind vaccine study comparing experimental combination vaccine regimens including DNA/AIDSVAX BE and DNA/CN54gp140 with placebo control. Simultaneously, daily oral PrEP is compared for efficacy against daily Truvada in the context of the current PrEP availability situation at the study sites. An important clinical trial outcome is the accurate measurement of in vivo antibody titer induced through vaccination. Here we report the validation of two ELISAs for CN54gp140 and AIDSVAX BE at Uganda Virus Research Institute that demonstrates precision, specificity, and robustness for assessing the reciprocal antibody end point titer in human serum. This is a critical endpoint for determining whether vaccination can provide any protection against HIV in populations at risk of acquiring HIV., Competing Interests: The authors have declared that no competing interests exist. more...
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- 2022
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33. Mobilization of systemic CCL4 following HIV pre-exposure prophylaxis in young men in Africa.
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Petkov S, Herrera C, Else L, Mugaba S, Namubiru P, Odoch G, Opoka D, Pillay AAP, Seiphetlo TB, Serwanga J, Ssemata AS, Kaleebu P, Webb EL, Khoo S, Lebina L, Gray CM, Martinson N, Fox J, and Chiodi F
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- Chemokine CCL3, HIV-1, Humans, Male, Proteomics, South Africa, Anti-HIV Agents administration & dosage, Chemokine CCL4 drug effects, Emtricitabine administration & dosage, HIV Infections prevention & control, HIV Seropositivity, Pre-Exposure Prophylaxis methods
- Abstract
HIV-1 pre-exposure prophylaxis (PrEP) relies on inhibition of HIV-1 replication steps. To understand how PrEP modulates the immunological environment, we derived the plasma proteomic profile of men receiving emtricitabine-tenofovir (FTC-TDF) or emtricitabine-tenofovir alafenamide (FTC-TAF) during the CHAPS trial in South Africa and Uganda (NCT03986970). The CHAPS trial randomized 144 participants to one control and 8 PrEP arms, differing by drug type, number of PrEP doses and timing from final PrEP dose to sampling. Blood was collected pre- and post-PrEP. The inflammatory profile of plasma samples was analyzed using Olink (N=92 proteins) and Luminex (N=33) and associated with plasma drug concentrations using mass spectrometry. The proteins whose levels changed most significantly from pre- to post-PrEP were CCL4, CCL3 and TNF-α; CCL4 was the key discriminator between pre- and post-PrEP samples. CCL4 and CCL3 levels were significantly increased in post-PrEP samples compared to control specimens. CCL4 was significantly correlated with FTC drug levels in plasma. Production of inflammatory chemokines CCL4 and CCL3 in response to short-term PrEP indicates the mobilization of ligands which potentially block virus attachment to CCR5 HIV-1 co-receptor. The significant correlation between CCL4 and FTC levels suggests that CCL4 increase is modulated as an inflammatory response to PrEP., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Petkov, Herrera, Else, Mugaba, Namubiru, Odoch, Opoka, Pillay, Seiphetlo, Serwanga, Ssemata, Kaleebu, Webb, Khoo, Lebina, Gray, Martinson, Fox and Chiodi.) more...
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- 2022
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34. Evaluation of the performance of 25 SARS-CoV-2 serological rapid diagnostic tests using a reference panel of plasma specimens at the Uganda Virus Research Institute.
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Lutalo T, Nalumansi A, Olara D, Kayiwa J, Ogwang B, Odwilo E, Watera C, Balinandi S, Kiconco J, Nakaseegu J, Serwanga J, Kikaire B, Ssemwanga D, Abiko B, Nsereko C, Cotten M, Buule J, Lutwama J, Downing R, and Kaleebu P more...
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- Academies and Institutes, Antibodies, Viral, Diagnostic Tests, Routine, Humans, Immunoglobulin M, Sensitivity and Specificity, Uganda epidemiology, COVID-19, SARS-CoV-2
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Introduction: Serological testing is needed to better understand the epidemiology of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus. Rapid diagnostic tests (RDTs) have been developed to detect specific antibodies, IgM and IgG, to the virus. The performance of 25 of these RDTs was evaluated., Methods: A serological reference panel of 50 positive and 100 negative plasma specimens was developed from SARS-CoV-2 PCR and antibody positive patients and pre-pandemic SARS-CoV-2-negative specimens collected in 2016. Test performance of the 25 RDTs was evaluated against this panel., Results: A total of 10 RDTs had a sensitivity ≥98%, while 13 RDTs had a specificity ≥98% to anti-SARS-CoV-2 IgG antibodies. Four RDTs (Boson, MultiG, Standard Q, and VivaDiag) had both sensitivity and specificity ≥98% to anti-SARS-CoV-2 IgG antibodies. Only three RDTs had a sensitivity ≥98%, while 10 RDTs had a specificity ≥98% to anti-SARS-CoV-2 IgM antibodies. Three RDTs (Autobio, MultiG, and Standard Q) had sensitivity and specificity ≥98% to combined IgG/IgM. The RDTs that performed well also had perfect or almost perfect inter-reader agreement., Conclusions: This evaluation identified three RDTs with a sensitivity and specificity to IgM/IgG antibodies of ≥98% with the potential for widespread antibody testing in Uganda., (Crown Copyright © 2021. Published by Elsevier Ltd. All rights reserved.) more...
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- 2021
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35. Differential Performance of CoronaCHEK SARS-CoV-2 Lateral Flow Antibody Assay by Geographic Origin of Samples.
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Baker OR, Grabowski MK, Galiwango RM, Nalumansi A, Serwanga J, Clarke W, Hsieh YH, Rothman RE, Fernandez RE, Serwadda D, Kagaayi J, Lutalo T, Reynolds SJ, Kaleebu P, Quinn TC, and Laeyendecker O
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- Antibodies, Viral, Female, Humans, Male, Sensitivity and Specificity, Uganda, COVID-19, SARS-CoV-2
- Abstract
We assessed the performance of the CoronaCHEK lateral flow assay on samples from Uganda and Baltimore to determine the impact of geographic origin on assay performance. Plasma samples from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) PCR-positive individuals (Uganda, 78 samples from 78 individuals, and Baltimore, 266 samples from 38 individuals) and from prepandemic individuals (Uganda, 1,077, and Baltimore, 532) were evaluated. Prevalence ratios (PR) were calculated to identify factors associated with a false-positive test. After the first positive PCR in Ugandan samples, the sensitivity was 45% (95% confidence interval [CI], 24,68) at 0 to 7 days, 79% (95% CI, 64 to 91) at 8 to 14 days, and 76% (95% CI, 50 to 93) at >15 days. In samples from Baltimore, sensitivity was 39% (95% CI, 30 to 49) at 0 to 7 days, 86% (95% CI, 79 to 92) at 8 to 14 days, and 100% (95% CI, 89 to 100) at 15 days after positive PCR. The specificity of 96.5% (95% CI, 97.5 to 95.2) in Ugandan samples was significantly lower than that in samples from Baltimore, 99.3% (95% CI, 98.1 to 99.8; P < 0.01). In Ugandan samples, individuals with a false-positive result were more likely to be male (PR, 2.04; 95% CI, 1.03,3.69) or individuals who had had a fever more than a month prior to sample acquisition (PR, 2.87; 95% CI, 1.12 to 7.35). Sensitivity of the CoronaCHEK was similar in samples from Uganda and Baltimore. The specificity was significantly lower in Ugandan samples than in Baltimore samples. False-positive results in Ugandan samples appear to correlate with a recent history of a febrile illness, potentially indicative of a cross-reactive immune response in individuals from East Africa. more...
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- 2021
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36. Field evaluation of the performance of a SARS-CoV-2 antigen rapid diagnostic test in Uganda using nasopharyngeal samples.
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Nalumansi A, Lutalo T, Kayiwa J, Watera C, Balinandi S, Kiconco J, Nakaseegu J, Olara D, Odwilo E, Serwanga J, Kikaire B, Ssemwanga D, Nabadda S, Ssewanyana I, Atwine D, Mwebesa H, Bosa HK, Nsereko C, Cotten M, Downing R, Lutwama J, and Kaleebu P more...
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- Adult, COVID-19 virology, Female, Humans, Male, Nasopharynx virology, Point-of-Care Systems, Real-Time Polymerase Chain Reaction, SARS-CoV-2 genetics, SARS-CoV-2 isolation & purification, Sensitivity and Specificity, Uganda, COVID-19 diagnosis, COVID-19 Serological Testing methods, SARS-CoV-2 immunology
- Abstract
Objectives: There is a high demand for SARS-CoV-2 testing to identify COVID-19 cases. Real-time quantitative PCR (qRT-PCR) is the recommended diagnostic test but a number of constraints prevent its widespread implementation, including cost. The aim of this study was to evaluate a low cost and easy to use rapid antigen test for diagnosing COVID-19 at the point of care., Methods: Nasopharyngeal swabs from suspected COVID-19 cases and low-risk volunteers were tested with the STANDARD Q COVID-19 Ag Test and the results were compared with the qRT-PCR results., Results: In total, 262 samples were collected, including 90 qRT-PCR positives. The majority of samples were from males (89%) with a mean age of 34 years and only 13 (14%) of the positives were mildly symptomatic. The sensitivity and specificity of the antigen test were 70.0% (95% confidence interval (CI): 60-79) and 92% (95% CI: 87-96), respectively, and the diagnostic accuracy was 84% (95% CI: 79-88). The antigen test was more likely to be positive for samples with qRT-PCR Ct values ≤29, with a sensitivity of 92%., Conclusions: The STANDARD Q COVID-19 Ag Test performed less than optimally in this evaluation. However, the test may still have an important role to play early in infection when timely access to molecular testing is not available but the results should be confirmed by qRT-PCR., (Copyright © 2020. Published by Elsevier Ltd.) more...
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- 2021
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37. Computational MHC-I epitope predictor identifies 95% of experimentally mapped HIV-1 clade A and D epitopes in a Ugandan cohort.
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Bugembe DL, Ekii AO, Ndembi N, Serwanga J, Kaleebu P, and Pala P
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- Adolescent, Adult, Child, Cohort Studies, Enzyme-Linked Immunospot Assay, Female, HIV Infections virology, Humans, Male, Middle Aged, Neural Networks, Computer, Peptides immunology, Uganda, Young Adult, Computational Biology methods, Epitope Mapping methods, Epitopes, T-Lymphocyte immunology, HIV Infections immunology, HIV-1 immunology, Histocompatibility Antigens Class I immunology
- Abstract
Background: Identifying immunogens that induce HIV-1-specific immune responses is a lengthy process that can benefit from computational methods, which predict T-cell epitopes for various HLA types., Methods: We tested the performance of the NetMHCpan4.0 computational neural network in re-identifying 93 T-cell epitopes that had been previously independently mapped using the whole proteome IFN-γ ELISPOT assays in 6 HLA class I typed Ugandan individuals infected with HIV-1 subtypes A1 and D. To provide a benchmark we compared the predictions for NetMHCpan4.0 to MHCflurry1.2.0 and NetCTL1.2., Results: NetMHCpan4.0 performed best correctly predicting 88 of the 93 experimentally mapped epitopes for a set length of 9-mer and matched HLA class I alleles. Receiver Operator Characteristic (ROC) analysis gave an area under the curve (AUC) of 0.928. Setting NetMHCpan4.0 to predict 11-14mer length did not improve the prediction (37-79 of 93 peptides) with an inverse correlation between the number of predictions and length set. Late time point peptides were significantly stronger binders than early peptides (Wilcoxon signed rank test: p = 0.0000005). MHCflurry1.2.0 similarly predicted all but 2 of the peptides that NetMHCpan4.0 predicted and NetCTL1.2 predicted only 14 of the 93 experimental peptides., Conclusion: NetMHCpan4.0 class I epitope predictions covered 95% of the epitope responses identified in six HIV-1 infected individuals, and would have reduced the number of experimental confirmatory tests by > 80%. Algorithmic epitope prediction in conjunction with HLA allele frequency information can cost-effectively assist immunogen design through minimizing the experimental effort. more...
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- 2020
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38. Interferon gamma (IFN-γ) negative CD4+ and CD8+ T-cells can produce immune mediators in response to viral antigens.
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Nakiboneka R, Mugaba S, Auma BO, Kintu C, Lindan C, Nanteza MB, Kaleebu P, and Serwanga J
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- Adenoviridae, Cohort Studies, Cross-Sectional Studies, Enzyme-Linked Immunospot Assay, Flow Cytometry, HIV Infections immunology, HIV-1, Humans, Interleukin-2 immunology, Leukocytes, Mononuclear immunology, Lymphocyte Activation, Peptides immunology, Perforin immunology, Tumor Necrosis Factor-alpha immunology, Antigens, Viral immunology, CD4-Positive T-Lymphocytes immunology, CD8-Positive T-Lymphocytes immunology, Immunologic Factors immunology, Interferon-gamma immunology
- Abstract
Evaluation of antigen-specific T-cell responses to viral antigens is frequently performed on IFN-γ secreting cells. However, T-cells are capable of producing many more functions than just IFN-γ, some of which, like Perforin, are associated with immune protection in HIV-1 disease elite controllers. We evaluated the extent of missed T-cell functions when IFN-γ secretion is used as a surrogate marker for further evaluation of T-cell functions. Intracellular cytokine staining assay and flow cytometry were used to assess peripheral blood mononuclear cells (PBMCs) from 31 HIV-infected ART-naive individuals for the extent to which gated CD4+ and CD8+ IFN-γ producing and non-producing T-cells also secreted IL-2, Perforin, and TNF-α functions. Similarly, the extent of missed virus-specific responses in IFN-γ ELISpot assay negative T-cells from 5 HIV-1 uninfected individuals was evaluated. Cells from HIV-infected individuals were stimulated with pooled consensus group M (Con M) peptides; and those from healthy individuals were stimulated with pooled adenovirus (Ad) peptides. Overall, frequencies of virus-specific IFN-γ secreting CD4+ and CD8+ cells were low. Proportions of IFN-γ negative CD4+ expressing IL-2, Perforin, or TNF-α to Con M were significantly higher (5 of 7 functional profiles) than the corresponding IFN-γ positive CD4+ (0 of 7) T-cell phenotype, p = 0.02; Fisher's Exact test. Likewise, proportions of CD8+ T-cells expressing other functions were significantly higher in 4 of the 7 IFN-γ negative CD8+ T-cells. Notably, newly stimulated Perforin, identified as Perforin co-expression with IL-2 or TNF-α, was significantly higher in IFN-γ negative CD8+ T-cell than in the positive CD8+ T-cells. Using SEB, lower responses in IFN-γ positive cells were most associated with CD4+ than CD8+ T-cells. These findings suggest that studies evaluating immunogenicity in response to HIV and Adenovirus viral antigens should not only evaluate T-cell responsiveness among IFN-γ producing cells but also among those T-cells that do not express IFN-γ., (Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.) more...
- Published
- 2019
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39. HIV-1 superinfection can occur in the presence of broadly neutralizing antibodies.
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Serwanga J, Ssemwanga D, Muganga M, Nakiboneka R, Nakubulwa S, Kiwuwa-Muyingo S, Morris L, Redd AD, Quinn TC, and Kaleebu P
- Subjects
- Antibodies, Neutralizing blood, CD4 Lymphocyte Count, Female, Genotype, HIV Antibodies blood, Humans, Male, Neutralization Tests, Antibodies, Neutralizing immunology, HIV Antibodies immunology, HIV Infections immunology, HIV Infections virology, HIV-1 immunology, Superinfection immunology
- Abstract
Background: Superinfection of individuals already infected with HIV-1 suggests that pre-existing immune responses may not adequately protect against re-infection. We assessed high-risk female sex workers initially infected with HIV-1 clades A, D or A/D recombinants, to determine if HIV-1 broadly neutralizing antibodies were lacking prior to superinfection., Methods: Six superinfected female sex workers previously stratified by HIV-1 high-risk behavior, infecting virus clade and volunteer CD4 counts were evaluated at baseline (n = 5) and at 350 days post-superinfection (n = 6); one superinfected volunteer lacked pre-superinfection plasma. Retrospective plasmas were assessed for neutralization of a multi-clade panel of 12 HIV-1 viruses before superinfection, and then at quarterly intervals thereafter. Similarly stratified singly infected female sex workers were correspondingly assessed at baseline (n = 19) and 350 days after superinfection (n = 24). Neutralization of at least 50% of the 12 viruses (broad neutralization), and geometric means of the neutralization titers (IC
50 ) were compared before and after superinfection; and were correlated with the volunteer HIV-1 superinfection status, CD4 counts, and pseudovirus clade., Results: Preexisting broad neutralization occurred in 80% (4/5) of the superinfected subjects with no further broadening by 350 days after superinfection. In one of the five subjects, HIV-1 superinfection occurred when broad neutralization was lacking; with subsequent broadening of neutralizing antibodies occuring within 9 months and plateauing by 30 months after detection of superinfection. Clade B and C pseudoviruses were more sensitive to neutralization (13; [87%]); and (12; [80%]) than the locally circulating clades A (10; [67%]) and D (6; [40%]), respectively (p = 0.025). Low antibody titers correlated with clade D viruses and with >500 CD4 T cell counts, but not with the superinfection status., Conclusion: These data demonstrate that HIV-1 superinfection can occur both in the presence, and in the absence of broadly neutralizing antibodies., (Copyright © 2017 Elsevier Ltd. All rights reserved.) more...- Published
- 2018
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40. Association between serotonin transporter gene polymorphisms and increased suicidal risk among HIV positive patients in Uganda.
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Kalungi A, Seedat S, Hemmings SMJ, van der Merwe L, Joloba ML, Nanteza A, Nakassujja N, Birabwa H, Serwanga J, Kaleebu P, and Kinyanda E
- Subjects
- Adolescent, Adult, Cross-Sectional Studies, Female, Genotype, HIV Infections psychology, HIV-1 isolation & purification, Humans, Male, Quality of Life, Risk Factors, Surveys and Questionnaires, Uganda, Young Adult, HIV Infections complications, HIV Infections genetics, Polymorphism, Genetic, Serotonin Plasma Membrane Transport Proteins genetics, Suicide psychology
- Abstract
Background: Persons living with HIV/AIDS (PLWHA) are at an increased risk of suicide. Increased suicidal risk is a predictor of future attempted and completed suicides and has been associated with poor quality of life and poor adherence with antiretroviral therapy. Clinical risk factors have low predictive value for suicide, hence the interest in potential neurobiological correlates and specific heritable markers of suicide vulnerability. The serotonin transporter gene has previously been implicated in the aetiology of increased suicidal risk in non-HIV infected study populations and its variations may provide a platform for identifying genetic risk for suicidality among PLWHA. The present cross-sectional study aimed at identifying two common genetic variants of the serotonin transporter gene and their association with increased suicidal risk among human immunodeficiency virus (HIV)-positive adults in Uganda., Results: The prevalence of increased suicidal risk (defined as moderate to high risk suicidality on the suicidality module of the Mini Neuropsychiatric Interview (M.I.N.I) was 3.3% (95% CI, 2.0-5.3). The 5-HTTLPR was found to be associated with increased suicidal risk before Bonferroni correction (p-value = 0.0174). A protective effect on increased suicidal risk was found for the 5-HTTLPR/rs25531 S
A allele (p-value = 0.0046)- which directs reduced expression of the serotonin transporter gene (5-HTT)., Conclusion: The SA allele at the 5-HTTLPR/rs25531 locus is associated with increased suicidal risk among Ugandan PLWHA. Further studies are needed to validate this finding in Ugandan and other sub-Saharan samples. more...- Published
- 2017
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41. Macrophage Inflammatory Protein-1 Beta and Interferon Gamma Responses in Ugandans with HIV-1 Acute/Early Infections.
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Obuku AE, Bugembe DL, Musinguzi K, Watera C, Serwanga J, Ndembi N, Levin J, Kaleebu P, and Pala P
- Subjects
- Adolescent, Adult, Cells, Cultured, Enzyme-Linked Immunospot Assay, Female, HIV Infections virology, HIV-1 isolation & purification, Humans, Male, Middle Aged, Prospective Studies, Uganda, Chemokine CCL4 metabolism, HIV Infections immunology, HIV-1 immunology, Interferon-gamma metabolism, Leukocytes, Mononuclear immunology
- Abstract
Control of HIV replication through CD4(+) and CD8(+) T cells might be possible, but the functional and phenotypic characteristics of such cells are not defined. Among cytokines produced by T cells, CCR5 ligands, including macrophage inflammatory protein-1 beta (MIP-1β), compete for the CCR5 coreceptor with HIV, promoting CCR5 internalization and decreasing its availability for virus binding. Interferon (IFN)-γ also has some antiviral activity and has been used as a read-out for T cell immunogenicity. We used cultured ELISpot assays to compare the relative contribution of MIP-1β and IFN-γ to HIV-specific responses. The magnitude of responses was 1.36 times higher for MIP-1β compared to IFN-γ. The breadth of the MIP-1β response (45.41%) was significantly higher than IFN-γ (36.88%), with considerable overlap between the peptide pools that stimulated both MIP-1β and IFN-γ production. Subtype A and D cross-reactive responses were observed both at stimulation and test level, but MIP-1β and IFN-γ responses displayed different effect patterns. We conclude that the MIP-1β ELISpot would be a useful complement to the evaluation of the immunogenicity of HIV vaccines and the activity of adjuvants. more...
- Published
- 2016
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42. Frequencies of Gag-restricted T-cell escape "footprints" differ across HIV-1 clades A1 and D chronically infected Ugandans irrespective of host HLA B alleles.
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Serwanga J, Nakiboneka R, Mugaba S, Magambo B, Ndembi N, Gotch F, and Kaleebu P
- Subjects
- AIDS Vaccines, Adult, Alleles, Black People genetics, Chronic Disease, Cytokines biosynthesis, Cytokines blood, Flow Cytometry, HIV Infections genetics, HIV Infections virology, HIV-1 genetics, HLA-B Antigens immunology, Humans, Interferon-gamma biosynthesis, Interferon-gamma immunology, Male, Middle Aged, Mutation, Selection, Genetic, T-Lymphocytes virology, Uganda, Epitopes, T-Lymphocyte immunology, Genes, MHC Class I, HIV Infections immunology, HIV-1 immunology, HLA-B Antigens genetics, T-Lymphocytes immunology, gag Gene Products, Human Immunodeficiency Virus immunology
- Abstract
Objective(s): We evaluated relationships between critical Gag T-cell escape mutations and concomitant T-cell responses to determine whether HLA-restricted Gag mutations that confer protection, occur at similar rates in a population infected with mixed HIV-1 clades A1 and D viruses., Methods: Assessment of Gag selective pressure, and adaptive T-cell functions to KAFSPEVIPMF (KF11), ISPRTLNAW (ISW9) and TSTLQEQIGW (TW10) Gag epitopes were combined with host HLA to assess correlations with rates of critical epitope escape mutations in clades A1- (n=23) and D- (n=21) infected, untreated subjects. Infecting clades and selection pressure were determined from the gag sequences., Results: Overall, Gag escape mutations A163X in KF11 were detected in 61% (14/23) A1- infected compared to 5% (1/21) in D-infected subjects (p=0.00015). Gag mutations I147X in the ISW9 epitope were seen in 43%: (10/23) clade A compared to 5%: (1/21) clade D infected subjects, p=0.007, Fisher's Exact test. Both mutations were more frequent in clade A1 infection. Frequencies of the measured epitope-specific T-cell responses were comparable across clades. Peptide binding affinities for the restricting HLA alleles did not differ across clades. Overall, selection pressure on the Gag protein was significantly greater in clade A than in clade D sequences., Conclusions: These findings imply that HIV-1 vaccine strategies designed to target structurally constrained T-cell epitopes may be further challenged by clade-driven outcomes in specific HLA-restricted Gag epitopes. Equally, the data are line with slower HIV-1 disease progression in clade A infection; and raise hope that increased selective pressure on Gag may be protective irrespective of host HLA alleles., (Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.) more...
- Published
- 2015
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43. Quantitative and qualitative differences in the T cell response to HIV in uninfected Ugandans exposed or unexposed to HIV-infected partners.
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Pala P, Serwanga J, Watera C, Ritchie AJ, Moodie Z, Wang M, Goonetilleke N, Birabwa E, Hughes P, Senkaali D, Nakiboneka R, Grosskurth H, Haynes B, McMichael A, and Kaleebu P
- Subjects
- Adult, Cross-Sectional Studies, Cytokines biosynthesis, Enzyme-Linked Immunospot Assay, Family Characteristics, Family Health, Female, Flow Cytometry, Humans, Male, Uganda, HIV immunology, T-Lymphocytes immunology
- Abstract
HIV-exposed and yet persistently uninfected individuals have been an intriguing, repeated observation in multiple studies, but uncertainty persists on the significance and implications of this in devising protective strategies against HIV. We carried out a cross-sectional analysis of exposed uninfected partners in a Ugandan cohort of heterosexual serodiscordant couples (37.5% antiretroviral therapy naive) comparing their T cell responses to HIV peptides with those of unexposed uninfected individuals. We used an objective definition of exposure and inclusion criteria, blinded ex vivo and cultured gamma interferon (IFN-γ) enzyme-linked immunospot assays, and multiparameter flow cytometry and intracellular cytokine staining to investigate the features of the HIV-specific response in exposed versus unexposed uninfected individuals. A response rate to HIV was detectable in unexposed uninfected (5.7%, 95% confidence interval [CI] = 3.3 to 8.1%) and, at a significantly higher level (12.5%, 95% CI = 9.7 to 15.4%, P = 0.0004), in exposed uninfected individuals. The response rate to Gag was significantly higher in exposed uninfected (10/50 [20.%]) compared to unexposed uninfected (1/35 [2.9%]) individuals (P = 0.0004). The magnitude of responses was also greater in exposed uninfected individuals but not statistically significant. The average number of peptide pools recognized was significantly higher in exposed uninfected subjects than in unexposed uninfected subjects (1.21 versus 0.47; P = 0.0106). The proportion of multifunctional responses was different in the two groups, with a higher proportion of single cytokine responses, mostly IFN-γ, in unexposed uninfected individuals compared to exposed uninfected individuals. Our findings demonstrate both quantitative and qualitative differences in T cell reactivity to HIV between HESN (HIV exposed seronegative) and HUSN (HIV unexposed seronegative) subject groups but do not discriminate as to whether they represent markers of exposure or of protection against HIV infection. more...
- Published
- 2013
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44. Profile of T cell recognition of HIV type 1 consensus group M Gag and Nef peptides in a clade A1- and D-infected Ugandan population.
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Serwanga J, Mugaba S, Pimego E, Nanteza B, Lyagoba F, Nakubulwa S, Heath L, Nsubuga RN, Ndembi N, Gotch F, and Kaleebu P
- Subjects
- Adult, Black People, Female, HIV Seropositivity genetics, Humans, Interferon-gamma immunology, Male, Receptors, Interferon genetics, T-Lymphocytes immunology, Uganda, Viral Load immunology, Interferon gamma Receptor, AIDS Vaccines immunology, HIV Seropositivity immunology, HIV-1 immunology, Immunodominant Epitopes immunology, Receptors, Interferon immunology, gag Gene Products, Human Immunodeficiency Virus immunology, nef Gene Products, Human Immunodeficiency Virus immunology
- Abstract
Reagents for evaluating non-clade B HIV-specific T cell responses are uncommon. Peptides based on highly conserved HIV-1 consensus group M sequences that are phylogenetically closer to most circulating strains may provide potential alternative reagents in populations with diverse infections, and may be relevant for vaccine design. Recognition of such reagents in clade A1-and D-infected populations has not been previously evaluated. Interferon (IFN)-γ ELISpot assay was used to evaluate T cell recognition of Gag and Nef peptides based on consensus group M sequences in 50 treatment-naive adults predominantly infected with HIV-1 clades A1 and D. Gag-induced T cell responses were correlated with gag sequence diversity. Infecting clades were determined from gag sequences for 45 of the 50 subjects as 40% clade A1 (18/45), 45% clade D (20/45), 2% clade C (1/45), 2% A1/C recombinant (1/45), 2% A1/D (1/45), 7% CRF10_CD (3/45), and 2% U (unclassifiable) (1/45). The mean genetic divergence and diversity of clade A and D gag region compared to group M consensus sequences at synonymous and nonsynonymous nucleotide and amino acid levels were not always significant. Gag peptides were targeted at significantly higher frequency [88% (44/50)] than Nef [64% (32/50)]; p=0.014, although their mean IFN-γ magnitudes were comparable ([3703 (95% CI 2567-4839)] vs. [2120 (95% CI 478-3762)]), respectively. Measurable virus-induced IFN-γ responses were detected in 96% (48/50) individuals, primarily targeting the more conserved Gag p24 and Nef central core regions. Use of these reagents to screen for HIV-specific IFN-γ responses may mitigate the challenge of viral diversity; although this targeting is apparently biased toward a few highly conserved epitopes. more...
- Published
- 2012
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45. CD8 T-Cell Responses before and after Structured Treatment Interruption in Ugandan Adults Who Initiated ART with CD4 T Cells <200 Cell/μL: The DART Trial STI Substudy.
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Serwanga J, Mugaba S, Betty A, Pimego E, Walker S, Munderi P, Gilks C, Gotch F, Grosskurth H, and Kaleebu P
- Abstract
Objective. To better understand attributes of ART-associated HIV-induced T-cell responses that might be therapeutically harnessed. Methods. CD8(+) T-cell responses were evaluated in some HIV-1 chronically infected participants of the fixed duration STI substudy of the DART trial. Magnitudes, breadths, and functionality of IFN-γ and Perforin responses were compared in STI (n = 42) and continuous treatment (CT) (n = 46) before and after a single STI cycle when the DART STI trial was stopped early due to inferior clinical outcome in STI participants. Results. STI and CT had comparable magnitudes and breadths of monofunctional CD8(+)IFNγ(+) and CD8(+)Perforin(+) responses. However, STI was associated with significant decline in breadth of bi-functional (CD8(+)IFNγ(+)Perforin(+)) responses; P = .02, Mann-Whitney test. Conclusions. STI in individuals initiated onto ART at <200 CD4(+) T-cell counts/μl significantly reduced occurrence of bifunctional CD8(+)IFNγ(+)/Perforin(+) responses. These data add to others that found no evidence to support STI as a strategy to improve HIV-specific immunity during ART. more...
- Published
- 2011
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46. Host HLA B*allele-associated multi-clade Gag T-cell recognition correlates with slow HIV-1 disease progression in antiretroviral therapy-naïve Ugandans.
- Author
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Serwanga J, Shafer LA, Pimego E, Auma B, Watera C, Rowland S, Yirrell D, Pala P, Grosskurth H, Whitworth J, Gotch F, and Kaleebu P
- Subjects
- Alleles, CD4-Positive T-Lymphocytes, Disease Progression, HIV Infections immunology, Humans, Interferon-gamma immunology, Uganda, Viral Load, HIV Infections pathology, HLA-B Antigens genetics, T-Lymphocytes immunology, gag Gene Products, Human Immunodeficiency Virus immunology
- Abstract
Background: Some HIV infected individuals remain asymptomatic for protracted periods of time in the absence of antiretroviral therapy (ART). Virological control, CD4 T cell loss and HIV-specific responses are some of the key interrelated determinants of HIV-1 disease progression. In this study, possible interactions between viral load, CD4 T cell slopes, host genetics and HIV-specific IFN-gamma responses were evaluated in chronically HIV-1-infected adults., Methodology/principal Findings: Multilevel regression modeling was used to stratify clade A or D HIV-infected individuals into disease progression groups based on CD4 T cell slopes. ELISpot assays were used to quantify the frequency and magnitude of HIV-induced IFN-gamma responses in 7 defined rapid progressors (RPs) and 14 defined slow progressors (SPs) at a single time point. HLA typing was performed using reference strand conformational analysis (RSCA). Although neither the breadth nor the magnitude of the proteome-wide HIV-specific IFN-gamma response correlated with viral load, slow disease progression was associated with over-representation of host immunogenetic protective HLA B* alleles (10 of 14 SPs compared to 0 of 7; p = 0.004, Fisher's Exact) especially B*57 and B*5801, multiclade Gag T-cell targeting (71%, 10 of 14 SPs compared to 14%, 1 of 7 RPs); p = 0.029, Fisher's Exact test and evident virological control (3.65 compared to 5.46 log10 copies/mL in SPs and RPs respectively); p<0.001, unpaired student's t-test, Conclusions: These data are consistent with others that associated protection from HIV disease with inherent host HLA B allele-mediated ability to induce broader Gag T-cell targeting coupled with apparent virological control. These immunogenetic features of Gag-specific immune response which could influence disease progression may provide useful insight in future HIV vaccine design. more...
- Published
- 2009
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47. Transmitted antiretroviral drug resistance surveillance among newly HIV type 1-diagnosed women attending an antenatal clinic in Entebbe, Uganda.
- Author
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Ndembi N, Lyagoba F, Nanteza B, Kushemererwa G, Serwanga J, Katongole-Mbidde E, Grosskurth H, and Kaleebu P
- Subjects
- Adolescent, Adult, Anti-HIV Agents therapeutic use, Base Sequence, Female, Genotype, HIV-1 drug effects, Humans, Molecular Sequence Data, Phylogeny, Polymorphism, Genetic, Pregnancy, Prevalence, RNA, Viral analysis, Uganda epidemiology, pol Gene Products, Human Immunodeficiency Virus genetics, Drug Resistance, Viral genetics, HIV Infections epidemiology, HIV-1 genetics
- Abstract
To evaluate transmitted HIV-1 drug resistance and study the natural polymorphism in pol of HIV-1 strains of newly diagnosed women attending an antenatal clinic in Uganda we sequenced the protease and reverse transcriptase genes for 46 HIV-1 strains from the threshold surveillance. Of the 46 sequences analyzed, 48.0% were subtype A1 (n 22), 39.0% subtype D (n 18), 2.0% subtype A2 (n 1), 2.0% subtype C (n 1), and 9.0% intersubtype recombinant A1/D (n 4). Overall, many minor mutations were identified in the protease sequences. None of the strains had major associated mutations to any RTI drug or drug class interest after genotyping 37 samples of our cohort. The HIV drug resistance prevalence estimate in Entebbe following the HIVDR-TS methodology is less than 5% as set out by WHO guidelines. more...
- Published
- 2008
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48. HIV type 1 antigen-responsive CD4+ T-lymphocytes in exposed yet HIV Type 1 seronegative Ugandans.
- Author
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Kebba A, Kaleebu P, Serwanga J, Rowland S, Yirrell D, Downing R, Gilmour J, Imami N, Gotch F, and Whitworth J
- Subjects
- Adult, Antigens, CD metabolism, Antigens, Differentiation, T-Lymphocyte metabolism, Female, HIV Seropositivity immunology, Humans, Interferon-gamma biosynthesis, Lectins, C-Type, Male, Spouses, Uganda, Viral Load, CD4-Positive T-Lymphocytes immunology, HIV Antigens immunology, HIV Seronegativity immunology, HIV-1 immunology
- Abstract
CD4(+) T cell help is important for the functionality of CD8(+) cytotoxic T-lymphocytes (CTLs) in limiting viral replication and may contribute to mediation of apparent resistance to HIV-1 infection in exposed seronegative (ESN) individuals. Using five HIV-1 antigens in an intracellular cytokine assay, the presence of specific antigen-responsive interferon- gamma-positive (IFN-gamma(+)) CD69(+) CD4(+) T-lymphocytes was evaluated in ESNs, their seropositive partners, and unexposed seronegative controls. Ten ESNs (five females, five uncircumcised males) were identified from 10 HIV-1 serodiscordant couples with a history of frequent unprotected sexual intercourse. All ESNs and controls were negative on two EIAs and for HIV-1 proviral DNA. The frequency of ESNs with antigen-responsive IFN-gamma(+) CD69(+) CD4(+) T-lymphocytes ranged from three to five of eight for the different HIV-1 antigens. Six of eight ESNs tested had a positive response to at least one of the five antigens. Responses were on average 3.5 times higher among seropositives compared to ESNs and absent in the five unexposed controls. A negative correlation was noted between responses in ESNs and the plasma viral load of their seropositive spouse. Clade-specific and cross-clade reactivity were noted in both ESNs and seropositive partners tested. The findings confirm that ESNs are in a state of HIV-1-specific immune activation and suggest that HIV-1-specific IFN-gamma(+) CD69(+) CD4(+) T-lymphocytes in addition to HIV-1-specific CD8(+) CTLs already described by others are potential immunological correlates of protection from persistent HIV-1 infection. more...
- Published
- 2004
- Full Text
- View/download PDF
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