527 results on '"Rochford Rosemary"'
Search Results
202. MOESM3 of Interaction between maternally derived antibodies and heterogeneity in exposure combined to determine time-to-first Plasmodium falciparum infection in Kenyan infants
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Reynaldi, Arnold, Dent, Arlene, Schlub, Timothy, Ogolla, Sidney, Rochford, Rosemary, and Davenport, Miles
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parasitic diseases ,3. Good health - Abstract
Additional file 3. Risk table for infants living in Kisumu (malariahi region).
203. Liver-targeted polymeric prodrugs delivered subcutaneously improve tafenoquine therapeutic window for malaria radical cure.
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Pottenger, Ayumi E., Roy, Debashish, Srinivasan, Selvi, Chavas, Thomas E. J., Vlaskin, Vladmir, Duy-Khiet Ho, Livingston, Vincent C., Maktabi, Mahdi, Hsiuling Lin, Jing Zhang, Pybus, Brandon, Kudyba, Karl, Roth, Alison, Senter, Peter, Tyson, George, Huber, Hans E., Wesche, David, Rochford, Rosemary, Burke, Paul A., and Stayton, Patrick S.
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MALARIA , *PRODRUGS , *PLASMODIUM vivax , *ANIMAL models in research , *ORAL medication - Abstract
Approximately 3.3 billion people live with the threat of Plasmodium vivax malaria. Infection can result in liver-localized hypnozoites, which when reactivated cause relapsing malaria. This work demonstrates that an enzyme-cleavable polymeric prodrug of tafenoquine addresses key requirements for a mass administration, eradication campaign: excellent subcutaneous bioavailability, complete parasite control after a single dose, improved therapeutic window compared to the parent oral drug, and low cost of goods sold (COGS) at less than $1.50 per dose. Liver targeting and subcutaneous dosing resulted in improved liver:plasma exposure profiles, with increased efficacy and reduced glucose 6-phosphate dehydrogenase-dependent hemotoxicity in validated preclinical models. A COGS and manufacturability analysis demonstrated global scalability, affordability, and the ability to redesign this fully synthetic polymeric prodrug specifically to increase global equity and access. Together, this polymer prodrug platform is a candidate for evaluation in human patients and shows potential for P. vivax eradication campaigns. [ABSTRACT FROM AUTHOR]
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- 2024
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204. Plasmodium falciparum Malaria Is Associated With Increased Kaposi Sarcoma–Associated Herpesvirus (KSHV) Seropositivity and Higher KSHV Antibody Breadth and Magnitude: Results of a Case-Control Study From Rural Uganda.
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Nalwoga, Angela, Sabourin, Katherine R, Miley, Wendell, Jackson, Conner, Maktabi, Mahdi, Labo, Nazzarena, Mugisha, Joseph, Whitby, Denise, Rochford, Rosemary, and Newton, Robert
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SEROCONVERSION , *PLASMODIUM falciparum , *RAPID diagnostic tests , *MALARIA , *CASE-control method - Abstract
Background Previously, we showed that children with asymptomatic Plasmodium falciparum (Pf) malaria infection had higher Kaposi sarcoma–associated herpesvirus (KSHV) viral load, increased risk of KSHV seropositivity, and higher KSHV antibody levels. We hypothesize that clinical malaria has an even larger association with KSHV seropositivity. In the current study, we investigated the association between clinical malaria and KSHV seropositivity and antibody levels. Methods Between December 2020 and March 2022, sick children (aged 5–10 years) presenting at a clinic in Uganda were enrolled in a case-control study. Pf was detected using malaria rapid diagnostic tests (RDTs) and subsequently with quantitative real-time polymerase chain reaction (qPCR). Children with malaria were categorized into 2 groups: RDT+/ Pf PCR+ and RDT–/ Pf PCR+. Results The seropositivity of KSHV was 60% (47/78) among Pf -uninfected children, 79% (61/77) among children who were RDT–/ Pf PCR+ (odds ratio [OR], 2.41 [95% confidence interval {CI}, 1.15–5.02]), and 95% (141/149) in children who were RDT+/ Pf PCR+ (OR, 10.52 [95% CI, 4.17–26.58]; P trend <.001). Furthermore, RDT+/ Pf PCR+ children followed by RDT–/ Pf PCR+ children had higher KSHV IgG and IgM antibody levels and reacted to more KSHV antigens compared to uninfected children. Conclusions Clinical malaria is associated with both increased KSHV seropositivity and antibody magnitude, suggesting that Pf is affecting KSHV immunity. [ABSTRACT FROM AUTHOR]
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- 2024
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205. Clinical and immunological outcomes of HIV-exposed uninfected and HIV-unexposed uninfected children in the first 24 months of life in Western Kenya.
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Ray, Jessica E., Dobbs, Katherine R., Ogolla, Sidney O., Daud, Ibrahim I., Midem, David, Omenda, Maxwel M., Nowacki, Amy S., Beeson, James G., Sabourin, Katherine R., Rochford, Rosemary, and Dent, Arlene E.
- Abstract
Background: Previous studies show increased morbidity in children who are HIV-exposed but uninfected (HEU) compared to children who are HIV-unexposed uninfected (HUU). We sought to evaluate the effects of prenatal HIV exposure on clinical and immunological outcomes in the first 24 months of life. Methods: Eighty-five HEU and 168 HUU children from Kenya were followed from birth to 24 months. All mothers living with HIV received combination antiretroviral therapy. Children who were HEU received standard-of-care cotrimoxazole prophylaxis through 18 months. Episodes of acute illness were identified through a combination of active and passive follow up. Trajectories of plasma cytokines, vaccine-specific antibodies, and antimalarial antibodies were examined. Results: Children who were HEU and children who were HUU had similar growth curves. Children who were HEU had lower rates of malaria (rate ratio 0.54, 95% CI 0.38, 0.77) and respiratory illness (rate ratio 0.80, 95% CI 0.68, 0.93). Trajectories of plasma cytokines and vaccine-specific antibodies were similar in children who were HEU and HUU. There were subtle differences in antimalarial antibody dynamics, in which children who were HEU had overall lower antibody levels against five of the 14 malaria antigens tested. Conclusions: Children who were HEU and born to optimally treated mothers living with HIV had similar growth characteristics and immune profiles compared to children who were HUU. Children who were HEU had reduced risk for malaria and respiratory illness, which may be secondary to cotrimoxazole prophylaxis. [ABSTRACT FROM AUTHOR]
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- 2024
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206. Effect of Malaria Infection on Epstein-Barr Virus Persistence in Kenyan Children.
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Samayoa-Reyes, Gabriela, Weigel, Christoph, Koech, Emmily, Waomba, Kevin, Jackson, Conner, Onditi, Ian A, Sabourin, Katherine R, Kenney, Shannon, Baiocchi, Robert A, Oakes, Christopher C, Ogolla, Sidney, and Rochford, Rosemary
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EPSTEIN-Barr virus diseases , *KENYANS , *MONONUCLEAR leukocytes , *MALARIA , *POLYMERASE chain reaction - Abstract
Background The 2 cofactors in the etiology of Burkitt lymphoma (BL) are Epstein-Barr virus (EBV) and repeated Plasmodium falciparum malaria infections. This study evaluated EBV loads in mucosal and systemic compartments of children with malaria and controls. Age was analyzed as a covariate because immunity to malaria in endemic regions is age dependent. Methods Children (2–10 years) with clinical malaria from Western Kenya and community controls without malaria were enrolled. Saliva and blood samples were collected, EBV viral load was assessed by quantitative polymerase chain reaction, and EpiTYPER MassARRAY was used to assess methylation of 3 different EBV genes. Results Regardless of the compartment, we detected EBV more frequently in malaria cases compared to controls, although the difference was not significant. When EBV was detected, there were no differences in viral load between cases and controls. However, EBV methylation was significantly lower in the malaria group compared to controls in both plasma and saliva (P <.05), indicating increased EBV lytic replication. In younger children before development of immunity to malaria, there was a significant effect of malaria on EBV load in peripheral blood mononuclear cells (P =.04). Conclusions These data suggest that malaria can directly modulate EBV persistence in children, increasing their risk for BL. [ABSTRACT FROM AUTHOR]
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- 2024
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207. Infant feeding and treatment practices could lead to enhanced transmission of Kaposi's sarcoma-associated herpesvirus (KSHV) and other orally shed infections via saliva, in rural south-western Uganda.
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Bukenya, Dominic, Marshall, Vickie A., Nabaggala, Georgina, Miley, Wendell, Mirembe, Miriam, Whitby, Denise, Seeley, Janet, Newton, Robert, Rochford, Rosemary, and Sabourin, Katherine R.
- Abstract
This qualitative sub-study investigated household practices affecting orally shed infections using Kaposi's sarcoma-associated herpesvirus (KSHV) as a focus. Participants enrolled from 50 households in rural south-western Uganda were followed monthly up to three times. At enrolment, in-depth interviews were completed, and venous blood collected. KSHV seropositivity was defined as anti-KSHV antibody detection to any of 25 antigens by multiplex bead-based assay. Mouthwash samples from every visit were tested by qPCR and KSHV shedders defined as individuals with KSHV DNA detected. At least one KSHV seropositive person was in 48/49(98%) households. Among those, 79% had 1+ KSHV shedders including 45% with 1+ always shedders and 92% with 1+ intermittent shedders, not mutually exclusively. All respondents reported feeding infants with pre-masticated hard food/fruits and testing food/tea temperature. Temperature was tested by tasting, pouring tea on their hand, or touching the cup to their cheek. Some cooled food/tea using a utensil or blowing over it. Food sharing amongst children and adults and using the same dish was common practice. To treat colic pain, carers/mothers reported chewing herbs and spitting into the child's mouth. Feeding and treatment practices did not vary by KSHV status. We identified potential KSHV transmission modes in rural Ugandan households. [ABSTRACT FROM AUTHOR]
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- 2024
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208. Erratum for Brunschwig et al., “UCT943, a Next-Generation Plasmodium falciparumPI4K Inhibitor Preclinical Candidate for the Treatment of Malaria”
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Brunschwig, Christel, Lawrence, Nina, Taylor, Dale, Abay, Efrem, Njoroge, Mathew, Basarab, Gregory S., Le Manach, Claire, Paquet, Tanya, Gonzàlez Cabrera, Diego, Nchinda, Aloysius T., de Kock, Carmen, Wiesner, Lubbe, Denti, Paolo, Waterson, David, Blasco, Benjamin, Leroy, Didier, Witty, Michael J., Donini, Cristina, Duffy, James, Wittlin, Sergio, White, Karen L., Charman, Susan A., Jiménez-Díaz, Maria Belén, Angulo-Barturen, Iñigo, Herreros, Esperanza, Gamo, Francisco Javier, Rochford, Rosemary, Mancama, Dalu, Coetzer, Theresa L., van der Watt, Mariëtte E., Reader, Janette, Birkholtz, Lyn-Marie, Marsh, Kennan C., Solapure, Suresh M., Burke, John E., McPhail, Jacob A., Vanaerschot, Manu, Fidock, David A., Fish, Paul V., Siegl, Peter, Smith, Dennis A., Wirjanata, Grennady, Noviyanti, Rintis, Price, Ric N., Marfurt, Jutta, Silue, Kigbafori D., Street, Leslie J., and Chibale, Kelly
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- 2018
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209. UCT943, a Next-Generation Plasmodium falciparumPI4K Inhibitor Preclinical Candidate for the Treatment of Malaria
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Brunschwig, Christel, Lawrence, Nina, Taylor, Dale, Abay, Efrem, Njoroge, Mathew, Basarab, Gregory S., Le Manach, Claire, Paquet, Tanya, Cabrera, Diego Gonzàlez, Nchinda, Aloysius T., de Kock, Carmen, Wiesner, Lubbe, Denti, Paolo, Waterson, David, Blasco, Benjamin, Leroy, Didier, Witty, Michael J., Donini, Cristina, Duffy, James, Wittlin, Sergio, White, Karen L., Charman, Susan A., Jiménez-Díaz, Maria Belén, Angulo-Barturen, Iñigo, Herreros, Esperanza, Gamo, Francisco Javier, Rochford, Rosemary, Mancama, Dalu, Coetzer, Theresa L., van der Watt, Mariëtte E., Reader, Janette, Birkholtz, Lyn-Marie, Marsh, Kennan C., Solapure, Suresh M., Burke, John E., McPhail, Jacob A., Vanaerschot, Manu, Fidock, David A., Fish, Paul V., Siegl, Peter, Smith, Dennis A., Wirjanata, Grennady, Noviyanti, Rintis, Price, Ric N., Marfurt, Jutta, Silue, Kigbafori D., Street, Leslie J., and Chibale, Kelly
- Abstract
The 2-aminopyridine MMV048 was the first drug candidate inhibiting Plasmodiumphosphatidylinositol 4-kinase (PI4K), a novel drug target for malaria, to enter clinical development. In an effort to identify the next generation of PI4K inhibitors, the series was optimized to improve properties such as solubility and antiplasmodial potency across the parasite life cycle, leading to the 2-aminopyrazine UCT943.
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- 2018
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210. Antimalarial efficacy of MMV390048, an inhibitor of Plasmodiumphosphatidylinositol 4-kinase
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Paquet, Tanya, Le Manach, Claire, Cabrera, Diego González, Younis, Yassir, Henrich, Philipp P., Abraham, Tara S., Lee, Marcus C. S., Basak, Rajshekhar, Ghidelli-Disse, Sonja, Lafuente-Monasterio, María José, Bantscheff, Marcus, Ruecker, Andrea, Blagborough, Andrew M., Zakutansky, Sara E., Zeeman, Anne-Marie, White, Karen L., Shackleford, David M., Mannila, Janne, Morizzi, Julia, Scheurer, Christian, Angulo-Barturen, Iñigo, Martínez, María Santos, Ferrer, Santiago, Sanz, Laura María, Gamo, Francisco Javier, Reader, Janette, Botha, Mariette, Dechering, Koen J., Sauerwein, Robert W., Tungtaeng, Anchalee, Vanachayangkul, Pattaraporn, Lim, Chek Shik, Burrows, Jeremy, Witty, Michael J., Marsh, Kennan C., Bodenreider, Christophe, Rochford, Rosemary, Solapure, Suresh M., Jiménez-Díaz, María Belén, Wittlin, Sergio, Charman, Susan A., Donini, Cristina, Campo, Brice, Birkholtz, Lyn-Marie, Hanson, Kirsten K., Drewes, Gerard, Kocken, Clemens H. M., Delves, Michael J., Leroy, Didier, Fidock, David A., Waterson, David, Street, Leslie J., and Chibale, Kelly
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MMV390048, a member of a new class of inhibitors of the Plasmodiumphosphatidylinositol 4-kinase, shows potential for both treatment and prophylaxis.
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- 2017
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211. Effects of Maternal HIV Infection on Early Kaposi Sarcoma-Associated Herpesvirus Seroconversion in a Kenyan Mother-Infant Cohort.
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Sabourin, Katherine R, Ogolla, Sidney, Reyes, Gabriela Samayoa, Daud, Ibrahim, Jackson, Conner L, Labo, Nazzarena, Miley, Wendell, Whitby, Denise, Lamb, Molly M, Rochford, Rosemary, and Dent, Arlene
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HIV infections , *SEROCONVERSION , *CORD blood , *HIV , *FALSE discovery rate - Abstract
Background We identified whether maternal human immunodeficiency virus (HIV) infection during pregnancy affects transplacental transfer of Kaposi sarcoma-associated herpesvirus (KSHV)-specific antibodies and subsequent infant infection. Methods We followed pregnant Kenyan women through delivery and their infants until age 2 years. Children were classified as HIV-exposed uninfected (HEU) or HIV-unexposed uninfected (HUU) based on maternal HIV status. Maternal venous and cord blood at delivery and child venous blood every 6 months were tested for antibodies to 20 KSHV antigens by multiplex bead-based immunoassay. Multiple comparisons were adjusted using false discovery rate (FDR). Results Maternal HIV infection was significantly associated with decreased transplacental transfer of antibodies against all KSHV antigens and lower cord blood levels for 8 antigens at FDR P <.10. Neither birth to 6-month antibody level changes nor 6-month levels differed in HEU and HUU, except for ORF50. By age 24 months, 74% of children KSHV seroconverted but HEU and HUU did not differ in time to seroconversion nor 2-year seropositivity after adjustment for child malaria infection. Conclusions Maternal HIV infection reduced a child's initial KSHV antibody levels but did not affect age of infection. Regardless of HIV exposure in utero, KSHV seroconversion in Kenyan children occurred early; associated factors must be identified. [ABSTRACT FROM AUTHOR]
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- 2023
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212. Epstein–Barr virus (EBV) antibody changes over time in a general population cohort in rural Uganda, 1992–2008.
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Sabourin, Katherine R., Mugisha, Joseph, Asiki, Gershim, Nalwoga, Angela, Labo, Nazzarena, Miley, Wendell, Beyer, Rachel, Rochford, Rosemary, Johnston, Thomas W., Newton, Robert, and Whitby, Denise
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HIV infections , *IMMUNOGLOBULINS , *TIME , *HIV seroconversion , *INFECTION , *KAPOSI'S sarcoma , *EPSTEIN-Barr virus , *RESEARCH funding , *DESCRIPTIVE statistics , *ENZYME-linked immunosorbent assay , *HERPESVIRUSES , *RURAL population , *LONGITUDINAL method - Abstract
Background: Epstein–Barr virus (EBV) infection is ubiquitous and in sub-Saharan Africa, occurs early in life. In a population-based rural African cohort, we leveraged historical samples from the General Population Cohort (GPC) in Uganda to examine the epidemiology of infection with EBV over time, in the era of HIV. Methods: We used 9024 serum samples collected from the GPC in 1992, 2000, 2008, from 7576 participants across the age range (0–99 years of age) and tested for anti-EBV immunoglobulin G (IgG) antibodies to EAd, VCA, and EBNA-1 using a multiplex bead-based assay. The related gammaherpesvirus, Kaposi's sarcoma-associated herpesvirus (KSHV) seropositivity was also determined by detection of anti-KSHV IgG antibodies to K8.1 or ORF73 measured by recombinant protein enzyme-linked immunosorbent assay. Data on sex, age, and HIV serostatus were also collected. EBV seropositivity was modeled with age (excluding those under one year, who may have had maternal antibodies), sex, HIV serostatus, and KSHV serostatus using generalized linear mixed effects models to produce beta estimates. Results: More than 93% of children were EBV seropositive by one year of age. EBV seropositivity was significantly associated with KSHV seropositivity. Anti-EBNA-1 antibody levels decreased with increasing age and were lower on average in people living with HIV. In general, anti-EAd antibody levels increased with age, were higher in males and KSHV seropositive persons, but decreased over calendar time. Anti-VCA antibody levels increased with age and with calendar time and were higher in KSHV seropositive persons but lower in males. Conclusions: This is the first study to identify factors associated with EBV antibodies across the entire life-course in rural sub-Saharan Africa. Consistent with other studies, EBV was near ubiquitous in the population by age one year. Patterns of antibodies show changes by age, sex and calendar time, but no association with HIV was evident, suggesting no relationship between EBV sero-epidemiology and the spread of HIV in the population over time in Uganda. [ABSTRACT FROM AUTHOR]
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- 2023
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213. Hemoglobinopathies, merozoite surface protein-2 gene polymorphisms, and acquisition of Epstein Barr virus among infants in Western Kenya.
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Olewe, Perez K., Awandu, Shehu Shagari, Munde, Elly O., Anyona, Samuel B., Raballah, Evans, Amolo, Asito S., Ogola, Sidney, Ndenga, Erick, Onyango, Clinton O., Rochford, Rosemary, Perkins, Douglas J., and Ouma, Collins
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GENETIC polymorphisms , *BURKITT'S lymphoma , *INFANTS , *SICKLE cell trait , *GENETIC variation - Abstract
Background: Epstein Barr virus (EBV)-associated endemic Burkitt's Lymphoma pediatric cancer is associated with morbidity and mortality among children resident in holoendemic Plasmodium falciparum regions in western Kenya. P. falciparum exerts strong selection pressure on sickle cell trait (SCT), alpha thalassemia (-α3.7/αα), glucose-6-phosphate dehydrogenase (G6PD), and merozoite surface protein 2 (MSP-2) variants (FC27, 3D7) that confer reduced malarial disease severity. The current study tested the hypothesis that SCT, (-α3.7/αα), G6PD mutation and (MSP-2) variants (FC27, 3D7) are associated with an early age of EBV acquisition. Methods: Data on infant EBV infection status (< 6 and ≥ 6–12 months of age) was abstracted from a previous longitudinal study. Archived infant DNA (n = 81) and mothers DNA (n = 70) samples were used for genotyping hemoglobinopathies and MSP-2. The presence of MSP-2 genotypes in maternal DNA samples was used to indicate infant in-utero malarial exposure. Genetic variants were determined by TaqMan assays or standard PCR. Group differences were determined by Chi-square or Fisher's analysis. Bivariate regression modeling was used to determine the relationship between the carriage of genetic variants and EBV acquisition. Results: EBV acquisition for infants < 6 months was not associated with -α3.7/αα (OR = 1.824, P = 0.354), SCT (OR = 0.897, P = 0.881), or G6PD [Viangchan (871G > A)/Chinese (1024 C > T) (OR = 2.614, P = 0.212)] and [Union (1360 C > T)/Kaiping (1388G > A) (OR = 0.321, P = 0.295)]. There was no relationship between EBV acquisition and in-utero exposure to either FC27 (OR = 0.922, P = 0.914) or 3D7 (OR = 0.933, P = 0.921). In addition, EBV acquisition in infants ≥ 6–12 months also showed no association with -α3.7/αα (OR = 0.681, P = 0.442), SCT (OR = 0.513, P = 0.305), G6PD [(Viangchan (871G > A)/Chinese (1024 C > T) (OR = 0.640, P = 0.677)], [Mahidol (487G > A)/Coimbra (592 C > T) (OR = 0.948, P = 0.940)], [(Union (1360 C > T)/Kaiping (1388G > A) (OR = 1.221, P = 0.768)], African A (OR = 0.278, P = 0.257)], or in utero exposure to either FC27 (OR = 0.780, P = 0.662) or 3D7 (OR = 0.549, P = 0.241). Conclusion: Although hemoglobinopathies (-α3.7/αα, SCT, and G6PD mutations) and in-utero exposure to MSP-2 were not associated with EBV acquisition in infants 0–12 months, novel G6PD variants were discovered in the population from western Kenya. To establish that the known and novel hemoglobinopathies, and in utero MSP-2 exposure do not confer susceptibility to EBV, future studies with larger sample sizes from multiple sites adopting genome-wide analysis are required. [ABSTRACT FROM AUTHOR]
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- 2023
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214. Comparison of Epstein–Barr virus and Kaposi's sarcoma-associated herpesvirus viral load in peripheral blood mononuclear cells and oral fluids of HIV-negative individuals aged 3–89 years from Uganda.
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Nalwoga, Angela, Marshall, Vickie, Miley, Wendell, Labo, Nazzarena, Whitby, Denise, Newton, Robert, and Rochford, Rosemary
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HERPESVIRUS diseases , *HIV infections , *MONONUCLEAR leukocytes , *SALIVA , *VIRAL load , *KAPOSI'S sarcoma , *COMPARATIVE studies , *MALARIA , *RESEARCH funding , *EPSTEIN-Barr virus diseases , *DISEASE complications - Abstract
We previously found that age, sex and malaria were associated with KSHV in individuals from Uganda. In this study, we have evaluated these same factors in relation to EBV in the same specimens. Overall, 74% (oral fluids) and 46% (PBMCs) had detectable EBV. This was significantly higher than observed for KSHV (24% oral fluids and 11% PBMCs). Individuals with EBV in PBMCs were more likely to have KSHV in PBMCs (P = 0.011). The peak age for detection of EBV in oral fluids was 3–5 years while that of KSHV was 6–12 years. In PBMCs, there was a bimodal peak age for detection of EBV (at 3–5 years and 66 + years) while for KSHV there was a single peak at 3–5 years. Individuals with malaria had higher levels of EBV in PBMCs compared to malaria-negative individuals (P = 0.002). In summary, our results show that younger age and malaria are associated with higher levels of EBV and KSHV in PBMCs suggesting malaria impacts immunity to both gamma-herpesviruses. [ABSTRACT FROM AUTHOR]
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- 2023
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215. Decline in EBV-Specific IFN T cell responses in Kenyan infants from a malaria holoendemic region of Kenya.
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Asito, Amolo S., Piriou, Erwan, Sumba, Odada P., Moormann, Ann M., and Rochford, Rosemary
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EPSTEIN-Barr virus ,LECTURE method in teaching ,LYMPHOMAS ,MALARIA ,RESEARCH funding - Abstract
The article presents a study which investigates the decline of Epstein-Barr virus (EBV)-specific IFN T cell responses among infants in a malaria holoendemic region in Kenya. It is inferred that the decline in IFN T cell responses may lead to Burkitt's lymphoma. The role of Plasmodium falciparum infections in the loss of EBV-specific immunity is outlined.
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- 2012
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216. Development of an ectopic huLiver model for Plasmodium liver stage infection.
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Samayoa-Reyes, Gabriela, Flaherty, Siobhan M., Wickham, Kristina S., Viera-Morilla, Sara, Strauch, Pamela M., Roth, Alison, Padrón, Laura, Jackson, Conner M., Meireles, Patricia, Calvo, David, Roobsoong, Wanlapa, Kangwanrangsan, Niwat, Sattabongkot, Jetsumon, Reichard, Gregory, Lafuente-Monasterio, Maria José, and Rochford, Rosemary
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PLASMODIUM , *DRUG discovery , *SUBCUTANEOUS injections , *LIVER , *PLASMODIUM falciparum , *INFECTION - Abstract
Early Plasmodium falciparum and P. vivax infection requires parasite replication within host hepatocytes, referred to as liver stage (LS). However, limited understanding of infection dynamics in human LS exists due to species-specificity challenges. Reported here is a reproducible, easy-to-manipulate, and moderate-cost in vivo model to study human Plasmodium LS in mice; the ectopic huLiver model. Ectopic huLiver tumors were generated through subcutaneous injection of the HC-04 cell line and shown to be infectible by both freshly dissected sporozoites and through the bite of infected mosquitoes. Evidence for complete LS development was supported by the transition to blood-stage infection in mice engrafted with human erythrocytes. Additionally, this model was successfully evaluated for its utility in testing antimalarial therapeutics, as supported by primaquine acting as a causal prophylactic against P. falciparum. Presented here is a new platform for the study of human Plasmodium infection with the potential to aid in drug discovery. [ABSTRACT FROM AUTHOR]
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- 2023
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217. Malaria and Pregnancy: Placental Cytokine Expression and Its Relationship to Intrauterine Growth Retardation.
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Moormann, Ann M., Sullivan, Amy D., Rochford, Rosemary A., Chensue, Stephen W., Bock, Paul J., and Nyirenda, Thomas
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MALARIA , *PREGNANCY , *INTERLEUKINS - Abstract
Malaria infections during pregnancy can lead to the delivery of low-birth-weight infants. In this study, cytokine mRNA was measured in placentas from 23 malaria-infected and 21 uninfected primigravid women who had delivered in Mangochi, Malawi, a region with a high rate of transmission of falciparum malaria. Significantly increased expression of interleukin (IL)-1beta, IL-8, and tumor necrosis factor (TNF)-alpha and decreased expression of IL-6 and transforming growth factor-beta1 were found in malaria-infected compared with uninfected placentas. TNF-alpha and IL-8 were produced by maternally derived hemozoin-laden placental macrophages. Increased TNF-alpha expression was associated with increased placental hemozoin concentrations. Increased TNF-alpha or IL-8 expression in the placenta was associated with intrauterine growth retardation but not with preterm delivery. The results suggest that malaria infections induce a potentially harmful proinflammatory response in the placenta. [ABSTRACT FROM AUTHOR]
- Published
- 1999
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218. Species composition and risk of transmission of some Aedes-borne arboviruses in some sites in Northern Ghana.
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Joannides, Joannitta, Dzodzomenyo, Mawuli, Azerigyik, Faustus, Agbosu, Eudocia Esinam, Pratt, Deborah, Nyarko Osei, Joseph Harold, Pwalia, Rebecca, Amlalo, Godwin Kwame, Appawu, Maxwell, Takashi, Hayashi, Iwanaga, Shiroh, Buchwald, Andrea, Rochford, Rosemary, Boakye, Daniel, Koram, Kwadwo, Bonney, Kofi, and Dadzie, Samuel
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ARBOVIRUS diseases , *MOSQUITO vectors , *AEDES aegypti , *YELLOW fever , *AEDES , *ARBOVIRUSES , *VIRUS diseases - Abstract
Aedes-borne viral diseases mainly Yellow Fever (YF), Dengue (DEN), Zika (ZIK) and Chikungunya (CHK) have contributed to many deaths' in the world especially in Africa. There have been major outbreaks of these diseases in West Africa. Although, YF outbreaks have occurred in Ghana over the years, no outbreak of DEN, ZIK and CHK has been recorded. However, the risk of outbreak is high due to its proximity to West African countries where outbreaks have been recently been recorded. This study surveyed the mosquito fauna to assess the risk of transmission of Yellow fever (YFV), Dengue (DENV), Chikungunya (CHKV) and Zika (ZIKV) viruses in Larabanga and Mole Game Reserve areas in Northern Ghana. The immature and adult stages of Aedes mosquitoes were collected from Larabanga and Mole Game Reserve area. There was a significant (P>0.001) number of mosquitoes collected during the rainy season than the dry season. A total of 1,930 Aedes mosquitoes were collected during the rainy season and morphologically identified. Of these, 1,915 (99.22%) were Aedes aegypti and 15 (0.22%) were Aedes vittatus. During the dry season, 27 Ae. aegypti mosquitoes were collected. A total of 415 Ae. aegypti mosquitoes were molecularly identified to subspecies level of which Ae. (Ae) aegypti aegypti was the predominant subspecies. Both Ae. aegypti aegypti and Ae aegypti formosus exist in sympatry in the area. All Aedes pools (75) were negative for DENV, ZIKV and CHKV when examined by RT- PCR. Three Larval indices namely House Index, HI (percentage of houses positive for Aedes larvae or pupae), Container Index, CI (the percentage of containers positive for Aedes larvae or pupae) and Breteau Index, BI (number of positive containers per 100 houses inspected) were assessed as a measure for risk of transmission in the study area. The HI, CI and BI for both sites were as follows; Mole Game Reserve (HI, 42.1%, CI, 23.5% and BI, 100 for rainy season and 0 for all indices for dry season) and Larabanga (39%, 15.5% and 61 for rainy season and 2.3%, 1.3% and 2.3 for dry season). The spatial distribution of Aedes breeding sites in both areas indicated that Aedes larvae were breeding in areas with close proximity to humans. Lorry tires were the main source of Aedes larvae in all the study areas. Information about the species composition and the potential role of Aedes mosquitoes in future outbreaks of the diseases that they transmit is needed to design efficient surveillance and vector control tools. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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219. IFN-λ4 genetic variants influence clinical malaria episodes in a cohort of Kenyan children.
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Samayoa-Reyes, Gabriela, Jackson, Conner, Ogolla, Sidney, Sabourin, Katherine, Obajemu, Adeola, Dent, Arlene E., Prokunina-Olsson, Ludmilla, and Rochford, Rosemary
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RESPIRATORY infections , *MALARIA , *VIRAL tropism , *HEPATITIS C virus , *GENES - Abstract
Background: Interferon (IFN)- λ4, a type III IFN, production is controlled by a dinucleotide frameshift variant (rs368234815-dG/TT) within the first exon of the IFNL4 gene. Carriers of the IFNL4-dG allele but not the IFNL4-TT allele are able to produce the IFN-λ4 protein. Patients with hepatitis C virus that do not produce the IFN-λ4 protein have higher rates of viral clearance suggesting a potential inhibitory role of IFN-λ4 in liver-tropic infections. Methods: In this study, it was investigated whether children infected with Plasmodium falciparum, which has a well-characterized liver stage infection, would be more susceptible to clinical malaria relative to their IFNL4-rs368234815 allele. A cohort of 122 children from a malaria holoendemic region of Kenya was analysed. Episodes of clinical malaria and upper respiratory tract infections (URTIs) were determined using information collected from birth to 2 years of age. The dinucleotide frameshift variant IFNL4-rs368234815-dG/TT was genotyped using a TaqMan assay. Results: In this cohort, 33% of the study participants had the dG/dG genotype, 45% had the dG/TT genotype, and 22% had TT/TT genotype. The number and time to first episode of clinical malaria and URTIs with respect to the IFNL4-rs368234815 allele was evaluated. It was found that children that carried the IFNL4-rs368234815-dG allele had an increased number of clinical malaria episodes. In addition, there was a significant association between earlier age of first malaria infection with carriers of the IFNL4-dG allele (p-value: 0.021). Conclusion: The results suggest that the ability to produce IFN-λ4 negatively affects host immune protection against P. falciparum malaria in Kenyan children. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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220. Liver-targeted polymeric prodrugs of 8-aminoquinolines for malaria radical cure.
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Srinivasan, Selvi, Roy, Debashish, Chavas, Thomas E.J., Vlaskin, Vladimir, Ho, Duy-Khiet, Pottenger, Ayumi, LeGuyader, Clare L.M., Maktabi, Mahdi, Strauch, Pamela, Jackson, Conner, Flaherty, Siobhan M., Lin, Hsiuling, Zhang, Jing, Pybus, Brandon, Li, Qigui, Huber, Hans E., Burke, Paul A., Wesche, David, Rochford, Rosemary, and Stayton, Patrick S.
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PRODRUGS , *ERYTHROCYTES , *HEMOLYTIC anemia , *INTRAVENOUS therapy , *PLASMODIUM vivax , *GLUCOSE-6-phosphate dehydrogenase - Abstract
Primaquine and tafenoquine are the two 8-aminoquinoline (8-AQ) antimalarial drugs approved for malarial radical cure - the elimination of liver stage hypnozoites after infection with Plasmodium vivax. A single oral dose of tafenoquine leads to high efficacy against intra-hepatocyte hypnozoites after efficient first pass liver uptake and metabolism. Unfortunately, both drugs cause hemolytic anemia in G6PD-deficient humans. This toxicity prevents their mass administration without G6PD testing given the approximately 400 million G6PD deficient people across malarial endemic regions of the world. We hypothesized that liver-targeted delivery of 8-AQ prodrugs could maximize liver exposure and minimize erythrocyte exposure to increase their therapeutic window. Primaquine and tafenoquine were first synthesized as prodrug vinyl monomers with self-immolative hydrolytic linkers or cathepsin-cleavable valine-citrulline peptide linkers. RAFT polymerization was exploited to copolymerize these prodrug monomers with hepatocyte-targeting GalNAc monomers. Pharmacokinetic studies of released drugs after intravenous administration showed that the liver-to-plasma AUC ratios could be significantly improved, compared to parent drug administered orally. Single doses of the liver-targeted, enzyme-cleavable tafenoquine polymer were found to be as efficacious as an equivalent dose of the oral parent drug in the P. berghei causal prophylaxis model. They also elicited significantly milder hemotoxicity in the humanized NOD/SCID mouse model engrafted with red blood cells from G6PD deficient donors. The clinical application is envisioned as a single subcutaneous administration, and the lead tafenoquine polymer also showed excellent bioavailability and liver-to-blood ratios exceeding the IV administered polymer. The liver-targeted tafenoquine polymers warrant further development as a single-dose therapeutic via the subcutaneous route with the potential for broader patient administration without a requirement for G6PD diagnosis. Unlabelled Image [ABSTRACT FROM AUTHOR]
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- 2021
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221. Determinants of Gammaherpesvirus Shedding in Saliva Among Ugandan Children and Their Mothers.
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Newton, Robert, Labo, Nazzarena, Wakeham, Katie, Marshall, Vickie, Roshan, Romin, Nalwoga, Angela, Sebina, Ismail, Muhangi, Lawrence, Webb, Emily L, Miley, Wendell, Rochford, Rosemary, Elliott, Alison M, and Whitby, Denise
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EPSTEIN-Barr virus genetics , *KAPOSI'S sarcoma-associated herpesvirus , *HERPESVIRUS diseases , *SALIVA microbiology , *MOLTING , *COMPARATIVE studies , *DNA , *EPSTEIN-Barr virus , *HERPESVIRUSES , *HUMAN reproduction , *IMMUNOGLOBULINS , *MATERNAL age , *RESEARCH methodology , *MEDICAL cooperation , *MOTHERS , *PROTOZOA , *RESEARCH , *SALIVA , *VIRAL antibodies , *VIRAL physiology , *VIRAL load , *EVALUATION research , *CROSS-sectional method , *BLIND experiment , *INFECTIOUS disease transmission - Abstract
Background: Epstein-Barr virus (EBV) and Kaposi sarcoma-associated herpesvirus (KSHV) are transmitted via saliva, but factors associated with salivary shedding are unknown.Methods: We measured the DNA load of both viruses in saliva specimens collected from approximately 500 Ugandan mothers and their 6-year-old children, testing all participants for EBV and KSHV-seropositive individuals for KSHV.Results: EBV and KSHV were shed by 72% and 22% of mothers, respectively, and by 85% and 40% of children, respectively; boys were more likely than girls to shed KSHV (48% vs 30%) but were equally likely to shed EBV. Children shed more KSHV and EBV than mothers, but salivary loads of EBV and KSHV were similar. KSHV shedding increased with increasing anti-KSHV (K8.1) antibodies in mothers and with decreasing antimalarial antibodies both in mothers and children. Among mothers, 40% of KSHV shedders also shed EBV, compared with 75% of KSHV nonshedders; among children, EBV was shed by 65% and 83%, respectively.Conclusions: In summary, in this population, individuals were more likely to shed EBV than KSHV in saliva. We identified several factors, including child's sex, that influence KSHV shedding, and we detected an inverse relationship between EBV and KSHV shedding, suggesting a direct or indirect interaction between the two viruses. [ABSTRACT FROM AUTHOR]- Published
- 2018
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222. Epstein-Barr Virus Type 2 Infects T Cells in Healthy Kenyan Children.
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Coleman, Carrie B., Daud, Ibrahim I., Ogolla, Sidney O., Ritchie, Julie A., Smith, Nicholas A., Sumba, Peter O., Dent, Arlene E., and Rochford, Rosemary
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CHILDREN , *EPSTEIN-Barr virus , *T cells , *BREAST milk , *SALIVA , *MOTHERS , *DISEASES , *COLLECTION & preservation of biological specimens , *DNA , *EPSTEIN-Barr virus diseases , *LONGITUDINAL method , *RESEARCH funding , *VIRAL physiology , *DISEASE prevalence , *PHYSIOLOGY , *DIAGNOSIS - Abstract
Background: The 2 strains of Epstein-Barr virus (EBV), EBV type 1 (EBV-1) and EBV-2, differ in latency genes, suggesting that they use distinct mechanisms to establish latency. We previously reported that EBV-2 infects T cells in vitro. In this study, we tested the possibility that EBV-2 infects T cells in vivo.Methods: Purified T-cell fractions isolated from children positive for EBV-1 or EBV-2 and their mothers were examined for the presence of EBV and for EBV type.Results: We detected EBV-2 in all T-cell samples obtained from EBV-2-infected children at 12 months of age, with some children retaining EBV-2-positive T cells through 24 months of age, suggesting that EBV-2 persists in T cells. We were unable to detect EBV-2 in T-cell samples from mothers but could detect EBV-2 in samples of their breast milk and saliva.Conclusions: These data suggest that EBV-2 uses T cells as an additional latency reservoir but that, over time, the frequency of infected T cells may drop below detectable levels. Alternatively, EBV-2 may establish a prolonged transient infection in the T-cell compartment. Collectively, these novel findings demonstrate that EBV-2 infects T cells in vivo and suggest EBV-2 may use the T-cell compartment to establish latency. [ABSTRACT FROM AUTHOR]- Published
- 2017
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223. Modeling of EBV Infection and Antibody Responses in Kenyan Infants With Different Levels of Malaria Exposure Shows Maternal Antibody Decay is a Major Determinant of Early EBV Infection.
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Reynaldi, Arnold, Schlub, Timothy E., Piriou, Erwan, Ogolla, Sidney, Sumba, Odada P., Moormann, Ann M., Rochford, Rosemary, and Davenport, Miles P.
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EPSTEIN-Barr virus diseases , *ANTIBODY formation , *INFANTS , *MALARIA , *IMMUNOGLOBULIN G , *B cell lymphoma , *EPSTEIN-Barr virus , *IMMUNOGLOBULINS , *PROTEINS , *RESEARCH funding , *VIRAL antibodies , *VIRAL antigens , *VIRAL load , *DISEASE complications - Abstract
The combination of Epstein-Barr virus (EBV) infection and high malaria exposure are risk factors for endemic Burkitt lymphoma, and evidence suggests that infants in regions of high malaria exposure have earlier EBV infection and increased EBV reactivation. In this study we analyzed the longitudinal antibody response to EBV in Kenyan infants with different levels of malaria exposure. We found that high malaria exposure was associated with a faster decline of maternally derived immunoglobulin G antibody to both the EBV viral capsid antigen and EBV nuclear antigen, followed by a more rapid rise in antibody response to EBV antigens in children from the high-malaria-transmission region. We also observed the long-term persistence of anti-viral capsid antigen immunoglobulin M responses in children from the high-malaria region. More rapid decay of maternal antibodies was a major predictor of EBV infection outcome, because decay predicted time to EBV DNA detection, independent of high or low malaria exposure. [ABSTRACT FROM AUTHOR]
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- 2016
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224. Impact of Plasmodium falciparum Coinfection on Longitudinal Epstein-Barr Virus Kinetics in Kenyan Children.
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Reynaldi, Arnold, Schlub, Timothy E., Chelimo, Kiprotich, Sumba, Peter Odada, Piriou, Erwan, Ogolla, Sidney, Moormann, Ann M., Rochford, Rosemary, and Davenport, Miles P.
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PLASMODIUM falciparum , *MIXED infections , *MALARIA , *BURKITT'S lymphoma , *EPSTEIN-Barr virus , *EPSTEIN-Barr virus diseases , *PHARMACOKINETICS , *PROTOZOA , *RESEARCH funding , *VIRAL load , *PROPORTIONAL hazards models , *DISEASE complications , *PHYSIOLOGY - Abstract
Endemic Burkitt lymphoma is associated with Epstein-Barr virus (EBV) and Plasmodium falciparum coinfection, although how P. falciparum exposure affects the dynamics of EBV infection is unclear. We have used a modeling approach to study EBV infection kinetics in a longitudinal cohort of children living in regions of high and low malaria transmission in Kenya. Residence in an area of high malaria transmission was associated with a higher rate of EBV expansion during primary EBV infection in infants and during subsequent episodes of EBV DNA detection, as well as with longer episodes of EBV DNA detection and shorter intervals between subsequent episodes of EBV DNA detection. In addition, we found that concurrent P. falciparum parasitemia also increases the likelihood of the first and subsequent peaks of EBV in peripheral blood. This suggests that P. falciparum infection is associated with increased EBV growth and contributes to endemic Burkitt lymphoma pathogenesis. [ABSTRACT FROM AUTHOR]
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- 2016
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225. Breast Milk as a Potential Source of Epstein-Barr Virus Transmission Among Infants Living in a Malaria-Endemic Region of Kenya.
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Daud, Ibrahim I., Coleman, Carrie B., Smith, Nicholas A., Ogolla, Sidney, Simbiri, Kenneth, Bukusi, Elizabeth A., Ng'ang'a, Zipporah W., Sumba, Peter O., Vulule, John, Ploutz-Snyder, Robert, Dent, Arlene E., and Rochford, Rosemary
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DNA analysis , *BREAST milk , *EPSTEIN-Barr virus , *EPSTEIN-Barr virus diseases , *LONGITUDINAL method , *MALARIA , *RESEARCH funding , *VIRAL load , *DISEASE prevalence , *INFECTIOUS disease transmission - Abstract
Background: We previously reported that infants in Kenya were infected with Epstein-Barr virus (EBV) at <6 months of age, suggesting that mothers were the likely source of transmissible virus to the infant. In this study, we investigated whether breast milk contained infectious EBV and the role of malaria in EBV shedding in breast milk.Methods: Breast milk samples were obtained from Kenyan mothers at postpartum weeks 6, 10, 14, and 18 and analyzed for presence of infectious EBV.Results: We found that the prevalence of EBV DNA and the mean EBV load were significantly higher at 6 weeks and decreased through postpartum week 18 (P < .0001). High EBV load in breast milk correlated with mothers who had Plasmodium falciparum malaria at delivery. To determine whether viral DNA was encapsidated, breast milk samples were treated with DNAse before DNA extraction. Sixty percent of samples were DNAse resistant, suggesting that the viral DNA in breast milk was encapsidated. Next, we exposed peripheral blood mononuclear cells to breast milk supernatant, which resulted in the generation of EBV-positive lymphoblastoid cell lines, indicating that the virus in breast milk was infectious.Conclusions: Our data suggest that breast milk contains infectious EBV and is a potential source of viral transmission to infants living in malaria-endemic regions. [ABSTRACT FROM AUTHOR]- Published
- 2015
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226. Plasmodium falciparum Infection is Associated with Epstein-Barr Virus Reactivation in Pregnant Women Living in Malaria Holoendemic Area of Western Kenya.
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Daud, Ibrahim, Ogolla, Sidney, Amolo, Asito, Namuyenga, Eunice, Simbiri, Kenneth, Bukusi, Elizabeth, Ng'ang'a, Zipporah, Ploutz-Snyder, Robert, Sumba, Peter, Dent, Arlene, and Rochford, Rosemary
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EPSTEIN-Barr virus diseases , *FISHER exact test , *MALARIA , *POLYMERASE chain reaction , *PREGNANCY complications , *RESEARCH funding , *T-test (Statistics) , *VIRAL load , *VERTICAL transmission (Communicable diseases) , *DATA analysis software , *DISEASE complications , *PREGNANCY , *DISEASE risk factors - Abstract
The role of Plasmodium falciparum malaria in Epstein-Barr virus (EBV) transmission among infants early in life remain elusive. We hypothesized that infection with malaria during pregnancy could cause EBV reactivation leading to high EBV load in circulation, which could subsequently enhance early age of EBV infection. Pregnant women in Kisumu, where P. falciparum malaria is holoendemic, were actively followed monthly through antenatal visits (up to 4 per mother) and delivery. Using real-time quantitative (Q)-PCR, we quantified and compared EBV and P. falciparum DNA levels in the blood of pregnant women with and without P. falciparum malaria. Pregnant women that had malaria detected during pregnancy were more likely to have detectable EBV DNA than pregnant women who had no evidence of malaria infection during pregnancy (64 vs. 36 %, p = 0.01). EBV load as analyzed by quantifying area under the longitudinal observation curve (AUC) was significantly higher in pregnant women with P. falciparum malaria than in women without evidence of malaria infection ( p = 0.01) regardless of gestational age of pregnancy. Increase in malaria load correlated with increase in EBV load ( p < 0.0001). EBV load was higher in third trimester ( p = 0.04) than first and second trimester of pregnancy independent of known infections. Significantly higher frequency and elevated EBV loads were found in pregnant women with malaria than in women without evidence of P. falciparum infection during pregnancy. The loss of control of EBV latency following P. falciparum infection during pregnancy and subsequent increase in EBV load in circulation could contribute to enhanced shedding of EBV in maternal saliva and breast milk postpartum, but further studies are needed. [ABSTRACT FROM AUTHOR]
- Published
- 2015
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227. MHV68 Latency Modulates the Host Immune Response to Influenza A Virus.
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Saito, Fumitake, Ito, Toshihiro, Connett, Judith, Schaller, Matthew, Carson, William, Hogaboam, Cory, Rochford, Rosemary, and Kunkel, Steven
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INFLUENZA A virus , *ALVEOLAR macrophages , *NEUTROPHILS , *LABORATORY mice , *INFLAMMATION , *LUNG physiology - Abstract
Murine gammaherpesvirus 68 (MHV68) is a natural rodent pathogen that has been used as a model to study the pathogenesis of human gammaherpesviruses. Like other herpesviruses, MHV68 causes acute infection and establishes life-long latency in the host. Recently, it has been shown that mice latently infected with MHV68 have resistance to unrelated pathogens in secondary infection models. We therefore hypothesized that latent MHV68 infection could modulate the host response to influenza A virus. To test this hypothesis, mice were infected intranasally with influenza virus following the establishment of MHV68 latency. Mice latently infected with MHV68 showed significantly higher survival to influenza A virus infection than did PBS mock-infected mice. Latent MHV68 infection led to lower influenza viral loads and decreased inflammatory pathology in the lungs. Alveolar macrophages of mice latently infected with MHV68 showed activated status, and adoptive transfer of those activated macrophages into mice followed the infection with influenza A virus had significantly greater survival rates than control mice, suggesting that activated alveolar macrophages are a key mechanistic component in protection from secondary infections. [ABSTRACT FROM AUTHOR]
- Published
- 2013
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228. Blk haploinsufficiency impairs the development, but enhances the functional responses, of MZ B cells.
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Samuelson, Elizabeth M, Laird, Renee M, Maue, Alexander C, Rochford, Rosemary, and Hayes, Sandra M
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B cells , *PROTEIN-tyrosine kinases , *CELL receptors , *RODENTS , *CELL membranes - Abstract
Blk was identified two decades ago as a B-cell-specific member of the Src family of tyrosine kinases. Recent studies, however, have discovered that Blk is expressed in many cell types outside of the B lineage, including early thymic precursors, interleukin-17-producing γδ T cells and pancreatic β-cells. In light of these recent discoveries, we performed a more comprehensive analysis of Blk expression patterns in hematopoietic cells and found that Blk is differentially expressed in mature B-cell subsets, with marginal zone (MZ) B cells expressing high levels, B1 B cells expressing intermediate-to-high levels and follicular (FO) B cells expressing low levels of Blk. To determine whether these differences in Blk expression levels reflected differential requirements for Blk in MZ, B1 and FO B-cell development, we analyzed the effects of reducing and eliminating Blk expression on B-cell development. We report that both Blk haploinsufficiency and Blk deficiency impaired the generation of MZ B cells. Moreover, although there were fewer MZ B cells in Blk+/− and Blk−/− mice as compared with Blk+/+ mice, Blk-mutant MZ B cells were hyper-responsive to B-cell receptor stimulation, both in vitro and in vivo. Thus, this study has revealed a previously unappreciated role for Blk in the development and activation of MZ B cells. [ABSTRACT FROM AUTHOR]
- Published
- 2012
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229. Early Age at Time of Primary Epstein-Barr Virus Infection Results in Poorly Controlled Viral Infection in Infants From Western Kenya: Clues to the Etiology of Endemic Burkitt Lymphoma.
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Piriou, Erwan, Asito, Amolo S., Sumba, Peter O., Fiore, Nancy, Middeldorp, Jaap M., Moormann, Ann M., Ploutz-Snyder, Robert, and Rochford, Rosemary
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EPSTEIN-Barr virus diseases , *LYMPHOMA risk factors , *VIRUS diseases , *RANDOMIZED controlled trials , *INFANT diseases , *ETIOLOGY of diseases ,MALARIA transmission - Abstract
Background. Infection with Epstein-Barr virus (EBV) early in life and repeated malaria exposure have been proposed as risk factors for endemic Burkitt lymphoma (eBL). Methods. Infants were enrolled from 2 rural sites in Kenya: the Kisumu District, where malaria transmission is holoendemic and risk for eBL is high, and the Nandi District, where malaria transmission is limited and the risk for eBL is low. Blood samples were taken from infants through 2 years of age to measure EBV viral load, EBV antibodies, and malaria parasitemia. Results. We observed a significantly younger age at time of primary EBV infection in children from Kisumu compared with children from Nandi (mean age, 7.28 months [±0.33 SEM] in Kisumu vs 8.39 months [±0.26 SEM] in Nandi), with 35.3% of children in Kisumu infected before 6 months of age. To analyze how different predictors affected EBV viral load over time, we performed multilevel mixed modeling. This modeling revealed that residence in Kisumu and younger age at first EBV infection were significant predictors for having a higher EBV viral load throughout the period of observation. Conclusions. Children from a region at high risk for eBL were infected very early in life with EBV, resulting in higher viral loads throughout infancy. [ABSTRACT FROM AUTHOR]
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- 2012
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230. Exposure to Holoendemic Malaria Results in Suppression of Epstein-Barr Virus--Specific T Cell Immunosurveillance in Kenyan Children.
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Moormann, Ann M., Chelimo, Kiprotich, Sumba, Peter O., Tisch, Daniel J., Rochford, Rosemary, and Kazura, James W.
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EPSTEIN-Barr virus , *MALARIA , *PATHOGENIC microorganisms , *ENZYME-linked immunosorbent assay , *PLASMODIUM falciparum , *LYMPHOCYTES - Abstract
Background. Malaria and Epstein-Barr virus (EBV) infection are cofactors in the pathogenesis of endemic Burkitt lymphoma (eBL). The mechanisms by which these pathogens predispose to eBL are not known. Methods. Healthy Kenyan children with divergent malaria exposure were measured for responses to EBV latent and lytic antigens by interferon (IFN)-γ enzyme-linked immunospot (ELISPOT) assay and interleukin (IL)-10 ELISA. Phytohemagglutinin (PHA), purified protein derivative (PPD), and T cell epitope peptides derived from merozoite surface protein (MSP)-1, a malaria blood-stage antigen, were also evaluated. Results. Children 5-9 years old living in an area holoendemic for malaria had significantly fewer EBV-specific IFN-g responses than did children of the same age living in an area with unstable malaria transmission. This effect was not observed for children <5 years old or those >9 years old. In contrast, IFN-γ responses to PHA, PPD, and Plasmodium falciparum MSP-1 peptides did not significantly differ by age. IL-10 responses to EBV lytic antigens, PPD, and PHA correlated inversely with malaria exposure regardless of age. Conclusions. Children living in malaria holoendemic areas have diminished EBV-specific T cell immunosurveillance between the ages of 5 and 9 years, which coincides with the peak age incidence of eBL. [ABSTRACT FROM AUTHOR]
- Published
- 2007
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231. Exposure to Holoendemic Malaria Results in Elevated Epstein-Barr Virus Loads in Children.
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Moormann, Ann M., Chelimo, Kiprotich, Sumba, Odada P., Lutzke, Mary L., Ploutz-Snyder, Robert, Newton, Duane, Kazura, James, and Rochford, Rosemary
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EPSTEIN-Barr virus , *EPSTEIN-Barr virus diseases , *POLYMERASE chain reaction , *B cells , *BLOOD , *MALARIA - Abstract
Perennial and intense malaria transmission (holoendemic malaria) and Epstein-Barr virus (EBV) infection are 2 cofactors in the pathogenesis of endemic Burkitt lymphoma (eBL). In the present study, we compared EBV loads in children living in 2 regions of Kenya with differing malaria transmission intensities: Kisumu District, where malaria transmission is holoendemic, and Nandi District, where malaria transmission is sporadic. For comparison, blood samples were also obtained from US adults, Kenyan adults, and patientswith eBL. Extraction of DNA from blood and quantification by polymerase chain reaction give an EBV load estimate that reflects the number of EBV-infected B cells. We observed a significant linear trend in mean EBV load, with the lowest EBV load detected in US adults and increasing EBV loads detected in Kenyan adults, Nandi children, Kisumu children, and patients with eBL, respectively. In addition, EBV loads were significantly higher in Kisumu children 1-4 years of age than in Nandi children of the same age. Our results support the hypothesis that repeated malaria infections in very young children modulate the persistence of EBV and increase the risk for the development of eBL. [ABSTRACT FROM AUTHOR]
- Published
- 2005
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232. Aging is associated with increased T-cell chemokine expression in C57BL/6 mice.
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Chen, Jun, Mo, Ruran, Lescure, Pascal A., Misek, David E., Hanash, Samir, Rochford, Rosemary, Hobbs, Monte, and Yung, Raymond L.
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CHEMOKINES , *RIBONUCLEASES , *PROTEINS , *LEUCOCYTES , *CHEMOTAXIS - Abstract
To better understand the contribution of the chemokine system in immune senescence, we determined the aging effect on CD4+ and CD8+ T-cell chemokine expression by microarray screening and ribonuclease protection assays. Compared with young C57BL/6 mice, freshly isolated CD4+ cells from aged mice express increased level of interferon-gamma-inducible protein 10 (IP-10), macrophage inflammatory protein (MIP)-1alpha, MIP-1beta, regulated upon activation, normal T-cell expressed and secreted (RANTES), and lymphotactin (Ltn). T-cell receptor (TCR)/coreceptor stimulation up-regulates MIP-1alpha, MIP-1beta, and Ltn, and down-regulates IP-10 and RANTES expression in CD4+ T cells. A similar increase in chemokine expression was demonstrated in the CD8+ T cell. Enzyme-linked immunosorbent assays confirmed increased T-cell chemokine protein production in old CD4+ and CD8+ T cells. Finally, supernatant of cultured T cells from old animals caused an enhanced leukocyte chemotaxis response compared with that from young animals, suggesting that the age-related difference in T-cell chemokine expression has an important functional consequence. [ABSTRACT FROM AUTHOR]
- Published
- 2003
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233. Age-related changes in mature <f>CD4+</f> T cells: cell cycle analysis
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Hale, Timothy J., Richardson, Bruce C., Sweet, Leonard I., McElligott, David L., Riggs, James E., Chu, Elton B., Glynn, Jacqueline M., LaFrenz, Dave, Ernst, David N., Rochford, Rosemary, and Hobbs, Monte V.
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T cells , *CELL cycle - Abstract
T cell proliferative responses decrease with age, but the mechanisms responsible are unknown. We examined the impact of age on memory and naive
CD4+ T cell entry and progression through the cell cycle using acridine orange to identify cell cycle stage. For both subsets, fewer stimulated cells from old donors were able to enter and progress through the first cell cycle, with an increased number of cells arrested inG0 and fewer cells in postG0 phases. The number of dead cells as assessed by sub-G0 DNA was also significantly greater in the old group.CD4+ T cells from old mice also exhibited a significant reduction in clonal history as assessed by CFSE staining. This was associated with a significant decline in cyclin D2 mRNA and protein. We propose that decreases in cyclin D2 are at least partially responsible for the proliferative decline found in agedCD4+ T cells. [Copyright &y& Elsevier]- Published
- 2002
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234. Malaria Enhances Expression of CC Chemokine Receptor 5 on Placental Macrophages.
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Tkachuk, Ariana N., Moormann, Ann M., Poore, Judy A., Rochford, Rosemary A., Chensue, Stephen W., Mwapasa, Victor, and Meshnick, Steven R.
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PREGNANCY complications , *MALARIA , *CHEMOKINES , *RNA - Abstract
Presents a study which showed that placentas of malaria-infected women contain three times as much chemokine receptor 5 RNA as placentas of women without malaria in sub-Saharan Africa. Study population; Methods; Results.
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- 2001
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235. Malaria during pregnancy and transplacental transfer of Kaposi sarcoma-associated herpesvirus (KSHV) antibodies: a cohort study of Kenyan mother and child pairs.
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Sabourin, Katherine R., Ogolla, Sidney, Daud, Ibrahim I., Jackson, Conner L., Miley, Wendell, Labo, Nazzarena, Whitby, Denise, and Rochford, Rosemary
- Subjects
- *
ENZYME-linked immunosorbent assay , *EPIDEMIOLOGICAL research , *HERPESVIRUS diseases , *IMMUNOGLOBULINS , *KAPOSI'S sarcoma , *LONGITUDINAL method , *MALARIA , *MATERNAL-fetal exchange , *MOTHERS , *PLACENTA , *PREGNANT women , *PROTOZOA , *VERTICAL transmission (Communicable diseases) , *PREGNANCY - Abstract
Background: Kaposi sarcoma-associated herpesvirus (KSHV) seroprevalence in sub-Saharan African children can range up to 50% by age 2 years but factors affecting early age of KSHV infection are not well understood. Malaria during pregnancy has been associated with hindered transplacental transfer of antibodies to several pathogens but whether it affects transplacental transfer of KSHV antibodies is unknown. We aimed to determine if in utero malaria exposure reduced the transfer of KSHV antibodies across the placenta. Methods: A cohort study in Kisumu, Kenya enrolled pregnant women at their first antenatal clinic (ANC) visit and followed them through delivery. We included 70 KSHV-positive, HIV-negative mothers and their children. KSHV antibody levels were measured by ELISA (K8.1, ORF73) and multiplex assay (K8.1, ORF73, K10.5, ORF38, ORF50). Transplacental transfer of antibodies was measured by the cord to maternal blood ratio (CMR) of KSHV antibodies. Malaria during pregnancy was defined as detection of Plasmodium falciparum (Pf) DNA at any ANC visit or delivery. Among women with malaria during pregnancy, we examined time of last malaria infection prior to delivery (< 27 vs. 27+ weeks gestation) and malaria incidence rate (MIR) (episodes/100 person-weeks). Results: KSHV seroprevalence (positive for K8.1 or ORF73 by ELISA) among pregnant women was 88%. Neither malaria during pregnancy, malaria infection timing, nor MIR were associated with maternal delivery KSHV antibody blood levels. Maternal delivery and cord blood KSHV antibody levels were highly correlated but these correlations did not differ by malaria during pregnancy. KSHV transplacental antibody transfer was not associated with malaria during pregnancy, malaria infection timing, nor MIR. Conclusions: Malaria during pregnancy does not appear to affect transfer of KSHV antibodies across the placenta. [ABSTRACT FROM AUTHOR]
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- 2020
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236. Factors affecting Kaposi's sarcoma-associated herpesvirus transmission in rural Ugandan households, a longitudinal study.
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Sabourin KR, Marshall VA, Eaton W, Kimono B, Mugisha J, Miley WJ, Labo N, Samayoa-Reyes G, Whitby D, Rochford R, and Newton R
- Abstract
Background: We report the impact of HIV infection within a household on oral Kaposi's sarcoma-associated herpesvirus (KSHV) shedding., Methods: We enrolled 469 individuals from 90 households. Mouthwash rinse samples collected at three monthly visits were analyzed for KSHV DNA using quantitative polymerase chain reaction (qPCR). Generalized linear mixed effects logistic models were applied to analyze factors associated with KSHV ever shedding, and among shedders, always versus intermittent shedding. Linear mixed effects models were applied to models of KSHV viral loads. Intraclass correlation coefficients (ICCs) were calculated to assess the contribution of household-level factors to variations in shedding probabilities. Hotspot analyses of geospatial feature clusters were calculated using Getis-Ord Gi* statistic and visualized using inverse distance weighted interpolation., Results: Analyses included 340 KSHV seropositive individuals, aged 3 + years, with qPCR results from 89 households. Forty households had 1 + persons living with HIV (PLWH), while 49 had none. Among participants, 149(44%) were KSHV ever shedders. Of 140 who shed KSHV at two or more visits, 34(24%) were always shedders. Increasing number of KSHV seropositive household members was significantly associated with ever shedding [Odds ratio(OR) (95% Confidence Interval(95%CI)):1.14(1.03,1.26);p = 0.013]. Among KSHV shedders, a statistically significant age-related trend was identified with 10-19 years being more likely to be always shedders (type III test p = 0.039) and to have higher viral loads (type III test p = 0.027). In addition, higher viral loads were significantly associated with increasing number of household members [coefficient(95%CI):0.06(0.01,0.12);p = 0.042], increasing number of KSHV seropositive members [coefficient(95%CI):0.08(0.01,0.15);p = 0.021], and living in households with 1 + PLWH [coefficient(95%CI):0.51(0.04,0.98);p = 0.033]. Always shedders exhibited higher viral loads than intermittent shedders [coefficient(95%CI):1.62(1.19,2.05);p < 0.001], and viral loads increased with the number of visits where KSHV DNA was detected in saliva (type III test p < 0.001). Household-level factors attributed for 19% of the variability in KSHV shedding (ICC:0.191;p = 0.010). Geospatial analysis indicated overlapping hotspots of households with more KSHV seropositive individuals and KSHV shedders, distinct from areas where PLWH were clustered., Discussion: KSHV oral shedding is influenced by multiple factors at the individual, household, and regional levels. To mitigate ongoing KSHV transmission a comprehensive understanding of factors contributing to oral KSHV reactivation and transmission within households is needed., (© 2024. The Author(s).)
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- 2024
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237. Challenges and Approaches to Establishing Multi-Pathogen Serosurveillance: Findings from the 2023 Serosurveillance Summit.
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Carcelen AC, Kong AC, Takahashi S, Hegde S, Jaenisch T, Chu M, Rochford R, Kostandova N, Gurley ES, Wesolowski A, Azman AS, van der Klis FRM, den Hartog G, Drakeley C, Heaney CD, Winter AK, Salje H, Rodriguez-Barraquer I, Leung DT, Njenga SM, Kagucia EW, Jambo KC, Wolter N, Charles RC, Saboyá-Díaz MI, Martin DL, and Moss WJ
- Subjects
- Humans, Seroepidemiologic Studies, Biosurveillance methods, Communicable Diseases epidemiology, Communicable Diseases immunology
- Abstract
Multiplex-based serological surveillance is a valuable but underutilized tool to understand gaps in population-level exposure, susceptibility, and immunity to infectious diseases. Assays for which blood samples can be tested for antibodies against several pathogens simultaneously, such as multiplex bead immunoassays, can more efficiently integrate public health surveillance in low- and middle-income countries. On March 7-8, 2023 a group of experts representing research institutions, multilateral organizations, private industry, and country partners met to discuss experiences, identify challenges and solutions, and create a community of practice for integrated, multi-pathogen serosurveillance using multiplex bead assay technologies. Participants were divided into six working groups: 1) supply chain; 2) laboratory assays; 3) seroepidemiology; 4) data analytics; 5) sustainable implementation; and 6) use case scenarios. These working groups discussed experiences, challenges, solutions, and research needs to facilitate integrated, multi-pathogen serosurveillance for public health. Several solutions were proposed to address challenges that cut across working groups.
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- 2024
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238. Geographic EBV variants confound disease-specific variant interpretation and predict variable immune therapy responses.
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Briercheck EL, Ravishankar S, Ahmed EH, Carías Alvarado CC, Barrios Menéndez JC, Silva O, Solórzano-Ortiz E, Siliézar Tala MM, Stevenson P, Xu Y, Wohns AW, Enriquez-Vera D, Barrionuevo C, Yu SC, Freud AG, Oakes C, Weigel C, Weinstock DM, Klimaszewski HL, Ngankeu A, Mutalima N, Samayoa-Reyes G, Newton R, Rochford R, Valvert F, Natkunam Y, Shustov A, Baiocchi RA, and Warren EH
- Subjects
- Humans, Genetic Variation, Genome, Viral, Immunotherapy, Herpesvirus 4, Human genetics, Epstein-Barr Virus Infections immunology
- Abstract
Abstract: Epstein-Barr virus (EBV) is a potent carcinogen linked to hematologic and solid malignancies and causes significant global morbidity and mortality. Therapy using allogeneic EBV-specific lymphocytes shows promise in certain populations, but the impact of EBV genome variation on these strategies remains unexplored. To address this, we sequenced 217 EBV genomes, including hematologic malignancies from Guatemala, Peru, Malawi, and Taiwan, and analyzed them alongside 1307 publicly available EBV genomes from cancer, nonmalignant diseases, and healthy individuals across Africa, Asia, Europe, North America, and South America. These included, to our knowledge, the first natural killer (NK)/T-cell lymphoma (NKTCL) EBV genomes reported outside of East Asia. Our findings indicate that previously proposed EBV genome variants specific to certain cancer types are more closely tied to geographic origin than to cancer histology. This included variants previously reported to be specific to NKTCL but were prevalent in EBV genomes from other cancer types and healthy individuals in East Asia. After controlling for geographic region, we did identify multiple NKTCL-specific variants associated with a 7.8-fold to 21.9-fold increased risk. We also observed frequent variations in EBV genomes that affected peptide sequences previously reported to bind common major histocompatibility complex alleles. Finally, we found several nonsynonymous variants spanning the coding sequences of current vaccine targets BALF4, BKRF2, BLLF1, BXLF2, BZLF1, and BZLF2. These results highlight the need to consider geographic variation in EBV genomes when devising strategies for exploiting adaptive immune responses against EBV-related cancers, ensuring greater global effectiveness and equity in prevention and treatment., (© 2024 by The American Society of Hematology. Licensed under Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0), permitting only noncommercial, nonderivative use with attribution. All other rights reserved.)
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- 2024
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239. Immune cell phenotype and function patterns across the life course in individuals from rural Uganda.
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Nalwoga A, Nakibuule M, Roshan R, Kwizera Mbonye M, Miley W, Whitby D, Newton R, Rochford R, and Cose S
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- Male, Female, Humans, Adult, Middle Aged, Herpesvirus 4, Human, CD4-Positive T-Lymphocytes, Life Change Events, Uganda, Phenotype, Epstein-Barr Virus Infections
- Abstract
Background: To determine the pattern of immune cell subsets across the life span in rural sub-Saharan Africa (SSA), and to set a reference standard for cell subsets amongst Africans, we characterised the major immune cell subsets in peripheral blood including T cells, B cells, monocytes, NK cells, neutrophils and eosinophils, in individuals aged 3 to 89 years from Uganda., Methods: Immune phenotypes were measured using both conventional flow cytometry in 72 individuals, and full spectrum flow cytometry in 80 individuals. Epstein-Barr virus (EBV) IFN-γ T cell responses were quantified in 332 individuals using an ELISpot assay. Full blood counts of all study participants were also obtained., Results: The percentages of central memory (T
CM ) and senescent CD4+ and CD8+ T cell subsets, effector memory (TEM ) CD8+ T cells and neutrophils increased with increasing age. On the other hand, the percentages of naïve T (TN ) and B (BN ) cells, atypical B cells (BA ), total lymphocytes, eosinophils and basophils decreased with increasing age. There was no change in CD4+ or CD8+ T effector memory RA (TEMRA ) cells, exhausted T cells, NK cells and monocytes with age. Higher eosinophil and basophil percentages were observed in males compared to females. T cell function as measured by IFN-γ responses to EBV increased with increasing age, peaking at 31-55 years., Conclusion: The percentages of cell subsets differ between individuals from SSA compared to those elsewhere, perhaps reflecting a different antigenic milieu. These results serve as a reference for normal values in this population., Competing Interests: Authors RRos, WM, and DW were employed by the company Leidos Biomedical Research, Inc. The remaining 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 Nalwoga, Nakibuule, Roshan, Kwizera Mbonye, Miley, Whitby, Newton, Rochford and Cose.)- Published
- 2024
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240. Expansion of extrafollicular B and T cell subsets in childhood-onset systemic lupus erythematosus.
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Baxter RM, Wang CS, Garcia-Perez JE, Kong DS, Coleman BM, Larchenko V, Schuyler RP, Jackson C, Ghosh T, Rudra P, Paul D, Claassen M, Rochford R, Cambier JC, Ghosh D, Cooper JC, Smith MJ, and Hsieh EWY
- Subjects
- Humans, Child, B-Lymphocytes, T-Lymphocyte Subsets metabolism, T-Lymphocytes, Helper-Inducer, Lupus Erythematosus, Systemic, Lupus Nephritis
- Abstract
Introduction: Most childhood-onset SLE patients (cSLE) develop lupus nephritis (cLN), but only a small proportion achieve complete response to current therapies. The prognosis of children with LN and end-stage renal disease is particularly dire. Mortality rates within the first five years of renal replacement therapy may reach 22%. Thus, there is urgent need to decipher and target immune mechanisms that drive cLN. Despite the clear role of autoantibody production in SLE, targeted B cell therapies such as rituximab (anti-CD20) and belimumab (anti-BAFF) have shown only modest efficacy in cLN. While many studies have linked dysregulation of germinal center formation to SLE pathogenesis, other work supports a role for extrafollicular B cell activation in generation of pathogenic antibody secreting cells. However, whether extrafollicular B cell subsets and their T cell collaborators play a role in specific organ involvement in cLN and/or track with disease activity remains unknown., Methods: We analyzed high-dimensional mass cytometry and gene expression data from 24 treatment naïve cSLE patients at the time of diagnosis and longitudinally, applying novel computational tools to identify abnormalities associated with clinical manifestations (cLN) and disease activity (SLEDAI)., Results: cSLE patients have an extrafollicular B cell expansion signature, with increased frequency of i) DN2, ii) Bnd2, iii) plasmablasts, and iv) peripheral T helper cells. Most importantly, we discovered that this extrafollicular signature correlates with disease activity in cLN, supporting extrafollicular T/B interactions as a mechanism underlying pediatric renal pathogenesis., Discussion: This study integrates established and emerging themes of extrafollicular B cell involvement in SLE by providing evidence for extrafollicular B and peripheral T helper cell expansion, along with elevated type 1 IFN activation, in a homogeneous cohort of treatment-naïve cSLE patients, a point at which they should display the most extreme state of their immune dysregulation., 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 Baxter, Wang, Garcia-Perez, Kong, Coleman, Larchenko, Schuyler, Jackson, Ghosh, Rudra, Paul, Claassen, Rochford, Cambier, Ghosh, Cooper, Smith and Hsieh.)
- Published
- 2023
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241. Hemin treatment drives viral reactivation and plasma cell differentiation of EBV latently infected B cells.
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Burnet AM, Brunetti T, and Rochford R
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- Humans, Herpesvirus 4, Human genetics, Heme, Cell Differentiation, Basic-Leucine Zipper Transcription Factors genetics, Hemin pharmacology, Epstein-Barr Virus Infections
- Abstract
Epstein-Barr virus (EBV) and Plasmodium falciparum have a well described role in the development of endemic Burkitt lymphoma (BL), yet the mechanisms involved remain unknown. A major hallmark of malarial disease is hemolysis and bystander eryptosis of red blood cells, which causes release of free heme in large quantities into peripheral blood. We hypothesized that heme released during malaria infection drives differentiation of latently infected EBV-positive B cells, resulting in viral reactivation and release of infectious virus. To test this hypothesis, we used the EBV-positive Mutu I B-cell line and treated with hemin (the oxidized form of heme) and evaluated evidence of EBV reactivation. Hemin treatment resulted in the expression of EBV immediate early, early and late lytic gene transcripts. In addition, expression of CD138, a marker of plasma cells was co-expressed with the late lytic protein gp350 on hemin treated Mutu I cells. Finally, DNase-resistant EBV DNA indicative of virion production was detected in supernatant. To assess the transcriptional changes induced by hemin treatment, RNA sequencing was performed on mock- and hemin-treated Mutu I cells, and a shift from mature B cell transcripts to plasma cell transcripts was identified. To identify the mechanism of hemin-induced B cell differentiation, we measured levels of the plasma cell transcriptional repressor, BACH2, that contains specific heme binding sites. Hemin treatment caused significant degradation of BACH2 by 24 hours post-treatment in four BL cell lines (two EBV positive, two EBV negative). Knockdown of BACH2 in Mutu I cells using siRNAs significantly increased CD138+gp350+ cells to levels similar to treatment with hemin. This suggested that hemin induced BACH2 degradation was responsible for plasma cell differentiation and viral reactivation. Together, these data support a model where EBV reactivation can occur during malaria infection via heme modulation, providing a mechanistic link between malaria and EBV., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2023 Burnet 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.)
- Published
- 2023
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242. Macrophages drive KSHV B cell latency.
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Szymula A, Samayoa-Reyes G, Ogolla S, Liu B, Li S, George A, Van Sciver N, Rochford R, Simas JP, and Kaye KM
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- Child, Humans, Proteomics, B-Lymphocytes, Macrophages, Monocytes, Virus Latency, Herpesvirus 8, Human
- Abstract
Kaposi's sarcoma herpesvirus (KSHV) establishes lifelong infection and persists in latently infected B cells. Paradoxically, in vitro B cell infection is inefficient, and cells rapidly die, suggesting the absence of necessary factor(s). KSHV epidemiology unexpectedly mirrors that of malaria and certain helminthic infections, while other herpesviruses are ubiquitous. Elevated circulating monocytes are common in these parasitic infections. Here, we show that KSHV infection of monocytes or M-CSF-differentiated (M2) macrophages is highly efficient. Proteomic analyses demonstrate that infection induces macrophage production of B cell chemoattractants and activating factor. We find that KSHV acts with monocytes or M2 macrophages to stimulate B cell survival, proliferation, and plasmablast differentiation. Further, macrophages drive infected plasma cell differentiation and long-term viral latency. In Kenya, where KSHV is endemic, we find elevated monocyte levels in children with malaria. These findings demonstrate a role for mononuclear phagocytes in KSHV B cell latency and suggest that mononuclear phagocyte abundance may underlie KSHV's geographic disparity., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2023 The Authors. Published by Elsevier Inc. All rights reserved.)
- Published
- 2023
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243. Clinical and Immunological Outcomes of HIV-Exposed Uninfected and HIV-Unexposed Uninfected Children in the First 24 Months of Life in Western Kenya.
- Author
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Ray JE, Dobbs KR, Ogolla SO, Daud II, Midem D, Omenda MM, Nowacki AS, Beeson JG, Sabourin KR, Rochford R, and Dent AE
- Abstract
Background: Previous studies show increased morbidity in children who are HIV-exposed but uninfected (HEU) compared to children who are HIV-unexposed uninfected (HUU). We sought to evaluate the effects of prenatal HIV exposure on clinical and immunological outcomes in the first 24 months of life., Methods: Eighty-five HEU and 168 HUU children from Kenya were followed from birth to 24 months. All mothers with HIV received combination antiretroviral therapy. HEU children received standard-of-care cotrimoxazole prophylaxis through 18 months. Episodes of acute illness were identified through a combination of active and passive follow up. Trajectories of plasma cytokines, vaccine-specific antibodies, and antimalarial antibodies were examined., Results: HEU and HUU children had similar growth curves. HEU children had lower rates of malaria and respiratory illness. Trajectories of plasma cytokines and vaccine-specific antibodies were similar in HEU and HUU children. There were subtle differences in antimalarial antibody dynamics, in which HEU children had overall lower antibody levels against five of the 14 malaria antigens tested., Conclusions: HEU children born to optimally treated mothers living with HIV had similar growth characteristics and immune profiles compared to HUU children. HEU children had reduced risk for malaria and respiratory illness, which may be secondary to cotrimoxazole prophylaxis., Competing Interests: Competing interests. The authors declare that they have no competing interests.
- Published
- 2023
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244. Evidence for Aerosol Transfer of SARS-CoV-2-Specific Humoral Immunity.
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Kedl RM, Hsieh EWY, Morrison TE, Samayoa-Reyes G, Flaherty S, Jackson CL, and Rochford R
- Subjects
- Humans, Immunity, Humoral, SARS-CoV-2, Respiratory Aerosols and Droplets, Pandemics, COVID-19
- Abstract
Infectious particles can be shared through aerosols and droplets formed as the result of normal respiration. Whether Abs within the nasal/oral fluids can similarly be shared between hosts has not been investigated. The circumstances of the SARS-CoV-2 pandemic facilitated a unique opportunity to fully examine this provocative idea. The data we show from human nasal swabs provides evidence for the aerosol transfer of Abs between immune and nonimmune hosts., (Copyright © 2023 The Authors.)
- Published
- 2023
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245. Comparison of Epstein-Barr virus and Kaposi's sarcoma-associated herpesvirus viral load in peripheral blood mononuclear cells and oral fluids of HIV-negative individuals aged 3 to 89 years from Uganda.
- Author
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Nalwoga A, Marshall V, Miley W, Labo N, Whitby D, Newton R, and Rochford R
- Abstract
We previously found that age, sex, and malaria were associated with KSHV viral load in individuals from Uganda. In this study, we have evaluated factors associated with presence of EBV DNA in blood and oral fluids among the same individuals, using the same biological samples. Overall, 74% of oral fluids samples and 46% of PBMCs had detectable EBV, compared to 24% and 11% for KSHV respectively Individuals with EBV in PBMCs were more likely to have KSHV in PBMCs (P=0.016). The peak age for detection of EBV in oral fluids was 3-5 years while that of KSHV was 6-12 years. In PBMCs, the peak age for detection of EBV was 66+ years and KSHV was 3-5 years. Individuals with malaria had higher levels of EBV in PBMCs compared to malaria-negative individuals (P=0.002). In summary, our results show that younger age and malaria are associated with higher levels of EBV and KSHV in PBMCs suggesting malaria impacts immunity to EBV and KSHV.
- Published
- 2023
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246. Editorial overview: Special section on immune responses to chronic infections.
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Rochford R
- Subjects
- Humans, Immunity, Persistent Infection
- Published
- 2023
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247. Creating climate-informed physician leaders: The evolution of a physician fellowship in climate and health science policy.
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Wheat S, Chekuri B, Sorensen C, Rochford R, and Lemery J
- Abstract
Climate change poses numerous near and long-term challenges for our society, and the human health consequences are increasingly recognized as unprecedented. Responding to these health hazards requires a healthcare workforce composed of climate-informed clinicians. As trusted messengers, physicians play a vital role in informing and preparing the public for health impacts of climate change. We describe an evolving graduate medical education fellowship for physicians from all specialties capable of training leaders in this field. Our program pairs fellows with federal and non-governmental partners to provide expertise in climate policy and empower them to be change agents. The accelerating response to climate change from the federal government coupled with an increased recognition of the impacts of climate hazards on health demands a climate-informed clinical workforce. The expansion of this fellowship to accommodate trainees from multiple specialties and its innovative structure leveraging local and national partnerships sets a standard for how similar programs can be developed in addressing the greatest public health threat and opportunity of the century., 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 Wheat, Chekuri, Sorensen, Rochford and Lemery.)
- Published
- 2022
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248. Burkitt lymphoma.
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López C, Burkhardt B, Chan JKC, Leoncini L, Mbulaiteye SM, Ogwang MD, Orem J, Rochford R, Roschewski M, and Siebert R
- Subjects
- Adolescent, Adult, Humans, Child, Herpesvirus 4, Human, B-Lymphocytes, Burkitt Lymphoma epidemiology, Burkitt Lymphoma metabolism, Burkitt Lymphoma pathology, Epstein-Barr Virus Infections complications, Epstein-Barr Virus Infections epidemiology, Lymphoma
- Abstract
Burkitt lymphoma (BL) is an aggressive form of B cell lymphoma that can affect children and adults. The study of BL led to the identification of the first recurrent chromosomal aberration in lymphoma, t(8;14)(q24;q32), and subsequent discovery of the central role of MYC and Epstein-Barr virus (EBV) in tumorigenesis. Most patients with BL are cured with chemotherapy but those with relapsed or refractory disease usually die of lymphoma. Historically, endemic BL, non-endemic sporadic BL and the immunodeficiency-associated BL have been recognized, but differentiation of these epidemiological variants is confounded by the frequency of EBV positivity. Subtyping into EBV
+ and EBV- BL might better describe the biological heterogeneity of the disease. Phenotypically resembling germinal centre B cells, all types of BL are characterized by dysregulation of MYC due to enhancer activation via juxtaposition with one of the three immunoglobulin loci. Additional molecular changes commonly affect B cell receptor and sphingosine-1-phosphate signalling, proliferation, survival and SWI-SNF chromatin remodelling. BL is diagnosed on the basis of morphology and high expression of MYC. BL can be effectively treated in children and adolescents with short durations of high dose-intensity multiagent chemotherapy regimens. Adults are more susceptible to toxic effects but are effectively treated with chemotherapy, including modified versions of paediatric regimens. The outcomes in patients with BL are good in high-income countries with low mortality and few late effects, but in low-income and middle-income countries, BL is diagnosed late and is usually treated with less-effective regimens affecting the overall good outcomes in patients with this lymphoma., (© 2022. Springer Nature Limited.)- Published
- 2022
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249. Mechanisms of 8-aminoquinoline induced haemolytic toxicity in a G6PDd humanized mouse model.
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Flaherty S, Strauch P, Maktabi M, Pybus BS, Reichard G, Walker LA, and Rochford R
- Subjects
- Aminoquinolines toxicity, Animals, Disease Models, Animal, Hemolysis, Mice, Primaquine therapeutic use, Antimalarials, Glucosephosphate Dehydrogenase Deficiency complications, Malaria, Vivax drug therapy, Malaria, Vivax epidemiology
- Abstract
Primaquine (PQ) and Tafenoquine (TQ) are clinically important 8-aminoquinolines (8-AQ) used for radical cure treatment of P. vivax infection, known to target hepatic hypnozoites. 8-AQs can trigger haemolytic anaemia in individuals with glucose-6-phosphate dehydrogenase deficiency (G6PDd), yet the mechanisms of haemolytic toxicity remain unknown. To address this issue, we used a humanized mouse model known to predict haemolytic toxicity responses in G6PDd human red blood cells (huRBCs). To evaluate the markers of eryptosis, huRBCs were isolated from mice 24-48 h post-treatment and analysed for effects on phosphatidylserine (PS), intracellular reactive oxygen species (ROS) and autofluorescence. Urinalysis was performed to evaluate the occurrence of intravascular and extravascular haemolysis. Spleen and liver tissue harvested at 24 h and 5-7 days post-treatment were stained for the presence of CD169+ macrophages, F4/80+ macrophages, Ter119+ mouse RBCs, glycophorin A+ huRBCs and murine reticulocytes (muRetics). G6PDd-huRBCs from PQ/TQ treated mice showed increased markers for eryptosis as early as 24 h post-treatment. This coincided with an early rise in levels of muRetics. Urinalysis revealed concurrent intravascular and extravascular haemolysis in response to PQ/TQ. Splenic CD169+ macrophages, present in all groups at day 1 post-dosing were eliminated by days 5-7 in PQ/TQ treated mice only, while liver F4/80 macrophages and iron deposits increased. Collectively, our data suggest 8-AQ treated G6PDd-huRBCs have early physiological responses to treatment, including increased markers for eryptosis indicative of oxidative stress, resulting in extramedullary haematopoiesis and loss of splenic CD169+ macrophages, prompting the liver to act as the primary site of clearance., (© 2022 The Authors. Journal of Cellular and Molecular Medicine published by Foundation for Cellular and Molecular Medicine and John Wiley & Sons Ltd.)
- Published
- 2022
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250. Environmental determinants of Kaposi's sarcoma-associated herpesvirus (KSHV) transmission in rural Uganda (ENDKU study): Contributions to research on KSHV infection and reactivation in African children; A longitudinal cohort study.
- Author
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Sabourin KR, Nalwoga A, Whitby D, Newton R, and Rochford R
- Subjects
- Child, Child, Preschool, Humans, Infant, Longitudinal Studies, Pandemics, Uganda epidemiology, Acquired Immunodeficiency Syndrome epidemiology, COVID-19, Herpesvirus 8, Human, Malaria epidemiology, Sarcoma, Kaposi epidemiology
- Abstract
Background: The Environmental Determinants of KSHV transmission in rural Uganda (ENDKU) study began enrollment in February 2020 with the purpose of defining the relationship between malaria, primarily caused by Plasmodium falciparum in sub-Saharan Africa, and KSHV susceptibility and reactivation. Uganda is an ideal study site, because both malaria and KSHV are endemic and widespread, even among young children., Methods: ENDKU is a longitudinal cohort study of infants enrolled at six months of age and followed until three years of age. The main study, and one smaller sub-study, is nested within the General Population Cohort (GPC), a long-standing population cohort in rural Uganda. The ENDKU study was created to test the hypothesis that P. falciparum malaria increases an infant's susceptibility to KSHV infection. A sub-study to evaluate the effects of P. falciparum on KSHV reactivation involves an additional cohort of 5-10-year-old children with and without acute malaria who presented to the GPC study clinic. For each study, participants provided demographic and behavioral data through administered questionnaires and blood and saliva samples., Results: Despite barriers presented by the COVID-19 pandemic, the study team was able to leverage the long-standing relationship of the UK Medical Research Council and the Uganda Virus Research Institute (MRC/UVRI) with the community, a strong commitment to research, and a multi-disciplinary team of experts to successfully implement the ENDKU study., Conclusion: The results of this multi-pronged approach will answer important questions about the etiology and transmission of KSHV in sub-Saharan Africa and the data and samples collected will be an important future resource for scientific research in the region., (Copyright © 2022. Published by Elsevier Ltd.)
- Published
- 2022
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