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Many vaccines require higher/additional doses or adjuvants to provide adequate protection for people with HIV (PWH). Our objective was to compare COVID-19 vaccine immunogenicity in PWH to HIV-negative individuals.In a Canadian multi-center prospective, observational cohort of PWH receiving at least two COVID-19 vaccinations, we measured vaccine-induced immunity at 3 and 6 months post 2nd and 1-month post 3rd doses.The primary outcome was the percentage of PWH mounting vaccine-induced immunity [co-positivity for anti-IgG against SARS-CoV2 Spike(S) and receptor-binding domain proteins] 6 months post 2nd dose. Univariable and multivariable logistic regressions were used to compare COVID-19-specific immune responses between groups and within subgroups.Data from 294 PWH and 267 controls were analyzed. Immunogenicity was achieved in over 90% at each time point in both groups. The proportions of participants achieving comparable anti-receptor-binding domain levels were similar between the group at each time point. Anti-S IgG levels were similar by group at month 3 post 2nd dose and 1-month post 3rd dose. A lower proportion of PWH vs. controls maintained vaccine-induced anti-S IgG immunity 6 months post 2nd dose [92% vs. 99%; odds ratio: 0.14 (95% confidence interval: 0.03, 0.80; P = 0.027)]. In multivariable analyses, neither age, immune non-response, multimorbidity, sex, vaccine type, or timing between doses were associated with reduced IgG response.Vaccine-induced IgG was elicited in the vast majority of PWH and was overall similar between groups. A slightly lower proportion of PWH vs. controls maintained vaccine-induced anti-S IgG immunity 6 months post 2nd dose demonstrating the importance of timely boosting in this population.

Background Longer-term humoral responses to 2-dose coronavirus disease 2019 (COVID-19) vaccines remain incompletely characterized in people living with human immunodeficiency virus (HIV) (PLWH), as do initial responses to a third dose. Methods We measured antibodies against the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike protein receptor-binding domain, angiotensin-converting enzyme 2 (ACE2) displacement, and viral neutralization against wild-type and Omicron strains up to 6 months after 2-dose vaccination, and 1 month after the third dose, in 99 PLWH receiving suppressive antiretroviral therapy and 152 controls. Results Although humoral responses naturally decline after 2-dose vaccination, we found no evidence of lower antibody concentrations or faster rates of antibody decline in PLWH compared with controls after accounting for sociodemographic, health, and vaccine-related factors. We also found no evidence of poorer viral neutralization in PLWH after 2 doses, nor evidence that a low nadir CD4+ T-cell count compromised responses. Post–third-dose humoral responses substantially exceeded post–second-dose levels, though Omicron-specific responses were consistently weaker than responses against wild-type virus. Nevertheless, post–third-dose responses in PLWH were comparable to or higher than controls. An mRNA-1273 third dose was the strongest consistent correlate of higher post–third-dose responses. Conclusion PLWH receiving suppressive antiretroviral therapy mount strong antibody responses after 2- and 3-dose COVID-19 vaccination. Results underscore the immune benefits of third doses in light of Omicron.

Supplementary Table 2 from Type 2 Bias of T Cells Expanded from the Blood of Melanoma Patients Switched to Type 1 by IL-12p70 mRNA–Transfected Dendritic Cells

Supplementary Table 1 from Type 2 Bias of T Cells Expanded from the Blood of Melanoma Patients Switched to Type 1 by IL-12p70 mRNA–Transfected Dendritic Cells

BackgroundLonger-term immune response data after 3 doses of coronavirus disease 2019 (COVID-19) mRNA vaccine remain limited, particularly among older adults and after Omicron breakthrough infection.MethodsWe quantified wild-type- and Omicron-specific serum immunoglobulin (Ig)G levels, angiotensin-converting enzyme 2 displacement activities, and live virus neutralization up to 6 months after third dose in 116 adults aged 24–98 years who remained COVID-19 naive or experienced their first severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection during this time.ResultsAmong the 78 participants who remained COVID-19 naive throughout follow up, wild-type- and Omicron-BA.1-specific IgG concentrations were comparable between younger and older adults, although BA.1-specific responses were consistently significantly lower than wild-type-specific responses in both groups. Wild-type- and BA.1-specific IgG concentrations declined at similar rates in COVID-19-naive younger and older adults, with median half-lives ranging from 69 to 78 days. Antiviral antibody functions declined substantially over time in COVID-19-naive individuals, particularly in older adults: by 6 months, BA.1-specific neutralization was undetectable in 96% of older adults, versus 56% of younger adults. Severe acute respiratory syndrome coronavirus 2 infection, experienced by 38 participants, boosted IgG levels and neutralization above those induced by vaccination alone. Nevertheless, BA.1-specific neutralization remained significantly lower than wild-type, with BA.5-specific neutralization lower still. Higher Omicron BA.1-specific neutralization 1 month after third dose was an independent correlate of lower SARS-CoV-2 infection risk.ConclusionsResults underscore the immune benefits of the third COVID-19 mRNA vaccine dose in adults of all ages and identify vaccine-induced Omicron-specific neutralization as a correlate of protective immunity. Systemic antibody responses and functions however, particularly Omicron-specific neutralization, decline rapidly in COVID-19-naive individuals, particularly in older adults, supporting the need for additional booster doses.

Background Routine HIV drug resistance genotyping identified an integrase sequence harbouring T97A, E138K, G140S and Q148H, with high predicted resistance to all integrase strand transfer inhibitors (INSTIs). Objectives To assess the impact of these substitutions alone and together on phenotypic INSTI susceptibility. Methods We constructed recombinant NL4.3 viruses harbouring all mutation combinations in the autologous integrase sequence. Viruses were grown in GFP-reporter CD4+ T-cells in the presence of 0.01–1000 nM raltegravir, elvitegravir, dolutegravir, bictegravir, and cabotegravir. Infection was measured by imaging cytometry. Results Q148H-containing viruses lacking G140S failed to propagate or mutated in vitro, consistent with fitness costs. Statistically significant reductions in INSTI susceptibility were observed for several mutation combinations, as follows. T97A or G140S alone conferred 3.6- to 5.6-fold decreased susceptibility to raltegravir and elvitegravir. Two-mutation combinations conferred low-to-moderate resistance to raltegravir and elvitegravir only, except G140S/Q148H which eliminated raltegravir and elvitegravir activity and conferred 24.6-, 7.9-, and 107.5-fold reduced susceptibility to dolutegravir, bictegravir and cabotegravir. Addition of E138K to G140S/Q148H conferred 35.5, 11.6 and 208-fold reduced susceptibility to dolutegravir, bictegravir, and cabotegravir, while addition of T97A to G140S/Q148H conferred 318, 121 and >1000-fold reduced susceptibility to these drugs. T97A/E138K/G140S/Q148H in the autologous backbone conferred >300-fold reduced susceptibility to all INSTIs. Notably, bictegravir EC50 was significantly lower when T97A/E138K/G140S/Q148H was introduced into NL4.3, suggesting that other mutations in the autologous sequence enhanced resistance. Conclusions High-level dolutegravir, bictegravir and cabotegravir resistance requires multiple integrase substitutions including compensatory mutations. T97A and E138K further enhance the resistance conferred by G140S/Q148H, yielding >300-fold decreased susceptibility to all INSTIs when all four mutations are present.

BackgroundLimited data exist regarding longer-term antibody responses following three-dose COVID-19 vaccination, and the impact of a first SARS-CoV-2 infection during this time, in people living with HIV (PLWH) receiving suppressive antiretroviral therapy (ART). We quantified wild-type-(WT), Omicron BA.1- and Omicron BA.5-specific responses up to six months post-third dose in 64 PLWH and 117 controls who remained COVID-19-naive or experienced their first SARS-CoV-2 infection during this time.DesignLongitudinal observational cohort.MethodsWe quantified WT- and Omicron-specific Anti-Spike receptor-binding domain IgG concentrations, ACE2 displacement activities and live virus neutralization at one, three and six months post-third vaccine dose.ResultsThird doses boosted all antibody measures above two-dose levels, but BA.1-specific responses remained significantly lower than WT-specific ones, with BA.5-specific responses lower still. Serum IgG concentrations declined at similar rates in COVID-19-naive PLWH and controls post-third dose (median WT- and BA.1-specific half-lives were between 66-74 days for both groups). Antibody function also declined significantly yet comparably between groups: six months post-third dose, BA.1-specific neutralization was undetectable in >80% of COVID-19 naive PLWH and >90% of controls. Breakthrough SARS-CoV-2 infection boosted antibody concentrations and function significantly above vaccine-induced levels in both PLWH and controls, though BA.5-specific neutralization remained significantly poorer than BA.1 even post-breakthrough.ConclusionsFollowing three-dose COVID-19 vaccination, antibody response durability in PLWH receiving ART is comparable to controls. PLWH also mounted strong responses to breakthrough infection. Due to temporal response declines however, COVID-19-naive individuals, regardless of HIV status, would benefit from a fourth dose within 6 months of their third.

BackgroundLonger-term immune response data after three doses of COVID-19 mRNA vaccine remain limited, particularly among older adults and following Omicron breakthrough infection.MethodsWe quantified wild-type- and Omicron-specific serum IgG levels, ACE2 displacement activities and live virus neutralization up to six months post-third dose in 116 adults aged 24-98 years who remained COVID-19-naïve or experienced their first SARS-CoV-2 infection during this time.ResultsAmong 78 participants who remained COVID-19-naïve throughout follow-up, wild-type- and Omicron BA.1-specific IgG concentrations were comparable between younger and older adults, though BA.1-specific responses were consistently significantly lower than wild-type-specific responses in both groups. Wild-type- and BA.1-specific IgG concentrations declined at similar rates among COVID-19-naïve younger and older adults, with median half-lives ranging from 69-78 days. Antiviral antibody function declined substantially over time in COVID-19-naïve individuals, particularly older adults: by six months, BA.1-specific neutralization was undetectable in 96% of older adults, versus 56% of younger adults. SARS-CoV-2 infection, experienced by 38 participants, boosted IgG levels and neutralization above those induced by vaccination alone. Nevertheless, BA.1-specific neutralization remained significantly lower than wild-type, with BA.5-specific neutralization lower still.ConclusionsOur findings underscore the immune benefits of third COVID-19 mRNA vaccine doses in adults of all ages, but rapid decline of Omicron-specific neutralization activity in COVID-19-naïve individuals, particularly among older adults, demonstrates the need for fourth doses within 3-6 months to maintain systemic responses. Individuals who experienced SARS-CoV-2 breakthrough infection post-third vaccine dose however can likely delay a fourth dose beyond this timeframe.

A sterilizing or functional cure for HIV is currently precluded by resting CD4(+) T cells that harbor latent but replication-competent provirus. The “shock-and-kill” pharmacological ap-proach aims to reactivate provirus expression in the presence of antiretroviral therapy and target virus-expressing cells for elimination. However, no latency reversal agent (LRA) to date effectively clears viral reservoirs in humans, suggesting a need for new LRAs and LRA combinations. Here, we screened 216 compounds from the pan-African Natural Product Library and identified knipholone anthrone (KA) and its basic building block anthralin (dithranol) as novel LRAs that reverse viral latency at low micromolar concentrations in multiple cell lines. Neither agent's activity depends on protein kinase C; nor do they inhibit class I/II histone deacetylases. However, they are differentially modulated by oxidative stress and metal ions and induce distinct patterns of global gene expression from established LRAs. When applied in combination, both KA and anthralin synergize with LRAs representing multiple functional classes. Finally, KA induces both HIV RNA and protein in primary cells from HIV-infected donors. Taken together, we describe two novel LRAs that enhance the activities of multiple “shock-and-kill” agents, which in turn may inform ongoing LRA combination therapy efforts.

BackgroundLonger-term humoral responses to two-dose COVID-19 vaccines remain incompletely characterized in people living with HIV (PLWH), as do initial responses to a third dose.MethodsWe measured antibodies against the SARS-CoV-2 spike protein receptor-binding domain, ACE2 displacement and viral neutralization against wild-type and Omicron strains up to six months following two-dose vaccination, and one month following the third dose, in 99 PLWH receiving suppressive antiretroviral therapy, and 152 controls.ResultsThough humoral responses naturally decline following two-dose vaccination, we found no evidence of lower antibody concentrations nor faster rates of antibody decline in PLWH compared to controls after accounting for sociodemographic, health and vaccine-related factors. We also found no evidence of poorer viral neutralization in PLWH after two doses, nor evidence that a low nadir CD4+ T-cell count compromised responses. Post-third-dose humoral responses substantially exceeded post-second-dose levels, though anti-Omicron responses were consistently weaker than against wild-type.Nevertheless, post-third-dose responses in PLWH were comparable to or higher than controls. An mRNA-1273 third dose was the strongest consistent correlate of higher post-third-dose responses.ConclusionPLWH receiving suppressive antiretroviral therapy mount strong antibody responses after two- and three-dose COVID-19 vaccination. Results underscore the immune benefits of third doses in light of Omicron.

Background. Two-dose mRNA vaccines reduce COVID-19 related hospitalization and mortality, but immune protection declines over time. As such, third vaccine doses are now recommended, particularly for older adults. We examined immune response durability up to six months after two vaccine doses, and immunogenicity after a third vaccine dose, in 151 adults ranging in age from 24 to 98 years. Methods. Specimens were collected from 81 healthcare workers (median age 41 years), 56 older adults (median 78 years) and 14 COVID-19 convalescent individuals (median 48 years), at one, three and six months following the second vaccine dose, and from 15 HCW, 28 older adults and 3 convalescent individuals at one month following a third vaccine dose. Binding antibodies to the SARS-CoV-2 spike receptor binding domain were quantified using a commercial immunoassay. Virus neutralizing activity was assessed using a live SARS-CoV-2 infection assay. Results. Compared to healthcare workers, older adults displayed ~0.3 log10 lower peak binding antibodies one month after the second vaccine dose (p

Background Africa bears a disproportionately high burden of globally significant disease but has lagged in knowledge production to address its health challenges. In this contribution, we discuss the challenges and approaches to health research capacity strengthening in sub-Saharan Africa and propose that the recent shift to an African-led approach is the most optimal. Methods and findings We introduce several capacity building approaches and recent achievements, explore why African-led research on the continent is a potentially paradigm-shifting and innovative approach, and discuss the advantages and challenges thereof. We reflect on the approaches used by the African Academy of Sciences (AAS)-funded Sub-Saharan African Network for TB/HIV Research Excellence (SANTHE) consortium as an example of an effective African-led science and capacity building programme. We recommend the following as crucial components of future efforts: 1. Directly empowering African-based researchers, 2. Offering quality training and career development opportunities to large numbers of junior African scientists and support staff, and 3. Effective information exchange and collaboration. Furthermore, we argue that long-term investment from international donors and increasing funding commitments from African governments and philanthropies will be needed to realise a critical mass of local capacity and to create and sustain world-class research hubs that will be conducive to address Africa’s intractable health challenges. Conclusions Our experiences so far suggest that African-led research has the potential to overcome the vicious cycle of brain-drain and may ultimately lead to improvement of health and science-led economic transformation of Africa into a prosperous continent.

Partner notification and treatment are essential components of sexually transmitted infection (STI) management, but little is known about such practices among adolescents and young adults. Using data from a prospective cohort study (AYAZAZI) of youth aged 16–24 years in Durban, South Africa, we assessed the STI care cascade across participant diagnosis, STI treatment, partner notification, and partner treatment; index recurrent STI and associated factors; and reasons for not notifying partner of STI. Participants completed laboratory-based STI screening ( Chlamydia trachomatis, Neisseria gonorrhoeae, Mycoplasma genitalium, Trichomonas vaginalis) at enrollment and at 12 months. Of the 37/216 participants with STI (17%), 27/37 (73%) were women and 10/37 (27%) were men. Median age was 19 years (IQR: 18–20). Of the participants with STI, 23/37 (62%) completed a Treatment and Partner Tracing Survey within 6 months of diagnosis. All survey participants reported completing STI treatment (100%), 17/23 (74%) notified a partner, and 6/23 (35%) reported partner treatment. Overall, 4/23 (11%) participants had 12-month recurrent C. trachomatis infection, with no association with partner notification or treatment. Stigma and lack of STI knowledge were reasons for not notifying partner of STI. STI partner notification and treatment is a challenge among youth. Novel strategies are needed to overcome barriers along the STI care cascade.

SUMMARY HIV-1 Nef enhances virion infectivity by counteracting host restriction factor SERINC5; however, the impact of natural Nef polymorphisms on this function is largely unknown. We characterize SERINC5 downregulation activity of 91 primary HIV-1 subtype B nef alleles, including isolates from 45 elite controllers and 46 chronic progressors. Controller-derived Nef clones display lower ability to downregulate SERINC5 (median 80% activity) compared with progressor-derived clones (median 96% activity) (p = 0.0005). We identify 18 Nef polymorphisms associated with differential function, including two CTL escape mutations that contribute to lower SERINC5 downregulation: K94E, driven by HLA-B*08, and H116N, driven by the protective allele HLA-B*57. HIV-1 strains encoding Nef K94E and/or H116N display lower infectivity and replication capacity in the presence of SERINC5. Our results demonstrate that natural polymorphisms in HIV-1 Nef can impair its ability to internalize SERINC5, indicating that variation in this recently described function may contribute to differences in viral pathogenesis., Graphical Abstract, In Brief HIV-1 Nef counteracts the cellular restriction factor SERINC5, but the importance of this for pathogenesis is unclear. Jin et al. show that Nef clones isolated from HIV controllers display lower ability to antagonize SERINC5, in part because of viral mutations that are selected to evade host T cells.

Curing HIV will require eliminating the reservoir of integrated, replication-competent proviruses that persist despite antiretroviral therapy (ART). Understanding the burden, genetic diversity and longevity of persisting proviruses in diverse individuals with HIV is critical to this goal, but these characteristics remain understudied in some groups. Among them are viremic controllers, individuals who naturally suppress HIV to low levels but for whom therapy is nevertheless recommended. We reconstructed within-host HIV evolutionary histories from longitudinal single-genome amplified viral sequences in four viremic controllers who eventually initiated ART, and used this information to characterize the age and diversity of proviruses persisting on therapy. We further leveraged these within-host proviral age distributions to estimate rates of proviral turnover prior to ART. This is an important yet understudied metric, since pre-ART proviral turnover dictates reservoir composition at ART initiation (and thereafter), which is when curative interventions, once developed, would be administered. Despite natural viremic control, all participants displayed significant within-host HIV evolution pre-therapy, where overall on-ART proviral burden and diversity broadly reflected the extent of viral replication and diversity pre-ART. Consistent with recent studies of non-controllers, the proviral pools of two participants were skewed towards sequences that integrated near ART initiation, suggesting dynamic proviral turnover during untreated infection. In contrast, proviruses recovered from the two other participants dated to time-points that were more evenly spread throughout infection, suggesting slow or negligible proviral decay following deposition. HIV cure strategies will need to overcome within-host proviral diversity, even in individuals who naturally controlled HIV replication before therapy.ImportanceHIV therapy is life-long because integrated, replication-competent viral copies persist within long-lived cells. To cure HIV, we need to understand when these viral reservoirs form, how large and genetically diverse they are, and how long they endure. Elite controllers, individuals who naturally suppress HIV to undetectable levels, are being intensely studied as models of HIV remission, but viremic controllers, individuals who naturally suppress HIV to low levels, remain understudied even though they too may hold valuable insights. We combined phylogenetics and mathematical modeling to reconstruct proviral seeding and decay from infection to therapy-mediated suppression in four viremic controllers. We recovered diverse proviruses persisting during therapy that broadly reflected HIV’s within-host evolutionary history, where the estimated half-lives of the persistent proviral pool during untreated infection ranged from

[Image: see text] The observation that stilbene 3 (5350150) blocks HIV replication through its impact on HIV mRNA processing prompted a program to develop non-cytotoxic analogues that maintain its mechanism of action. This initially involved replacement of the central double bond in 3 by an amide function and the quinoline motif by a 2-aminobenzothiazole subunit, as in 12jj (R′ = Cl), 12pp (R = NO(2)), and 12vv (R = CF(3)). On the basis of the possible CF(3) ↔ NO(2) bioisostere relationship in 12vv and 12pp, compound 23 was prepared and also found to be active. In the final step, the thiazole compounds 28 (GPS488) (EC(50) = 1.66 μM) and 29 (GPS491) (EC(50) = 0.47 μM) were prepared and evaluated. Similar activity and cell viability values (therapeutic index (TI = CC(50)/EC(50)) values of 50–100) were observed in primary peripheral blood mononuclear cells. Furthermore, they remained active against a panel of HIV mutant strains displaying resistance to individual drugs used in antiretroviral therapy. It was determined that compound 29 suppressed expression of the HIV-1 structural protein Gag and altered HIV-1 RNA accumulation, decreasing the abundance of RNAs encoding the structural proteins while increasing levels of viral RNAs encoding the regulatory proteins, a pattern similar to that seen for compound 3.

Humoral responses to COVID-19 vaccines in people living with HIV (PLWH) remain incompletely understood. We measured circulating antibodies against the receptor-binding domain (RBD) of the SARS-CoV-2 spike protein, ACE2 displacement and live viral neutralization activities one month following the first and second COVID-19 vaccine doses in 100 adult PLWH and 152 controls. All PLWH were receiving suppressive antiretroviral therapy, with median CD4+ T-cell counts of 710 (IQR 525-935) cells/mm3. Nadir CD4+ T-cell counts ranged as low as 3. After adjustment for sociodemographic, health and vaccine-related variables, HIV infection was significantly associated with 0.2 log10 lower anti-RBD antibody concentrations (p=0.03) and ∼11% lower ACE2 displacement activity (p=0.02), but not lower viral neutralization (p=0.1) after one vaccine dose. Following two doses however, HIV was no longer significantly associated with the magnitude of any response measured. Rather, older age, a higher burden of chronic health conditions, and having received two ChAdOx1 doses (versus a heterologous or dual mRNA vaccine regimen) were independently associated with lower responses. After two vaccine doses, no significant correlation was observed between the most recent or nadir CD4+ T-cell counts and vaccine responses in PLWH. These results suggest that PLWH with well-controlled viral loads on antiretroviral therapy and CD4+ T-cell counts in a healthy range will generally not require a third COVID-19 vaccine dose as part of their initial immunization series, though other factors such as older age, co-morbidities, vaccine regimen type, and durability of vaccine responses will influence when this group may benefit from additional doses. Further studies of PLWH who are not receiving antiretroviral treatment and/or who have low CD4+ T-cell counts are needed.

BackgroundmRNA vaccines reduce COVID-19 incidence and severity, but the durability of vaccine-induced immune responses, particularly among the elderly, remains incompletely characterized.MethodsAnti-spike RBD antibody titers, ACE2 competition and virus neutralizing activities were longitudinally assessed in 151 healthcare workers and older adults (overall aged 24-98 years) up to three months after vaccination.ResultsOlder adults exhibited lower antibody responses after one and two vaccine doses for all measures. In multivariable analyses correcting for sociodemographic, chronic health and vaccine-related variables, age remained independently associated with all response outcomes. The number of chronic health conditions was additionally associated with lower binding antibody responses after two doses, and male sex with lower ACE2 competition activity after one dose. Responses waned universally at three months after the second dose, but binding antibodies, ACE2 competition and neutralizing activities remained significantly lower with age. Older adults also displayed reduced ability to block ACE2 binding by the Delta variant.ConclusionsThe humoral immune response to COVID-19 mRNA vaccines is significantly weaker with age, and universally wanes over time. This will likely reduce antibody-mediated protection against SARS-CoV-2 and the Delta variant as the pandemic progresses. Older adults may benefit from additional immunizations as a priority.

Background The magnitude and durability of immune responses to coronavirus disease 2019 (COVID-19) mRNA vaccines remain incompletely characterized in the elderly. Methods Anti-spike receptor-binding domain (RBD) antibodies, angiotensin-converting enzyme 2 (ACE2) competition, and virus neutralizing activities were assessed in plasma from 151 health care workers and older adults (range, 24–98 years of age) 1 month following the first vaccine dose, and 1 and 3 months following the second dose. Results Older adults exhibited significantly weaker responses than younger health care workers for all humoral measures evaluated and at all time points tested, except for ACE2 competition activity after 1 vaccine dose. Moreover, older age remained independently associated with weaker responses even after correction for sociodemographic factors, chronic health condition burden, and vaccine-related variables. By 3 months after the second dose, all humoral responses had declined significantly in all participants, and remained significantly lower among older adults, who also displayed reduced binding antibodies and ACE2 competition activity towards the Delta variant. Conclusions Humoral responses to COVID-19 mRNA vaccines are significantly weaker in older adults, and antibody-mediated activities in plasma decline universally over time. Older adults may thus remain at elevated risk of infection despite vaccination.

CD8(+) T cell responses restricted by MHC-E, a nonclassical MHC molecule, have been associated with protection in an SIV/rhesus macaque model. The biological relevance of HLA-E–restricted CD8(+) T cell responses in HIV infection, however, remains unknown. In this study, CD8(+) T cells responding to HIV-1 Gag peptides presented by HLA-E were analyzed. Using in vitro assays, we observed HLA-E–restricted T cell responses to what we believe to be a newly identified subdominant Gag-KL9 as well as a well-described immunodominant Gag-KF11 epitope in T cell lines derived from chronically HIV-infected patients and also primed from healthy donors. Blocking of the HLA-E/KF11 binding by the B7 signal peptide resulted in decreased CD8(+) T cell responses. KF11 presented via HLA-E in HIV-infected cells was recognized by antigen-specific CD8(+) T cells. Importantly, bulk CD8(+) T cells obtained from HIV-infected individuals recognized infected cells via HLA-E presentation. Ex vivo analyses at the epitope level showed a higher responder frequency of HLA-E–restricted responses to KF11 compared with KL9. Taken together, our findings of HLA-E–restricted HIV-specific immune responses offer intriguing and possibly paradigm-shifting insights into factors that contribute to the immunodominance of CD8(+) T cell responses in HIV infection.

Background The ubiquity of cellular phone (cellphone) use in young people’s daily lives has emerged as a priority area of concern for youth mental health. Objective This study measured the prevalence of depression and its association with high cellphone use among youth in Soweto and Durban, South Africa. Methods We analysed cross-sectional, baseline survey data among youth aged 16–24 who participated in a dual-site cohort study, ‘AYAZAZI’, conducted from 2014 to 2017. The primary outcome was depression using the 10-item Center for Epidemiologic Studies Depression Scale, with a score of ≥ 10 indicating probable depression. Cellphone use was measured via self-reported average number of hours of active use, with ‘high cellphone use’ defined as daily usage of ≥ 8. Multivariable logistic regression models assessed the independent relationship between high cellphone use and probable depression, adjusting for potential confounders. Results Of 425 participants with a median age of 19 years (IQR = 18–21), 59.5% were young women. Overall, 43.3% had probable depression, with a higher prevalence among women (49.0% vs. 34.9%, P = .004). Nearly all (94.6%) owned a cellphone. About one-third (29.5%) reported spending ≥ 8 hours per day using their cellphone (39.3% of women vs. 14.9% of men, P

Background: Understanding young women and men's perceived barriers and facilitators to participation in biomedical HIV prevention research is important for designing youth friendly services (YFS) and acceptable technologies, which are necessary for preventing high sustained HIV incidence in South Africa. This study explores the multileveled barriers and facilitators to young men and women's willingness to participate in hypothetical biomedical HIV prevention research.Methods: Eight age- (16–18 and 19–24 years) and gender-stratified focus group discussions (FGDs) were conducted using semi-structured interview guides to explore young South African women and men's willingness, perceived barriers, and facilitators to participating in biomedical HIV prevention research. FGD transcripts were uploaded to NVivo and coded collaboratively with youth study team members. Thematic analysis using Bronfenbrenner's ecological model (individual, inter-personal, community, and societal) was used to guide a deductive coding procedure, which was documented and compared by gender.Results: Thirty-one participants from Durban and 34 from Soweto participated in FGDs. Individual facilitators for participation were discussed more by young men and included financial incentives and altruism. Concerns about side-effects of biomedical products were a common barrier. Interpersonal relationships with peers, intimate partners and caregivers influenced young people's willingness to participate in HIV prevention research, more so among young women. For young women, gendered power dynamics and distrust of intimate partners and parents influenced both communication regarding participation and willingness to participate in research that is often stigmatized, due to societal norms around women's sexuality. On a societal level, participants expressed distrust in medical and research institutions, however a sense of community that was developed with the study staff of this project, was a motivator to participate in future studies.Discussion: At each level of the ecological model, we found participants expressed gendered barriers and facilitators for participation. Gender norms as well as distrust of partners, parents, and health care professionals were key barriers that cut across all levels. At each level participants discussed facilitators that were youth-engaged, underscoring the need to implement YFS, establish trust and address gender inequities within future biomedical HIV prevention studies wishing to engage and retain South African youth.

Background High rates of adolescent pregnancies in South Africa continues to be a pressing public health concern. This study examines (1) the prevalence of current contraceptive use; and (2) the independent association between adolescent pregnancy and effective contraception use. Methods This study uses baseline cross-sectional data from a youth-centered sexual and reproductive health (SRH) cohort study among youth (aged 16–24) in Soweto and Durban (2011–2017). Among 207/253 females reporting consensual sexual activity, crude and adjusted logistic regression examine associations between ever having an adolescent pregnancy (aged 15–19) or pregnancy at age 20–24 (ref no pregnancy) and effective contraception use (barrier and/or hormonal methods) in the last 6 months. Results Over one-third (34.3%, n = 71) of females reported a history of adolescent pregnancy and 13.0% (n = 27) had a pregnancy at age 20–24. Nearly all (95.9%, n = 94) first pregnancies were unintentional. Current effective contraceptive use was reported by 74.6% (n = 53) with an adolescent pregnancy, 66.6% (n = 18) of those pregnant at 20–24 years, and 46.8% (n = 51) of never pregnant females (p

Functional characterisation of different HIV-1 subtypes may improve understanding of viral pathogenesis and spread. Here, we evaluated the ability of 345 unique HIV-1 Nef clones representing subtypes A, B, C and D to inhibit NFAT signalling following TCR stimulation. The contribution of this Nef function to disease progression was also assessed in 211 additional Nef clones isolated from unique subtype C infected individuals in early or chronic infection. On average, subtype A and C Nef clones exhibited significantly lower ability to inhibit TCR-mediated NFAT signalling compared to subtype B and D Nef clones. While this observation corroborates accumulating evidence supporting relative attenuation of subtypes A and C that may paradoxically contribute to their increased global prevalence and spread, no significant correlations between Nef-mediated NFAT inhibition activity and clinical markers of HIV-1 infection were observed, indicating that the relationship between Nef function and pathogenesis is complex.

Objective To assess the prevalence of food insecurity and the independent association between depression and food insecurity among youth living in two urban settings in South Africa. Methods Baseline cross-sectional survey data was analysed from a prospective cohort study conducted between 2014 and 2016 among youth (aged 16-24 years) in Soweto and Durban. Interviewer-administered questionnaires collecting socio-demographic, sexual and reproductive health and mental health data were conducted. Household food insecurity was measured using the 3-item Household Hunger scale, with food insecure participants defined as having 'moderate' or 'severe hunger' compared to 'no hunger'. Depression was assessed using the 10-item Center for Epidemiological Studies Depression (CES-D 10) Scale (range 0-30, probable depression ≥10). Multivariable logistic regression models were used to estimate the association between depression and food insecurity. Results There were 422 participants. Median age was 19 years (Interquartile Range [IQR] 18-21) and 60% were women. Overall, 18% were food insecure and 42% had probable depression. After adjustment for socio-demographic variables (age, gender, female-headed household, household size, and school enrollment), participants with probable depression had higher odds of being food-insecure than non-depressed participants (2.79, 95%CI 1.57-4.94). Conclusion Nearly one-fifth of youth in this study were food-insecure. Those with probable depression had increased odds of food insecurity. Interventions are needed to address food insecurity among urban youth in South Africa, combining nutritional support and better access to quality food with mental health support.

While combination antiretroviral therapy (cART) durably suppresses HIV replication, virus persists in CD4+ T-cells that harbor latent but spontaneously inducible and replication-competent provirus. One strategy to inactivate these viral reservoirs involves the use of agents that continue to reinforce HIV latency even after their withdrawal. To identify new chemical leads with such properties, we investigated a series of naturally-occurring flavones (chrysin, apigenin, luteolin, and luteolin-7-glucoside (L7G)) and functionally-related cyclin dependent kinase 9 (CDK9) inhibitors (flavopiridol and atuveciclib) which are reported or presumed to suppress HIV replication in vitro. We found that, while all compounds inhibit provirus expression induced by latency-reversing agents in vitro, only aglycone flavonoids (chrysin, apigenin, luteolin, flavopiridol) and atuveciclib, but not the glycosylated flavonoid L7G, inhibit spontaneous latency reversal. Aglycone flavonoids and atuveciclib, but not L7G, also inhibit CDK9 and the HIV Tat protein. Aglycone flavonoids do not reinforce HIV latency following their in vitro withdrawal, which corresponds with their ability to also inhibit class I/II histone deacetylases (HDAC), a well-established mechanism of latency reversal. In contrast, atuveciclib and flavopiridol, which exhibit little or no HDAC inhibition, continue to reinforce latency for 9 to 14+ days, respectively, following their withdrawal in vitro. Finally, we show that flavopiridol also inhibits spontaneous ex vivo viral RNA production in CD4+ T cells from donors with HIV. These results implicate CDK9 inhibition (in the absence of HDAC inhibition) as a potentially favorable property in the search for compounds that durably reinforce HIV latency.

HIV Nef counteracts cellular host restriction factors SERINC3 and SERINC5, but our understanding of how naturally occurring global Nef sequence diversity impacts these activities is limited. Here, we quantify SERINC3 and SERINC5 internalization function for 339 Nef clones, representing the major pandemic HIV-1 group M subtypes A, B, C and D. We describe distinct subtype-associated hierarchies for Nef-mediated internalization of SERINC5, for which subtype B clones display the highest activities on average, and of SERINC3, for which subtype B clones display the lowest activities on average. We further identify Nef polymorphisms that modulate its ability to counteract SERINC proteins, including substitutions in the N-terminal domain that selectively impair SERINC3 internalization. Our findings demonstrate that the SERINC antagonism activities of HIV Nef differ markedly among major viral subtypes and between individual isolates within a subtype, suggesting that variation in these functions may contribute to global differences in viral pathogenesis., Author summary Cellular restriction factors dampen viral replication and reduce pathogenesis. In response, HIV has evolved a variety of mechanisms to counteract restriction factors, including the ability of its Nef protein to internalize Serine incorporator (SERINC) proteins 3 and 5 from the infected cell surface, thereby enhancing infectivity of viral particles. Nef displays substantial sequence diversity, but how this impacts SERINC antagonism remains unclear. To examine this, we used cell culture models to measure SERINC internalization function for 339 participant-derived Nef clones, representing four globally relevant HIV-1 group M subtypes. We observed significant variability in Nef function among circulating viral strains and subtypes. We also identified naturally occurring Nef mutations that modulate its ability to counteract SERINC proteins, including some that selectively impair SERINC3 internalization. These findings uncover viral features that may contribute to global differences in HIV pathogenesis and provide new insight into the interactions between Nef and SERINC restriction factors that can inform future mechanistic studies.

The HIV-1 accessory protein Vpu enhances viral spread by downregulating CD4 and BST-2/tetherin on the surface of infected cells. Natural variability in these Vpu functions may contribute to HIV-1 pathogenesis, but this has not been investigated among the diverse viral subtypes that contribute to the HIV-1 pandemic. In this study, we found that Vpu function differs significantly among HIV-1 subtypes A, B, C, and D. On average, subtype C clones displayed the lowest ability to downregulate both CD4 and tetherin, while subtype B and D clones were more functional. We also identified Vpu polymorphisms that associate with functional differences among HIV-1 isolates and subtypes. Our study suggests that genetic diversity in Vpu may play an important role in the differential pathogenesis and/or spread of HIV-1., Downregulation of BST-2/tetherin and CD4 by HIV-1 viral protein U (Vpu) promotes viral egress and allows infected cells to evade host immunity. Little is known however about the natural variability in these Vpu functions among the genetically diverse viral subtypes that contribute to the HIV-1 pandemic. We collected Vpu isolates from 332 treatment-naive individuals living with chronic HIV-1 infection in Uganda, Rwanda, South Africa, and Canada. Together, these Vpu isolates represent four major HIV-1 group M subtypes (A [n = 63], B [n = 84], C [n = 94], and D [n = 59]) plus intersubtype recombinants and uncommon strains (n = 32). The ability of each Vpu clone to downregulate endogenous CD4 and tetherin was quantified using flow cytometry following transfection into an immortalized T-cell line and compared to that of a reference Vpu clone derived from HIV-1 subtype B NL4.3. Overall, the median CD4 downregulation function of natural Vpu isolates was similar to that of NL4.3 (1.01 [interquartile range {IQR}, 0.86 to 1.18]), while the median tetherin downregulation function was moderately lower than that of NL4.3 (0.90 [0.79 to 0.97]). Both Vpu functions varied significantly among HIV-1 subtypes (Kruskal-Wallis P

The HIV reservoir, which comprises diverse proviruses integrated into the genomes of infected, primarily CD4+ T cells, is the main barrier to developing an effective HIV cure. Our understanding of the genetics and dynamics of proviruses persisting within distinct CD4+ T cell subsets, however, remains incomplete. Using single-genome amplification, we characterized subgenomic proviral sequences (nef region) from naive, central memory, transitional memory, and effector memory CD4+ T cells from five HIV-infected individuals on long-term combination antiretroviral therapy (cART) and compared these to HIV RNA sequences isolated longitudinally from archived plasma collected prior to cART initiation, yielding HIV data sets spanning a median of 19.5 years (range, 10 to 20 years) per participant. We inferred a distribution of within-host phylogenies for each participant, from which we characterized proviral ages, phylogenetic diversity, and genetic compartmentalization between CD4+ T cell subsets. While three of five participants exhibited some degree of proviral compartmentalization between CD4+ T cell subsets, combined analyses revealed no evidence that any particular CD4+ T cell subset harbored the longest persisting, most genetically diverse, and/or most genetically distinctive HIV reservoir. In one participant, diverse proviruses archived within naive T cells were significantly younger than those in memory subsets, while for three other participants we observed no significant differences in proviral ages between subsets. In one participant, "old" proviruses were recovered from all subsets, and included one sequence, estimated to be 21.5 years old, that dominated (>93%) their effector memory subset. HIV eradication strategies will need to overcome within- and between-host genetic complexity of proviral landscapes, possibly via personalized approaches.IMPORTANCE The main barrier to HIV cure is the ability of a genetically diverse pool of proviruses, integrated into the genomes of infected CD4+ T cells, to persist despite long-term suppressive combination antiretroviral therapy (cART). CD4+ T cells, however, constitute a heterogeneous population due to their maturation across a developmental continuum, and the genetic "landscapes" of latent proviruses archived within them remains incompletely understood. We applied phylogenetic techniques, largely novel to HIV persistence research, to reconstruct within-host HIV evolutionary history and characterize proviral diversity in CD4+ T cell subsets in five individuals on long-term cART. Participants varied widely in terms of proviral burden, genetic diversity, and age distribution between CD4+ T cell subsets, revealing that proviral landscapes can differ between individuals and between infected cell types within an individual. Our findings expose each within-host latent reservoir as unique in its genetic complexity and support personalized strategies for HIV eradication.