Zambia Emory HIV Research Project

Lusaka, Zambia

Zambia Emory HIV Research Project

Lusaka, Zambia
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Amornkul P.N.,International AIDS Vaccine Initiative | Karita E.,Project San Francisco | Kamali A.,Medical Research Council Uganda Virus Research Unit | Rida W.N.,Biostatistics Consultant | And 14 more authors.
AIDS | Year: 2013

Objective: To describe immunologic, virologic, and clinical HIV disease progression by HIV-1 subtype among Africans with well documented estimated dates of HIV infection (EDIs). Design: Prospective cohort. Methods: Adults and youth with documented HIV-1 infection in the past 12 months were recruited from seroincidence cohorts in East and Southern Africa and followed at 3-6 month intervals. Blood for lymphocyte subset and viral load determination was collected at each visit. Pol was sequenced from the first positive specimen to ascertain subtype. Preantiretroviral therapy disease progression was measured by three time-toevent endpoints: CD4+ cell count 350 cells/ml or less, viral load measurement at least 1*105 copies/ml, and clinical AIDS. Results: From 2006 to 2011, 615 participants were enrolled at nine research centers in Kenya, Rwanda, South Africa, Uganda, and Zambia; 579 (94.1%) had viral subtyping completed. Predominant subtypes were C (256, 44.2%), A (209, 36.1%), and D (84, 14.5%). After adjustment for age, sex, and human leukocyte antigen alleles in Cox regression analyses, subtype C-infected participants progressed faster than subtype A to all three endpoints [CD4+ hazard ratio 1.60, 95% (confidence interval) CI 1.16, 2.20; viral load hazard ratio 1.59, 95% CI 1.12, 2.25; and AIDS hazard ratio 1.60, 95% CI 1.11, 2.31). Subtype D-infected participants reached high viral load more rapidly (hazard ratio 1.61, 95% CI 1.01, 2.57) and progressed nearly twice as fast to AIDS compared to subtype A (hazard ratio 1.93, 95% CI 1.21, 3.09). Conclusion: Subtype-specific differences in HIV disease progression suggest that the local subtype distribution be considered when planning HIV programs and designing and defining clinical endpoints for HIV prevention trials. © 2013 Wolters Kluwer Health | Lippincott Williams & Wilkins.

Prince J.L.,Emory University | Claiborne D.T.,Emory University | Carlson J.M.,Microsoft | Schaefer M.,Emory University | And 19 more authors.
PLoS Pathogens | Year: 2012

Initial studies of 88 transmission pairs in the Zambia Emory HIV Research Project cohort demonstrated that the number of transmitted HLA-B associated polymorphisms in Gag, but not Nef, was negatively correlated to set point viral load (VL) in the newly infected partners. These results suggested that accumulation of CTL escape mutations in Gag might attenuate viral replication and provide a clinical benefit during early stages of infection. Using a novel approach, we have cloned gag sequences isolated from the earliest seroconversion plasma sample from the acutely infected recipient of 149 epidemiologically linked Zambian transmission pairs into a primary isolate, subtype C proviral vector, MJ4. We determined the replicative capacity (RC) of these Gag-MJ4 chimeras by infecting the GXR25 cell line and quantifying virion production in supernatants via a radiolabeled reverse transcriptase assay. We observed a statistically significant positive correlation between RC conferred by the transmitted Gag sequence and set point VL in newly infected individuals (p = 0.02). Furthermore, the RC of Gag-MJ4 chimeras also correlated with the VL of chronically infected donors near the estimated date of infection (p = 0.01), demonstrating that virus replication contributes to VL in both acute and chronic infection. These studies also allowed for the elucidation of novel sites in Gag associated with changes in RC, where rare mutations had the greatest effect on fitness. Although we observed both advantageous and deleterious rare mutations, the latter could point to vulnerable targets in the HIV-1 genome. Importantly, RC correlated significantly (p = 0.029) with the rate of CD4+ T cell decline over the first 3 years of infection in a manner that is partially independent of VL, suggesting that the replication capacity of HIV-1 during the earliest stages of infection is a determinant of pathogenesis beyond what might be expected based on set point VL alone. © 2012 Prince et al.

PubMed | Medical Research Council Uganda Virus Research Institute, University of Oxford, IAVI, Kenya AIDS Vaccine Institute Institute of Clinical Research and 10 more.
Type: Journal Article | Journal: PloS one | Year: 2015

HIV epidemiology informs prevention trial design and program planning. Nine clinical research centers (CRC) in sub-Saharan Africa conducted HIV observational epidemiology studies in populations at risk for HIV infection as part of an HIV prevention and vaccine trial network. Annual HIV incidence ranged from below 2% to above 10% and varied by CRC and risk group, with rates above 5% observed in Zambian men in an HIV-discordant relationship, Ugandan men from Lake Victoria fishing communities, men who have sex with men, and several cohorts of women. HIV incidence tended to fall after the first three months in the study and over calendar time. Among suspected transmission pairs, 28% of HIV infections were not from the reported partner. Volunteers with high incidence were successfully identified and enrolled into large scale cohort studies. Over a quarter of new cases in couples acquired infection from persons other than the suspected transmitting partner.

PubMed | Zambia Emory HIV Research Project, Projet San Francisco, International AIDS Vaccine Initiative IAVI and Emory University
Type: Journal Article | Journal: PLoS pathogens | Year: 2016

A recent study of plasma neutralization breadth in HIV-1 infected individuals at nine International AIDS Vaccine Initiative (IAVI) sites reported that viral load, HLA-A*03 genotype, and subtype C infection were strongly associated with the development of neutralization breadth. Here, we refine the findings of that study by analyzing the impact of the transmitted/founder (T/F) envelope (Env), early Env diversification, and autologous neutralization on the development of plasma neutralization breadth in 21 participants identified during recent infection at two of those sites: Kigali, Rwanda (n = 9) and Lusaka, Zambia (n = 12). Single-genome analysis of full-length T/F Env sequences revealed that all 21 individuals were infected with a highly homogeneous population of viral variants, which were categorized as subtype C (n = 12), A1 (n = 7), or recombinant AC (n = 2). An extensive amino acid sequence-based analysis of variable loop lengths and glycosylation patterns in the T/F Envs revealed that a lower ratio of NXS to NXT-encoded glycan motifs correlated with neutralization breadth. Further analysis comparing amino acid sequence changes, insertions/deletions, and glycan motif alterations between the T/F Env and autologous early Env variants revealed that extensive diversification focused in the V2, V4, and V5 regions of gp120, accompanied by contemporaneous viral escape, significantly favored the development of breadth. These results suggest that more efficient glycosylation of subtype A and C T/F Envs through fewer NXS-encoded glycan sites is more likely to elicit antibodies that can transition from autologous to heterologous neutralizing activity following exposure to gp120 diversification. This initiates an Env-antibody co-evolution cycle that increases neutralization breadth, and is further augmented over time by additional viral and host factors. These findings suggest that understanding how variation in the efficiency of site-specific glycosylation influences neutralizing antibody elicitation and targeting could advance the design of immunogens aimed at inducing antibodies that can transition from autologous to heterologous neutralizing activity.

PubMed | Kenya AIDS Vaccine Initiative, Zambia Emory HIV Research Project, MRC UVRI Uganda Virus Research Unit on AIDS, Chelsea and Westminster Hospital and 5 more.
Type: Journal Article | Journal: Journal of virology | Year: 2016

In individuals with HIV-1 infection, depletion of CD4Longitudinal data from 497 HIV-1 seroconverters allowed us to systematically evaluate the dynamics and correlates of CD8

Kelley A.L.,Rwanda Zambia HIV Research Group | Karita E.,Rwanda Zambia HIV Research Group | Sullivan P.S.,Emory University | Katangulia F.,Scientific Monitoring, Inc. | And 8 more authors.
PLoS ONE | Year: 2011

Background: Most incident HIV infections in sub-Saharan Africa occur between cohabiting, discordant, heterosexual couples. Though couples' voluntary HIV counseling and testing (CVCT) is an effective, well-studied intervention in Africa, <1% of couples have been jointly tested. Methods: We conducted cross-sectional household surveys in Kigali, Rwanda (n = 600) and Lusaka, Zambia (n = 603) to ascertain knowledge, perceptions, and barriers to use of CVCT. Results: Compared to Lusaka, Kigali respondents were significantly more aware of HIV testing sites (79% vs. 56%); had greater knowledge of HIV serodiscordance between couples (83% vs. 43%); believed CVCT is good (96% vs. 72%); and were willing to test jointly (91% vs. 47%). Stigma, fear of partner reaction, and distance/cost/logistics were CVCT barriers. Conclusions: Though most respondents had positive attitudes toward CVCT, the majority were unaware that serodiscordance between cohabiting couples is possible. Future messages should target gaps in knowledge about serodiscordance, provide logistical information about CVCT services, and aim to reduce stigma and fear. © 2011 Kelley et al.

PubMed | CNRS Institute of Pharmacology and Structural Biology, Zambia Emory HIV Research Project, Monogram Biosciences, Scripps Research Institute and 2 more.
Type: Journal Article | Journal: Immunity | Year: 2016

The high-mannose patch on HIV Env is a preferred target for broadly neutralizing antibodies (bnAbs), but to date, no vaccination regimen has elicited bnAbs against this region. Here, we present the development of a bnAb lineage targeting the high-mannose patch in an HIV-1 subtype-C-infected donor from sub-Saharan Africa. The Abs first acquired autologous neutralization, then gradually matured to achieve breadth. One Ab neutralized >47% of HIV-1 strains with only 11% somatic hypermutation and no insertions or deletions. By sequencing autologous env, we determined key residues that triggered the lineage and participated in Ab-Env coevolution. Next-generation sequencing of the Ab repertoire showed an early expansive diversification of the lineage followed by independent maturation of individual limbs, several of them developing notable breadth and potency. Overall, the findings are encouraging from a vaccine standpoint and suggest immunization strategies mimicking the evolution of the entire high-mannose patch and promoting maturation of multiple diverse Ab pathways.

Sullivan P.S.,Emory University | Fideli U.,U.S. National Institutes of Health | Wall K.M.,Emory University | Chomba E.,Zambia Emory HIV Research Project | And 9 more authors.
AIDS | Year: 2012

OBJECTIVE:: To describe symptoms, physical examination findings, and set-point viral load associated with acute HIV seroconversion in a heterosexual cohort of HIV-discordant couples in Zambia. DESIGN:: We followed HIV serodiscordant couples in Lusaka, Zambia from 1995 to 2009 with HIV testing of negative partners and symptom inventories 3 monthly, and physical examinations annually. METHODS:: We compared prevalence of self-reported or treated symptoms (malaria syndrome, chronic diarrhea, asthenia, night sweats, and oral candidiasis) and annual physical examination findings (unilateral or bilateral neck, axillary, or inguinal adenopathy; and dermatosis) in seroconverting vs. HIV-negative or HIV-positive intervals, controlling for repeated observations, age, and sex. A composite score comprised of significant symptoms and physical examination findings predictive of seroconversion vs. HIV-negative intervals was constructed. We modeled the relationship between number of symptoms and physical examination findings at seroconversion and log set-point viral load using linear regression. RESULTS:: Two thousand, three hundred and eighty-eight HIV-negative partners were followed for a median of 18 months; 429 seroconversions occurred. Neither symptoms nor physical examination findings were reported for most seroconverters. Seroconversion was significantly associated with malaria syndrome among nondiarrheic patients [adjusted odds ratio (aOR)=4.0], night sweats (aOR=1.4), and bilateral axillary (aOR=1.6), inguinal (aOR=2.2), and neck (aOR=2.2) adenopathy relative to HIV-negative intervals. Median number of symptoms and findings was positively associated with set-point viral load (P<0.001). CONCLUSION:: Although most acute and early infections were asymptomatic, malaria syndrome was more common and more severe during seroconversion. When present, symptoms and physical examination findings were nonspecific and associated with higher set-point viremia. © 2012 Lippincott Williams & Wilkins, Inc.

Lambdin B.H.,Pangaea Global AIDS Foundation | Kanweka W.,Us Agency For International Development | Inambao M.,Zambia Emory HIV Research Project | Mwananyanda L.,mothers2mothers | And 6 more authors.
Health Affairs | Year: 2011

Couples in sub-Saharan Africa are the largest group in the world at risk for HIV infection. Couples counseling and testing programs have been shown to reduce HIV transmission, but such programs remain rare in Africa. Before couples counseling and testing can become the norm, it is essential to increase demand for the services. We evaluated the effectiveness of several promotional strategies during a two-year program in Kitwe and Ndola, Zambia. The program attracted more than 7,600 couples through the use of radio broadcasts, billboards, and other strategies. The most effective recruiting technique was the use of local residents trained as "influence agents" to reach out to friends, neighbors, and others in their sphere of influence. © 2011 Project HOPE-The People-to-People Health Foundation, Inc.

Deymier M.J.,Emory University | Ende Z.,Emory University | Fenton-May A.E.,University of Oxford | Dilernia D.A.,Emory University | And 4 more authors.
PLoS Pathogens | Year: 2015

Heterosexual transmission of HIV-1 is characterized by a genetic bottleneck that selects a single viral variant, the transmitted/founder (TF), during most transmission events. To assess viral characteristics influencing HIV-1 transmission, we sequenced 167 near full-length viral genomes and generated 40 infectious molecular clones (IMC) including TF variants and multiple non-transmitted (NT) HIV-1 subtype C variants from six linked heterosexual transmission pairs near the time of transmission. Consensus-like genomes sensitive to donor antibodies were selected for during transmission in these six transmission pairs. However, TF variants did not demonstrate increased viral fitness in terms of particle infectivity or viral replicative capacity in activated peripheral blood mononuclear cells (PBMC) and monocyte-derived dendritic cells (MDDC). In addition, resistance of the TF variant to the antiviral effects of interferon-α (IFN-α) was not significantly different from that of non-transmitted variants from the same transmission pair. Thus neither in vitro viral replicative capacity nor IFN-α resistance discriminated the transmission potential of viruses in the quasispecies of these chronically infected individuals. However, our findings support the hypothesis that within-host evolution of HIV-1 in response to adaptive immune responses reduces viral transmission potential. © 2015 Deymier et al.

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