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Host restriction factors play key roles in innate antiviral defense, but it remains poorly understood which of them restricts HIV-1 in vivo. Here, we used single-cell transcriptomic analysis to identify host factors associated with HIV-1 control during acute infection by correlating host gene expression with viral RNA abundance within individual cells. Wide sequencing of cells from one participant with the highest plasma viral load revealed that intracellular viral RNA transcription correlates inversely with expression of the gene PTMA , which encodes prothymosin α. This association was genome-wide significant ( P < 0.05) and was validated in 28 additional participants from Thailand and the Americas with HIV-1 CRF01&#95;AE and subtype B infections, respectively. Overexpression of prothymosin α in vitro confirmed that this cellular factor inhibits HIV-1 transcription and infectious virus production. Our results identify prothymosin α as a host factor that restricts HIV-1 infection in vivo, which has implications for viral transmission and cure strategies.adjusted < 0.05) and was validated in 28 additional participants from Thailand and the Americas with HIV-1 CRF01&#95;AE and subtype B infections, respectively. Overexpression of prothymosin α in vitro confirmed that this cellular factor inhibits HIV-1 transcription and infectious virus production. Our results identify prothymosin α as a host factor that restricts HIV-1 infection in vivo, which has implications for viral transmission and cure strategies.

Much has been learnt about the role of human leukocyte antigen (HLA) alleles during natural infection of HIV-1, but far less is known about their role in people living with HIV (PLWH) on suppressive antiretroviral therapy (ART). In this study we used variable selection to identify predictors of HIV reservoir size, as measured by total HIV DNA in 192 participants in an acute HIV infection (AHI) cohort. Baseline clinical data including pre-ART CD4 T cell counts and plasma viral load (VL) were available from all participants along with longitudinal measurements after ART initiation during AHI. Time to VL suppression, time to CD4 reconstitution, and pre-ART viremia were the strongest predictors of undetectable total HIV DNA at 24 weeks after ART initiation. We next performed HLA typing in 526 participants from the same cohort and investigated associations with the three predictors of reservoir size. HLA-B*57 and B*58 both associated significantly with time to VL suppression, which was one of the predictors of the size of the HIV reservoir. These findings are significant in PLWH and have to be considered in the context of therapeutic intervention when conducting analytic treatment interruption studies as participants with these alleles could impact clinical findings given the small sizes of these studies.

Background: Harnessing CD8 + T cell responses is being explored to achieve HIV remission. Although HIV-specific CD8 + T cells become dysfunctional without treatment, antiretroviral therapy (ART) partially restores their function. However, the extent of this recovery under long-term ART is less understood., Methods: We analyzed the differentiation status and function of HIV-specific CD8 + T cells after long-term ART initiated in acute or chronic HIV infection ex vivo and upon in vitro recall., Findings: ART initiation in any stage of acute HIV infection promoted the persistence of long-lived HIV-specific CD8 + T cells with high expansion (P<0·0008) and cytotoxic capacity (P=0·02) after in vitro recall, albeit at low cell number (P=0·003). This superior expansion capacity correlated with stemness (r=0·90, P=0·006), measured by TCF-1 expression, similar to functional HIV-specific CD8 + T cells found in spontaneous controllers. Importanly, TCF-1 expression in these cells was associated with longer time to viral rebound ranging from 13 to 48 days after ART interruption (r =0·71, P=0·03). In contrast, ART initiation in chronic HIV infection led to more differentiated HIV-specific CD8 + T cells lacking stemness properties and exhibiting residual dysfunction upon recall, with reduced proliferation and cytolytic activity., Interpretation: ART initiation in acute HIV infection preserves functional HIV-specific CD8 + T cells, albeit at numbers too low to control viral rebound post-ART. HIV remission strategies may need to boost HIV-specific CD8 + T cell numbers and induce stem cell-like properties to reverse the residual dysfunction persisting on ART in people treated after acute infection prior to ART release., Funding: U.S. National Institutes of Health and U.S. Department of Defense., Competing Interests: Declaration of interests All the other authors declare that they have no competing interests., (Copyright © 2022 The Author(s). Published by Elsevier B.V. All rights reserved.)

A gene signature was previously found to be correlated with mosaic adenovirus 26 vaccine protection in simian immunodeficiency virus and simian-human immunodeficiency virus challenge models in non-human primates. In this report, we investigated the presence of this signature as a correlate of reduced risk in human clinical trials and potential mechanisms of protection. The absence of this gene signature in the DNA/rAd5 human vaccine trial, which did not show efficacy, strengthens our hypothesis that this signature is only enriched in studies that demonstrated protection. This gene signature was enriched in the partially effective RV144 human trial that administered the ALVAC/protein vaccine, and we find that the signature associates with both decreased risk of HIV-1 acquisition and increased vaccine efficacy (VE). Total RNA-seq in a clinical trial that used the same vaccine regimen as the RV144 HIV vaccine implicated antibody-dependent cellular phagocytosis (ADCP) as a potential mechanism of vaccine protection. CITE-seq profiling of 53 surface markers and transcriptomes of 53,777 single cells from the same trial showed that genes in this signature were primarily expressed in cells belonging to the myeloid lineage, including monocytes, which are major effector cells for ADCP. The consistent association of this transcriptome signature with VE represents a tool both to identify potential mechanisms, as with ADCP here, and to screen novel approaches to accelerate the development of new vaccine candidates., Competing Interests: SS, PE, AG, LY, GK, KM, SF, KN, LW, SS, EL, PP, SN, SC, SR, MR, DD, PG, GT, NM, SV, RT No competing interests declared

Determining which immunological mechanisms contribute to the development of broad neutralizing antibodies (bNAbs) during HIV-1 infection is a major goal to inform vaccine design. Using samples from a longitudinal HIV-1 acute infection cohort, we found key B cell determinants within the first 14-43 days of viremia that predict the development of bNAbs years later. Individuals who develop neutralization breadth had significantly higher B cell engagement with the autologous founder HIV envelope (Env) within 1 month of initial viremia. A higher frequency of founder-Env-specific naive B cells was associated with increased B cell activation and differentiation and predictive of bNAb development. These data demonstrate that the initial B cell interaction with the founder HIV Env is important for the development of broadly neutralizing antibodies and provide evidence that events within HIV acute infection lead to downstream functional outcomes., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Current HIV vaccines are only partially efficacious, presenting an opportunity to identify correlates of protection and, thereby, potential insight into mechanisms that prevent HIV acquisition. Two independent preclinical challenge studies in nonhuman primates (NHPs) previously showed partial efficacy of a mosaic adenovirus 26 (Ad26)-based HIV-1 vaccine candidate. To investigate the basis of this protection, we performed whole transcriptomics profiling by RNA sequencing (RNA-seq) in sorted lymphocytes from peripheral blood samples taken during these studies at different time points after vaccination but before challenge. We observed a transcriptional signature in B cells that associated with protection from acquisition of simian immunodeficiency virus (SIV) or the simian-human immunodeficiency virus (SHIV) in both studies. Strong antibody responses were elicited, and genes from the signature for which expression was enriched specifically associated with higher magnitude of functional antibody responses. The same gene expression signature also associated with protection in RV144 in the only human HIV vaccine trial to date that has shown efficacy and in two additional NHP studies that evaluated similar canarypox-based vaccine regimens. A composite gene expression score derived from the gene signature was one of the top-ranked correlates of protection in the NHP vaccine studies. This study aims to bridge preclinical and clinical data with the identification of a gene signature in B cells that is associated with protection from SIV and HIV infection by providing a new approach for evaluating future vaccine candidates., (Copyright © 2019 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.)

The RV144 HIV vaccine trial in Thailand elicited antibody responses to the envelope of HIV-1, which correlated significantly with the risk of HIV-1 acquisition. Human leukocyte antigen (HLA) class II molecules are essential in antigen presentation to CD4 T cells for activation of B cells to produce antibodies. We genotyped the classical HLA-DRB1, DQB1, and DPB1 genes in 450 individuals from the placebo arm of the RV144 study to determine the background allele and haplotype frequencies of these genes in this cohort. High-resolution 4 and 6-digit class II HLA typing data was generated using sequencing-based methods. The observed diversity for the HLA loci was 33 HLA-DRB1, 15 HLA-DQB1, and 26 HLA-DPB1 alleles. Common alleles with frequencies greater than 10% were DRB1*07:01, DRB1*09:01, DRB1*12:02, DRB1*15:02, DQB1*02:01/02, DQB1*03:01, DQB1*03:03, DQB1*05:01, DQB1*05:02, DPB1*04:01:01, DPB1*05:01:01, and DPB1*13:01:01. We identified 28 rare alleles with frequencies of less than 1% in the Thai individuals. Ambiguity for HLA-DPB1*28:01 in exon 2 was resolved to DPB1*296:01 by next-generation sequencing of all exons. Multi-locus haplotypes including HLA class I and II loci were reported in this study. This is the first comprehensive report of allele and haplotype frequencies of all three HLA class II genes from a Thai population. A high-resolution genotyping method such as next-generation sequencing avoids missing rare alleles and resolves ambiguous calls. The HLA class II genotyping data generated in this study will be beneficial not only for future disease association/vaccine efficacy studies related to the RV144 study, but also for similar studies in other diseases in the Thai population, as well as population genetics and transplantation studies., (© 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

RV144 is the first phase 3 HIV vaccine clinical trial to demonstrate efficacy. This study consisted of more than 8,000 individuals in each arm of the trial, representing the four major regions of Thailand. Human leukocyte antigen (HLA) class I and killer cell immunoglobulin-like receptor (KIR) genes, as well as 96 genome-wide ancestry informative markers (AIMs) were genotyped in 450 placebo HIV-1-uninfected individuals to identify the immunogenetic diversity and population structure of this cohort. High-resolution genotyping identified the common HLA alleles as A*02:03, A*02:07, A*11:01, A*24:02, A*24:07, A*33:03, B*13:01, B*15:02, B*18:01, B*40:01, B*44:03, B*46:01, B*58:01, C*01:02, C*03:02, C*03:04, C*07:01, C*07:02, C*07:04, and C*08:01. The most frequent three-loci haplotype was B*46:01-C*01:02-A*02:07. Framework genes KIR2DL4, 3DL2, and 3DL3 were present in all samples, and KIR2DL1, 2DL3, 3DL1, 2DS4, and 2DP1 occurred at frequencies greater than 90 %. The combined HLA and KIR profile suggests admixture with neighboring Asian populations. Principal component and correspondence analyses comparing the RV144 samples to the phase 3 International HapMap Project (HapMap3) populations using AIMs corroborated these findings. Structure analyses identified a distinct profile in the Thai population that did not match the Asian or other HapMap3 samples. This shows genetic variability unique to Thais in RV144, making it essential to take into account population stratification while performing genetic association studies. The overall analyses from all three genetic markers indicate that the RV144 samples are representative of the Thai population. This will inform subsequent host genetic analyses in the RV144 cohort and provide insight for future genetic association studies in the Thai population.