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Clinical trials including an analytical treatment interruption (ATI) are vital for evaluating the efficacy of novel strategies for HIV remissions. We briefly describe an interactive tool for predicting viral rebound timing in ATI trials and the impact of posttreatment controller (PTC) definitions on PTC frequency estimates. A 4-week viral load threshold of 1000 cps/ml provides both high specificity and sensitivity for PTC detection. PTC frequency varies greatly based on the definition of a PTC.

ObjectiveThe contribution of HLA-DR+ memory CD4 T cells to the HIV reservoir during prolonged antiretroviral therapy is unclear as these cells are commonly excluded when assessing for replication-competent HIV. To address this issue, we examined the distribution of genetically intact HIV DNA within HLA-DR- and HLA-DR+ memory CD4 T cells and the RNA transcriptional profile of these cells during antiretroviral therapy.Design/methodsFull-length DNA sequencing was used to examine the HIV DNA landscape within HLA-DR+ and HLA-DR- memory CD4 T cells. RNA quantification and sequencing was used to interrogate the relationship between HLA-DR status and HIV RNA transcription.ResultsHLA-DR+ CD4 T cells contained a high frequency of genetically intact HIV genomes, contributing over half of the genetically intact viral sequences to the reservoir. Expansions of genetically identical sequences were identified in all T-cell subsets, indicating that cellular proliferation maintains genetically intact and defective viral DNA during therapy. Intracellular HIV RNA levels in HLA-DR+ and HLA-DR- T cells were not statistically different by either long terminal repeat quantitative PCR quantification or single-genome RNA sequencing of the p6-RT region.ConclusionThe high proportion of intact viral DNA sequences in the proliferative HLA-DR+ subset suggests they are critical in maintaining HIV infection during effective therapy. As such, these cells should be included in any immune intervention targeting HIV during effective therapy.

Objective(s)To determine whether variation in cell-associated unspliced (CA-US) HIV RNA in HIV-infected individuals on antiretroviral therapy (ART) has a circadian basis.MethodsProspective observational study of HIV-infected individuals on ART. Blood was collected on three occasions and CA-US HIV RNA and mRNA of the circadian-locomotor-output-cycles-kaput (CLOCK)-associated genes quantified by real time PCR. CLOCK-associated proteins were over-expressed in a cell line stably transfected with an HIV long-terminal repeat (LTR) luciferase reporter.ResultsUsing a mixed effects model, there was a significant increase in log-CA-US RNA at the third visit compared with the first visit (effect size of 0.619 with standard error (SE) of 0.098, P

ObjectiveAssays for classifying HIV infections as 'recent' or 'nonrecent' for incidence surveillance fail to simultaneously achieve large mean durations of 'recent' infection (MDRIs) and low 'false-recent' rates (FRRs), particularly in virally suppressed persons. The potential for optimizing recent infection testing algorithms (RITAs), by introducing viral load criteria and tuning thresholds used to dichotomize quantitative measures, is explored.DesignThe Consortium for the Evaluation and Performance of HIV Incidence Assays characterized over 2000 possible RITAs constructed from seven assays (Limiting Antigen, BED, Less-sensitive Vitros, Vitros Avidity, BioRad Avidity, Architect Avidity, and Geenius) applied to 2500 diverse specimens.MethodsMDRIs were estimated using regression, and FRRs as observed 'recent' proportions, in various specimen sets. Context-specific FRRs were estimated for hypothetical scenarios. FRRs were made directly comparable by constructing RITAs with the same MDRI through the tuning of thresholds. RITA utility was summarized by the precision of incidence estimation.ResultsAll assays produce high FRRs among treated patients and elite controllers (10-80%). Viral load testing reduces FRRs, but diminishes MDRIs. Context-specific FRRs vary substantially by scenario - BioRad Avidity and Limiting Antigen provided the lowest FRRs and highest incidence precision in scenarios considered.ConclusionThe introduction of a low viral load threshold provides crucial improvements in RITAs. However, it does not eliminate nonzero FRRs, and MDRIs must be consistently estimated. The tuning of thresholds is essential for comparing and optimizing the use of assays. The translation of directly measured FRRs into context-specific FRRs critically affects their magnitudes and our understanding of the utility of assays.

BackgroundHIV latent infection can be established in vitro by treating resting CD4 T cells with chemokines that bind to chemokine receptors (CKR), CCR7, CXCR3, and CCR6, highly expressed on T cells.ObjectiveTo determine if CKR identify CD4 T cells enriched for HIV in HIV-infected individuals receiving suppressive antiretroviral therapy (ART).DesignA cross-sectional study of CKR expression and HIV persistence in blood from HIV-infected individuals on suppressive ART for more than 3 years (n = 48). A subset of 20 individuals underwent leukapheresis and sorting of specific CD4 T-cell subsets.MethodsWe used flow cytometry to quantify CCR5, CCR6, CXCR3, and CXCR5 expression on CD4 T cells. HIV persistence was quantified using real-time Polymerase Chain Reaction to detect total, integrated HIV DNA, 2-long terminal repeat circles and cell-associated unspliced (CA-US) HIV RNA in total CD4 T cells from blood or sorted T-cell subsets. Associations between CKR and HIV persistence in CD4 T cells in blood were determined using regression models and adjusted for current and nadir CD4 T-cell counts.ResultsThe frequency of cells harbouring integrated HIV DNA was inversely associated with current CD4 T-cell count and positively associated with CCR5+ CD4 T cells, CXCR3+CCR6+ and CXCR3+CCR6- expression on total memory CD4 T cells (P

ObjectivePrior hypothesis-driven studies identified immunophenotypic characteristics associated with the control of HIV replication without antiretroviral therapy (HIV controllers) as well as with the degree of CD4 T-cell recovery during ART. We hypothesized that an unbiased 'discovery-based' approach might identify novel immunologic characteristics of these phenotypes.DesignWe performed immunophenotyping on four 'aviremic' patient groups: HIV controllers (n = 98), antiretroviral-treated immunologic nonresponders (CD4  350, n = 142), and as a control group HIV-negative adults (n = 43). We measured levels of T-cell maturation, activation, dysfunction, senescence, functionality, and proliferation.MethodsSupervised learning assessed the relative importance of immune parameters in predicting clinical phenotypes (controller, immunologic responder, or immunologic nonresponder). Unsupervised learning clustered immune parameters and examined if these clusters corresponded to clinical phenotypes.ResultsHIV controllers were characterized by high percentages of HIV-specific T-cell responses and decreased percentages of cells expressing human leukocytic antigen-antigen D related in naive, central memory, and effector T-cell subsets. Immunologic nonresponders were characterized by higher percentages of CD4 T cells that were TNFα+ or INFγ+, higher percentages of activated naive and central memory T cells, and higher percentages of cells expressing programmed cell death protein 1. Unsupervised learning found two distinct clusters of controllers and two distinct clusters of immunologic nonresponders, perhaps suggesting different mechanisms for the clinical outcomes.ConclusionOur discovery-based approach confirmed previously reported characteristics that distinguish aviremic individuals, but also identified novel immunologic phenotypes and distinct clinical subpopulations that should lead to more focused pathogenesis studies that might identify targets for novel therapeutic interventions.

ObjectiveThe eradication of HIV necessitates elimination of the HIV latent reservoir. Identifying host determinants governing latency and reservoir size in the setting of antiretroviral therapy (ART) is an important step in developing strategies to cure HIV infection. We sought to determine the impact of cell-intrinsic immunity on the HIV latent reservoir.DesignWe investigated the relevance of a comprehensive panel of established anti-HIV-1 host restriction factors to multiple established virologic and immunologic measures of viral persistence in HIV-1-infected, ART-suppressed individuals.MethodsWe measured the mRNA expression of 42 anti-HIV-1 host restriction factors, levels of cell-associated HIV-1 RNA, levels of total pol and 2-long terminal repeat (2-LTR) circle HIV-1 DNA and immunophenotypes of CD4 T cells in 72 HIV-1-infected individuals on suppressive ART (23 individuals initiated ART less than 1 year post-infection, and 49 individuals initiated ART greater than 1 year post-infection). Correlations were analysed using nonparametric tests.ResultsThe enhanced expression of a few select host restriction factors, p21, schlafen 11 and PAF1, was strongly associated with reduced CD4 T-cell associated HIV RNA during ART (P

ObjectiveCross-sectional HIV incidence surveillance, using assays that distinguish 'recent' from 'nonrecent' infections, has been hampered by inadequate performance and characterization of incidence assays. In this study, the Consortium for the Evaluation and Performance of HIV Incidence Assays presents results of the first independent evaluation of five incidence assays (BED, Limiting Antigen Avidity, Less-sensitive Vitros, Vitros Avidity and BioRad Avidity).DesignA large repository of diverse specimens from HIV-positive patients was established, multiple assays were run on 2500 selected specimens, and data were analyzed to estimate assay characteristics relevant for incidence surveillance.MethodsThe mean duration of recent infection (MDRI, average time 'recent' while infected for less than some time cut-off T) was estimated from longitudinal data on seroconverters by regression. The false-recent rate (FRR, probability of testing 'recent' when infected for longer than T) was explored by measuring the proportions of 'recent' results in various subsets of patients.ResultsAssays continue to fail to attain the simultaneously large MDRI and small FRR demanded by existing performance guidelines. All assays produce high FRRs amongst virally suppressed patients (>40%), including elite controllers and treated patients.ConclusionsResults from this first independent evaluation provide valuable information about the current performance of assays, and suggest the need for further optimization. Variation of 'recent'/'nonrecent' thresholds and the use of multiple antibody-maturation assays, as well as other biomarkers, can now be explored, using the rich data generated by the Consortium for the Evaluation and Performance of HIV Incidence Assays. Consistently high FRRs amongst those virally suppressed suggest that viral load will be a particularly valuable supplementary marker.

BackgroundThere is intense interest in the role of programmed death 1 (PD-1) in causing persistent T-cell dysfunction in HIV infection. However, the impact of HIV infection and antiretroviral treatment (ART) on the expression of PD-1 on T cells is still poorly defined.MethodsPD-1 was measured longitudinally in a cohort of recently HIV-infected individuals (n = 121) who started ART early (

ObjectiveHIV-infected individuals are at high risk of developing cardiovascular disease. Whether earlier initiation of HIV therapy at higher CD4 cell counts has any effect on cardiovascular risk as assessed by endothelial function is unknown.DesignCross-sectional study of 74 antiretroviral-treated men with undetectable plasma HIV RNA levels.MethodsParticipants underwent noninvasive assessment of endothelial function using brachial artery flow-mediated dilation (FMD). The association of nadir and current CD4 T-cell count with FMD was assessed using multivariable linear regression.ResultsThe median age was 47 years [interquartile range (IQR) 42-55], median current CD4 T-cell count was 659 cells/μl (IQR 542-845), and nadir CD4 cell count was 314 cells/μl (IQR 150-490). Twenty-eight percent had hypertension, and 32% hyperlipidemia. Nadir CD4 T-cell count less than 350 cells/μl was associated with lower FMD in age-adjusted and race-adjusted analyses and remained an independent predictor of FMD after adjustment for cardiovascular risk factors (hypertension, diabetes, smoking, hyperlipidemia) and HIV-related characteristics (HIV duration, HAART duration). After multivariable adjustment, individuals with nadir CD4 T-cell count less than 350 cells/μl had a 1.22% lower FMD compared with those with higher T-cell counts [95% confidence interval (CI) -2.20 to -0.19, P=0.02]. Proximal CD4 T-cell count showed little association with FMD.ConclusionAmong treated HIV-infected individuals, nadir CD4 T-cell count less than 350 cells/μl is independently associated with lower FMD, suggesting that delayed therapy results in sustained harm to endothelial function. Our data support future prospective studies evaluating cardiovascular effects of HAART initiation at higher CD4 cell counts.