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With advances in HIV treatment, people with HIV (PWH) are living longer but experience aging-related comorbidities, including cognitive deficits, at higher rates than the general population. Previous studies have shown alterations in lysosomal proteins in blood from PWH with severe dementia. However, these markers have not been evaluated in PWH with milder neurocognitive impairment. We sought to determine whether levels of the lysosomal cysteine protease cathepsin B (CatB) and its endogenous inhibitor cystatin B (CysB) were altered in PWH with neurocognitive impairment and whether antiretroviral therapy (ART) further influenced these levels. Peripheral blood mononuclear cells were obtained from the tenofovir arm of a multicenter clinical trial in which ART-naive, HIV+ participants received treatment for 48 weeks (ACTG A5303, NCT01400412). PWH were divided by neurocognitive status (eg, with or without neurocognitive impairment) before ART initiation. Intracellular levels of CatB and CysB were measured in T cells and monocytes by means of flow cytometry. Levels of CysB were significantly decreased in both CD4 + T cells and CD8 + T cells after 48 weeks of ART in HIV+ participants without neurocognitive impairment but not in participants with neurocognitive impairment. Levels of CysB were increased in CD14 + monocytes from the participants with neurocognitive impairment after ART. Levels of CysB and CatB positively correlated regardless of HIV, neurocognitive status, or exposure to ART. These findings suggest that CysB has the potential to provide mechanistic insight into HIV-associated neurocognitive disorders or provide a molecular target for systemic monitoring or treatment of neurocognitive impairment in the context of ART and should be investigated further.

Background Cryopreserved peripheral blood mononuclear cells (PBMCs) are frequently collected and provide disease- and treatment-relevant data in clinical studies. Here, we developed combined protein (40 antibodies) and transcript single-cell (sc)RNA sequencing (scRNA-seq) in PBMCs. Results Among 31 participants in the Women’s Interagency HIV Study (WIHS), we sequenced 41,611 cells. Using Boolean gating followed by Seurat UMAPs (tool for visualizing high-dimensional data) and Louvain clustering, we identified 50 subsets among CD4+ T, CD8+ T, B, NK cells, and monocytes. This resolution was superior to flow cytometry, mass cytometry, or scRNA-seq without antibodies. Combined protein and transcript scRNA-seq allowed for the assessment of disease-related changes in transcriptomes and cell type proportions. As a proof-of-concept, we showed such differences between healthy and matched individuals living with HIV with and without cardiovascular disease. Conclusions In conclusion, combined protein and transcript scRNA sequencing is a suitable and powerful method for clinical investigations using PBMCs.

People newly diagnosed with HIV often have previous contact with health care professionals, often on multiple occasions, including within emergency departments (EDs). Although EDs have become vital partners in routine screening and linkage to care for persons with HIV, ED engagement in HIV prevention efforts, to include HIV risk assessment and pre-exposure prophylaxis (PrEP) referral, are rare. In this study, we electronically queried the hospital electronic health record (EHR) for ED encounters in 2019 and 2020 for patients who screened negative for HIV (

Background The CD4/CD8 ratio is an indicator of immunosenescence and a predictor of all-cause mortality in HIV-infected patients. The effects of different ART regimens on CD4/CD8 ratio recovery remain unclear. Methods Clinical cohort study of ART-treated patients from the CFAR Network of Integrated Clinical Systems (CNICS). We included ART-naive adults with HIV infection who achieved undetectable HIV RNA during the first 48 weeks of treatment and had additional follow-up 48 weeks after virological suppression (VS). Primary endpoints included increase in CD4/CD8 ratio at both timepoints and secondary endpoints were CD4/CD8 ratio recovery at cut-offs of ≥0.5 or ≥1.0. Results Of 3971 subjects who met the study criteria, 1876 started ART with an NNRTI, 1804 with a PI and 291 with an integrase strand transfer inhibitor (INSTI). After adjusting for age, sex, race, year of entry, risk group, HCV serostatus, baseline viral load and baseline CD4/CD8 ratio, subjects on an NNRTI showed a significantly greater CD4/CD8 ratio gain compared with those on a PI, either 48 weeks after ART initiation or after 48 weeks of HIV RNA VS. The greater CD4/CD8 ratio improvement in the NNRTI arm was driven by a higher decline in CD8 counts. The INSTI group showed increased rates of CD4/CD8 ratio normalization at the ≥1.0 cut-off compared with the PI group. Conclusions NNRTI therapy was associated with a greater increase in the CD4/CD8 ratio compared with PIs. NNRTI- and INSTI-based first-line ART were associated with higher rates of CD4/CD8 ratio normalization at a cut-off of 1.0 than a PI-based regimen, which might have clinical implications.

People living with HIV infection (PLWH) in the United States continue to experience a high symptom burden despite improvements in antiretroviral therapy.The purpose of this study was to determine if the number and types of symptom clusters differed based on whether symptom occurrence rates or distress ratings were used to create the clusters.Data from 2,000 patients with complete symptom occurrence rates and distress scores on the 20-item HIV Symptom Index from their first ambulatory clinic visit at one of six national HIV centers of excellence in the Center for AIDS Research Network of Integrated Clinical Systems were used in these analyses. Exploratory factor analysis was used to create the symptom clusters.The same four symptom clusters (i.e., gastrointestinal, psychological, pain, body image) were identified using occurrence rates and distress ratings. For both dimensions of the symptom experience, the psychological, pain, and body image clusters each had the same symptoms. For the gastrointestinal cluster, four symptoms loaded on the occurrence dimension and six symptoms loaded on the distress dimension.The number and types of symptom clusters were relatively similar across the occurrence and distress dimensions of the symptom experience. Symptom clusters in PLWH may provide insights into the development of targeted interventions for multiple co-occurring symptoms.

Loss of T cell immunogenicity due to mutations in virally encoded epitopes is a well-described adaptation strategy to limit host anti-viral immunity. Another described, but less understood, adaptation strategy involves the selection of mutations within epitopes that retain immune recognition, suggesting a benefit for the virus despite continued immune pressure (termed non-classical adaptation). To understand this adaptation strategy, we utilized a single cell transcriptomic approach to identify features of the HIV-specific CD8+ T cell responses targeting non-adapted (NAE) and adapted (AE) forms of epitopes containing a non-classical adaptation. T cell receptor (TCR) repertoire and transcriptome were obtained from antigen-specific CD8+ T cells of chronic (n=7) and acute (n=4) HIV-infected subjects identified by either HLA class I tetramers or upregulation of activation markers following peptide stimulation. CD8+ T cells were predominantly dual tetramer+, confirming a large proportion of cross-reactive TCR clonotypes capable of recognizing the NAE and AE form. However, single-reactive CD8+ T cells were identified in acute HIV-infected subjects only, providing the potential for the selection of T cell clones over time. The transcriptomic profile of CD8+ T cells was dependent on the autologous virus: subjects whose virus encoded the NAE form of the epitope (and who transitioned to the AE form at a later timepoint) exhibited an ‘effective’ immune response, as indicated by expression of transcripts associated with polyfunctionality, cytotoxicity and apoptosis (largely driven by the genes GZMB, IFNɣ, CCL3, CCL4 and CCL5). These data suggest that viral adaptation at a single amino acid residue can provide an alternative strategy for viral survival by modulating the transcriptome of CD8+ T cells and potentially selecting for less effective T cell clones from the acute to chronic phase.

The emergency department (ED) may represent a missed opportunity to proactively intervene upon patients at "high risk" for HIV. We sought to describe characteristics of ED HIV seroconverters (individuals who screened positive in the ED for HIV who had either (1) a previous prior negative HIV test in the electronic health record (EHR) or who (2) self-reported a prior negative HIV test) to identify a "high-risk" phenotype for pre-infection engagement. A retrospective chart-review was performed of HIV seroconverters at an academic, urban ED. General demographics, mental health illness comorbidities, and Centers for Disease Control and Prevention (CDC)-identified "high risk" factors, including intravenous drug use (IVDU) and history of sexually transmitted infection (STI) were noted. One hundred thirty total patients were identified, 48 (36.9%) with prior HER-negative test and 82 (63.1%) with self-reported previous negative test. Of total seroconverters: 100 (76.9%) were male and 77 (59.2%) were between the ages of 13-34, comparable to national rates of new HIV diagnoses. Ninety-two patients (70.8%) were Black and 16 (12.3%) had a history of IVDU, significantly increased compared with regional and national new HIV rates (

Type 1 interferons (IFN-I) are potent innate antiviral effectors that constrain HIV-1 transmission. However, harnessing these cytokines for HIV-1 cure strategies has been hampered by an incomplete understanding of their antiviral activities at later stages of infection. Here, we characterized the IFN-I sensitivity of 500 clonally derived HIV-1 isolates from the plasma and CD4+ T cells of 26 individuals sampled longitudinally after transmission or after antiretroviral therapy (ART) and analytical treatment interruption. We determined the concentration of IFNα2 and IFNβ that reduced viral replication in vitro by 50% (IC50) and found consistent changes in the sensitivity of HIV-1 to IFN-I inhibition both across individuals and over time. Resistance of HIV-1 isolates to IFN-I was uniformly high during acute infection, decreased in all individuals in the first year after infection, was reacquired concomitant with CD4+ T cell loss, and remained elevated in individuals with accelerated disease. HIV-1 isolates obtained by viral outgrowth during suppressive ART were relatively IFN-I sensitive, resembling viruses circulating just before ART initiation. However, viruses that rebounded after treatment interruption displayed the highest degree of IFNα2 and IFNβ resistance observed at any time during the infection course. These findings indicate a dynamic interplay between host innate responses and the evolving HIV-1 quasispecies, with the relative contribution of IFN-I to HIV-1 control affected by both ART and analytical treatment interruption. Although elevated at transmission, host innate pressures are the highest during viral rebound, limiting the viruses that successfully become reactivated from latency to those that are IFN-I resistant.

The prevalence of chronic widespread pain (CWP) in people with HIV is high, yet the underlying mechanisms are elusive. Leukocytes synthesize the endogenous opioid, β-endorphin, within their endoplasmic reticulum (ER). When released into plasma, β-endorphin dampens nociception by binding to opioid receptors on sensory neurons. We hypothesized that the heme-dependent redox signaling induces ER stress, which attenuates leukocyte β-endorphins levels/release, thereby increasing pain sensitivity in people with HIV. Results demonstrated that HIV positive individuals with CWP had increased plasma methemoglobin, erythrocytes membrane oxidation, hemolysis, and low plasma heme scavenging enzyme, hemopexin, compared to people with HIV without CWP and HIV-negative individuals with or without pain. In addition, the leukocytes from people with HIV with CWP had attenuated levels of the heme metabolizing enzyme, heme oxygenase-1, which metabolizes free heme to carbon-monoxide and biliverdin. These individuals also had elevated ER stress, and low β-endorphin in leukocytes. In vitro, heme exposure or heme oxygenase-1 deletion, decreased β-endorphins in murine monocytes/macrophages. Treating cells with a carbon-monoxide donor or an ER stress inhibitor, increased β-endorphins. To mimic hemolytic effects in a preclinical model, C57BL/6 mice were injected with phenylhydrazine hydrochloride (PHZ). PHZ increased cell-free heme and ER stress, decreased leukocyte β-endorphin levels and hindpaw mechanical sensitivity thresholds. Treatment of PHZ-injected mice with hemopexin blocked these effects, suggesting that heme-induced ER stress and a subsequent decrease in leukocyte β-endorphin is responsible for hypersensitivity in people with HIV.

Aims During virally suppressed chronic HIV infection, persistent inflammation contributes to the development of cardiovascular disease (CVD), a major comorbidity in people living with HIV (LWH). Classical blood monocytes (CMs) remain activated during antiretroviral therapy and are a major source of pro-inflammatory and pro-thrombotic factors that contribute to atherosclerotic plaque development and instability. Methods and results Here, we identify transcriptomic changes in circulating CMs in peripheral blood mononuclear cell samples from participants of the Women’s Interagency HIV Study, selected by HIV and subclinical CVD (sCVD) status. We flow-sorted CM from participants of the Women’s Interagency HIV Study and deep-sequenced their mRNA (n = 92). CMs of HIV+ participants showed elevated interleukin (IL)-6, IL-1β, and IL-12β, overlapping with many transcripts identified in sCVD+ participants. In sCVD+ participants LWH, those reporting statin use showed reduced pro-inflammatory gene expression to a level comparable with healthy (HIV−sCVD−) participants. Statin non-users maintained an elevated inflammatory profile and increased cytokine production. Conclusion Statin therapy has been associated with a lower risk of cardiac events, such as myocardial infarction in the general population, but not in those LWH. Our data suggest that women LWH may benefit from statin therapy even in the absence of overt CVD.

AimsTo test whether human immunodeficiency virus (HIV) infection and subclinical cardiovascular disease (sCVD) are associated with expression of CXCR4 and other surface markers on classical, intermediate, and non-classical monocytes in women.Methods and resultssCVD was defined as presence of atherosclerotic lesions in the carotid artery in 92 participants of the Women’s Interagency HIV Study (WIHS). Participants were stratified into four sets (n = 23 each) by HIV and sCVD status (HIV−/sCVD−, HIV−/sCVD+, HIV+/sCVD−, and HIV+/sCVD+) matched by age, race/ethnicity, and smoking status. Three subsets of monocytes were determined from archived peripheral blood mononuclear cells. Flow cytometry was used to count and phenotype surface markers. We tested for differences by HIV and sCVD status accounting for multiple comparisons. We found no differences in monocyte subset size among the four groups. Expression of seven surface markers differed significantly across the three monocyte subsets. CXCR4 expression [median fluorescence intensity (MFI)] in non-classical monocytes was highest among HIV−/CVD− [628, interquartile range (IQR) (295–1389)], followed by HIV+/CVD− [486, IQR (248–699)], HIV−/CVD+ (398, IQR (89–901)), and lowest in HIV+/CVD+ women [226, IQR (73–519)), P = 0.006 in ANOVA. After accounting for multiple comparison (Tukey) the difference between HIV−/CVD− vs. HIV+/CVD+ remained significant with P = 0.005 (HIV−/CVD− vs. HIV+/CVD− P = 0.04, HIV−/CVD− vs. HIV−/CVD+ P = 0.06, HIV+/CVD+ vs. HIV+/CVD− P = 0.88, HIV+/CVD+ vs. HIV−/CVD+ P = 0.81, HIV+/CVD− vs. HIV−/CVD+, P = 0.99). All pairwise comparisons with HIV−/CVD− were individually significant (P = 0.050 vs. HIV−/CVD+, P = 0.028 vs. HIV+/CVD−, P = 0.009 vs. HIV+/CVD+). CXCR4 expression on non-classical monocytes was significantly higher in CVD− (501.5, IQR (249.5–887.3)) vs. CVD+ (297, IQR (81.75–626.8) individuals (P = 0.028, n = 46 per group). CXCR4 expression on non-classical monocytes significantly correlated with cardiovascular and HIV−related risk factors including systolic blood pressure, platelet and T cell counts along with duration of antiretroviral therapy (P ConclusionCXCR4 expression in non-classical monocytes was significantly lower among women with both HIV infection and sCVD, suggesting a potential atheroprotective role of CXCR4 in non-classical monocytes.

Background: The role and mechanism of drug use or abuse in Antiretroviral Therapy (ART)-treated HIV disease are not completely known. Methods: To investigate the impact of drug use on HIV pathogenesis without confounding by HIV replication and ART adherence, we first analyzed the data from our clinical database in 103 HIV+ subjects with viral-suppressed ART treatment by a multiple regression test. Results: We found that HIV+ drug users had lower CD4+ T cell counts but higher CD8+ T cell counts compared to HIV+ non-drug users, and both drug use and nadir CD4+ T cell counts was independently associated with CD4+ T cell recovery after controlling for sex and age. Next, we enrolled individuals from four study groups, HIV-negative and HIV+ subjects without any substance use, HIV-negative and HIV+ subjects with current illicit drug use (either non-injection cocaine or cannabis). All HIV+ subjects were viral-suppressed with ART treatment (≥ 2 years). Notably, HIV+ drug users had increased plasma anti-CD4 IgG levels compared to the other three study groups which were inversely correlated with decreased CD4+ T cell counts only in HIV+ drug users. There was a significant increase in CD4+ T cell recovery following ART in HIV+ non-drug users but not in HIV+ drug users. Anti-CD4 IgGs purified from plasma of HIV+ drug users induced CD4+ T cell death in vitro through Antibody-Dependent Cytotoxicity (ADCC). Conclusion: These results suggest that drug use prevents immune reconstitution in HIV-infected individuals despite long-term ART treatment and viral suppression.

During chronic HIV-1 infection, regulatory CD4 T cells (Tregs) frequently represent the largest subpopulation of CD4 T cell subsets, implying relative resistant to HIV-1. When HIV-1 infection of CD4 T cells was explored in vitro and ex vivo from patient samples, Tregs possessed lower levels of HIV-1 DNA and RNA in comparison with conventional effector and memory CD4 T cells. Moreover, Tregs suppressed HIV-1 expression in other CD4 T cells in an in vitro co-culture system. This suppression was mediated in part via multiple inhibitory surface proteins expressed on Tregs. Antibody blockade of CTLA-4, PD-1, and GARP on Tregs resulted in increased HIV-1 DNA integration and mRNA expression in neighboring CD4 T cells. Moreover, antibody blockade of Tregs inhibitory proteins resulted in increased HIV-1 LTR transcription in co-cultured CD4 T cells. Thus, Tregs inhibit HIV-1 infection of other CD4 T cell subsets via interactions with inhibitory cell surface proteins.

Although effective antiretroviral therapy (ART) suppresses HIV viral replication, prevents AIDS-related complications, and prolongs life, a proportion of patients fails to restore the patients’ CD4+ T cell number to the level of healthy individuals. Increased mortality and morbidity have been observed in these patients. In the current study, we have investigated the role of auto-IgGs in CD4+ T cell apoptosis and recovery in a cross-sectional study. All HIV+ subjects were on viral-suppressive ART treatment with a different degree of CD4+ T cell reconstitution. Total auto-IgG binding on CD4+ T cell surfaces and its associated apoptosis and CD4+ T cell recovery were analyzed by flow cytometry ex vivo. Total IgGs from plasma were tested for their binding capacities to CD4+ T cell surfaces and their mediation to CD4+ T cell death through NK cell cytotoxicity in vitro. HIV+ subjects had increased surface binding of auto-IgGs on CD4+ T cells compared with healthy controls, and IgG binding was associated with elevated CD4+ T cell apoptosis in HIV+ subjects but not in healthy controls. Plasma IgGs from HIV+ subjects bound to CD4+ T cells and induced cell apoptosis through NK cytotoxicity in vitro. Soluble CD4 (sCD4) preincubation prevented NK cell-mediated CD4+ T cell death. Our results suggest that plasma autoantibodies may play a role in some HIV+ patients with poor CD4+ T cell recovery under viral-suppressive ART.

Women living with HIV may present with high levels of body fat that are associated with altered bioenergetic function. Excess body fat may therefore exacerbate the bioenergetic dysfunction observed with HIV infection. To determine if body fat is associated with bioenergetic function in HIV, we conducted a cross-sectional study of 42 women with HIV who were virologically suppressed on antiretroviral therapy. Body composition was determined via dual-energy x-ray absorptiometry. Oxygen consumption rate (OCR) of monocytes was sorted from peripheral blood mononuclear cells obtained from participants in the fasting state. Differences in bioenergetic function, as measured by OCR, was assessed using Kruskal-Wallis tests and Spearman correlations adjusted for age, race, and smoking status. Participants were 86% Black, 45.5 years old, 48% current smokers, and 57% were obese (body mass index ≥30). Nearly all women (93%) had >30% total fat mass, while 12% had >50% total fat mass. Elevated levels of total fat mass, trunk fat, and leg fat were inversely correlated with measures of bioenergetic health as evidenced by lower maximal and reserve capacity OCR, and Bioenergetic Health Index. Measures of extracellular acidification (ECAR) in the absence (basal) or maximal (with oligomycin) were positively correlated with measures of bioenergetics, except proton leak, and were negatively correlated with fat mass. Despite virological suppression, women with HIV present with extremely high levels of adiposity that correlate with impaired bioenergetic health. Without effective interventions, this syndemic of HIV infection and obesity will likely have devastating consequences for our patients, potentially mediated through altered mitochondrial and glycolytic function., Graphical abstract fx1, Highlights • Women with HIV have high levels of total, central, and leg body fat. • High body fat levels are inversely correlated to bioenergetic function in monocytes. • Excess body fat may exacerbate bioenergetics dysfunction observed in people living with HIV.

Increased mortality and morbidity occur among human immunodeficiency virus (HIV)-infected patients in whom CD4+ T-cell counts do not increase despite viral suppression with antiretroviral therapy (ART). Here we identified an underlying mechanism. Significantly elevated plasma levels of anti-CD4 immunoglobulin G (IgG) were found in HIV-positive immunologic nonresponders (ie, HIV-positive individuals with CD4+ T-cell counts of ≤350 cells/μL), compared with levels in HIV-positive immunologic responders (ie, HIV-positive individuals with CD4+ T-cell counts of ≥500 cells/μL) and healthy controls. Higher plasma level of anti-CD4 IgG correlated with blunted CD4+ T-cell recovery. Furthermore, purified anti-CD4 IgG from HIV-positive immunologic nonresponders induced natural killer (NK) cell-dependent CD4+ T-cell cytolysis and apoptosis through antibody-dependent cell-mediated cytotoxicity (ADCC) in vitro. We also found that anti-CD4 IgG-mediated ADCC exerts greater apoptosis of naive CD4+ T cells relative to memory CD4+ T cells. Consistently, increased frequencies of CD107a+ NK cells and profound decreases of naive CD4+ T cells were observed in immunologic nonresponders as compared to responders and healthy controls ex vivo. These data indicate that autoreactive anti-CD4 IgG may play an important role in blunted CD4+ T-cell reconstitution despite effective ART.

Summary The complement system is now a therapeutic target for the management of serious and life-threatening conditions such as paroxysmal nocturnal hemoglobinuria, atypical hemolytic uremic syndrome, glomerulonephritis and other diseases caused by complement deficiencies or genetic variants. As complement therapeutics expand into more clinical conditions, monitoring complement activation is increasingly important, as is the baseline levels of complement activation fragments in blood or other body fluid levels. Although baseline complement levels have been reported in the literature, the majority of these data were generated using non-standard assays and with variable sample handling, potentially skewing results. In this study, we examined the plasma and serum levels of the soluble membrane attack complex of complement (sMAC). sMAC is formed in the fluid phase when complement is activated through the terminal pathway. It binds the regulatory proteins vitronectin and/or clusterin and cannot insert into cell membranes, and can serve as a soluble diagnostic marker in infectious disease settings, as previously shown for intraventricular shunt infections. Here we show that in healthy adults, serum sMAC levels were significantly higher than those in plasma, that plasma sMAC levels were similar between in African Americans and Caucasians and that plasma sMAC levels increase with age. Plasma sMAC levels were significantly higher in virally suppressed people living with HIV (PLWH) compared to non-HIV infected healthy donors. More specifically, PLWH with CD4+ T cell counts below 200 had even greater sMAC levels, suggesting diagnostic value in monitoring sMAC levels in this group.

Background Increased autoreactive antibodies have been reported in HIV disease; however, the mechanism accounting for autoantibody induction in HIV remains unknown. Results Herein, we show that seasonal influenza vaccination induces autoantibody production (e.g., IgG anti-nuclear antibody (ANA) and anti-double-stranded DNA antibody (anti-dsDNA)) in some viral-suppressed antiretroviral therapy (ART)-treated HIV+ subjects, but not in healthy controls. These autoantibodies were not derived from antigen-specific B cells but from activated “bystander” B cells analyzed by single-cell assay and by study of purified polyclonal ANAs from plasma. To explore the mechanism of autoantibody generation in HIV+ subjects, plasma level of microbial products, gene expression profile of B cells, and B cell receptor (BCR) repertoires were analyzed. We found that autoantibody production was associated with increased plasma level of microbial translocation; the patients with high autoantibodies had skewed B cell repertoires and upregulation of genes related to innate immune activation in response to microbial translocation. By analyzing circulating microbial 16S rDNA in plasma, the relative abundance of Staphylococcus was found to be associated with autoantibody production in HIV+ subjects. Finally, we found that injection of heat-killed Staphylococcus aureus promoted germinal center B cell responses and autoantibody production in mice, consistent with the notion that autoantibody production in HIV+ patients is triggered by microbial products. Conclusions Our results showed that translocation of Staphylococcus can promote B cell activation through enhancing germinal center response and induces autoantibody production. It uncovers a potential mechanism linking microbial translocation and autoimmunity in HIV+ disease and provides a strong rationale for targeting Staphylococcus to prevent autoantibody production. Electronic supplementary material The online version of this article (10.1186/s40168-019-0646-1) contains supplementary material, which is available to authorized users.

Chronic pain in persons living with HIV (PLWH) may be related to alterations in endogenous pain modulatory processes (e.g., high facilitation and low inhibition of nociception) that promote exaggerated pain responses, known as hyperalgesia, and central nervous system (CNS) sensitization. This observational study examined differences in endogenous pain modulatory processes between 59 PLWH with chronic pain, 51 PLWH without chronic pain, and 50 controls without HIV or chronic pain. Quantitative sensory testing for temporal summation (TS) of mechanical and heat pain as well as conditioned pain modulation (CPM) were used to assess endogenous pain facilitatory and inhibitory processes, respectively. Associations among TS, CPM, and self-reported clinical pain severity were also examined in PLWH with chronic pain. Findings demonstrated significantly greater TS of mechanical and heat pain for PLWH with chronic pain compared to PLWH without chronic pain and controls. CPM effects were present in controls, but not in either PLWH with or without chronic pain. Among PLWH with chronic pain, greater TS of mechanical pain was significantly associated with greater average clinical pain severity. Results of this study suggest that enhanced facilitation and diminished inhibition characterizes the pronociceptive endogenous pain modulatory balance of persons living with HIV and chronic pain.

It is recommended that HIV-infected individuals receive annual influenza vaccination due to their high susceptibility to influenza infection, especially among women. However, there have been few studies investigating sex-related responses to influenza vaccine in antiretroviral therapy (ART)-treated HIV-infected individuals.In this study, 26 aviremic ART-treated HIV-infected individuals and 16 healthy controls were enrolled in the current study. Blood was collected prior to vaccination (D0), on days 7-10 (D7) and on days 14-21 (D14) following administration of the 2013-2014 seasonal influenza vaccine. A series of analyses evaluated the serological and cellular responses following influenza vaccination.Female HIV-infected individuals had increased influenza-specific antibody avidity relative to male HIV-infected individuals, but similar plasma levels of influenza-specific binding antibodies and neutralizing antibodies. Increased cycling B cells and follicular helper CD4 T (Tfh) cells were observed in female HIV-infected individuals pre and postvaccination compared with male HIV-infected individuals, and cycling Tfh cells were directly correlated with influenza-specific antibody avidity. Moreover, plasma testosterone levels were inversely correlated with antibody avidity index. The magnitude of microbial translocation [plasma lipopolysaccharide (LPS)] level was directly correlated with influenza-specific antibody avidity. Circulating 16S rDNA microbiome showed that enrichment of specific species within Proteobacteria was associated with influenza-specific antibody avidity. These results, including differences based on sex and correlations, were only observed in HIV-infected individuals but not in the healthy controls.This study demonstrated sex differences in influenza-specific antibody avidity in ART-treated HIV disease, and provides valuable information on vaccination strategy in the ART-treated HIV-infected population.

"Intersectional health-related stigma" (IHRS) refers to stigma that arises at the convergence of multiple health conditions. People living with HIV (PLWH) and chronic pain have two highly stigmatized health conditions, and thus may be at especially high risk for internalizing these stigmas and consequently experiencing depression. This study examined the intersectionality of internalized HIV and chronic pain stigma in relation to depressive symptoms in a sample of PLWH and chronic pain. Sixty participants were recruited from an HIV clinic in the Southeastern United States. Chronic pain was defined as pain that has been present for at least three consecutive months, and that has been an ongoing problem for at least half the days in the past six months. All participants completed the HIV Stigma Mechanisms Scale, Internalized Stigma in Chronic Pain Scale, the Short-Form Brief Pain Inventory, and the Center for Epidemiological Studies - Depression Scale. Clinical data was collected from medical records. An intersectional HIV and chronic pain composite variable was created and participants were categorized as either high (28%), moderate (32%), or low (40%). Results revealed that intersectional HIV and chronic pain stigma was significantly associated with severity of depressive symptoms (p = .023). Pairwise contrasts revealed that participants with high (p = .009) and moderate (p = .033) intersectional stigma reported significantly greater mean depressive symptom severity than those with low intersectional stigma. Participants who reported the highest levels of internalized HIV and chronic pain stigma also reported the greatest severity of depressive symptoms. This suggests that the experience of both HIV and chronic pain stigma (i.e., IHRS) among PLWH and chronic pain may synergistically perpetuate negative mood in a more profound manner than experiencing either one stigma alone.

Objective. The Centers for Disease Control and Prevention has recommended emergency department (ED) opt-out HIV screening since 2006. Routine screening can prove challenging due to the ED's complexity and competing priorities. This study examined the implementation and evolution of a routine, integrated, opt-out HIV screening program at an urban academic ED in Alabama since August 2011. Methods. ED routine, opt-out HIV screening was implemented as a standard of care in September 2011. To describe the outcomes and escalation of the screening program, data analyses were performed from three separate data queries: ( 1) encounter-level HIV screening questionnaire and test results from September 21, 2011, through December 31, 2013; ( 2) test-level, fourth-generation HIV results from July 9 through December 31, 2013; and ( 3) daily HIV testing rates and trends from September 9, 2011, through June 30, 2014. Results. Of the 46,385 HIV screening tests performed, 252 (0.5%) were confirmed to be positive. Acute HIV infection accounted for 11.8% of all HIV patients identified using the fourth-generation HIV screening assay. Seventy-six percent of confirmed HIV-positive patients had successful linkage to care. Implementation of fourth-generation HIV instrument-based testing resulted in a 15.0% decline in weekly HIV testing rates. Displacement of nursing provider HIV test offers from triage to the bedside resulted in a 31.6% decline in weekly HIV testing rates. Conclusion. This program demonstrated the capacity for high-volume, routine, opt-out HIV screening. Evolving ED challenges require program monitoring and adaptation to sustain scalable HIV screening in EDs.

Microbial signals have been linked to autoantibody induction. Recently, we found that purified anti-CD4 autoantibodies from the plasma of chronic HIV-1-infected patients under viral-suppressed antiretroviral therapy (ART) play a pathologic role in poor CD4+ T cell recovery. The purpose of the study was to investigate the association of systemic microbiome and anti-CD4 autoantibody production in HIV. Plasma microbiome from 12 healthy controls and 22 HIV-infected subjects under viral-suppressed ART were analyzed by MiSeq sequencing. Plasma level of autoantibodies and microbial translocation (LPS, total bacterial 16S rDNA, soluble CD14, and LPS binding protein) were analyzed by ELISA, limulus amebocyte assay, and qPCR. We found that plasma level of anti-CD4 IgGs but not anti-CD8 IgGs was increased in HIV+ subjects compared to healthy controls. HIV+ subjects with plasma anti-CD4 IgG > 50 ng/mL (high) had reduced microbial diversity compared to HIV+ subjects with anti-CD4 IgG ≤ 50 ng/mL (low). Moreover, plasma anti-CD4 IgG level was associated with elevated microbial translocation and reduced microbial diversity in HIV+ subjects. The Alphaproteobacteria class was significantly enriched in HIV+ subjects with low anti-CD4 IgG compared to patients with high anti-CD4 IgG even after controlling for false discovery rate (FDR). The microbial components were different from the phylum to genus level in HIV+ subjects with high anti-CD4 IgGs compared to the other two groups, but these differences were not significant after controlling for FDR. These results suggest that systemic microbial translocation and microbiome may associate with anti-CD4 autoantibody production in ART-treated HIV disease.

Objective Animal models have previously shown that HIV is associated with hyperalgesia, or heightened sensitivity to painful stimuli. Efforts to determine whether this finding translates to humans are presently lacking. Among persons living with HIV (PLWH), those with detectable viral loads may be at greatest risk for heightened pain sensitivity. It was hypothesized that PLWH with detectable viral loads would be more sensitive to painful stimuli compared with PLWH without detectable viral loads and healthy controls without HIV. Design A total of 47 PLWH and 50 community-dwelling, healthy adults without HIV (controls) were recruited. Participants completed a quantitative sensory testing protocol to assess threshold, tolerance, and temporal summation in response to painful mechanical and heat stimuli. Most recent viral load was collected from medical records, and viral load was considered detectable if the count was greater than 50 copies/mL of blood. Of the 47 PLWH, 11 (23.4%) had detectable viral loads, the median viral load count was 10,200 copies/mL. Results PLWH with detectable viral loads demonstrated significantly lower pain thresholds for mechanical stimuli (F2,89 = 3.15, P = 0.049), significantly lower heat pain tolerances (F2,89 = 3.38, P = 0.039), and significantly greater temporal summation of heat pain at 48 °C (F2,89 = 10.66, P

Estimating the population with undiagnosed HIV (PUHIV) is the most methodologically challenging aspect of evaluating 90-90-90 goals. The objective of this review is to discuss assumptions, strengths, and shortcomings of currently available methods of this estimation. Articles from 2000 to 2018 on methods to estimate PUHIV were reviewed. Back-calculation methods including CD4 depletion and test–retest use diagnosis CD4 count, or previous testing history to determine likely infection time thus, providing an estimate of PUHIV for previous years. Biomarker methods use immunoassays to differentiate recent from older infections. Statistical techniques treat HIV status as missing data and impute data for models of infection. Lastly, population surveys using HIV rapid testing most accurately calculates the current HIV prevalence. Although multiple methods exist to estimate the number of PUHIV, the appropriate method for future applications depends on multiple factors, namely data availability and population of interest.

Interleukin-21 (IL-21) can be produced by CD8 T cells from HIV-1-infected individuals and those with autoimmune disease, but the mechanism remains poorly understood. Here we demonstrate that IL-21-producing CD8 T cells are not associated with CD4 depletion and are absent in patients with idiopathic CD4 lymphocytopenia. Instead, IL-21 production by CD8 T cells was associated with high levels of activation, suggesting that these cells emerge as a consequence of excessive chronic immune activation rather than CD4 lymphopenia.

HIV-1 infection is associated with an early and profound depletion of mucosal memory CD4+ T cells, a population that plays an indispensable role in the regulation of isotype switching and transepithelial transport of antibodies. In this study, we addressed whether the depletion of CD4+ T cell in HIV-1-infected individuals results in altered humoral responses specific to antigens encountered at mucosal surfaces. Comprehensive protein microarray of systemic humoral responses to intestinal microbiota demonstrated reduced IgG responses to antigens derived from Proteobacteria and Firmicutes but not Bacteroidetes. Importantly, intestinal secretions of antiretroviral therapy-treated HIV-1-infected individuals exhibited a significant elevation of IgM levels and decreased IgA/IgM and IgG/IgM ratios of antibodies specific to a variety of microbial and food antigens. The presented findings indicate reduced competence of mucosal B cells for class switch recombination from IgM to other isotypes limiting their capacity to react to changing antigenic variety in the gut lumen. Decreased availability of microbiota-specific IgA and IgG may be an important factor contributing to the translocation of microbial antigens across the intestinal mucosal barrier and their systemic dissemination that drives chronic inflammation in HIV-1-infected individuals., Author Summary Despite significant effort, our understanding of how HIV-1 virus undermines the immune system is limited. HIV-1infection is characterized by extensive damage to intestinal mucosal barrier and translocation of bacteria and microbial products into the systemic circulation. Immune activation induced by microbial products results in chronic inflammation that drives HIV-1 pathogenesis and progression to AIDS despite successful control of HIV-1 replication by antiretroviral therapy. Here we provide evidence indicating that antibody-producing cells in the intestinal mucosa of HIV-1-infected individuals have decreased capacity to switch from the production of IgM to IgA and IgG, the types of antibodies that normally restrict the translocation of bacterial antigens across the mucosal barrier. This may facilitate systemic dissemination of microbial products and subsequent inflammation in HIV-1-infected individuals. Furthermore, the accumulation of IgM in gut mucosa may contribute to the exacerbation of inflammatory processes by the formation of inflammatory immune complexes. This newly identified dysregulation of immune system alters our understanding of HIV-1 pathogenesis and may facilitate the design of novel therapies targeting immune dysfunction in HIV-1/AIDS.

The role of natural killer (NK) cell function in HIV disease especially in the setting of long-term antiretroviral therapy (ART) and viral suppression is not fully understood. In the current study, we have investigated NK cell activation in healthy controls and aviremic ART-treated HIV+ subjects with different degrees of immune restoration. We performed a cross sectional study in 12 healthy controls and 24 aviremic ART-treated HIV-infected subjects including 13 HIV+ subjects with CD4+ T cells above 500 cells/μL defined as "immunologic responders" and 11 HIV+ subjects with CD4+ T cells below 350 cells/μL defined as "immunologic non-responders". We analyzed NK cell number, subset, and activation by expression of CD107a and NKG2D and co-expression of CD38 and HLA-DR. NK cell-mediated cytotoxicity against uninfected CD4+ T cells was tested in vitro. We found that NK cell absolute number, percentage of NK cells, and percentage of NK cell subsets were similar in the three study groups. The increased NK cell activation was found predominantly in CD56dimCD16+ subset of immunologic non-responders but not immunologic responders compared to healthy controls. The activation of NK cells was inversely correlated with the peripheral CD4+ T cell count in HIV+ subjects, even after controlling for chronic T cell activation, sex, and age, potential contributors for CD4+ T cell counts in HIV disease. Interestingly, NK cells from immunologic non-responders mediated cytotoxicity against uninfected CD4+ T cells ex vivo. NK cells may play a role in blunted CD4+ T cell recovery in ART-treated HIV disease.

GV-TH-01, a Phase 1 open-label trial of a DNA prime—Modified Vaccinia Ankara (MVA) boost vaccine (GOVX-B11), was undertaken in HIV infected participants on antiretroviral treatment (ART) to evaluate safety and vaccine-elicited T cell responses, and explore the ability of elicited CD8+ T cells to control viral rebound during analytical treatment interruption (TI). Nine men who began antiretroviral therapy (ART) within 18 months of seroconversion and had sustained plasma HIV-1 RNA

Background Monocytes and monocyte-derived macrophages promote atherosclerosis through increased inflammation and vascular remodeling. This may be especially true in chronic human immunodeficiency virus (HIV) infection. Methods We examined 778 women (74% HIV+) in the Women's Interagency HIV Study and 503 men (65% HIV+) in the Multicenter AIDS Cohort Study who underwent repeated B-mode carotid artery ultrasound imaging in 2004-2013. We assessed baseline associations of the serum macrophage inflammation markers soluble (s)CD163, sCD14, galectin-3 (Gal-3), and Gal-3 binding protein (Gal-3BP) with carotid plaque formation (focal intima-media thickness >1.5 mm) over 7 years. Results Marker levels were higher in HIV+ persons versus HIV- persons. Presence of focal plaque increased over time: from 8% to 15% in women, and 24% to 34% in men. After adjustment for demographic, behavioral, and cardiometabolic factors, and CRP and interleukin-6, each standard deviation increase in sCD14 was associated with increased plaque formation (risk ratio [RR] 1.24, 95% confidence interval [CI] 1.07-1.43). This pattern was consistentby sex. sCD163 was associated with plaque formation in virally suppressed HIV+ men (RR 1.52, 95% CI 1.04-2.22); Gal-3BP and Gal-3 were not associated with increased plaque. Conclusions sCD14 and sCD163 may play important roles in atherogenesis among HIV+ persons.

BACKGROUND Assays to measure the induction of HIV-1-specific CD8 T-cell responses often rely on measurements of indirect effector function such as chemokine and cytokine production, which may not reflect direct elimination of an invading pathogen. Assessment of the functional ability of CD8 T cells to suppress HIV-1 replication has been viewed as a surrogate marker of an effectual immune response. To further investigate this, we measured the capacity of virus-specific CD8 T cells to inhibit HIV-1 replication in an in vitro suppression assay. METHODS We expanded 15 epitope-specific CD8 T-cell lines from peripheral blood mononuclear cells of chronically HIV--infected progressors (n = 5) and controllers (n = 4) who were not on antiretroviral therapy. Cell lines were tested for their ability to produce effector molecules (CD107a, IL-2, IFN-γ, TNF-α, perforin) and suppress virus replication in autologous CD4 T cells. RESULTS CD8 T-cell lines from both progressors and controllers had largely similar effector function profiles as determined by intracellular cytokine staining. In contrast, we observed that CD8 T-cell lines derived from controllers show enhanced virus suppression when compared with progressors. Virus suppression was mediated in an major histocompatibility complex-dependent manner and found to correlate with a polyfunctional IL-2 CD8 T-cell response. CONCLUSIONS Using a sensitive in vitro suppression assay, we demonstrate that CD8 T-cell-mediated suppression of HIV-1 replication is a marker of HIV-1 control. Suppressive capacity was found to correlate with polyfunctional IL-2 production. Assessment of CD8 T-cell-mediated suppression may be an important tool to evaluate vaccine-induced responses.

Understanding the correlates of immunity that control HIV-1 infection is imperative to our understanding of HIV-1 disease and vaccine development. HIV-1-specific cytotoxic T lymphocytes are fundamental to the control of viremia; however, which T-cell repertoire components enact this control remains unclear. We hypothesize that polyfunctional HIV-1-specific CD8 T cells capable of viral control are present in most patients early in infection and these cells are distinguished by their ability to secrete interleukin (IL)-2 and proliferate. We examined HIV-1-specific CD8 T-cell proliferation and cytokine secretion in primary HIV-1 infection (PHI) using known HIV-1 cytotoxic T-cell epitopes to exclude CD4 bystander effect. We found that only a subset of patients with PHI demonstrated "CD4-independent" CD8 proliferation ex vivo. The remainder of the patients lacked HIV-1-specific CD8 T cells with proliferative capacity, even after the addition of exogenous IL-2. Among the proliferators, IL-2 production from the total HIV-specific CD8 T-cell population correlated with proliferation. Surprisingly, though, we did not routinely detect both IL-2 secretion and proliferative capacity from the same antigen-specific CD8 T cells. Thus, there are distinct and heterogeneous populations of CD8 T cells, phenotypically characterized by either proliferation or IL-2 secretion and few with dual capacity. Generation of these responses may be an important measure of HIV-1 control but are not universal after PHI. Furthermore, the heterogeneity of this population suggests that a simple measure of an effective vaccine response remains elusive.

A hallmark of human immunodeficiency virus type 1 (HIV-1) pathogenesis is the rapid loss of CD4 T cells leading to generalized immune dysfunction, including an exhausted CD8 T cell phenotype. Understanding the necessary factors that govern the functional quality and protective potential of antiviral T cell responses would facilitate rational vaccine design and improve therapeutic strategies to combat persistent infections. Mouse models of chronic viral infection demonstrate that interleukin-21 (IL-21), produced primarily by CD4 T cells, is required for the generation and maintenance of functionally competent CD8 T cells and viral containment. We reasoned that preserved IL-21 production during HIV-1 infection would be associated with enhanced CD8 T cell function, allowing improved viral control. Here we analyzed the ability of CD4 and CD8 T cells to produce several cytokines in addition to IL-21 ex vivo following stimulation with overlapping HIV-1 peptides. Both CD4 and CD8 T cells were able to produce IL-21 in response to HIV-1 infection, with the latter cell type more closely associated with viral control. Furthermore, IL-21-producing HIV-1-specific CD4 T cells (compared to those producing other cytokines) were the best indicator of functional CD8 T cells. Our results demonstrate that HIV-1-specific IL-21-producing CD8 T cells are induced following primary infection and enriched in elite controllers, suggesting a critical role for these cells in the maintenance of viremia control.

Retroviruses pack multiple genes into relatively small genomes by encoding several genes in the same genomic region with overlapping reading frames. Both sense and antisense HIV-1 transcripts contain open reading frames for known functional proteins as well as numerous alternative reading frames (ARFs). At least some ARFs have the potential to encode proteins of unknown function, and their antigenic properties can be considered as cryptic epitopes (CEs). To examine the extent of active immune response to virally encoded CEs, we analyzed human leukocyte antigen class I–associated polymorphisms in HIV-1 gag, pol, and nef genes from a large cohort of South Africans with chronic infection. In all, 391 CEs and 168 conventional epitopes were predicted, with the majority (307; 79%) of CEs derived from antisense transcripts. In further evaluation of CD8 T cell responses to a subset of the predicted CEs in patients with primary or chronic infection, both sense- and antisense-encoded CEs were immunogenic at both stages of infection. In addition, CEs often mutated during the first year of infection, which was consistent with immune selection for escape variants. These findings indicate that the HIV-1 genome might encode and deploy a large potential repertoire of unconventional epitopes to enhance vaccine-induced antiviral immunity.

The importance of functional CD4+ T cells and antigen control in the maintenance of CD127 expression on antigen-specific CD8+ T cells is poorly understood in humans. We compared CD127 expression on antigen-specific CD8+ T cells in 4 groups of human immunodeficiency virus (HIV)-infected patients. This analysis demonstrated that HIV-specific CD8+ CD127(hi) T cells are maintained as long-lived memory cells only in HIV-infected individuals treated early with antiretroviral therapy (ART). This population of CD127(hi) T cells fluctuates with viral load (VL) such that the antigen-specific T cell pool oscillates from a CD127(hi) memory to a CD127(lo) effector phenotype depending on the levels of plasma VL. In individuals with chronic infection, the CD127(hi) pool diminishes or is lost with time despite virologic control while receiving ART. These studies show that functionally competent subsets of antigen-specific memory CD8+ T cells in HIV-infected individuals are maintained but only if control of viremia is attained early during the course of infection.

Prior work has demonstrated that HIV-1–specific CD8 T cells can cross-recognize variant epitopes. However, most of these studies were performed in the context of chronic infection, where the presence of viral quasispecies makes it difficult to ascertain the true nature of the original antigenic stimulus. To overcome this limitation, we evaluated the extent of CD8 T cell cross-reactivity in patients with acute HIV-1 clade B infection. In each case, we determined the transmitted founder virus sequence to identify the autologous epitopes restricted by individual HLA class I molecules. Our data show that cross-reactive CD8 T cells are infrequent during the acute phase of HIV-1 infection. Moreover, in the uncommon instances where cross-reactive responses were detected, the variant epitopes were poorly recognized in cytotoxicity assays. Molecular analysis revealed that similar antigenic structures could be cross-recognized by identical CD8 T cell clonotypes mobilized in vivo, yet even subtle differences in a single TCR-accessible peptide residue were sufficient to disrupt variant-specific reactivity. These findings demonstrate that CD8 T cells are highly specific for autologous epitopes during acute HIV-1 infection. Polyvalent vaccines may therefore be required to provide optimal immune cover against this genetically labile pathogen.

Symptoms guide disease management, and patients frequently report HIV-related symptoms, but HIV symptom patterns reported by patients have not been described in the era of improved antiretroviral treatment. The objectives of our study were to investigate the prevalence and burden of symptoms in people living with HIV and attending an outpatient clinic. The prevalence, burden, and bothersomeness of symptoms reported by patients in routine clinic visits during 2011 were assessed using the 20-item HIV Symptom Index. Principal component analysis was used to identify symptom clusters and relationships between groups using appropriate statistic techniques. Two main clusters were identified. The most prevalent and bothersome symptoms were muscle aches/joint pain, fatigue, and poor sleep. A third of patients had seven or more symptoms, including the most burdensome symptoms. Even with improved antiretroviral drug side-effect profiles, symptom prevalence and burden, independent of HIV viral load and CD4+ T cell count, are high.

Microbial translocation within the context of HIV disease has been described as one of the contributing causes of inflammation and disease progression in HIV infection. HIV-associated symptoms have been related to inflammatory markers and sCD14, a surrogate marker for microbial translocation, suggesting a plausible link between microbial translocation and symptom burden in HIV disease. Similar pathophysiological responses and symptoms have been reported in inflammatory bowel disease. We provide a comprehensive review of microbial translocation, HIV-associated symptoms, and symptoms connected with inflammation. We identify studies showing a relationship among inflammatory markers, sCD14, and symptoms reported in HIV disease. A conceptual framework and rationale to investigate the link between microbial translocation and symptoms is presented. The impact of inflammation on symptoms supports recommendations to reduce inflammation as part of HIV symptom management. Research in reducing microbial translocation-induced inflammation is limited, but needed, to further promote positive health outcomes among HIV-infected patients.

HIV-specific cytotoxic T lymphocytes (CTL) are preferentially primed for apoptosis, and this may represent a viral escape mechanism. We hypothesized that HIV-infected individuals that control virus to undetectable levels without antiretroviral therapy (ART) (elite controllers [EC]) have the capacity to upregulate survival factors that allow them to resist apoptosis. To address this, we performed cross-sectional and longitudinal analysis of proapoptotic (cleaved caspase-3) and antiapoptotic (Bcl-2) markers of cytomegalovirus (CMV) and HIV-specific CD8 T cells in a cohort of HIV-infected subjects with various degrees of viral control on and off ART. We demonstrated that HIV-specific CTL from EC are more resistant to apoptosis than those with pharmacologic control (successfully treated patients [ST]), despite similar in vivo conditions. Longitudinal analysis of chronically infected persons starting ART revealed that the frequency of HIV-specific T cells prone to death decreased, suggesting that this phenotype is partially reversible even though it never achieves the levels present in EC. Elucidating the apoptotic factors contributing to the survival of CTL in EC is paramount to our development of effective HIV-1 vaccines. Furthermore, a better understanding of cellular markers that can be utilized to predict response durability in disease- or vaccine-elicited responses will advance the field.

Antiretroviral therapy, antibody and CD8+ T cell-mediated responses targeting human immunodeficiency virus-1 (HIV-1) exert selection pressure on the virus necessitating escape; however, the ability of CD4+ T cells to exert selective pressure remains unclear. Using a computational approach on HIV gag/pol/nef sequences and HLA-II allelic data, we identified 29 HLA-II associated HIV sequence polymorphisms or adaptations (HLA-AP) in an African cohort of chronically HIV-infected individuals. Epitopes encompassing the predicted adaptation (AE) or its non-adapted (NAE) version were evaluated for immunogenicity. Using a CD8-depleted IFN-γ ELISpot assay, we determined that the magnitude of CD4+ T cell responses to the predicted epitopes in controllers was higher compared to non-controllers (p, Author Summary In HIV, CD4+ T cells are best known as the primary targets of infection. Although emerging data has suggested a more active role in viral pathogenesis, the CD4+ T cell population remains relatively understudied. Using a novel computational approach, we predicted 29 different epitopes with mutations that potentially represent escape from CD4+ T cell responses. The predicted escaped epitopes were found to be less immunogenic than the wild type forms, suggesting that the identified escapes allow HIV to reduce its visibility to the immune system. Using longitudinal samples, we were able to show CD4+ T cells driving viral escape following acute infection. Overall, these findings significantly expand our knowledge of how CD4+ T cells can exert HIV control and influence HIV evolution, providing important implications to future vaccine development strategies.

Large amounts of human immunodeficiency virus (HIV) localize on follicular dendritic cells (FDC) in the follicles of secondary lymphoid tissues following viral infection. During clinical latency, active viral infection occurs primarily at these sites. As HIV on FDC is in the form of immune complexes, some of which may be formed with neutralizing antibody, we investigated whether HIV on FDC is infectious. We report here that HIV on FDC is highly infectious. Furthermore, FDC can convert neutralized HIV into an infectious form even in the presence of a vast excess of neutralizing antibody. Thus FDC may provide a mechanism whereby HIV infection can continue in the presence of neutralizing antibody.