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A stable latent reservoir for HIV-1 in resting CD4 + T cells is the principal barrier to a cure 1 – 3 . Curative strategies that target the reservoir are being tested 4 , 5 and require accurate, scalable reservoir assays. The reservoir was defined with quantitative viral outgrowth assays for cells that release infectious virus after one round of T cell activation 1 . However, these quantitative outgrowth assays and newer assays for cells that produce viral RNA after activation 6 may underestimate the reservoir size because one round of activation does not induce all proviruses 7 . Many studies rely on simple assays based on polymerase chain reaction to detect proviral DNA regardless of transcriptional status, but the clinical relevance of these assays is unclear, as the vast majority of proviruses are defective 7 – 9 . Here we describe a more accurate method of measuring the HIV-1 reservoir that separately quantifies intact and defective proviruses. We show that the dynamics of cells that carry intact and defective proviruses are different in vitro and in vivo. These findings have implications for targeting the intact proviruses that are a barrier to curing HIV infection. An assay to measure the latent HIV-1 reservoir that separately quantifies intact and defective proviruses will facilitate evaluation of HIV-1 cure strategies by measuring the provirues that pose a barrier to cure.

Despite receiving antiretroviral therapy, most patients with HIV still have latent reservoirs of the virus; here, these reservoirs are shown to be dominated by viruses with cytotoxic T lymphocyte escape mutations, with potential implications for the development of therapeutic vaccines. HIV-1 reservoirs analysed Antiretroviral therapy does not cure HIV-1 infection: despite drug treatment, most patients still have latent reservoirs of the virus. This study of immune cells isolated from 30 HIV-1-infected patients who had been on antiretroviral therapy for at least two years and had maintained undetectable plasma HIV-1 RNA levels, shows that these viral reservoirs are dominated by viruses with cytotoxic T lymphocyte escape mutations. This finding implies that future directions in therapeutic vaccine design may need to focus on boosting broad cytotoxic T lymphocyte responses. Despite antiretroviral therapy (ART), human immunodeficiency virus (HIV)-1 persists in a stable latent reservoir 1 , 2 , primarily in resting memory CD4 + T cells 3 , 4 . This reservoir presents a major barrier to the cure of HIV-1 infection. To purge the reservoir, pharmacological reactivation of latent HIV-1 has been proposed 5 and tested both in vitro and in vivo 6 , 7 , 8 . A key remaining question is whether virus-specific immune mechanisms, including cytotoxic T lymphocytes (CTLs), can clear infected cells in ART-treated patients after latency is reversed. Here we show that there is a striking all or none pattern for CTL escape mutations in HIV-1 Gag epitopes. Unless ART is started early, the vast majority (>98%) of latent viruses carry CTL escape mutations that render infected cells insensitive to CTLs directed at common epitopes. To solve this problem, we identified CTLs that could recognize epitopes from latent HIV-1 that were unmutated in every chronically infected patient tested. Upon stimulation, these CTLs eliminated target cells infected with autologous virus derived from the latent reservoir, both in vitro and in patient-derived humanized mice. The predominance of CTL-resistant viruses in the latent reservoir poses a major challenge to viral eradication. Our results demonstrate that chronically infected patients retain a broad-spectrum viral-specific CTL response and that appropriate boosting of this response may be required for the elimination of the latent reservoir.

Background. Human immunodeficiency virus (HIV)–induced inflammation and immune activation persist after initiation of combination antiretroviral therapy (cART) and HIV suppression and may contribute to mortality risks that exceed those in HIV-uninfected populations, though associations are unclear. Methods. In the prospective Multicenter AIDS Cohort Study, comprising men who have sex with men from Baltimore, Chicago, Los Angeles, and Pittsburgh, concentrations of 24 biomarkers of inflammation and immune activation were measured in stored serum from HIV-positive men obtained after cART-induced HIV suppression between 1996 and 2009. The outcome was nonaccidental death, with follow-up until 2014. We used Cox proportional hazards models to test whether biomarker concentrations predict time from HIV suppression to death and adjusted for multiple tests. Exploratory factor analysis (EFA) was employed to identify groupings of biomarkers that predict mortality risk. Results. Of 670 men followed up from HIV suppression, 54 died by the end of 2013. After adjustment for age, CD4+ cell count, hepatitis B or C virus infection, and smoking, concentrations in the highest quartile of 4 biomarkers were significantly associated with mortality risk after controlling the false discovery rate at 5%: interleukin (IL) 6 (hazard ratio, 3.54; 95% confidence interval, 2.06–6.10), soluble IL 2Rα (3.29, 1.85–5.85), soluble CD14 (2.67, 1.55–4.61), and chemokine (CXC motif) ligand 13 (CXCL13; 2.26; 1.29–3.95). EFA yielded 2 biomarker groupings that were independent predictors of mortality risk. Conclusions. Despite having undetectable HIV RNA levels during cART, men with higher concentrations of several biomarkers (particularly IL 6, soluble IL 2Rα, soluble CD14, and CXCL13) had higher hazards of long-term mortality. Correlations observed among biomarker concentrations may represent underlying inflammatory processes that contribute to mortality risk.

Side-population (SP) cells within cancers and cell lines are rare cell populations known to enrich cancer stem-like cells. In this study, we characterized SP cells from the human breast cancer cell line MCF7 as a model for cancer stem-like cells. Compared with non-SP cells, MCF7 SP cells had higher colony-formation ability in vitro and greater tumorigenicity in vivo, suggesting that MCF7 SP cells enrich cancer stem-like cells. cDNA microarray analysis of the SP cells indicated higher expression of ATP-binding cassette transporters and genes involved in quiescence, which were confirmed by quantitative RT-PCR and flow cytometry cell cycle analysis. To identify signal pathways important for cancer stem-like cells, we analyzed cDNA microarray data and identified nine pathways that were altered in the SP cells. To analyze the protein signaling networks, we used reverse-phase signaling pathway protein microarray technology and identified three signaling proteins that are significantly different between MCF7 SP and non-SP cells. Notably, signaling of phosphatidylinositol 3-kinase (PI3K)/mammalian target of rapamycin (mTOR), signal transduction and activator of transcription (STAT3), and phosphatase and tensin homolog (PTEN) was confirmed to be critical for MCF7 SP cell survival and proliferation by pathway specific inhibitors, selected gene knockdown, and in vivo tumorigenicity assay. The STAT3 pathway was found to be positively regulated by mTOR signaling, whereas PTEN served as a negative regulator of both STAT3 and mTOR signaling. This study suggests the existence of prosurvival signaling pathways critical for cancer stem-like cell maintenance, which could be selectively targeted for inhibiting cancer stem-like cells for improved treatment.

Exosomes are important vehicles of intercellular communication that shape host responses to physiologic, tumorigenic, and pathogenic conditions. The composition and function of exosomes are dynamic and depends on the state and condition of the cellular source. In prior work, we found that semen exosomes (SE) from healthy donors who do not use illicit drugs potently inhibit HIV-1. Following semen donation, specimens are either used immediately or frozen for use at a later time. It has been shown that short-term freezing of semen has no effect on SE-mediated HIV-1 inhibition. However, the effect of illicit drugs and prolonged freezing on SE bioactivity is unknown. Here, we show preservation of SE physical properties, (morphology, concentration, intensity/size) irrespective of illicit drug use or duration of semen freezing. Interestingly, illicit drugs and prolonged freezing decreased the levels of SE-bound CD63/CD9 and acetylcholinesterase activity respectively. Furthermore, we show differential effects of illicit drug use and prolonged freezing on SE-mediated HIV-1 inhibition. Our results highlight the importance of the source of SE and condition of semen storage on SE content and function. In-depth evaluation of donor drug-use and duration of semen storage on SE cargo and bioactivity will advance our understanding of SE composition and function.

People living with HIV are at higher risk of heart failure and associated left atrial remodeling compared to people without HIV. Mechanisms are unclear but have been linked to inflammation and premature aging. Here we obtain plasma proteomics concurrently with cardiac magnetic resonance imaging in two independent study populations to identify parallels between HIV-related and aging-related immune dysfunction that could contribute to atrial remodeling and clinical heart failure. We discover a plasma proteomic signature that may in part reflect or contribute to HIV-associated atrial remodeling, many features of which are associated with older age and time to incident heart failure among an independent community-based cohort without HIV. This proteomic profile was statistically enriched for immune checkpoint proteins, tumor necrosis factor signaling, ephrin signaling, and extracellular matrix organization, identifying possible shared pathways in HIV and aging that may contribute to risk of heart failure. Mechanisms underlying excess risk of heart failure among people with HIV are unclear. Here, the authors identify a proteomic signature enriched in immune activation and extracellular matrix remodeling that may reflect shared pathways in HIV and aging that contribute to risk of heart failure.

In light of a recent report that short-term treatment with valproic acid (VA) might accelerate the decay of the latent reservoir for HIV-1 in patients receiving combination therapy and allow eventual eradication of the infection, we studied patients with prolonged suppression of viremia who were receiving combination therapy and who had also been receiving chronic VA therapy for neurological or psychiatric conditions. Latently infected cells were readily detected in all patients at levels comparable to those seen in patients receiving combination therapy alone. We conclude that the clinical use of VA has no ancillary effect on the decay of the latent reservoir.

We investigated the association of HIV infection and highly active antiretroviral therapy (HAART) with sleep disordered breathing (SDB), fatigue, and sleepiness. HIV-uninfected men (HIV-; n = 60), HIV-infected men using HAART (HIV+/HAART+; n = 58), and HIV-infected men not using HAART (HIV+/HAART-; n = 41) recruited from two sites of the Multicenter AIDS cohort study (MACS) underwent a nocturnal sleep study, anthropometric assessment, and questionnaires for fatigue and the Epworth Sleepiness Scale. The prevalence of SDB in HIV- men was compared to that in men matched from the Sleep Heart Health Study (SHHS). The prevalence of SDB was unexpectedly high in all groups: 86.7% for HIV-, 70.7% for HIV+/HAART+, and 73.2% for HIV+/HAART-, despite lower body-mass indices (BMI) in HIV+ groups. The higher prevalence in the HIV- men was significant in univariate analyses but not after adjustment for BMI and other variables. SDB was significantly more common in HIV- men in this study than those in SHHS, and was common in participants with BMIs <25 kg/m2. HIV+ men reported fatigue more frequently than HIV- men (25.5% vs. 6.7%; p = 0.003), but self-reported sleepiness did not differ among the three groups. Sleepiness, but not fatigue, was significantly associated with SDB. SDB was highly prevalent in HIV- and HIV+ men, despite a normal or slightly elevated BMI. The high rate of SDB in men who have sex with men deserves further investigation. Sleepiness, but not fatigue, was related to the presence of SDB. Clinicians caring for HIV-infected patients should distinguish between fatigue and sleepiness when considering those at risk for SDB, especially in non-obese men.

Background Chronic cytomegalovirus (CMV) infection has been postulated as a driver of chronic inflammation that has been associated with frailty and other age-related conditions in both HIV-infected (HIV+) and -uninfected (HIV-) people. Methods To study the T cell response to CMV as a predictor of onset and maintenance of frailty, baseline CMV-specific T cell responses of 42 men (20 HIV-, 22 HIV+; 21 frail, 21 nonfrail) in the Multicenter AIDS Cohort Study (MACS) were assessed by flow cytometric analysis of cytokine production (IFN-γ, TNF-⍺, and IL-2) in response to overlapping peptide pools spanning 19 CMV open reading frames. The Fried frailty phenotype was assessed at baseline and semiannually thereafter. Times to transition into or out of frailty were compared by tertiles of percentages of cytokine-producing T cells using Kaplan-Meier estimators and the exact log-rank test. Results Over a median follow-up of 6.5 (interquartile range: 2) years, faster onset of frailty was significantly predicted by higher (HIV- men) or lower (HIV+ men) percentages of CD4 T cells producing only IFN-γ (IFN-γ-single-producing (SP)), and by lower percentages of IFN-γ-, TNF-⍺-, and IL-2-triple-producing CD8 T cells (HIV- men). Greater maintenance of frailty was significantly predicted by lower percentages of both these T cell subsets in HIV- men, and by lower percentages of IFN-γ-SP CD4 T cells in HIV+ men. The antigenic specificity of IFN-γ-SP CD4 T cells was different between HIV- and HIV+ nonfrail men, as were the correlations between these cells and serum inflammatory markers. Conclusions In this pilot study, percentages of CMV-specific T cells predicted the onset and maintenance of frailty in HIV- and HIV+ men. Predictive responses differed by HIV status, which may relate to differential control of CMV reactivation and inflammation by anti-CMV T cell responses.

Increased expression of the voltage-gated potassium channel Kν1.3 on activated effector memory T cells (T(EM)) is associated with pathology in multiple sclerosis (MS). To date, most studies of Kν1.3 channels in MS have focused on CD4+ T(EM) cells. Much less is known about the functional relevance of Kv1.3 on CD8+ T(EM) cells. Herein, we examined the effects of Kν1.3 blockade on CD8+ T cell proliferation, differentiation into cytotoxic effector cells, and release of granzyme B (GrB), a key effector of CD8+ T cell-mediated cytotoxicity. We confirmed the expression of Kv1.3 channels on activated human CD8+ T lymphocytes by immunofluorescent staining. To test the functional relevance of the Kv1.3 channel in CD8+ T cells, we inhibited this channel via pharmacological blockers or a lentiviral-dominant negative (Kv1.xDN) approach and determined the effects of the blockade on critical pathogenic parameters of CD8+ T cells. We found that blockade of Kv1.3 with both lentivirus and pharmacologic agents effectively inhibited cytotoxic effector memory cells' proliferation, secretion of GrB, and their ability to kill neural progenitor cells. Intriguingly, the KvDN transduced T cells exhibited arrested differentiation from central memory (T(CM)) to effector memory (T(EM)) states. Transduction of cells that had already differentiated into T(EM) with KvDN led to their conversion into T(CM). CD8+ T(EM) have a critical role in MS and other autoimmune diseases. Our present results indicate a critical role for Kv1.3 in the conversion of CD8+ T cells into potential pathogenic effector cells with cytotoxic function.