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Interleukin 32 (IL-32) is a potent multi-isoform proinflammatory cytokine, which is upregulated in people with HIV (PWH) and is associated with cardiovascular disease (CVD) risk. However, the impact of IL-32 isoforms on CD4 T-cell cardiotropism, a mechanism potentially contributing to heart inflammation, remains unknown. Here we show that IL-32 isoforms β and γ induce the generation of CCR4+CXCR3+ double positive (DP) memory CD4 T-cell subpopulation expressing the tyrosine kinase receptor c-Met, a phenotype associated with heart-homing of T cells. Our ex vivo studies on PWH show that the frequency of DP CD4 T cells is significantly higher in individuals with, compared to individuals without, subclinical atherosclerosis and that DP cells from antiretroviral-naive and treated individuals are highly enriched with HIV DNA. Together, these data demonstrate that IL-32 isoforms have the potential to induce heart-homing of HIV-infected CD4 T cells, which may further aggravate heart inflammation and CVD in PWH. [ABSTRACT FROM AUTHOR]

ObjectiveGut microbial translocation is a major driving force behind chronic immune activation during HIV-1 infection. HIV-1-related intestinal dysbiosis, including increases in mucosa-associated pathobionts, may influence microbial translocation and contribute to mucosal and systemic inflammation. Thus, it is critical to understand the mechanisms by which gut microbes and their metabolic products, such as butyrate, influence immune cell function during HIV-1 infection.DesignA cross-sectional study was performed to compare the relative abundance of butyrate-producing bacterial (BPB) species in colonic biopsies and stool of untreated, chronic HIV-1-infected (n = 18) and HIV-1-uninfected (n = 14) study participants. The effect of exogenously added butyrate on gut T-cell activation and HIV-1 infection was evaluated using an ex-vivo human intestinal cell culture model.MethodsSpecies were identified in 16S ribosomal RNA sequence datasets. Ex-vivo isolated lamina propria mononuclear cells were infected with C-C chemokine receptor type 5-tropic HIV-1Bal, cultured with enteric gram-negative bacteria and a range of butyrate doses, and lamina propria T-cell activation and HIV-1 infection levels measured.ResultsRelative abundance of total BPB and specifically of Roseburia intestinalis, were lower in colonic mucosa of HIV-1-infected versus HIV-1-uninfected individuals. In HIV-1-infected study participants, R. intestinalis relative abundance inversely correlated with systemic indicators of microbial translocation, immune activation, and vascular inflammation. Exogenous butyrate suppressed enteric gram-negative bacteria-driven lamina propria T-cell activation and HIV-1 infection levels in vitro.ConclusionReductions in mucosal butyrate from diminished colonic BPB may exacerbate pathobiont-driven gut T-cell activation and HIV replication, thereby contributing to HIV-associated mucosal pathogenesis.

Knowledge of aging biology needs to be expanded due to the continuously growing number of elderly people worldwide. Aging induces changes that affect all systems of the body. The risk of cardiovascular disease and cancer increases with age. In particular, the age-induced adaptation of the immune system causes a greater susceptibility to infections and contributes to the inability to control pathogen growth and immune-mediated tissue damage. Since the impact of aging on immune function, is still to be fully elucidated, this review addresses some of the recent understanding of age-related changes affecting key components of immunity. The emphasis is on immunosenescence and inflammaging that are impacted by common infectious diseases that are characterized by a high mortality, and includes COVID-19, HIV and tuberculosis. [ABSTRACT FROM AUTHOR]

CD4+ T-cell depletion is pathognomonic for AIDS in both HIV and simian immunodeficiency virus (SIV) infections. It occurs early, is massive at mucosal sites, and is not entirely reverted by antiretroviral therapy (ART), particularly if initiated when T-cell functions are compromised. HIV/SIV infect and kill activated CCR5-expressing memory and effector CD4+ T-cells from the intestinal lamina propria. Acute CD4+ T-cell depletion is substantial in progressive, nonprogressive and controlled infections. Clinical outcome is predicted by the mucosal CD4+ T-cell recovery during chronic infection, with no recovery occurring in rapid progressors, and partial, transient recovery, the degree of which depends on the virus control, in normal and long-term progressors. The nonprogressive infection of African nonhuman primate SIV hosts is characterized by partial mucosal CD4+ T-cell restoration, despite high viral replication. Complete, albeit very slow, recovery of mucosal CD4+ T-cells occurs in controllers. Early ART does not prevent acute mucosal CD4+ T-cell depletion, yet it greatly improves their restoration, sometimes to preinfection levels. Comparative studies of the different models of SIV infection support a critical role of immune activation/inflammation (IA/INFL), in addition to viral replication, in CD4+ T-cell depletion, with immune restoration occurring only when these parameters are kept at bay. CD4+ T-cell depletion is persistent, and the recovery is very slow, even when both the virus and IA/INFL are completely controlled. Nevertheless, partial mucosal CD4+ T-cell recovery is sufficient for a healthy life in natural hosts. Cell death and loss of CD4+ T-cell subsets critical for gut health contribute to mucosal inflammation and enteropathy, which weaken the mucosal barrier, leading to microbial translocation, a major driver of IA/INFL. In turn, IA/INFL trigger CD4+ T-cells to become either viral targets or apoptotic, fueling their loss. CD4+ T-cell depletion also drives opportunistic infections, cancers, and comorbidities. It is thus critical to preserve CD4+ T cells (through early ART) during HIV/SIV infection. Even in early-treated subjects, residual IA/INFL can persist, preventing/delaying CD4+ T-cell restoration. New therapeutic strategies limiting mucosal pathology, microbial translocation and IA/INFL, to improve CD4+ T-cell recovery and the overall HIV prognosis are needed, and SIV models are extensively used to this goal. [ABSTRACT FROM AUTHOR]

Persistent immune activation and inflammation in people living with HIV (PLWH) are associated with immunosenescence, premature aging and increased risk of non-AIDS comorbidities, with the underlying mechanisms not fully understood. In this study, we show that downregulation of the T-cell immunoglobulin receptor CD96 on CD8+ T cells from PLWH is associated with decreased expression of the co-stimulatory receptors CD27 and CD28, higher expression of the senescence marker CD57 and accumulation of a terminally differentiated T-cell memory phenotype. In addition, we show that CD96-low CD8+ T-cells display lower proliferative potential compared to their CD96-high counterparts and that loss of CD96 expression by HIV-specific CD8+ T-cells is associated with a suboptimal response to HIV antigens. In conclusion, our results suggest that CD96 marks CD8+ T-cells with competent responses to HIV and the loss of its expression might be used as a biomarker for CD8+ T-cell senescence and dysfunction in PLWH. [ABSTRACT FROM AUTHOR]

Background Food insecurity is associated with increased morbidity and mortality in people with human immunodeficiency virus (HIV) on antiretroviral therapy, but its relationship with immune dysregulation, a hallmark of HIV infection and comorbidity, is unknown. Methods In 241 women participating in the Women's Interagency HIV Study, peripheral blood mononuclear cells were characterized by flow cytometry to identify cell subsets, comprising surface markers of activation (%CD38+HLADR+), senescence (%CD57+CD28−), exhaustion (%PD-1+), and co-stimulation (%CD57− CD28+) on CD4+ and CD8+ T cells. Mixed-effects linear regression models were used to assess the relationships of food insecurity with immune outcomes, accounting for repeated measures at ≤3 study visits and adjusting for sociodemographic and clinical factors. Results At the baseline study visit, 71% of participants identified as non-Hispanic Black, 75% were virally suppressed, and 43% experienced food insecurity. Food insecurity was associated with increased activation of CD4+ and CD8+ T cells, increased senescence of CD8+ T cells, and decreased co-stimulation of CD4+ and CD8+ T cells (all P  < .05), adjusting for age, race/ethnicity, income, education, substance use, smoking, HIV viral load, and CD4 count. In stratified analyses, the association of food insecurity with CD4+ T-cell activation was more pronounced in women with uncontrolled HIV (viral load >40 copies/mL and CD4 <500 cells/mm3) but remained statistically significant in those with controlled HIV. Conclusions Food insecurity may contribute to the persistent immune activation and senescence in women with HIV on antiretroviral therapy, independently of HIV control. Reducing food insecurity may be important for decreasing non–AIDS-related disease risk in this population. [ABSTRACT FROM AUTHOR]

HIV, therapeutic vaccine, T cell, HIV remission, immunotherapy In general, these vaccines have been safe and well-tolerated, and some of the vaccine approaches had promising results with regard to increasing HIV-specific T cell immune responses. Keywords: HIV; therapeutic vaccine; T cell; HIV remission; immunotherapy EN HIV therapeutic vaccine T cell HIV remission immunotherapy 1 3 3 05/02/22 20220427 NES 220427 Despite significant advancements in our understanding of HIV persistence and immunology, long-term remission of HIV off antiretroviral therapy (ART) has not been achieved except in a few reported cases ([1]-[3]). [Extracted from the article]

Background: Hypertension is a major source of cardiovascular morbidity and mortality. Recent evidence from mouse models, genetic, and cross-sectional human studies suggest increased proportions of selected immune cell subsets may be associated with levels of systolic blood pressure (SBP). Methods: We assayed immune cells from cryopreserved samples collected at the baseline examination (2000-2002) from 1195 participants from the multi-ethnic study of atherosclerosis (MESA). We used linear mixed models, with adjustment for age, sex, race/ethnicity, smoking, exercise, body mass index, education, diabetes, and cytomegalovirus titers, to estimate the associations between 30 immune cell subsets (4 of which were a priori hypotheses) and repeated measures of SBP (baseline and up to four follow-up measures) over 10 years. The analysis provides estimates of the association with blood pressure level. Results: The mean age of the MESA participants at baseline was 64 ± 10 years and 53% were male. A one standard deviation (1-SD) increment in the proportion of γδ T cells was associated with 2.40 mmHg [95% confidence interval (CI) 1.34-3.42] higher average systolic blood pressure; and for natural killer cells, a 1-SD increment was associated with 1.88 mmHg (95% CI 0.82-2.94) higher average level of systolic blood pressure. A 1-SD increment in classical monocytes (CD14++CD16-) was associated with 2.01 mmHG (95% CI 0.79-3.24) lower average systolic blood pressure. There were no associations of CD4+ T helper cell subsets with average systolic blood pressure. Conclusion: These findings suggest that the innate immune system plays a role in levels of SBP whereas there were no associations with adaptive immune cells. [ABSTRACT FROM AUTHOR]

AIDS Clinical Trials Group study A5308 found reduced T-cell activation and exhaustion in human immunodeficiency virus (HIV) controllers start antiretroviral therapy (ART). We further assessed HIV-specific T-cell responses and post-ART viral loads. Before ART, the 31% of participants with persistently undetectable viremia had more robust HIV-specific T-cell responses. During ART, significant decreases were observed in a broad range of T-cell responses. Eight controllers in A5308 and the Study of the Consequences of the Protease Inhibitor Era (SCOPE) cohort showed no viremia above the level of quantification in the first 12 weeks after ART discontinuation. ART significantly reduced HIV-specific T-cell responses in HIV controllers but did not adversely affect controller status after ART discontinuation. [ABSTRACT FROM AUTHOR]

Background: A higher proportion of circulating memory CD4+ T cells is associated with prevalent diabetes mellitus in the general population. Given the broad changes in adaptive immunity, including memory T-cell expansion, and rising prevalence of diabetes in the human immunodeficiency virus (HIV) population, we assessed whether similar relationships were present in persons with HIV (PWH).Methods: Multiple CD4+ and CD8+ T-cell subsets were measured by flow cytometry, and prevalent diabetes cases were adjudicated by 2 physicians for PWH and HIV-negative participants in the Veterans Aging Cohort Study. Multivariable logistic regression models evaluated the association of T-cell subsets and diabetes stratified by HIV status, adjusted for cytomegalovirus serostatus and traditional risk factors.Results: Among 2385 participants (65% PWH, 95% male, 68% African American), higher CD45RO+ memory CD4+ T cells and lower CD38+ CD4+ T cells were associated with prevalent diabetes, and had a similar effect size, in both the PWH and HIV-negative (P ≤ .05 for all). Lower CD38+CD8+ T cells were also associated with diabetes in both groups.Conclusions: The CD4+ and CD8+ T-cell subsets associated with diabetes are similar in PWH and HIV-negative individuals, suggesting that diabetes in PWH may be related to chronic immune activation. [ABSTRACT FROM AUTHOR]

Background: We examined changes in soluble inflammatory cytokines and T-cell activation after antiretroviral therapy (ART) initiation in an AIDS Clinical Trials Group (ACTG) nested case-control study.Methods: Cases were 143 human immunodeficiency virus (HIV)-infected adults who developed a non-AIDS event; 315 controls remained event-free. Specimens were tested pre-ART, year 1 post-ART, and at the visit preceding the event. Conditional logistic regression evaluated the associations of biomarker changes with non-AIDS events.Results: Inflammatory and most activation biomarkers declined from pre-ART to year 1 for cases and controls. Subsequently, inflammatory biomarkers remained mostly stable in controls but not cases. Cellular activation markers generally declined for both cases and controls between year 1 and the pre-event sampling. Controls with greater pre-ART RNA levels or lower CD4+ levels had higher biomarker levels while also experiencing greater biomarker declines in the first year of ART. Changes in biomarkers to year 1 showed no significant associations with non-AIDS events. Cases, however, had significantly greater increases in all plasma biomarkers (but not cellular activation) from year 1 to the visit preceding the event.Conclusions: Inflammation increases prior to non-AIDS events in treated HIV-infected adults. These biomarker changes may reflect subclinical disease processes or other alterations in the inflammatory environment that causally contribute to disease.Clinical Trials Registration: NCT00001137. [ABSTRACT FROM AUTHOR]

Untreated HIV infection is associated with progressive CD4+ T cell depletion, which is generally recovered with combination antiretroviral therapy (cART). However, a significant proportion of cART-treated individuals have poor CD4+ T cell reconstitution. We investigated associations between HIV disease progression and CD4+ T cell glucose transporter-1 (Glut1) expression. We also investigated the association between these variables and specific single nucleotide polymorphisms (SNPs) within the Glut1 regulatory gene AKT (rs1130214, rs2494732, rs1130233, and rs3730358) and in the Glut1-expressing gene SLC2A1 (rs1385129 and rs841853) and antisense RNA 1 region SLC2A1-AS1 (rs710218). High CD4+Glut1+ T cell percentage is associated with rapid CD4+ T cell decline in HIV-positive treatment-naïve individuals and poor T cell recovery in HIV-positive individuals on cART. Evidence suggests that poor CD4+ T cell recovery in treated HIV-positive individuals is linked to the homozygous genotype (GG) associated with SLC2A1 SNP rs1385129 when compared to those with a recessive allele (GA/AA) (odds ratio = 4.67; P = 0.04). Furthermore, poor response to therapy is less likely among Australian participants when compared against American participants (odds ratio: 0.12; P = 0.01) despite there being no difference in prevalence of a specific genotype for any of the SNPs analyzed between nationalities. Finally, CD4+Glut1+ T cell percentage is elevated among those with a homozygous dominant genotype for SNPs rs1385129 (GG) and rs710218 (AA) when compared to those with a recessive allele (GA/AA and AT/TT respectively) (P < 0.04). The heterozygous genotype associated with AKT SNP 1130214 (GT) had a higher CD4+Glut1+ T cell percentage when compared to the dominant homozygous genotype (GG) (P = 0.0068). The frequency of circulating CD4+Glut1+ T cells and the rs1385129 SLC2A1 SNP may predict the rate of HIV disease progression and CD4+ T cell recovery in untreated and treated infection, respectively. [ABSTRACT FROM AUTHOR]

Background. Rifaximin, a nonabsorbable antibiotic that decreases lipopolysaccharide (LPS) in cirrhotics, may decrease the elevated levels of microbial translocation, T-cell activation and inflammation in human immunodeficiency virus (HIV)-positive immune nonresponders to antiretroviral therapy (ART).Methods. HIV-positive adults receiving ART for ≥96 weeks with undetectable viremia for ≥48 weeks and CD4+ T-cell counts <350 cells/mm3 were randomized 2:1 to rifaximin versus no study treatment for 4 weeks. T-cell activation, LPS, and soluble CD14 were measured at baseline and at weeks 2, 4, and 8. Wilcoxon rank sum tests compared changes between arms.Results. Compared with no study treatment (n = 22), rifaximin (n = 43) use was associated with a significant difference between study arms in the change from baseline to week 4 for CD8+T-cell activation (median change, 0.0% with rifaximin vs +0.6% with no treatment; P = .03). This difference was driven by an increase in the no-study-treatment arm because there was no significant change within the rifaximin arm. Similarly, although there were significant differences between study arms in change from baseline to week 2 for LPS and soluble CD14, there were no significant changes within the rifaximin arm.Conclusions. In immune nonresponders to ART, rifaximin minimally affected microbial translocation and CD8+T-cell activation.Trial registration number. NCT01466595. [ABSTRACT FROM PUBLISHER]

Background. Defining the association of non–AIDS-defining events with inflammation and immune activation among human immunodeficiency virus (HIV)–infected persons with antiretroviral therapy (ART)–associated virological suppression is critical to identifying interventions to decrease the occurrence of these events.Methods. We conducted a case-control study of HIV-infected subjects who had achieved virological suppression within 1 year after ART initiation. Cases were patients who experienced non–AIDS-defining events, defined as myocardial infarction, stroke, non–AIDS-defining cancer, non–AIDS-defining serious bacterial infection, or death. Controls were matched to cases on the basis of age, sex, pre-ART CD4+ T-cell count, and ART regimen. Peripheral blood mononuclear cells and plasma specimens obtained at the visit before ART initiation (hereafter, baseline), the visit approximately 1 year after ART initiation (hereafter, year 1), and the visit immediately preceding the non–AIDS-defining event (hereafter, pre-event) were analyzed for activated CD4+ and CD8+ T cells, plasma interleukin 6 (IL-6) level, soluble tumor necrosis factor receptor I (sTNFR-I) level, sTNFR-II level, soluble CD14 level, kynurenine-to-tryptophan (KT) ratio, and D-dimer level. Conditional logistic regression analysis was used to study the association between biomarkers and outcomes, with adjustment for potential confounders.Results. Higher IL-6 level, sTNFR-I level, sTNFR-II level, KT ratio, and D-dimer level at year 1 were associated with the occurrence of a non–AIDS-defining event. Significant associations were also seen between non–AIDS-defining events and values of these biomarkers in specimens obtained at baseline and the pre-event time points. Effects remained significant after control for confounders. T-cell activation was not significantly related to outcomes.Conclusions. Interventional trials to decrease the incidence of non–AIDS-defining events among HIV-infected persons with virological suppression should consider targeting the pathways represented by these soluble markers.Clinical Trials Registration. NCT00001137. [ABSTRACT FROM AUTHOR]

Cell-mediated immunity is implicated in atherosclerosis. We evaluated whether innate and adaptive immune cell subsets in peripheral blood are risk factors for coronary heart disease. A nested case-cohort study (n = 2155) was performed within the Multi-Ethnic Study of Atherosclerosis (MESA) and the Cardiovascular Health Study (CHS). Cases of incident myocardial infarction (MI) and incident angina (n = 880 total cases) were compared with a cohort random sample (n = 1275). Immune cell phenotypes (n = 34, including CD14+ monocytes, natural killer cells, γδ T cells, CD4+, CD8+ and CD19+ lymphocyte subsets) were measured from cryopreserved cells by flow cytometry. Cox proportional hazards models with adjustment for cardiovascular disease risk factors were used to evaluate associations of cell phenotypes with incident MI and a composite phenotype of incident MI or incident angina (MI-angina) over a median 9.3 years of follow-up. Th1, Th2, Th17, T regulatory (CD4+CD25+CD127-), naive (CD4+CD45RA+), memory (CD4+CD45RO+), and CD4+CD28− cells were specified as primary hypotheses. In secondary analyses, 27 additional cell phenotypes were investigated. After correction for multiple testing, there were no statistically significant associations of CD4+ naive, memory, CD28−, or T helper cell subsets with MI or MI-angina in MESA, CHS, or combined-cohort meta analyses. Null associations were also observed for monocyte subsets, natural killer cells, γδ T cells, CD19+ B cell and differentiated CD4+ and CD8+ cell subsets. The proportions of peripheral blood monocyte and lymphocyte subsets are not strongly related to the future occurrence of MI or angina in adults free of autoimmune disease. Image 1 • Cell-mediated immunity is established in animal models of atherosclerosis. • Unclear if immune cell levels in blood are risk factors for future coronary events. • CD4+ and CD8+ T cells were not related to incident myocardial infarction or angina. • Monocytes, innate lymphocytes, and B cells were not related to coronary risk. • Blood lymphocytes and monocytes may have limited utility as cardiovascular disease (CVD) biomarkers. [ABSTRACT FROM AUTHOR]

Highly active antiretroviral therapy (HAART) for the treatment of HIV infection sustains viral suppression and increases CD4 + T cells in HIV patients. However, in 10–25% of subjects, known as immunological non-responders (INRs), HAART does not increase CD4 count. We investigated a potential role for galectin-9 and TIM-3 in INRs as galectin-9 and TIM-3 have been described to modulate NK and T cell function. PBMCs were isolated from healthy controls, HIV immunological responders (IRs, > 350 CD4 + cells/mm 3 ) and HIV INRs (< 350 CD4 + cells/mm 3 ) and TIM-3 and galectin-9 expressions on NK cell subsets and CD4 + T cells were assessed. HIV INRs and HIV IRs showed increased galectin-9 expression on CD16 − CD56 bright and CD16 + CD56 + NK cells and CD4 + T cells. Only HIV INRs showed a reduced frequency of TIM-3-expressing CD16 + CD56 + , CD16 + CD56 − and CD4 + cells, which correlated with low peripheral CD4 counts. These data suggest that TIM-3 expression may be characteristic for HIV INRs. [ABSTRACT FROM AUTHOR]