Single-cell analysis shows that adipose tissue of persons with both HIV and diabetes is enriched for clonal, cytotoxic, and CMV-specific CD4+ T cells

Persons with HIV are at increased risk for diabetes mellitus compared with individuals without HIV. Adipose tissue is an important regulator of glucose and lipid metabolism, and adipose tissue T cells modulate local inflammatory responses and, by extension, adipocyte function. Persons with HIV and diabetes have a high proportion of CX3CR1+ GPR56+ CD57+ (C-G-C+) CD4+ T cells in adipose tissue, a subset of which are cytomegalovirus specific, whereas individuals with diabetes but without HIV have predominantly CD69+ CD4+ T cells. Adipose tissue CD69+ and C-G-C+ CD4+ T cell subsets demonstrate higher receptor clonality compared with the same cells in blood, potentially reflecting antigen-driven expansion, but C-G-C+ CD4+ T cells have a more inflammatory and cytotoxic RNA transcriptome. Future studies will explore whether viral antigens have a role in recruitment and proliferation of pro-inflammatory C-G-C+ CD4+ T cells in adipose tissue of persons with HIV

The economic benefits of high CD4 counts among people living with HIV/AIDS in Zambia

Background The economic effects of poor immunologic recovery among HIV-infected patients receiving antiretroviral therapy (ART) in subSaharan Africa are not well understood. We examined the relationship between the CD4 counts of patients on long-term ART and employment outcomes in HIV-affected households in Lusaka, Zambia.Methods Administrative data and a household survey captured information on the clinical records, demographics and employment outcomes of the ART-treated adults and their adult family members (n = 311). Multivariable regression analyses were used to assess relationships between CD4 counts of ART-treated adults and household employment outcomes.Results Patients with a CD4 count of at least 350 cells/mu l were 22 percentage points more likely to be engaged in the labor force(P= 500 compared with = 350 versus <350.Conclusion These findings suggest that interventions to improve or maintain robust immune recovery during ART may confer economic benefits for both HIV-infected individuals and HIV-affected households

High CD8 T-cell receptor clonality and altered CDR3 properties are associated with elevated isolevuglandins in adipose tissue during diet-induced obesity

Adipose tissue (AT) CD4+ and CD8+ T cells contribute to obesity-associated insulin resistance. Prior studies identified conserved T-cell receptor (TCR) chain families in obese AT, but the presence and clonal expansion of specific TCR sequences in obesity has not been assessed. We characterized AT and liver CD8+ and CD4+ TCR repertoires of mice fed a low-fat diet (LFD) and high-fat diet (HFD) using deep sequencing of the TCRβ chain to quantify clonal expansion, gene usage, and CDR3 sequence. In AT CD8+ T cells, HFD reduced TCR diversity, increased the prevalence of public TCR clonotypes, and selected for TCR CDR3 regions enriched in positively charged and less polarized amino acids. Although TCR repertoire alone could distinguish between LFD- and HFD-fed mice, these properties of the CDR3 region of AT CD8+ T cells from HFD-fed mice led us to examine the role of negatively charged and nonpolar isolevuglandin (isoLG) adduct-containing antigen-presenting cells within AT. IsoLG-adducted protein species were significantly higher in AT macrophages of HFD-fed mice; isoLGs were elevated in M2-polarized macrophages, promoting CD8+ T-cell activation. Our findings demonstrate that clonal TCR expansion that favors positively charged CDR3s accompanies HFD-induced obesity, which may be an antigen-driven response to isoLG accumulation in macrophages

Adipose tissue in persons with HIV is enriched for CD4+ T effector memory and T effector memory RA+ cells, which show higher CD69 expression and CD57, CX3CR1, GPR56 Co-expression With Increasing Glucose Intolerance

Chronic T cell activation and accelerated immune senescence are hallmarks of HIV infection, which may contribute to the increased risk of cardiometabolic diseases in people living with HIV (PLWH). T lymphocytes play a central role in modulating adipose tissue inflammation and, by extension, adipocyte energy storage and release. Here, we assessed the CD4+ and CD8+ T cell profiles in the subcutaneous adipose tissue (SAT) and blood of non-diabetic (n = 9; fasting blood glucose [FBG] < 100 mg/dL), pre-diabetic (n = 8; FBG = 100–125 mg/dL) and diabetic (n = 9; FBG ≥ 126 mg/dL) PLWH, in addition to non- and pre-diabetic, HIV-negative controls (n = 8). SAT was collected by liposuction and T cells were extracted by collagenase digestion. The proportion of naïve (TNai) CD45RO−CCR7+, effector memory (TEM) CD45RO+CCR7−, central memory (TCM) CD45RO+CCR7+, and effector memory revertant RA+(TEMRA) CD45RO−CCR7− CD4+ and CD8+ T cells were measured by flow cytometry. CD4+ and CD8+ TEM and TEMRA were significantly enriched in SAT of PLWH compared to blood. The proportions of SAT CD4+ and CD8+ memory subsets were similar across metabolic status categories in the PLWH, but CD4+ T cell expression of the CD69 early-activation and tissue residence marker, particularly on TEM cells, increased with progressive glucose intolerance. Use of t-distributed Stochastic Neighbor Embedding (t-SNE) identified a separate group of predominantly CD69lo TEM and TEMRA cells co-expressing CD57, CX3CR1, and GPR56, which were significantly greater in diabetics compared to non-diabetics. Expression of the CX3CR1 and GPR56 markers indicate these TEM and TEMRA cells may have anti-viral specificity. Compared to HIV-negative controls, SAT from PLWH had an increased CD8:CD4 ratio, but the distribution of CD4+ and CD8+ memory subsets was similar irrespective of HIV status. Finally, whole adipose tissue from PLWH had significantly higher expression of TLR2, TLR8, and multiple chemokines potentially relevant to immune cell homing compared to HIV-negative controls with similar glucose tolerance

Adipose tissue is enriched for activated and Late-differentiated CD8+ T cells, and shows distinct CD8+ receptor usage, compared to blood in HIV-infected persons

BACKGROUND: Adverse viral and medication effects on adipose tissue contribute to the development of metabolic disease in HIV-infected persons, but T cells also have a central role modulating local inflammation and adipocyte function. We sought to characterize potentially proinflammatory T-cell populations in adipose tissue among persons on long-term antiretroviral therapy and assess whether adipose tissue CD8 T cells represent an expanded, oligoclonal population. METHODS: We recruited 10 HIV-infected, non-diabetic, overweight or obese adults on efavirenz, tenofovir, and emtricitabine for >4 years with consistent viral suppression. We collected fasting blood and subcutaneous abdominal adipose tissue to measure the percentage of CD4 and CD8 T cells expressing activation, exhaustion, late differentiation/senescence, and memory surface markers. We performed T-cell receptor (TCR) sequencing on sorted CD8 cells. We compared the proportion of each T-cell subset and the TCR repertoire diversity, in blood versus adipose tissue. RESULTS: Adipose tissue had a higher percentage of CD3CD8 T cells compared with blood (61.0% vs. 51.7%, P < 0.01) and was enriched for both activated CD8HLA-DR T cells (5.5% vs. 0.9%, P < 0.01) and late-differentiated CD8CD57 T cells (37.4% vs. 22.7%, P < 0.01). Adipose tissue CD8 T cells displayed distinct TCRβ V and J gene usage, and the Shannon Entropy index, a measure of overall TCRβ repertoire diversity, was lower compared with blood (4.39 vs. 4.46; P = 0.05). CONCLUSIONS: Adipose tissue is enriched for activated and late-differentiated CD8 T cells with distinct TCR usage. These cells may contribute to tissue inflammation and impaired adipocyte fitness in HIV-infected persons

Defining an adipose tissue single cell atlas to understand metabolic disease in HIV

Background: Adipose tissue (AT) is a critical regulator of metabolic health and is emerging as important in HIV. Despite this, data on the complex cellular milieu and immune regulation are lacking. We sought to assess the AT microenvironment in persons with HIV (PWH). Methods: We performed subcutaneous abdominal liposuction and isolated the stromal vascular fraction (SVF) from 16 HIV-negative diabetics, 16 HIV-positive non-diabetics and 16 HIV-positive diabetics on long-term ART. Cells were stained with a panel of 5’ DNA-sequence tagged antibodies (TotalSeq-C) that represented standard lineages, activation and regulatory markers (45 antibodies). For the analysis, CellRanger (version 3.0.0) was used to demultiplex the raw sequencing data, extract filter and correct barcodes and unique molecular identifiers, remove cDNA PCR duplicates and align reads to the human transcriptome (GRCh38). The resulting BAM files and filtered count matrices were used in analyses. We assessed the AT cell types and their association of these subsets with the preadipocytes (Spearman rank correlation). Results: Agnostic to metabolic disease, PWH had lower proportions of pre-adipocytes (median 20.4% in non-diabetic and 36.4% in diabetic) compared with HIV-negative diabetic participants (62.7%) (Figure 1). The proportion of CD8 T cells, monocytes and NK cells were significantly higher in PWH compared with HIV-negative participants, irrespective of metabolic disease. Pre-adipocyte and NK cells were inversely related in non-diabetic PWH (r = _0.68, p = 0.005), diabetic PWH (r = _0.70, p = 0.004) and HIV-negative diabetics (r = _0.51, p = 0.05). A similar trend was observed between CD8 T cells and pre-adipocytes. Conclusions: We have generated a detailed atlas of AT SVF by HIV and diabetes status and show that PWH have higher proportions of NK and T cells compared with diabetic HIV negative. We hypothesize that this may correlate with the HIV reservoir. Future studies will pair this data with measurements of the HIV reservoir quantification and ART drug levels to understand how AT contributes to viral persistence

Interleukin-17A is associated with flow-mediated dilation and interleukin-4 with carotid plaque in persons with HIV

Objective: Chronic inflammation contributes to the high burden of cardiovascular disease (CVD) in persons with HIV (PWH). HIV has broad effects on innate and adaptive immune cells, including innate lymphoid cells (ILCs) and CD4+ T-helper cells. At present, the relationship between CVD and plasma cytokines reflecting ILC/T-helper responses in PWH is not well defined. We investigated relationships between plasma cytokines and subclinical atherosclerosis. Design: A cross-sectional study. Methods: We recruited 70 PWH on a single antiretroviral regimen (efavirenz, teno- fovir, and emtricitabine) with at least 12 months of suppressed viremia and 30 HIVnegative controls. We quantified plasma cytokines and chemokines, including inter- feron-g, interleukin (IL)-4, IL-13, and IL-17A, markers of macrophage activation, and markers of endothelial activation using multiplex assays and ELISA. Cytokines were grouped using Ward's hierarchical clustering. Brachial artery flow-mediated dilation (FMD) and carotid plaque burden were determined using ultrasound. Multivariable linear regression and negative binomial regression analyses were used to assess the relationships of plasma biomarkers and endpoints adjusted for CVD risk factors. Results: We identified three distinct clusters in PWH, one containing Th1/Th2/ILC1/ ILC2 type cytokines, one with Th17/ILC3/macrophage-related cytokines, and a less specific third cluster. Lower FMD was associated with higher plasma IL-17A and macrophage inflammatory protein-1 a. In contrast, IL-4, a Th2/ILC2 type cytokine, was associated with carotid plaque. When HIV-negative controls were added to the models clustering was more diffuse, and these associations were attenuated or absent. Conclusion: Th17/ILC3 and Th2/ILC2-mediated immune mechanisms may have distinct roles in endothelial dysfunction and atherosclerotic plaque formation, respectively, in PWH