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.