Circulating CD3+ CD14+ T Cell-Monocyte complexes are dynamic, metabolically glucose-dependent HIV reservoirs and increased in individuals with glucose intolerance
Persistent and elevated systemic inflammation contributes to the increased risk of cardiovascular and metabolic diseases in persons with HIV (PWH). , but aspects of the innate and adaptive immune response to HIV and other chronic co-infections that promote the development of these comorbid conditions remain unclear. We used mass cytometry and the tracking responders expanding (T-REX) workflow to define differences in circulating cells of the innate and adaptive immune arms, which differentiate non-diabetic and prediabetic/diabetic persons with HIV (PWH) on long-term antiretroviral therapy (ART). We found a significantly higher proportion of circulating CD14+ monocytes complexed with T cells, B cells, and NK cells among PWH with diabetes. The CD3+ T cells in these complexes were predominantly CD8+ memory T cells. The CD3+ CD14+ T cell-monocyte complexes are pro-inflammatory and negatively associated with plasma interleukin-10 levels and circulating CD4+ T regulatory cells. Using transmission electron microscopy, we observed heterogeneous interactions between CD3+ T cells and monocytes within the complexes, including formation of immune synapses and phagocytosis. 10x Chromium single-cell sequencing RNA transcriptomic analysis of CD3+ CD14+ doublets showed differential expression of genes involved in T cell activation and the adaptive immune response compared to monocytes that were not complexed with other immune cells. Notably, there were significantly more copies of HIV RNA  per cell in the CD3+ CD14+ T cell-monocyte complexes compared to CD14+ monocytes or CD3+ CD4+ T cells alone, and HIV virions were observed in both T cells and monocytes within the doublets?. Metabolically, CD3+ CD14+ T cell-monocyte complexes had high glucose-dependence with minimal mitochondrial dependence. Taken together, CD3+ CD14+ T cell-monocyte pairs are functional and physically interacting immune cell complexes which might be enriched with HIV. These complexesare increased among individuals with diabetes and may be a target for future HIV cure studies and diseases of aging. Overall design: Circulating peripheral blood mononuclear cells were isolated and analyzed using scRNAseq.