Elevated TGF-β/IL-10 in platelet-monocyte complexes exacerbates atherosclerosis in people with HIV 2252272

Abstract

Abstract Introduction People living with HIV (PLWH) are more susceptible to atherosclerosis (AS). Here, we examine the functional consequences of platelet-monocyte complexes (PMCs), which are elevated in PLWH and are hypothesized to contribute to HIV-associated comorbidities. Methods We performed single-cell RNA sequencing (scRNAseq) of monocytes isolated from age-, sex-, and cardiovascular risk score-matched participants categorized based on HIV and early AS status (n = 8 per group). Monocytes and platelets were cocultured ex vivo ± LPS (to simulate chronic inflammation) and analyzed at multiple time points as PMCs (24 hours) and PMC-derived macrophages (Mϕs, six days) via bulk RNA sequencing/RT-qPCR, ELISA, and flow cytometry. PMCs were cocultured with primary human endothelial cells (ECs) between three and six days of macrophage differentiation to assess endothelial to mesenchymal transition (EndMT) via RT-qPCR and ELISA. Results scRNAseq PMCs in PLWH and AS had increased TGF-β/IL-10 signaling compared to either PLWH or people living with AS (PLWAS) alone. Ex-vivo PMCs upregulated expression of genes involved in TGF-β signaling and IL-10 expression at both the monocyte and Mϕ developmental states. LPS stimulation increased IL-10 and TGF-β secretion and reduced TNF-α levels in culture supernatants. PMC-derived Mϕs increased expression of costimulatory molecules CD86 and CD80. When cultured with primary ECs, PMC-derived Mϕs reduced Pecam1 and Cdh5 and increased S100a4 expression. CCL2 and IL-6 were elevated in PMC-derived Mϕ-EC cocultures. LPS stimulation of cocultures increased expression of adhesion molecules Icam1 and Vcam. Conclusion Platelet interactions underscore monocyte-Mα¦ differentiation that promotes EndMT via TGF-β and IL-10, suggesting a pro-AS role of these factors in early disease. Enhanced TGF-β/IL-10 expression in PMCs of PLWH and AS suggests an increased relevance of this pathology in these individuals and defines a mechanistic link between aberrant platelet activation, PMC formation, and AS in PLWH. Funding Source T32AI118689, R01HL160229 Topic Categories Innate Immune Responses and Host Defense: Cellular Mechanisms (INC)