Extracellular Vesicles Favor Early Peripheral Immunosenescence Through Modulation of the Senescence-Associated Secretory Phenotype in HIV Infection.

HIV infection induces chronic immune activation, predisposing people living with HIV (PLWH) to early immunosenescence. It is essential to understand the mechanisms behind the senescence-associated secretory phenotype (SASP). This study investigates the role of extracellular vesicles (EVs) in peripheral immunosenescence in HIV infection associated with SASP modulation. Biological and in silico analyses were performed to explore the crosstalk between EVs, miR-21-5p, and SASP. Plasma EVs from PLWH were isolated and used to stimulate peripheral blood mononuclear cells (PBMCs) to evaluate their potential to induce SASP. Mononuclear cells were transfected in vitro to induce the production of EVs carrying specific miR-21-5p and assess their role in SASP induction. Inflammatory and senescence markers were analyzed using an immunoassay, flow cytometry, and RT-qPCR. Biological verifications revealed that plasma EVs from PLWH predominantly induce SASP and drive IL-6 production in HIV-uninfected PBMCs. We confirmed that miR-21-5p expression was increased in plasma EVs from chronically infected PLWH on antiretroviral therapy (ART). Furthermore, we demonstrated that EVs overexpressing miR-21-5p induced SASP, specifically increasing IL-6 levels. SASP-associated cytokines were associated with PLWH with impaired CD4 T cell recovery and a higher prevalence of CD8+ and CD4+ CD57+ T cells. We also corroborate that IP-10, IFN-γ, and IL-6 could be potential biomarkers for identifying PLWH at greater risk of immunosenescence. Our findings provide insights into EVs driving SASP/IL-6 release, and this effect becomes more evident in EVs that carry miR-21-5p. This finding highlights a potential mechanism by which EVs and IL-6 contribute to peripheral immunosenescence in HIV-uninfected cells.