Nef in impaired efferocytosis: a novel mechanism for vascular disease in HIV

Project Summary Anti-retroviral therapy (ART) has protected many HIV patients against the development of AIDS. HIV infection has become a treatable disease. Increased risk for atherosclerotic vascular diseases in long-term HIV survivors or people living with HIV (PLWH) with no detectable virus load, however, is projected to become a global health burden. Despite its clinical impact, underlying mechanisms for accelerated atherogenesis in PLWH remain obscure. Macrophages promote the formation of high-risk plaques prone to vascular events (e.g., macrophage-rich, large necrotic core, think fibrous cap). Macrophages are heterogeneous and the imbalance of their subpopulations may accelerate atherogenesis. Evidence suggests that extracellular vesicles (EVs) that contain the HIV-associated protein Nef (Nef EVs) promote chronic inflammation. We will examine the effects of Nef EVs in the heterogeneity and functions of macrophages and the formation of atherogenesis. Our study represents a dynamic interplay of biology and data science to identify novel mechanisms and therapeutic targets. We will use a systems approach to test the central hypothesis that Nef EVs modulate macrophage heterogeneity, shifting the balance toward an atherogenic or less atheroprotective phenotype. Our preliminary data have led us to the specific biological hypothesis that Nef EVs impair efferocytosis and contribute to the formation of high-risk atherosclerotic plaques that we will test in three Specific Aims. In Specific Aim 1, we will conduct a systems-based macrophage profiling, involving unbiased multi-omics, data integration, and network analysis to identify novel mechanisms for macrophage activation by Nef EVs. Pilot multi-omics data suggested that Nef EVs suppresses efferocytosis. In Specific Aim 2, we will validate omics data in vitro and in vivo and address underlying mechanisms for impaired macrophage efferocytosis by Nef EVs.