Functional differences in behavior of monocyte/macrophage from HIV+ patients versus healthy subjects

Abstract

Abstract Increased risk of atherosclerotic cardiovascular diseases is common in HIV+ adults on stable antiretroviral treatment (ART). A key step in the development of the atherosclerotic plaque is the transmigration of monocytes to the plaque area and their differentiation into macrophages and eventually foam cells. The objective of this study was to determine if the propensity of monocytes to transmigrate as well as their ability to take up and efflux cholesterol is affected by HIV infection. Monocytes (transmigration) and differentiated macrophages (lipid metabolism) from HIV+ ART treated patients were compared against those from matched controls as a single point cross-sectional study. Monocyte transmigration was assessed by transwell assay using MCP1 as a chemoattractant, whereas lipid uptake was measured by flow cytometry analysis of internalized acetylated LDL and cholesterol efflux by tracking tritiated cholesterol excreted from the cell after exposure to HDL. Interestingly, isolation of monocytes via negative selection with magnetic beads revealed that the yield of monocyte was significantly lower from HIV+ patients compared to controls. While no significant differences were found in cholesterol uptake or efflux parameter, the ability of monocyte to transmigrate was slightly increased in HIV patients compared to controls suggesting that the chemotactic function of monocytes may be partly responsible for the differences in the atherosclerosis risk in patients with HIV.