CELL-MEDIATED-IMMUNITY IN ATHEROSCLEROSIS

Immunocompetent cells infiltrate atherosclerotic plaques of all stages . Plaque-infiltrating T-cells recognize oxidized LDL and heat shock pr oteins and this elicits antibody responses that have been proposed as markers of disease activity. Cytokines secreted by activated T-cells m ay control macrophage activation, scavenger receptor expression and me talloproteinase secretion. Furthermore, cytokines secreted by T-cells and macrophages modulate smooth muscle proliferation, nitric oxide pro duction and apoptosis, and induce endothelial activation. However, bot h positive and negative signals, as well as feedback loops, may be ind uced because of the complexity of the immune system. The possibility t hat some of these signals may be protective against atherosclerosis is currently under investigation in several laboratories. Recent studies in experimental animals show that immunomodulation affects the develo pment of plaques and that immunization with oxidized LDL can inhibit l esion formation. This review provides a brief overview of cellular imm unology and an analysis of its potential role in atherogenesis.