FIGURE 2.
Proinflammatory and anti-inflammatory functions of macrophages and dendritic cells (DC) in atherosclerosis. (a) Atheroprotective mechanisms at early stages of atherosclerosis are mediated by anti-inflammatory functions of macrophages and DC, which includes induction of regulatory T cells (Treg) and anti-inflammatory cytokine production. The phagocytic function of macrophages contributes to clearance of dead cells and extracellular lipids. (b) During the later stages of atherosclerosis the proinflammatory mechanisms dominate. Both macrophages and dendritic cell produce proinflammatory cytokines and chemokines, which promote local inflammation. Antigen presentation is a signature of dendritic cells, however macrophages are able to present antigens to antigen-experienced T cells. Both macrophages and dendritic cells could become foam cells. Filled with lipids, foam cells can die forming the necrotic core inside the plaque, resulting in plaque instability and potential rupture.