Figure 1.

Characteristics of advanced atherosclerotic disease. As luminal LDL is deposited into the subendothelial space of the blood vessel wall, it becomes oxidized. Oxidized lipids trigger the recruitment of leukocytes to the subendothelial space. Monocytes differentiate into dendritic cells or tissue macrophages that take up oxidized lipids and become foam cells. Without effective clearance of these apoptotic-prone cells, they accumulate, secrete pro-inflammatory cytokines and undergo apoptosis and necrosis, dumping their lipid contents into the extracellular space to create a necrotic core. Cytokines and immunoglobulins produced by vessel wall and immune cells can further modulate atherosclerosis. ATLOs are found in the adventitia of diseased vessels and are composed of T cells, B cells, macrophages, and other leukocytes. Soluble factors can cross into the media through conduits and may contribute to plaque development. Abbreviation: oxLDL, oxidized LDL; ATLO, aortic tertiary lymphoid organ; EC, endothelial cell; SMC, smooth muscle cell; Adip, adipocyte; Mono, monocyte; Mac, macrophage; FC, foam cell; DC, dendritic cell.