Antigen-Induced Immunomodulation in the Pathogenesis of Atherosclerosis
Figure 3
Schematic representation of the low-density
lipoprotein particle (LDL). The LDL particle has a size of approximately 21–24 nm and is the
main transporter of unesterified cholesterol, cholesterol esters, and
triglycerides in the blood. It contains an outer layer composed of phospholipids
and unesterified cholesterol in which a single protein is embedded, the apolipoprotein
B-100 (apoB-100). These components are more susceptible to oxidation by free
radicals in the subendothelial space during inflammation. They are also targets
for the recognition of the LDL by scavenger receptors, proteoglycans, and low-density
lipoprotein receptor (LDLr). The core of the particle contains primarily
cholesterol esters and triglycerides. In atherogenesis, a large number of IgM
antibodies are created in response to oxidative stress-modified phospholipids, whereas
IgG antibodies and T-cell clones are generated against apoB-100.