Intracellular adhesion molecules (ICAM)

Endothelial cells

FIGURE 14-29 (Continued)

B. Selectin-mediated leukocyte-endothelial interaction results in the rolling of leukocytes along the endothelium and facilitates the firm adhesion and immobilization of leukocytes. Immobilization of leukocytes to endothelium is mediated by the l^-integrin adhesion molecules on leukocytes and their ICAM ligands on endothelial cells. Immobilization of leukocytes is necessary for diapedesis of leukocytes between endothelial cells into parenchymal tissue. Leukocytes release proteases, elastases, and reactive oxygen radicals that induce tissue injury. Activated leukocytes also elaborate cytokines such as interleukin 1 and tumor necrosis factor which attract additional leukocytes to the site, causing further injury.

0 0

Post a comment