The importance of leukocyte integrin activation in myeloid cell interaction with endothelium

The dynamic interaction of monocytes and neutrophils with endothelium controls the vital process of phagocyte entry into tissues. At least three families of adhesion molecules participate in these events, which are probably initiated by chemotactic agents or cytokines released by endothelium in close association with traumatised tissue cells (1-4). The three families are the leukocyte integrins, with relevant members being LFA1/CD11a, CR3/Mac1/CD11b, p150,95 and VLA4; the immunoglobulin (Ig) superfamily to which belong ICAM-1, ICAM-2 and VCAM-1; and the Selectins or LEC-CAMs with members Mel14/LAM-1/LEC-CAM-1, ELAM-1/LEC-CAM-2 and PADGEM/GMP140/CD62/LEC-CAM-3.