CELL-ADHESION MOLECULES - UPDATE

Cell adhesion molecules are glycoproteins expressed on the cell surfac e and play an important role in inflammatory as well as neoplastic dis eases. There are four main groups: the integrin family, the immunoglob ulin superfamily, selectins, and cadherins. The integrin family has ei ght subfamilies, designated as beta(1), through beta(8). The most wide ly studied subfamilies are beta(1) (CD29, very late activation [VLA] m embers), beta(2) (leukocyte integrins such as CDlla/CD18, CD11b/CD18, CD11c/CD18, and alpha(d),beta(2)), beta(3) (CD61, cytoadhesions), and beta(7) (alpha(4) beta(7) and alpha(E) beta(7)). The immunoglobulin su perfamily includes leukocyte function antigen-2 (LFA-2 or CD2), leukoc yte function antigen-3 (LFA-3 or CD58), intercellular adhesion molecul es (ICAMs), vascular adhesion molecule-1 (VCAM-1), platelet-endothelia l cell adhesion molecule-1 (PE-CAM-1), and mucosal addressin cell adhe sion molecule-1 (MAdCAM-1). The selectin family includes E-selectin (C D62E), P-selectin (CD62P), and L-selectin (CD62L). Cadherins are major cell-cell adhesion molecules and include epithelial (E), placental (P ), and neural (N) subclasses. The binding sites (ligands/receptors) ar e different for each of these cell adhesion molecules (e.g., ICAM bind s to CD11/CD18; VCAM-1 binds to VLA-4). The specific cell adhesion mol ecules and their ligands that may be involved in pathologic conditions and potential therapeutic strategies by modulating the expression of these molecules will be discussed.