ITGB2
MIM.600065
Beta2-integrins
The β2 integrins are also called CD11a-cCD18, or the leukocyte function-associated antigen-1 (LFA-1) family, CD11a-c referring to different α chains (ITGAs) and CD18 to the common β2 subunit (ITGB2).
LFA-1 (CD11aCD18) plays an important role in the adhesion of lymphocytes and other leukocytes with other cells, such as antigen-presenting cells and vascular endothelium.
Other members of the family include CD11bCD18 (Mac-1 or CR3) and CD11cCD18 (p150,95 or CR4), which mediate leukocyte attachment to endothelial cells and subsequent extravasation.
CD11bCD18 also functions as a fibrinogen receptor and as a complement receptor on phagocytic cells, binding particles opsonized with a by-product of complement activation called the inactivated C3b (iC3b) fragment.
ITGB2 and ITGB3
Signaling by beta(2) and beta(3) integrins in various cell types (neutrophils, macrophages, osteoclasts and platelets) use components of the signal transduction machinery of lymphocyte antigen receptors.
Central to this immunoreceptor-like signaling is the phosphorylation of immunoreceptor tyrosine-based activation motif (ITAM)-containing adapters (such as DAP12 and the Fc receptor gamma-chain) by Src-family kinases and the concomitant recruitment of the Syk tyrosine kinase through its dual SH2 domains.
Pathology
ITGB2 deficiency (CD18 deficiency or LFA1 leukocyte adhesion deficiency)
References
Lee SH, Corry DB. Homing alone? CD18 in infectious and allergic disease. Trends Mol Med. 2004 Jun;10(6):258-62. PMID: #15177189#