ITGB2

ITGB2 Full Name

integrin, beta 2 (complement component 3 receptor 3 and 4 subunit)

ITGB2 Introduction

ITGB2 encodes integrin subunit beta 2, a non-enzymatic transmembrane adhesion protein traditionally referred to as CD18, that pairs with various α-integrin chains to assemble functionally distinct β2 integrin receptors expressed mainly on leukocytes. These heterodimeric complexes include LFA-1 (αLβ2), Mac-1 (αMβ2), αXβ2, and αDβ2, each of which engages different ligands such as ICAM1–4, iC3b and fibrinogen fragments to mediate cell–cell adhesion and signaling in the immune system. Rather than acting in isolation, ITGB2-containing integrins operate as dynamic surface organizers on neutrophils, monocytes, macrophages, dendritic cells and subsets of lymphocytes, where they reinforce adhesive contacts and coordinate extracellular cues with intracellular responses during immune surveillance and inflammation.

Figure 1. Structural schematic of the extended β 2 integrin.(Sources:Fan Z, et al.; 2015 )

What sets ITGB2 apart from many immune receptors is its dual role in anchoring leukocytes and shaping signaling networks that govern leukocyte trafficking, phagocytosis and effector functions. Upon encountering inflammatory signals, β2 integrins undergo conformational changes that increase affinity for endothelial ligands, enabling leukocytes to slow, adhere and transmigrate out of blood vessels toward sites of injury; in addition, these integrins contribute to complement-mediated phagocytosis, activation of natural killer cytotoxicity and interactions with pattern recognition receptors that modulate cytokine production. Beyond facilitating physical tethering, ITGB2 influences the assembly of immunological synapses and can temper or amplify innate and adaptive responses through crosstalk with Toll-like receptors and cytoskeletal regulators, illustrating its multifaceted participation in immune regulation.

Aberrant ITGB2 function has clear clinical relevance, ranging from rare immunodeficiency to roles in chronic inflammation and tissue damage. Leukocyte adhesion deficiency type 1 (LAD1) results from mutations that impair β2 integrin expression or membrane localization, leaving immune cells unable to adhere and migrate effectively, which manifests as recurrent bacterial and fungal infections with impaired wound healing. Beyond congenital immunodeficiency, altered ITGB2 expression has been implicated in autoimmune and inflammatory disorders such as systemic sclerosis, rheumatoid arthritis and osteoarthritis—where its upregulation correlates with disease activity and may serve as a diagnostic or prognostic marker—and evidence also suggests involvement in leukocyte-driven tissue remodeling and tumor-associated immune responses. Within research and translational contexts, ITGB2 antibodies for flow cytometry, immunohistochemistry, Western blotting, recombinant integrins and functional assays are widely used to study leukocyte adhesion, migration, receptor–ligand interactions and potential therapeutic modulation of β2 integrin-mediated pathways.

Alternate Names for ITGB2

ITGB2; integrin, beta 2 (complement component 3 receptor 3 and 4 subunit); LAD; CD18; MF17; MFI7; LCAMB; LFA-1; MAC-1; integrin beta-2; integrin beta chain, beta 2; complement receptor C3 beta-subunit; leukocyte cell adhesion molecule CD18; leukocyte-associated antigens CD18/11A, CD18/11B, CD18/11C; cell surface adhesion glycoprotein (LFA-1/CR3/P150,959 beta subunit precursor);

• 1. Fan Z, Ley K. Leukocyte arrest: Biomechanics and molecular mechanisms of β2 integrin activation. Biorheology. 2015;52(5-6):353-77.