The antibody IVA35 reacts with an extracellular epitope of CD18 antigen (bovine), a 90-95 kDa type I transmembrane protein (integrin) expressed on all leukocytes.
Integrin subunit beta 2,CD18, integrin beta2 subunit, forms heterodimers with four types of CD11 Molecule to constitute leukocyte (beta2) integrins: alphaLbeta2 (CD11a/CD18, LFA-1), alphaMbeta2 (CD11b/CD18, Mac-1, CR3), alphaXbeta2 (CD11c/CD18) and alphaDbeta2 (CD11d/CD18). In most cases, the response mediated by the integrin is a composite of the functions of its individual subunits. These integrins are essential for proper leukocyte migration, mediating intercellular contacts. Absence of CD18 leads to leukocyte adhesion deficiency-1, severe reduction of CD18 expression leads to the development of a psoriasiform skin disease. CD18 is also a target of Mannheimia (Pasteurella) haemolytica leukotoxin and is sufficient to mediate leukotoxin-mediated cytolysis.,Integrin beta2, Complement receptor C3 subunit beta, ITGB2