Invitrogen™ CD11b (activation epitope) Monoclonal Antibody (CBRM1/5), APC, eBioscience™

Description

Description: The CBRM1/5 monoclonal antibody reacts with an activation-specific epitope of human Mac-1. CBRM1/5 binds a subset of Mac-1 molecules on neutrophils and monocytes after stimulation with chemoattractants or phorbol esters but does not recognize Mac-1 on resting myeloid cells. Through interactions with its ligands, Mac-1 participates in adhesive cell interactions. The epitope recognized by this mAb localizes to the I domain on the alpha chain of Mac-1 very close to the ligand binding site in a region that is widely exposed. CBRM1/5 blocks Mac-1 dependent adhesion to fibrinogen and ICAM-1 and inhibits chemoattractant-stimulated adhesion of eosinophils to the Intercellular Adhesion Molecule-1 (ICAM-1). It should be noted that low level activation may occur during processing of freshly drawn blood. Therefore the CBRM1.5 antibody may exhibit some binding to Mac-1 in these unstimulated samples. However, higher levels of Mac-1 expression are observed in activated samples when compared to unstimulated cells. Applications Reported: This CBRM1/5 antibody has been reported for use in flow cytometric analysis. Applications Tested: This CBRM1/5 antibody has been pre-titrated and tested by flow cytometric analyis of stimulated peripheral blood cells. This can be used at 5 μL (0.5 μg) per test. A test is defined as the amount (μg) of antibody that will stain a cell sample in a final volume of 100 μL. Cell number should be determined empirically but can...

CD11b (integrin alpha-M, ITGAM, integrin alpha-X, ITGAX) is a 165 kDa adhesion molecule that associates non-covalently with integrin beta-2 (CD18). The CD11b/CD18 heterodimeric complex is also known as integrin alpha-M beta-2, Mac-1, and CR3 (complement receptor 3). CD11b is expressed on the surface of monocytes/macrophages, granulocytes, activated lymphocytes, a subset of NK cells, a subset of dendritic cells, and microglia in the brain. CD11b/CD18 functions as the receptor for ICAM-1 (CD54), ICAM-2 (CD102), ICAM-4 (CD242), CD14, CD50, CD23, heparin, iC3b, fibrinogen, and Factor X -these adhesions are critical for cell-cell and cell-matrix interactions. CD11b is expressed on 8% of spleen cells, 44% of bone marrow cells, and less than 1% of thymocytes, and is commonly used as a microglial marker in nervous tissue. The expression of CD11b increases during monocyte maturation and expression levels vary on tissue macrophages. Further, peritoneal macrophages are reported to express higher levels of CD11b than splenic macrophages. Diseases associated with CD11b dysfunction include systemic lupus erythematosus 6 and ITGAM-related susceptibility to systemic lupus erythematosus.