CD18

Integrin beta-2 (CD18) is a protein that in humans is encoded by the ITGB2 gene.

It is the beta subunit of four different structures:

• LFA-1 (paired with CD11a)
• Macrophage-1 antigen (paired with CD11b)
• Integrin alphaXbeta2 (paired with CD11c)
• Integrin alphaDbeta2 (paired with CD11d)

Function

The ITGB2 protein product is the integrin beta chain beta 2. Integrins are integral cell-surface proteins composed of an alpha chain and a beta chain. A given chain may combine with multiple partners resulting in different integrins. For example, beta 2 combines with the alpha L chain to form the integrin LFA-1, and combines with the alpha M chain to form the integrin Mac-1. Integrins are known to participate in cell adhesion as well as cell-surface mediated signalling. In humans lack of CD18 causes Leukocyte Adhesion Deficiency, a disease defined by a lack of leukocyte extravasation from blood into tissues. The beta 2 integrins have also been found in a soluble form. The soluble beta 2 integrins are ligand binding and plasma levels are inversely associated with disease activity in the autoimmune disease spondyloarthritis.

Interactions

CD18 has been shown to interact with:

• FHL2,
• GNB2L1,
• ICAM-1, and
• PSCD1.

See also

• leukocyte adhesion deficiency
• integrin

External links

• CD18 antigen at the US National Library of Medicine Medical Subject Headings (MeSH)
• ITGB2 Info with links in the Cell Migration Gateway