Lymphocyte function-associated antigen 1, also known as LFA-1 is found on all T-cells and also on B-cells, macrophages and neutrophils and is involved in recruitment to the site of infection. It binds to ICAM-1

ICAM-1

ICAM-1 also known as CD54 is a protein that in humans is encoded by the ICAM1 gene. This gene encodes a cell surface glycoprotein which is typically expressed on endothelial cells and cells of the immune system...

 on antigen-presenting cells and functions as an adhesion molecule. LFA-1 is the first to bind T-cells to antigen-presenting cells and initially binds weakly. A signal from the T-cell receptor and/or the cytokine receptor changes the conformation and prolongs the cell contact, allowing the T-cell to proliferate.

LFA-1 is part of the family of leukocyte integrin

Integrin

Integrins are receptors that mediate attachment between a cell and the tissues surrounding it, which may be other cells or the ECM. They also play a role in cell signaling and thereby regulate cellular shape, motility, and the cell cycle....

s that are recognised by their common β-chains (CD18

CD18

Integrin beta-2 is a protein that in humans is encoded by the ITGB2 gene.It is the beta subunit of four different structures:* LFA-1 * Macrophage-1 antigen * Integrin alphaXbeta2...

). LFA-1 also has a distinct α-chain (CD11a

CD11a

Integrin, alpha L , also known as ITGAL, is a human gene which functions in the immune system. It is involved in cellular adhesion and costimulatory signaling...

).

Further reading

• Janeway, Travers, Walport, Shlomchik, Immunobiology 6th ed. (2005) Garland Science:NY
• Parham, Peter, The Immune System 3rd ed. (2009) Garland Science: London and New York

External links

• ITGAL ITGB2 Info with links in the Cell Migration Gateway