The Migration JAM

Science's STKE  19 Feb 2002:
Vol. 2002, Issue 120, pp. tw74
DOI: 10.1126/stke.2002.120.tw74

Exposure of leukocytes to chemokines during an immune response stimulates their migration across the vasculature into surrounding tissue. This process involves leukocyte-endothelial cell interactions, which are mediated by various cell-surface proteins, including integrins (which are expressed on leukocytes) and adhesion molecules of the immunoglobulin superfamily (IgSF) (which are expressed on endothelial cells). Ostermann et al. report that the lymphocyte integrin LFA-1 binds to an IgSF protein that is a junctional adhesion molecule (JAM-1) typically found in tight junctions that mediate endothelial cell-cell adhesion. Upon exposure to proinflammatory cytokines, JAM-1 relocated from tight junctions to the endothelial cell surface where it bound to LFA-1 molecules expressed on T cells and neutrophils. Antibodies to JAM-1 also impaired transendothelial migration of leukocytes in a cultured cell system. Hence, JAM-1 also mediates a cell-cell interaction that facilitates leukocyte extravasation during inflammation.

G. Ostermann, K. S. C. Weber, A. Zernecke, A. Schroder, C. Weber, JAM-1 is a ligand of the
β 2 integrin LFA-1 involved in transendothelial migration of leukocytes. Nature Immmunol. 3, 151-158 (2002). [Online Journal]