Triggering of the CD44 antigen on T lymphocytes promotes T cell adhesion through the LFA-1 pathway

• Published in: The Journal of immunology (1950) Vol. 145; no. 11; pp. 3589 - 3592
• Main Authors: Koopman, G, van Kooyk, Y, de Graaff, M, Meyer, CJ, Figdor, CG, Pals, ST
• Format: Journal Article
• Language: English
• Published: Bethesda, MD Am Assoc Immnol 01.12.1990; American Association of Immunologists
• Subjects: Antibodies, Monoclonal - immunology; Biological and medical sciences; Cell Adhesion; Cell Aggregation; Cell interactions, adhesion; Cytoskeleton - physiology; Fundamental and applied biological sciences. Psychology; Humans; Lymphocyte Activation; Lymphocyte Function-Associated Antigen-1 - physiology; Magnesium - pharmacology; Molecular and cellular biology; Receptors, Lymphocyte Homing - physiology; T-Lymphocytes - immunology; T-Lymphocytes - physiology; Human; Cell line; T-Lymphocyte; Cell cell interaction; Extracellular matrix; Activation; Adhesion; Mechanism
• ISSN: 0022-1767; 1550-6606
• DOI: 10.4049/jimmunol.145.11.3589

The CD44 molecule, a molecule which has been previously known as Hermes, Pgp-1, extracellular matrix receptor III, and In(Lu)-related p80, is currently thought to be involved in several steps of normal immune cell function, including lymphocyte adhesion to high endothelial venules and to the extracellular matrix and T cell activation. We now demonstrate that triggering of CD44 on T lymphocytes by anti-CD44 mAb promotes cell adhesion. The induced homotypic adhesion is mediated by lymphocyte function-associated antigen-1 (LFA-1), because it was inhibited by anti-LFA-1 antibodies and not by anti-LFA-3 antibodies. This notion is supported by the temperature and Mg2+ dependence which is characteristic of LFA-1-mediated adhesion. Moreover, the sensitivity of CD44-induced adhesion to AMG and H7, which both prevent the activation of protein kinase C, and to cytochalasin B, which inhibits microfilament formation, suggests that the activation of the LFA-1 pathway via CD44 involves protein kinase C activation and requires an intact cytoskeleton.