The β1 and β3 Integrins Promote T Cell Receptor-mediated Cytotoxic T Lymphocyte Activation

doi:10.1074/jbc.M302709200

The β₁ and β₃ Integrins Promote T Cell Receptor-mediated Cytotoxic T Lymphocyte Activation*

^aInstitute for Biochemistry, University of Lausanne, 1066 Epalinges, Switzerland, the ^dLudwig Institute for Cancer Research, Lausanne Branch, University of Lausanne, 1066 Epalinges, Switzerland, ^cINSERM U563, CHU Purpan, 31059 Toulouse, France, the ^eKantonsspital, University of Basel, 4031 Basel, Switzerland, and the ^fCentre Pluridisciplinaire d'Oncologie, University of Lausanne Medical School, 1066 Epalinges, Switzerland

b To whom correspondence should be addressed. Tel.: 41-21-692-5745; Fax: 41-21-692-5705; E-mail: ma_doucey{at}hotmail.com.

Abstract

Recognition by CD8⁺ cytotoxic T lymphocytes (CTLs) of antigenic peptides bound to major histocompatibility class (MHC) I molecules on target cells leads to sustained calcium mobilization and CTL degranulation resulting in perforin-dependent killing. We report that β₁ and β₃ integrin-mediated adhesion to extracellular matrix proteins on target cells and/or surfaces dramatically promotes CTL degranulation. CTLs, when adhered to fibronectin but not CTL in suspension, efficiently degranulate upon exposure to soluble MHC·peptide complexes, even monomeric ones. This adhesion induces recruitment and activation of the focal adhesion kinase Pyk2, the cytoskeleton linker paxillin, and the Src kinases Lck and Fyn in the contact site. The T cell receptor, by association with Pyk2, becomes part of this adhesion-induced activation cluster, which greatly increases its signaling.

Footnotes

↵1 The abbreviations used are: CTLs, cytotoxic T lymphocytes; TCR, T cell receptor; MHC, major histocompatibility complex; APCs, antigen-presenting cells; LFA-1, lymphocyte function associated antigen-1; ICAMs, intracellular adhesion molecule; ECM, extracellular matrix; PbCS, P. berghei circumsporozite; ABA, 4-azidobenzoic acid; DMEM, Dulbecco's modified Eagle's medium; FACS, fluorescence-activated cell sorting; mAb, monoclonal antibody; FRET, fluorescence resonance energy transfer; PBS, phosphate-buffered saline; BSA, bovine serum albumin; pY, phosphotyrosine; PP2, 4-amino-5-(4-chlorophenyl)-7-(t-butyl)pyrazolo[3,4-d]pyrimidine; PE, phycoerythrin; GM1, Galβ1,3GalNacβ1,4NeuAcα2,3Galβ1,4Glc-ceramide.
↵2 M.-A. Doucey, D. F. Legler, M. Faroudi, N. Boucheron, P. Baumgaertner, D. Naeher, M. Cebecauer, D. Hudrisier, C. Rüegg, E. Palmer, S. Valitutti, C. Bron, and I. F. Luescher, unpublished results.
↵* The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked “advertisement” in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.
↵g Supported by grants from La Ligue contre le Cancer, l'Association de la Recherche contre le Cancer, and la Fondation pour la Recherche Médicale.
↵h Supported by a grant of the Gabriella Giorgi-Cavaglieri Foundation and by the Swiss National Science Foundation (Grant 31-061960.00).
↵i Supported by the Swiss National Science Foundation (Grant 3100-061946.00).
- Received March 17, 2003.
- Revision received April 9, 2003.
The American Society for Biochemistry and Molecular Biology, Inc.