αEβ7 integrin interaction with E-cadherin promotes antitumor CTL activity by triggering lytic granule polarization and exocytosis

AL Floc'h, A Jalil, I Vergnon, BLM Chansac… - The Journal of …, 2007 - rupress.org
AL Floc'h, A Jalil, I Vergnon, BLM Chansac, V Lazar, G Bismuth, S Chouaib
The Journal of experimental medicine, 2007rupress.org
Various T cell adhesion molecules and their cognate receptors on target cells promote T cell
receptor (TCR)–mediated cell killing. In this report, we demonstrate that the interaction of
epithelial cell marker E-cadherin with integrin αE (CD103) β7, often expressed by tumor-
infiltrating lymphocytes (TILs), plays a major role in effective tumor cell lysis. Indeed, we
found that although tumor-specific CD103+ TIL-derived cytotoxic T lymphocyte (CTL) clones
are able to kill E-cadherin+/intercellular adhesion molecule 1− autologous tumor cells …
Various T cell adhesion molecules and their cognate receptors on target cells promote T cell receptor (TCR)–mediated cell killing. In this report, we demonstrate that the interaction of epithelial cell marker E-cadherin with integrin αE(CD103)β7, often expressed by tumor-infiltrating lymphocytes (TILs), plays a major role in effective tumor cell lysis. Indeed, we found that although tumor-specific CD103+ TIL-derived cytotoxic T lymphocyte (CTL) clones are able to kill E-cadherin+/intercellular adhesion molecule 1 autologous tumor cells, CD103 peripheral blood lymphocyte (PBL)-derived counterparts are inefficient. This cell killing is abrogated after treatment of the TIL clones with a blocking anti-CD103 monoclonal antibody or after targeting E-cadherin in the tumor using ribonucleic acid interference. Confocal microscopy analysis also demonstrated that αEβ7 is recruited at the immunological synapse and that its interaction with E-cadherin is required for cytolytic granule polarization and subsequent exocytosis. Moreover, we report that the CD103 profile, frequently observed in PBL-derived CTL clones and associated with poor cytotoxicity against the cognate tumor, is up-regulated upon TCR engagement and transforming growth factor β1 treatment, resulting in strong potentiation of antitumor lytic function. Thus, CD8+/CD103+ tumor-reactive T lymphocytes infiltrating epithelial tumors most likely play a major role in antitumor cytotoxic response through αEβ7–E-cadherin interactions.
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