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Published in: European Journal of Immunology, 1998, 28 (1), pp.264-76. <a target="_blank" href="https://dx.doi.org/10.1002/(SICI)1521-4141(199801)28:013.0.CO;2-O">⟨10.1002/(SICI)1521-4141(199801)28:013.0.CO;2-O⟩

Authors: Eric Le Dréan, Frédéric Vély, Lucia Olcese, Anna Cambiaggi, Sophie Guia, Gerald Krystal, Nadine Gervois, Alessandro Moretta, Francine Jotereau, Eric Vivier

Summary

Subsets of T and natural killer (NK) lymphocytes express the CD94-NKG2A heterodimer, a receptor for major histocompatibility complex class I molecules. We show here that engagement of the CD94-NKG2A heterodimer inhibits both antigen-driven tumor necrosis factor (TNF) release and cytotoxicity on melanoma-specific human T cell clones. Similarly, CD16-mediated NK cell cytotoxicity is extinguished by cross-linking of the CD94-NKG2A heterodimer. Combining in vivo and in vitro analysis, we report that both I/VxYxxL immunoreceptor tyrosine-based inhibition motifs (ITIM) present in the NKG2A intracytoplasmic domain associate upon tyrosine phosphorylation with the protein tyrosine phosphatases SHP-1 and SHP-2, but not with the polyinositol phosphatase SHIP Determination of the dissociation constant, using surface plasmon resonance analysis, indicates that NKG2A phospho-ITIM interact directly with the SH2 domains of SHP-1 and SHP-2 with a high affinity. Engagement of the CD94-NKG2A heterodimer therefore appears as a protein-tyrosine phosphatase-based strategy that negatively regulates both antigen-induced T cell response and antibody-induced NK cell cytotoxicity. Our results suggest that this inhibitory pathway sets the threshold of T and NK cell activation.

Link to HAL – inserm-03350053

Link to DOI – 10.1002/(SICI)1521-4141(199801)28:01<264::aid-immu264>3.0.CO;2-O