title: MHC-I molecules selectively inhibit cell-mediated cytotoxicity triggered by ITAM-coupled activating receptors and 2B4.
abstract: NK cell effector functions are controlled by a combination of inhibitory receptors, which modulate NK cell activation initiated by stimulatory receptors. Most of the canonical NK cell inhibitory receptors recognize allelic forms of classical and non-classical MHC class I molecules. Furthermore, high expression of MHC-I molecules on effector immune cells is also associated with reverse signaling, giving rise to several immune-regulatory functions. Consequently, the inhibitory function of MHC class I expressed on a human NKL cell line and activated primary NK and T cells on different activating receptors are analyzed in this paper. Our results reveal that MHC-I molecules display specific patterns of "selective" inhibition over cytotoxicity and cytokine production induced by ITAM-dependent receptors and 2B4, but not on NKG2D. This contrasts with the best known "canonical" inhibitory receptors, which constitutively inhibit both functions, regardless of the activating receptor involved. Our results support the existence of a new fine-tuner inhibitory function for MHC-I molecules expressed on cytotoxic effector cells that could be involved in establishing self-tolerance in mature activated NK cells, and could also be important in tumor and infected cell recognition.
authors.affiliation: Department of Biochemistry and Molecular Biology B and Immunology, School of Medicine, University of Murcia, Campus of International Excellence "Campus Mare Nostrum" and IMIB (Instituto Murciano de Investigaciones Biosanitarias)-Arrixaca, Murcia, Spain.
authors.forename: Rubén
authors.initials: R
authors.lastname: Corral-San Miguel
authors.affiliation: Department of Biochemistry and Molecular Biology B and Immunology, School of Medicine, University of Murcia, Campus of International Excellence "Campus Mare Nostrum" and IMIB (Instituto Murciano de Investigaciones Biosanitarias)-Arrixaca, Murcia, Spain.
authors.forename: Trinidad
authors.initials: T
authors.lastname: Hernández-Caselles
authors.affiliation: Department of Biochemistry and Molecular Biology B and Immunology, School of Medicine, University of Murcia, Campus of International Excellence "Campus Mare Nostrum" and IMIB (Instituto Murciano de Investigaciones Biosanitarias)-Arrixaca, Murcia, Spain.
authors.forename: Antonio José
authors.initials: AJ
authors.lastname: Ruiz Alcaraz
authors.affiliation: Department of Biochemistry and Molecular Biology B and Immunology, School of Medicine, University of Murcia, Campus of International Excellence "Campus Mare Nostrum" and IMIB (Instituto Murciano de Investigaciones Biosanitarias)-Arrixaca, Murcia, Spain.
authors.forename: María
authors.initials: M
authors.lastname: Martínez-Esparza
authors.affiliation: Department of Biochemistry and Molecular Biology B and Immunology, School of Medicine, University of Murcia, Campus of International Excellence "Campus Mare Nostrum" and IMIB (Instituto Murciano de Investigaciones Biosanitarias)-Arrixaca, Murcia, Spain.
authors.forename: Pilar
authors.initials: P
authors.lastname: García-Peñarrubia
mesh_terms: D015703:Antigens, CD / Q000378:metabolism*; D016207:Cytokines / Q000096:biosynthesis; D003602:Cytotoxicity, Immunologic / Q000276:immunology*; D015395:Histocompatibility Antigens Class I / Q000276:immunology* / Q000378:metabolism*; D006801:Humans; D016130:Immunophenotyping; D007371:Interferon-gamma / Q000096:biosynthesis; D007694:Killer Cells, Natural / Q000276:immunology / Q000378:metabolism; D008213:Lymphocyte Activation / Q000276:immunology; D018448:Models, Immunological; D011485:Protein Binding; D011971:Receptors, Immunologic / Q000378:metabolism*; D055607:Receptors, Natural Killer Cell / Q000378:metabolism; D000071176:Signaling Lymphocytic Activation Molecule Family; D013601:T-Lymphocytes / Q000276:immunology / Q000378:metabolism
chemical_list: D015703:Antigens, CD; C084093:CD244 protein, human; D016207:Cytokines; D015395:Histocompatibility Antigens Class I; D011971:Receptors, Immunologic; D055607:Receptors, Natural Killer Cell; D000071176:Signaling Lymphocytic Activation Molecule Family; D007371:Interferon-gamma