title: The gp49B1 inhibitory receptor regulates the IFN-gamma responses of T cells and NK cells.
abstract: The magnitude and diversity of Ag-specific T cell effector activity have been proposed to be controlled by an integration of positive signals transduced by the TCR and negative signals originating from inhibitory cell surface molecules. Although the lectin family of NK cell-associated inhibitory receptors has been reported to regulate the function of murine CTLs, gp49B1, the Ig superfamily member is not known to be expressed on T cells. Moreover, the consequences of the lack of an endogenously expressed NK cell-associated inhibitory receptor on T cell functions are not known. We report that gp49B1 is expressed by nearly all activated CD8 and CD4 T cells in addition to NK cells during an immune response to viral, bacterial, or tumor challenge. Kinetics of gp49B1 expression parallel functional capability and subside in the memory phase. Following vaccinia viral infection, IFN-gamma production by both subsets of T cells and NK cells is enhanced in gp49B1-deficient mice compared with gp49B1(+/+) mice. The stimulation threshold for IFN-gamma production is also lower in gp49B1-deficient T cells. In contrast, no significant differences were observed in the cytotoxic responses. We conclude that gp49B1 is a unique inhibitory receptor that is induced in multiple lineages of innate and adaptive immune cells during an infection and controls their IFN-gamma, but not cytotoxic responses.
authors.affiliation: Center for Blood Research and. Department of Medicine, Harvard Medical School, Boston, MA 02115, USA.
authors.forename: Xiaogang
authors.initials: X
authors.lastname: Gu
authors.forename: Amale
authors.initials: A
authors.lastname: Laouar
authors.forename: Junmei
authors.initials: J
authors.lastname: Wan
authors.forename: Massoud
authors.initials: M
authors.lastname: Daheshia
authors.forename: Judy
authors.initials: J
authors.lastname: Lieberman
authors.forename: Wayne M
authors.initials: WM
authors.lastname: Yokoyama
authors.forename: Howard R
authors.initials: HR
authors.lastname: Katz
authors.forename: N
authors.initials: N
authors.lastname: Manjunath
mesh_terms: D000276:Adjuvants, Immunologic / Q000096:biosynthesis / Q000172:deficiency / Q000235:genetics / Q000502:physiology; D000818:Animals; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology / Q000378:metabolism / Q000821:virology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology / Q000378:metabolism / Q000821:virology; D003601:Cytotoxicity Tests, Immunologic; D015536:Down-Regulation / Q000235:genetics / Q000276:immunology; D018984:Epitopes, T-Lymphocyte / Q000276:immunology; D007156:Immunologic Memory / Q000235:genetics; D007371:Interferon-gamma / Q000378:metabolism / Q000502:physiology*; D007694:Killer Cells, Natural / Q000276:immunology* / Q000378:metabolism* / Q000821:virology; D008089:Listeria monocytogenes / Q000276:immunology; D008213:Lymphocyte Activation / Q000235:genetics; D008297:Male; D008562:Membrane Glycoproteins / Q000096:biosynthesis / Q000172:deficiency / Q000235:genetics / Q000502:physiology*; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D008822:Mice, Transgenic; D011971:Receptors, Immunologic / Q000096:biosynthesis / Q000172:deficiency / Q000235:genetics / Q000502:physiology*; D012513:Sarcoma, Experimental / Q000235:genetics / Q000276:immunology; D016176:T-Lymphocyte Subsets / Q000276:immunology* / Q000378:metabolism* / Q000821:virology; D014407:Tumor Cells, Cultured; D014616:Vaccinia virus / Q000276:immunology
chemical_list: D000276:Adjuvants, Immunologic; D018984:Epitopes, T-Lymphocyte; C489447:Gp49a protein, mouse; C489448:Lilrb4 protein, mouse; D008562:Membrane Glycoproteins; D011971:Receptors, Immunologic; D007371:Interferon-gamma