title: Cumulative inhibition of NK cells and T cells resulting from engagement of multiple inhibitory Ly49 receptors.
abstract: Inhibitory receptors specific for MHC class I molecules are expressed on partially overlapping subpopulations of NK cells and memory T cells. A central question pertinent to NK cell development and function is how the combinatorial expression of different receptors with distinct class I specificities affects functional recognition. We therefore studied the quantitative effects resulting from class I engagement of multiple inhibitory Ly49 receptors. We used a transgenic mouse model in which all NK cells and T cells express two different Ly49 receptors with shared class I specificity. Comparisons of cells from these mice with cells from single transgenic mice and wild-type mice revealed that Ly49 receptors cumulatively inhibit lymphocyte effector functions. Multiple Ly49 interactions also had a cumulative impact on NK cell development. The findings suggest that the interactions of inhibitory receptors with class I are interpreted quantitatively rather than as on/off switches. They have intriguing implications concerning NK cell tolerance and reactivity toward cells with extinguished expression of a limited number of class I molecules.
authors.affiliation: Institute for Virology and Immunobiology, University of Wurzburg, Wurzburg, Germany.
authors.forename: T
authors.initials: T
authors.lastname: Hanke
authors.forename: D H
authors.initials: DH
authors.lastname: Raulet
mesh_terms: D000818:Animals; D000950:Antigens, Ly; D002352:Carrier Proteins / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology; D002478:Cells, Cultured; D003602:Cytotoxicity, Immunologic / Q000235:genetics; D006183:H-2 Antigens / Q000235:genetics / Q000276:immunology; D064532:Histocompatibility Antigen H-2D; D007108:Immune Tolerance / Q000235:genetics; D015979:Killer Cells, Lymphokine-Activated / Q000276:immunology / Q000378:metabolism; D007694:Killer Cells, Natural / Q000276:immunology* / Q000378:metabolism; D037181:Lectins, C-Type; D008213:Lymphocyte Activation / Q000235:genetics; D007959:Lymphocyte Culture Test, Mixed; D008562:Membrane Glycoproteins / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D008565:Membrane Proteins / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology; D051379:Mice; D008810:Mice, Inbred C57BL; D008811:Mice, Inbred DBA; D008822:Mice, Transgenic; D011971:Receptors, Immunologic / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism*; D055630:Receptors, NK Cell Lectin-Like; D013601:T-Lymphocytes / Q000276:immunology* / Q000378:metabolism; D014407:Tumor Cells, Cultured; D019282:Wasting Syndrome / Q000235:genetics / Q000276:immunology
chemical_list: D000950:Antigens, Ly; D002352:Carrier Proteins; D006183:H-2 Antigens; C024755:H-2K(K) antigen; D064532:Histocompatibility Antigen H-2D; D037181:Lectins, C-Type; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; D011971:Receptors, Immunologic; D055630:Receptors, NK Cell Lectin-Like