Natural killer cell receptors for major histocompatibility complex class I and related molecules in cytomegalovirus infection.
Downmodulation of major histocompatibility complex (MHC) class I molecules by cytomegalovirus (CMV) impairs the engagement of specific leucocyte-inhibitory receptors, rendering infected cells vulnerable to natural killer (NK) cells. Members of the murine Ly49 and human KIR families, CD85j (ILT2 or leucocyte Ig-like receptor-1), as well as the CD94/NKG2A-inhibitory killer lectin-like receptor (KLR) fulfil this surveillance role. On the other hand, NK-activating receptors specific to ligands expressed on virus-infected cells may overcome the control by inhibitory receptors. In this regard, NKG2D and Ly49H lectin-like molecules trigger NK-cell functions recognizing, respectively class I-related stress-inducible molecules and the m157 murine CMV glycoprotein. Among a variety of immune evasion strategies, CMV promotes the synthesis of class I surrogates and selectively preserves the expression of some class I molecules in infected cells; moreover, CMV interferes with the expression of ligands for NKG2D. We herein review these aspects of the host-pathogen interaction, discussing a number of open issues.
Molecular Immunopathology Unit, DCEXS Universitat Pompeu Fabra, Barcelona, Spain. miguel.lopez-bote-t@upf.edu
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M
López-Botet
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Angulo
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Gumá
D000818:Animals; D015703:Antigens, CD / Q000276:immunology; D000956:Antigens, Viral / Q000276:immunology; D003587:Cytomegalovirus / Q000276:immunology*; D003586:Cytomegalovirus Infections / Q000276:immunology*; D003602:Cytotoxicity, Immunologic; D015395:Histocompatibility Antigens Class I / Q000276:immunology*; D006801:Humans; D007694:Killer Cells, Natural / Q000276:immunology*; D008562:Membrane Glycoproteins / Q000276:immunology*; D051379:Mice; D011971:Receptors, Immunologic / Q000276:immunology*
D015703:Antigens, CD; D000956:Antigens, Viral; D015395:Histocompatibility Antigens Class I; D008562:Membrane Glycoproteins; D011971:Receptors, Immunologic