title: CMV-encoded Fcγ receptors: modulators at the interface of innate and adaptive immunity.
abstract: The constant region of IgG antibodies mediates antiviral activities upon engaging host Fcγ receptors (FcγRs) expressed by a variety of immune cells, such as antibody-dependent cellullar cytotoxcity (ADCC) executed by natural killer (NK)cells. Human cytomegalovirus (HCMV) is unique among viruses by encoding also an array of several Fcγ-binding glycoproteins with cell surface disposition and concomitant incorporation into the virion. Evidence is increasing that the virus-encoded Fcγ receptors differ in their Fcγ binding mode but effectively operate as adversaries of host FcγRs since they are able to prevent IgG-mediated triggering of activating host FcγRs, i.e., FcγRI, FcγRIIA, and FcγRIIIA. Here we discuss virus-encoded FcγRs as the first known HCMV inhibitors of IgG-mediated immunity which could account for the limited efficacy of HCMV hyperimmune globulin in clinical settings. A better understanding of their molecular mode of action opens up new perspectives for improving IgG therapies against HCMV disease.
authors.affiliation: Virology-CIET, Faculty of Microbiology, University of Costa Rica, 11501-2060, San José, Costa Rica.
authors.forename: Eugenia
authors.initials: E
authors.lastname: Corrales-Aguilar
authors.forename: Katja
authors.initials: K
authors.lastname: Hoffmann
authors.forename: Hartmut
authors.initials: H
authors.lastname: Hengel
mesh_terms: D056704:Adaptive Immunity; D000818:Animals; D000914:Antibodies, Viral / Q000276:immunology; D002352:Carrier Proteins / Q000378:metabolism; D003587:Cytomegalovirus / Q000235:genetics* / Q000276:immunology*; D003586:Cytomegalovirus Infections / Q000235:genetics / Q000276:immunology* / Q000378:metabolism / Q000628:therapy; D006801:Humans; D007113:Immunity, Innate; D007074:Immunoglobulin G / Q000276:immunology; D056747:Immunomodulation; D007167:Immunotherapy; D008024:Ligands; D011485:Protein Binding; D017452:Receptors, IgG / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D014764:Viral Proteins / Q000235:genetics* / Q000378:metabolism
chemical_list: D000914:Antibodies, Viral; D002352:Carrier Proteins; D007074:Immunoglobulin G; D008024:Ligands; D017452:Receptors, IgG; D014764:Viral Proteins