title: Increased natural cytotoxicity receptor expression and relevant IL-10 production in NK cells from chronically infected viremic HCV patients.
abstract: Hepatitis C virus (HCV) readily establishes high-level lifelong persistent infection in the majority of immunocompetent adults with failure of HCV-specific CD8+ CTL to clear viral replication. Virus-induced conditioning of innate immune responses is a possible mechanism that may contribute to the impairment of virus-specific CD8+ CTL responses. Here, we analyzed whether triggering of NK cell receptor expression and function is affected during chronic viremic HCV infection. Flow cytometric analysis of purified resting peripheral NK cells showed no evidence of NK cell activation, while analysis of natural cytotoxicity receptors (NCR) showed that NK cells from HCV-infected patients had selective increased expression of NKp30 and NKp46. NK cells had corresponding conserved cytotoxic activity against all targets with the exception of HepG2 hepatoma cells. Freshly separated NK cells from HCV patients showed significant production of IL-10 and normal concentrations of IFN-gamma upon cell-mediated triggering. Thus, increased expression of NKp30 during HCV infection with increased IL-10 production could contribute, once NK cells localize in the liver, to a NK-DC crosstalk leading to skewing of subsequent adaptive immune responses and lack of virus control.
authors.affiliation: Department of Internal Medicine, University of Genova, Genova, Italy. de-maria@unige.it
authors.forename: Andrea
authors.initials: A
authors.lastname: De Maria
authors.forename: Manuela
authors.initials: M
authors.lastname: Fogli
authors.forename: Stefania
authors.initials: S
authors.lastname: Mazza
authors.forename: Monica
authors.initials: M
authors.lastname: Basso
authors.forename: Antonio
authors.initials: A
authors.lastname: Picciotto
authors.forename: Paola
authors.initials: P
authors.lastname: Costa
authors.forename: Sonia
authors.initials: S
authors.lastname: Congia
authors.forename: Maria Cristina
authors.initials: MC
authors.lastname: Mingari
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Moretta
mesh_terms: D003602:Cytotoxicity, Immunologic; D005434:Flow Cytometry; D005455:Fluorescent Antibody Technique; D019698:Hepatitis C, Chronic / Q000276:immunology*; D006801:Humans; D007371:Interferon-gamma / Q000096:biosynthesis; D016753:Interleukin-10 / Q000096:biosynthesis*; D007694:Killer Cells, Natural / Q000276:immunology*; D008562:Membrane Glycoproteins / Q000096:biosynthesis* / Q000276:immunology; D055627:Natural Cytotoxicity Triggering Receptor 1; D055628:Natural Cytotoxicity Triggering Receptor 3; D011971:Receptors, Immunologic / Q000096:biosynthesis* / Q000276:immunology; D014766:Viremia
chemical_list: D008562:Membrane Glycoproteins; C112260:NCR1 protein, human; C431710:NCR3 protein, human; D055627:Natural Cytotoxicity Triggering Receptor 1; D055628:Natural Cytotoxicity Triggering Receptor 3; D011971:Receptors, Immunologic; D016753:Interleukin-10; D007371:Interferon-gamma