Critical role of MHC class I-related chain A and B expression on IFN-alpha-stimulated dendritic cells in NK cell activation: impairment in chronic hepatitis C virus infection.
Dendritic cells (DCs) augment effector functions of NK cells, but the underlying mechanisms are not fully understood. Here we show in an in vitro coculture system that human monocyte-derived DCs enhance IFN-gamma production, CD69 expression, and K562 cytolytic ability of NK cells when DCs are prestimulated with various maturation stimuli such as IFN-alpha or LPS. Of interest is the finding that NK cell activation mediated by LPS-stimulated DCs was dependent on IL-12 produced in DC/NK coculture, but that IFN-alpha-stimulated DC-mediated activation was not. Alternatively, MHC class I-related chain A and B (MICA/B), ligands for NKG2D activating receptor, were found to be induced on DCs upon IFN-alpha stimulation and to be responsible for the NK activation because mAb-mediated masking of MICA/B as well as inhibition of direct cell-to-cell contact using transwell insert completely abolished DC-dependent NK cell activation by IFN-alpha. Finally, DCs recovered from chronic hepatitis C virus-infected patients showed defects in the induction of MICA/B and impaired ability to activate NK cells in response to IFN-alpha stimulation. These findings suggested that MICA/B induction on DCs may be one of the mechanisms by which IFN-alpha activates NK cells; this impairment might affect IFN-alpha responsiveness in hepatitis C virus infection.
Jinushi
Masahisa
M
Department of Molecular Therapeutics, Osaka University Graduate School of Medicine, Suita, Osaka, Japan.
Takehara
Tetsuo
T
Kanto
Tatsuya
T
Tatsumi
Tomohide
T
Groh
Veronika
V
Spies
Thomas
T
Miyagi
Takuya
T
Suzuki
Takahiro
T
Sasaki
Yutaka
Y
Hayashi
Norio
N
D015703:Antigens, CD / Q000096:biosynthesis; D000945:Antigens, Differentiation, T-Lymphocyte / Q000096:biosynthesis; D002450:Cell Communication / Q000276:immunology; D002454:Cell Differentiation / Q000276:immunology; D002478:Cells, Cultured; D018920:Coculture Techniques; D003602:Cytotoxicity, Immunologic; D003713:Dendritic Cells / Q000166:cytology / Q000276:immunology* / Q000378:metabolism / Q000473:pathology; D016174:Hepacivirus / Q000276:immunology*; D019698:Hepatitis C, Chronic / Q000276:immunology* / Q000473:pathology; D015395:Histocompatibility Antigens Class I / Q000096:biosynthesis / Q000502:physiology*; D006801:Humans; D016898:Interferon-alpha / Q000494:pharmacology*; D007371:Interferon-gamma / Q000096:biosynthesis; D018664:Interleukin-12 / Q000502:physiology; D020014:K562 Cells; D007694:Killer Cells, Natural / Q000276:immunology*; D037181:Lectins, C-Type; D008070:Lipopolysaccharides / Q000494:pharmacology; D008213:Lymphocyte Activation; D021122:Protein Subunits / Q000096:biosynthesis / Q000502:physiology; D000099192:CD69 Antigens
D015703:Antigens, CD; D000945:Antigens, Differentiation, T-Lymphocyte; D015395:Histocompatibility Antigens Class I; D016898:Interferon-alpha; D007371:Interferon-gamma; D018664:Interleukin-12; D037181:Lectins, C-Type; D008070:Lipopolysaccharides; D021122:Protein Subunits; D000099192:CD69 Antigens; C099187:MHC class I-related chain A; C098080:MICB antigen