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.

Abstract

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.

• Authors: Masahisa Jinushi, Tetsuo Takehara, Tatsuya Kanto, Tomohide Tatsumi, Veronika Groh, Thomas Spies, Takuya Miyagi, Takahiro Suzuki, Yutaka Sasaki, Norio Hayashi
• Journal: Journal of immunology (Baltimore, Md. : 1950) (J Immunol) Vol. 170 Issue 3 Pg. 1249-56 (Feb 01 2003) ISSN: 0022-1767 [Print] United States
• PMID: 12538683 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Antigens, CD
• Antigens, Differentiation, T-Lymphocyte
• CD69 antigen
• Histocompatibility Antigens Class I
• Interferon-alpha
• Lectins, C-Type
• Lipopolysaccharides
• MHC class I-related chain A
• MICB antigen
• Protein Subunits
• Interleukin-12
• Interferon-gamma

Topics

• Antigens, CD (biosynthesis)
• Antigens, Differentiation, T-Lymphocyte (biosynthesis)
• Cell Communication (immunology)
• Cell Differentiation (immunology)
• Cells, Cultured
• Coculture Techniques
• Cytotoxicity, Immunologic
• Dendritic Cells (cytology, immunology, metabolism, pathology)
• Hepacivirus (immunology)
• Hepatitis C, Chronic (immunology, pathology)
• Histocompatibility Antigens Class I (biosynthesis, physiology)
• Humans
• Interferon-alpha (pharmacology)
• Interferon-gamma (biosynthesis)
• Interleukin-12 (physiology)
• K562 Cells
• Killer Cells, Natural (immunology)
• Lectins, C-Type
• Lipopolysaccharides (pharmacology)
• Lymphocyte Activation
• Protein Subunits (biosynthesis, physiology)