title: Human monocyte-derived and CD83(+) blood dendritic cells enhance NK cell-mediated cytotoxicity.
abstract: Dendritic cells (DC) are known to be the most potent APC and to stimulate antigen-specific T cell responses. Recently it was reported that murine DC were also capable of modulating the innate immunity by stimulating NK cells through cell-to-cell contact. In the present study, we examined whether human DC could affect NK activity. Both monocyte-derived and CD83(+) blood DC were tested. The addition of DC to cultures of CD56(+) cells resulted in the significant dose-dependent enhancement of the killing activity against various NK-sensitive targets. The resultant activity was comparable to that induced by optimal concentrations of various cytokines, including IL-2, IL-12, IL-15 and IFN-gamma. Interestingly, DC enhanced the cytotoxicity of CD3(-)CD56(+) NK cells, but not that of CD3(+)CD56(+) T cells. Experiments using transwells clearly demonstrated that the enhancement of NK activity by DC was mediated by soluble factors produced by DC. The culture supernatants of DC also stimulated NK activity. The treatment of both DC and their supernatants with anti-human IL-12 or IL-18 antibodies did not block the enhancement of NK cell-mediated cytolysis by DC, indicating that other factor(s) produced by DC were responsible for the enhancement of NK activity. These results suggest that human myeloid DC can modulate innate immunity by enhancing NK activity.
authors.affiliation: Third Department of Internal Medicine, University of Tokushima School of Medicine, Tokushima, Japan. yasuhiko@clin.med.tokushima-u.ac.jp
authors.forename: Y
authors.initials: Y
authors.lastname: Nishioka
authors.forename: N
authors.initials: N
authors.lastname: Nishimura
authors.forename: Y
authors.initials: Y
authors.lastname: Suzuki
authors.forename: S
authors.initials: S
authors.lastname: Sone
mesh_terms: D000906:Antibodies / Q000276:immunology; D015703:Antigens, CD; D001769:Blood / Q000276:immunology*; D017252:CD3 Complex / Q000032:analysis; D019002:CD56 Antigen / Q000032:analysis; D002478:Cells, Cultured; D003601:Cytotoxicity Tests, Immunologic; D003602:Cytotoxicity, Immunologic; D003713:Dendritic Cells / Q000276:immunology*; D006801:Humans; D007136:Immunoglobulins / Q000032:analysis*; D007155:Immunologic Factors / Q000502:physiology; D020382:Interleukin-18 / Q000276:immunology; D007376:Interleukin-2 / Q000276:immunology; D007694:Killer Cells, Natural / Q000276:immunology*; D008562:Membrane Glycoproteins / Q000032:analysis*; D009000:Monocytes / Q000276:immunology*; D013234:Stem Cells / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology; D014407:Tumor Cells, Cultured; D000097802:CD83 Antigen
chemical_list: D000906:Antibodies; D015703:Antigens, CD; D017252:CD3 Complex; D019002:CD56 Antigen; D007136:Immunoglobulins; D007155:Immunologic Factors; D020382:Interleukin-18; D007376:Interleukin-2; D008562:Membrane Glycoproteins; D000097802:CD83 Antigen