title: CD40L-expressing CD8 T cells prime CD8alpha(+) DC for IL-12p70 production.
abstract: CD8alpha(+) DC are implicated as the principle DC subset for cross-presentation and cross-priming of cytotoxic CD8 T cell responses. In this study, we demonstrate another unique facet of the CD8alpha(+) DC and CD8 T cell relationship, by showing that CD8 T cells reciprocally activate CD8alpha(+) DC, but not CD8alpha(-) DC, for IL-12p70 production, the key Th1-promoting cytokine. This effect was observed during an antigen-specific interaction between DC and activated CD8 T cells, along with secondary TLR stimulation of DC by LPS. Activated CD8 T cells use a combination of IFN-gamma and CD40L, which is rapidly up-regulated post-stimulation, to prime DC for IL-12p70 production during an antigen-specific response. Our results suggest that the interaction between CD8alpha(+) DC and antigen-primed CD8 T cells may form an important component of Th1-mediated immunity through the induction of IL-12p70.
authors.affiliation: Immunology Program and Department of Microbiology, Centre for Life Sciences, National University of Singapore, Singapore.
authors.forename: Kok Loon
authors.initials: KL
authors.lastname: Wong
authors.forename: Fei Chuin
authors.initials: FC
authors.lastname: Lew
authors.forename: Paul A
authors.initials: PA
authors.lastname: MacAry
authors.forename: David M
authors.initials: DM
authors.lastname: Kemeny
mesh_terms: D000818:Animals; D023201:CD40 Ligand / Q000502:physiology*; D016827:CD8 Antigens / Q000502:physiology*; D018414:CD8-Positive T-Lymphocytes / Q000502:physiology*; D002450:Cell Communication; D003713:Dendritic Cells / Q000378:metabolism*; D006183:H-2 Antigens / Q000276:immunology; D007371:Interferon-gamma / Q000502:physiology; D018664:Interleukin-12 / Q000096:biosynthesis*; D051379:Mice; D008810:Mice, Inbred C57BL
chemical_list: D016827:CD8 Antigens; C409469:CD8 antigen, alpha chain; D006183:H-2 Antigens; C032876:H-2Kb protein, mouse; D023201:CD40 Ligand; D018664:Interleukin-12; D007371:Interferon-gamma