title: Induction of CTL and nonpolarized Th cell responses by CD8alpha(+) and CD8alpha(-) dendritic cells.
abstract: Two distinct dendritic cell (DC) subpopulations have been evidenced in mice on the basis of their differential CD8alpha expression and their localization in lymphoid organs. Several reports suggest that CD8alpha(+) and CD8alpha(-) DC subsets could be functionally different. In this study, using a panel of MHC class I- and/or class II-restricted peptides, we analyzed CD4(+) and CD8(+) T cell responses obtained after i.v. injection of freshly purified peptide-pulsed DC subsets. First, we showed that both DC subsets efficiently induce specific CTL responses and Th1 cytokine production in the absence of CD4(+) T cell priming. Second, we showed that in vivo activation of CD4(+) T cells by CD8alpha(+) or CD8alpha(-) DC, injected i.v., leads to a nonpolarized Th response with production of both Th1 and Th2 cytokines. The CD8alpha(-) subset induced a higher production of Th2 cytokines such as IL-4 and IL-10 than the CD8alpha(+) subset. However, IL-5 was produced by CD4(+) T cells activated by both DC subsets. When both CD4(+) and CD8(+) T cells were primed by DC injected i.v., a similar pattern of cytokines was observed, but, under these conditions, Th1 cytokines were mainly produced by CD8(+) T cells, while Th2 cytokines were produced by CD4(+) T cells. Thus, this study clearly shows that CD4(+) T cell responses do not influence the development of specific CD8(+) T cell cytotoxic responses induced either by CD8alpha(+) or CD8alpha(-) DC subsets.
authors.affiliation: Unité de Biologie des Régulations Immunitaires, Institut Pasteur, Paris, France.
authors.forename: G
authors.initials: G
authors.lastname: Schlecht
authors.forename: C
authors.initials: C
authors.lastname: Leclerc
authors.forename: G
authors.initials: G
authors.lastname: Dadaglio
mesh_terms: D000818:Animals; D017951:Antigen Presentation / Q000276:immunology*; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D016827:CD8 Antigens / Q000276:immunology*; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology; D016207:Cytokines / Q000096:biosynthesis; D003713:Dendritic Cells / Q000145:classification / Q000276:immunology*; D004333:Drug Administration Routes; D005260:Female; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology*; D018417:Th1 Cells / Q000276:immunology; D018418:Th2 Cells / Q000276:immunology
chemical_list: D016827:CD8 Antigens; D016207:Cytokines