title: CD4-8- dendritic cells prime CD4+ T regulatory 1 cells to suppress antitumor immunity.
abstract: It is clear that dendritic cells (DCs) are essential for priming of T cell responses against tumors. However, the distinct roles DC subsets play in regulation of T cell responses in vivo are largely undefined. In this study, we investigated the capacity of OVA-presenting CD4-8-, CD4+8-, or CD4-8+ DCs (OVA-pulsed DC (DC(OVA))) in stimulation of OVA-specific T cell responses. Our data show that each DC subset stimulated proliferation of allogeneic and autologous OVA-specific CD4+ and CD8+ T cells in vitro, but that the CD4-8- DCs did so only weakly. Both CD4+8- and CD4-8+ DC(OVA) induced strong tumor-specific CD4+ Th1 responses and fully protective CD8+ CTL-mediated antitumor immunity, whereas CD4-8- DC(OVA), which were less mature and secreted substantial TGF-beta upon coculture with TCR-transgenic OT II CD4+ T cells, induced the development of IL-10-secreting CD4+ T regulatory 1 (Tr1) cells. Transfer of these Tr1 cells, but not T cells from cocultures of CD4-8- DC(OVA) and IL-10-/- OT II CD4+ T cells, into CD4-8+ DC(OVA)-immunized animals abrogated otherwise inevitable development of antitumor immunity. Taken together, CD4-8- DCs stimulate development of IL-10-secreting CD4+ Tr1 cells that mediated immune suppression, whereas both CD4+8- and CD4-8+ DCs effectively primed animals for protective CD8+ CTL-mediated antitumor immunity.
authors.affiliation: Department of Oncology, University of Saskatchewan, Saskatoon, Canada.
authors.forename: Xueshu
authors.initials: X
authors.lastname: Zhang
authors.forename: Hui
authors.initials: H
authors.lastname: Huang
authors.forename: Jinying
authors.initials: J
authors.lastname: Yuan
authors.forename: Deming
authors.initials: D
authors.lastname: Sun
authors.forename: Wu-Shiun
authors.initials: WS
authors.lastname: Hou
authors.forename: John
authors.initials: J
authors.lastname: Gordon
authors.forename: Jim
authors.initials: J
authors.lastname: Xiang
mesh_terms: D000818:Animals; D000951:Antigens, Neoplasm / Q000276:immunology; D015704:CD4 Antigens / Q000032:analysis; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D016827:CD8 Antigens / Q000032:analysis*; D003713:Dendritic Cells / Q000502:physiology*; D016753:Interleukin-10 / Q000502:physiology; D008213:Lymphocyte Activation; D051379:Mice; D008810:Mice, Inbred C57BL; D009374:Neoplasms, Experimental / Q000276:immunology*; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology; D016212:Transforming Growth Factor beta / Q000502:physiology
chemical_list: D000951:Antigens, Neoplasm; D015704:CD4 Antigens; D016827:CD8 Antigens; D016212:Transforming Growth Factor beta; D016753:Interleukin-10