title: Prolonged exposure of dendritic cells to maturation stimuli favors the induction of type-2 cytotoxic T lymphocytes.
abstract: Dendritic cell (DC) maturation influences the priming and polarization of T lymphocytes. We recently found that early activated DC (i.e. DC exposed to pro-maturation stimuli for 8 h) were more prone to prime in vivo a type-1 cytotoxic T cell (Tc1) response than DC exposed to pro-maturation stimuli for 48 h (48h-DC). We investigated whether 48h-DC, conversely, allowed the induction of Tc2 cells. Antigen-pulsed mouse bone-marrow-derived DC at any maturation stage, in the presence of exogenous IL-12, skewed in vitro naive CD8(+) T cells towards Tc1 cells, but 48h-DC most potently, in the presence of exogenous IL-4, favored the induction of Tc2 cells. In vivo, full maturation of DC promoted expansion of Tc2 and fall of Tc1 cells. Tc2 cells maintained a high cytolytic activity and produced significant amounts of IL-4, IL-5, IL-10 and TGF-beta. Our results indicate that polarization of naive CD8(+) T cells to Tc2 cells is dependent on the amount of time DC have been exposed to maturation stimuli, and might be favored in late and/or chronic phases of an immune response.
authors.affiliation: Cancer Immunotherapy and Gene Therapy Program, Istituto Scientifico H San Raffaele, Milan, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Boni
authors.forename: Giandomenica
authors.initials: G
authors.lastname: Iezzi
authors.forename: Elena
authors.initials: E
authors.lastname: Degl'Innocenti
authors.forename: Matteo
authors.initials: M
authors.lastname: Grioni
authors.forename: Elena
authors.initials: E
authors.lastname: Jachetti
authors.forename: Annalisa
authors.initials: A
authors.lastname: Camporeale
authors.forename: Matteo
authors.initials: M
authors.lastname: Bellone
mesh_terms: D000818:Animals; D002454:Cell Differentiation / Q000276:immunology*; D003713:Dendritic Cells / Q000166:cytology / Q000276:immunology* / Q000378:metabolism*; D005260:Female; D016130:Immunophenotyping; D015847:Interleukin-4 / Q000502:physiology; D008070:Lipopolysaccharides / Q000494:pharmacology; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D016192:Resting Phase, Cell Cycle / Q000276:immunology; D016176:T-Lymphocyte Subsets / Q000166:cytology* / Q000276:immunology / Q000378:metabolism; D013602:T-Lymphocytes, Cytotoxic / Q000166:cytology* / Q000276:immunology / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000502:physiology
chemical_list: D008070:Lipopolysaccharides; D014409:Tumor Necrosis Factor-alpha; D015847:Interleukin-4