title: Expression of T-bet by CD4 T cells is essential for resistance to Salmonella infection.
abstract: Despite the recognized role of the T-bet transcription factor in the differentiation of Th1 cells, T-bet-deficient mice can develop small numbers of IFN-gamma-producing CD4 T cells. Although these are not sufficient to allow normal handling of some pathogens, T-bet-deficient mice do resolve infection with the intracellular pathogen Listeria monocytogenes. In contrast, we report that expression of T-bet is required for resistance to Salmonella infection. T-bet-deficient mice succumbed to infection with attenuated Salmonella and did not generate IFN-gamma-producing CD4 T cells or isotype-switched Salmonella-specific Ab responses. Spleen cells from Salmonella-infected T-bet-deficient mice secreted increased levels of IL-10, but not IL-4, upon in vitro restimulation. A Salmonella-specific TCR transgenic adoptive transfer system was used to further define the involvement of T-bet expression in the development of Salmonella-specific Th1 cells. Wild-type Salmonella-specific CD4 T cells activated in T-bet-deficient recipient mice displayed no defect in clonal expansion, contraction, or IFN-gamma production. In contrast, T-bet-deficient, Salmonella-specific CD4 T cells activated in wild-type recipient mice produced less IFN-gamma and more IL-2 upon in vivo restimulation. Therefore, expression of T-bet by CD4 T cells is required for the development of Salmonella-specific Th1 cells, regulation of IL-10 production, and resistance to Salmonella infection.
authors.affiliation: Department of Medicine, Division of Immunology, University of Connecticut Health Center, Farmington, CT 06030, USA.
authors.forename: Rajesh
authors.initials: R
authors.lastname: Ravindran
authors.forename: Joseph
authors.initials: J
authors.lastname: Foley
authors.forename: Thomas
authors.initials: T
authors.lastname: Stoklasek
authors.forename: Laurie H
authors.initials: LH
authors.lastname: Glimcher
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: McSorley
mesh_terms: D000818:Animals; D001402:B-Lymphocytes / Q000276:immunology; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology / Q000378:metabolism*; D002454:Cell Differentiation / Q000235:genetics / Q000276:immunology; D007113:Immunity, Innate / Q000235:genetics; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D008822:Mice, Transgenic; D012481:Salmonella Infections, Animal / Q000276:immunology*; D012486:Salmonella typhimurium / Q000276:immunology*; D020825:T-Box Domain Proteins; D018417:Th1 Cells / Q000166:cytology / Q000276:immunology / Q000378:metabolism; D014157:Transcription Factors / Q000096:biosynthesis* / Q000172:deficiency / Q000235:genetics / Q000502:physiology*; D000098815:T-bet Transcription Factor
chemical_list: D020825:T-Box Domain Proteins; D000098815:T-bet Transcription Factor; D014157:Transcription Factors