title: SLAT/Def6 plays a critical role in the development of Th17 cell-mediated experimental autoimmune encephalomyelitis.
abstract: SWAP-70-like adapter of T cells (SLAT; also known as Def6) is a novel guanine nucleotide exchange factor for Rho GTPases that has been previously shown to play a role in CD4+ T cell activation and Th1/Th2 differentiation. However, the role of SLAT/Def6 in autoimmunity and its associated Th1- and Th17-specific responses has not yet been clearly elucidated. We used a prototypical and pathologically relevant Th1/Th17-mediated autoimmune model, that is, experimental autoimmune encephalomyelitis, to assess the role of SLAT/Def6 in autoantigen-specific T cell response. We found that T cell-expressed SLAT/Def6 was critical for experimental autoimmune encephalomyelitis development and pathogenesis, as evidenced by the resistance of Def6-deficient (Def6(-/-)) mice to clinical signs of the disease associated with a lack of CNS inflammation and demyelination in myelin oligodendrocyte glycoprotein-immunized Def6(-/-) mice. Moreover, Def6 deficiency resulted in a severely diminished myelin oligodendrocyte glycoprotein-specific CD4+ T cell proliferation as well as a defect in IFN-gamma and IL-17 production in secondary lymphoid organs and the CNS. Lastly, Def6(-/-) CD4+ T cells were grossly deficient in their ability to differentiate into Th17 cells both in vitro and in vivo in a T cell-intrinsic manner. Therefore, our study establishes T cell-expressed SLAT/Def6 as a pivotal positive regulator of Th17 inflammatory responses and, thus, essential in controlling autoimmune and inflammatory diseases.
authors.affiliation: Division of Cell Biology, La Jolla Institute for Allergy and Immunology, La Jolla, CA 92037, USA.
authors.forename: Ann J
authors.initials: AJ
authors.lastname: Canonigo-Balancio
authors.forename: Camille
authors.initials: C
authors.lastname: Fos
authors.forename: Thomas
authors.initials: T
authors.lastname: Prod'homme
authors.forename: Stéphane
authors.initials: S
authors.lastname: Bécart
authors.forename: Amnon
authors.initials: A
authors.lastname: Altman
mesh_terms: D019264:Adoptive Transfer; D000818:Animals; D015496:CD4-Positive T-Lymphocytes / Q000166:cytology / Q000276:immunology* / Q000378:metabolism; D002454:Cell Differentiation / Q000276:immunology; D004268:DNA-Binding Proteins / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology*; D004681:Encephalomyelitis, Autoimmune, Experimental / Q000276:immunology* / Q000473:pathology; D020662:Guanine Nucleotide Exchange Factors; D020381:Interleukin-17 / Q000096:biosynthesis / Q000276:immunology*; D051379:Mice; D018345:Mice, Knockout; D009687:Nuclear Proteins / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology*; D016176:T-Lymphocyte Subsets / Q000166:cytology / Q000276:immunology* / Q000378:metabolism
chemical_list: D004268:DNA-Binding Proteins; D020662:Guanine Nucleotide Exchange Factors; D020381:Interleukin-17; D009687:Nuclear Proteins; C473249:Def6 protein, mouse