title: Gfi1 negatively regulates T(h)17 differentiation by inhibiting RORgammat activity.
abstract: T(h) cells have long been divided into two subsets, T(h)1 and T(h)2; however, recently, T(h)17 and inducible regulatory T (iTreg) cells were identified as new T(h) cell subsets. Although T(h)1- and T(h)2-polarizing cytokines have been shown to suppress T(h)17 and iTreg development, transcriptional regulation of T(h)17 and iTreg differentiation by cytokines remains to be clarified. In this study, we found that expression of the growth factor independent 1 (Gfi1) gene, which has been implicated in T(h)2 development, was repressed in T(h)17 and iTreg cells compared with T(h)1 and T(h)2 lineages. Gfi1 expression was enhanced by the IFN-gamma/STAT1 and IL-4/STAT6 pathways, whereas it was repressed by the transforming growth factor-beta1 stimulation at the promoter level. Over-expression of Gfi1 strongly reduced IL-17A transcription in the EL4 T cell line, as well as in primary T cells. This was due to the blockade of recruitment of retinoid-related orphan receptor gammat to the IL-17A promoter. In contrast, IL-17A expression was significantly enhanced in Gfi1-deficient T cells under T(h)17-promoting differentiation conditions as compared with wild-type T cells. In contrast, the impacts of Gfi1 in iTregs were not as strong as in T(h)17 cells. Taken together, these data strongly suggest that Gfi1 is a negative regulator of T(h)17 differentiation, which represents a novel mechanism for the regulation of T(h)17 development by cytokines.
authors.affiliation: Department of Microbiology and Immunology, Keio University School of Medicine, Shinjuku-ku, Tokyo, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Ichiyama
authors.forename: Masayuki
authors.initials: M
authors.lastname: Hashimoto
authors.forename: Takashi
authors.initials: T
authors.lastname: Sekiya
authors.forename: Ryusuke
authors.initials: R
authors.lastname: Nakagawa
authors.forename: Yu
authors.initials: Y
authors.lastname: Wakabayashi
authors.forename: Yuki
authors.initials: Y
authors.lastname: Sugiyama
authors.forename: Kyoko
authors.initials: K
authors.lastname: Komai
authors.forename: Ingrid
authors.initials: I
authors.lastname: Saba
authors.forename: Tarik
authors.initials: T
authors.lastname: Möröy
authors.forename: Akihiko
authors.initials: A
authors.lastname: Yoshimura
mesh_terms: D000818:Animals; D002454:Cell Differentiation; D002460:Cell Line; D045744:Cell Line, Tumor; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D015536:Down-Regulation; D051858:Forkhead Transcription Factors / Q000276:immunology / Q000378:metabolism; D006801:Humans; D007371:Interferon-gamma / Q000276:immunology / Q000378:metabolism; D020381:Interleukin-17 / Q000276:immunology*; D015847:Interleukin-4 / Q000276:immunology / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D057132:Nuclear Receptor Subfamily 1, Group F, Member 3; D012333:RNA, Messenger / Q000378:metabolism; D018168:Receptors, Retinoic Acid / Q000378:metabolism*; D011988:Receptors, Thyroid Hormone / Q000378:metabolism*; D050794:STAT1 Transcription Factor / Q000276:immunology / Q000378:metabolism; D050800:STAT6 Transcription Factor / Q000276:immunology / Q000378:metabolism; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology*; D050378:T-Lymphocytes, Regulatory / Q000276:immunology; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D015854:Up-Regulation
chemical_list: D004268:DNA-Binding Proteins; D051858:Forkhead Transcription Factors; C498833:Foxp3 protein, mouse; C079873:Gfi1 protein, mouse; D020381:Interleukin-17; D057132:Nuclear Receptor Subfamily 1, Group F, Member 3; D012333:RNA, Messenger; C539900:RORC protein, human; D018168:Receptors, Retinoic Acid; D011988:Receptors, Thyroid Hormone; C539901:Rorc protein, mouse; D050794:STAT1 Transcription Factor; D050800:STAT6 Transcription Factor; D014157:Transcription Factors; D015847:Interleukin-4; D007371:Interferon-gamma