title: IL-6-gp130-STAT3 in T cells directs the development of IL-17+ Th with a minimum effect on that of Treg in the steady state.
abstract: IL-17-producing Th (Th17) comprise a distinct lineage of pro-inflammatory Th that are major contributors to autoimmune diseases. Treatment with IL-6 and transforming growth factor beta (TGFbeta) induces naive CD4+ T cells to generate Th17, which also requires expression of the IL-6/TGFbeta target RORgammat. We reported that IL-6 transduces two signaling pathways via tyrosine redidues of the signal transducer gp130: one depends on signal transducers and activators of transcription (STAT)-3 activation and the other on Src homology region 2 domain-containing phosphatase 2 (SHP2)/Grb2 associated binder (Gab)/mitogen-activated protein kinase (MAPK) activation. Here, we showed that CD4+ T cells carrying a mutant gp130 that transduces the SHP2/Gab/MAPK pathway but not the STAT3-mediated one failed to develop into Th17, while CD4+ T cells whose mutant gp130 transduces the STAT3 signal only generated Th17, indicating that IL-6 acts directly on T cells through the tyrosine residues of gp130 required for STAT3 activation to promote the development of Th17. Moreover, we found that gp130-STAT3 pathway is essential for Th17 development and for the expression of RORgammat by using T cells specifically lacking gp130 and STAT3. Noteworthy is that the regulatory T cell (Treg) percentages and numbers were comparable between all mutant mice we tested in vivo, although we showed that IL-6-gp130-STAT3 pathway suppressed Treg development in vitro. Thus, we conclude that IL-6 acts directly to promote the development of Th17 by activating the T cell gp130-STAT3 pathway but has a minimum effect on Treg development at least in the steady state in vivo. Therefore, blockade of IL-6-gp130-STAT3 pathway in CD4+ T cells could be a good target for controlling unwanted Th17-mediated immune responses including autoimmune diseases.
authors.affiliation: Laboratory of Developmental Immunology, Graduate School of Frontier Biosciences and Graduate School of Medicine, Osaka University, Osaka, Japan. hirano@molonc.med.osaka-u.ac.jp
authors.forename: Mika
authors.initials: M
authors.lastname: Nishihara
authors.forename: Hideki
authors.initials: H
authors.lastname: Ogura
authors.forename: Naoko
authors.initials: N
authors.lastname: Ueda
authors.forename: Mineko
authors.initials: M
authors.lastname: Tsuruoka
authors.forename: Chika
authors.initials: C
authors.lastname: Kitabayashi
authors.forename: Fumio
authors.initials: F
authors.lastname: Tsuji
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Aono
authors.forename: Katsuhiko
authors.initials: K
authors.lastname: Ishihara
authors.forename: Eric
authors.initials: E
authors.lastname: Huseby
authors.forename: Ulrich A K
authors.initials: UA
authors.lastname: Betz
authors.forename: Masaaki
authors.initials: M
authors.lastname: Murakami
authors.forename: Toshio
authors.initials: T
authors.lastname: Hirano
mesh_terms: D000818:Animals; D001169:Arthritis, Experimental / Q000097:blood / Q000276:immunology / Q000473:pathology; D015496:CD4-Positive T-Lymphocytes / Q000166:cytology / Q000276:immunology; D002452:Cell Count; D002454:Cell Differentiation / Q000187:drug effects / Q000276:immunology; D050822:Cytokine Receptor gp130 / Q000235:genetics / Q000502:physiology*; D005434:Flow Cytometry; D051858:Forkhead Transcription Factors / Q000378:metabolism; D020381:Interleukin-17 / Q000097:blood / Q000276:immunology / Q000378:metabolism*; D015850:Interleukin-6 / Q000235:genetics / Q000494:pharmacology / Q000502:physiology*; D008198:Lymph Nodes / Q000166:cytology / Q000276:immunology; D008213:Lymphocyte Activation / Q000187:drug effects / Q000276:immunology; D051379:Mice; D008810:Mice, Inbred C57BL; D008811:Mice, Inbred DBA; D018345:Mice, Knockout; D008822:Mice, Transgenic; D057132:Nuclear Receptor Subfamily 1, Group F, Member 3; D018168:Receptors, Retinoic Acid / Q000378:metabolism; D011988:Receptors, Thyroid Hormone / Q000378:metabolism; D050796:STAT3 Transcription Factor / Q000235:genetics / Q000502:physiology*; D015398:Signal Transduction / Q000187:drug effects / Q000276:immunology; D013154:Spleen / Q000166:cytology / Q000276:immunology; D006377:T-Lymphocytes, Helper-Inducer / Q000166:cytology / Q000276:immunology* / Q000378:metabolism; D050378:T-Lymphocytes, Regulatory / Q000166:cytology / Q000276:immunology* / Q000378:metabolism
chemical_list: D051858:Forkhead Transcription Factors; C498833:Foxp3 protein, mouse; D020381:Interleukin-17; D015850:Interleukin-6; D057132:Nuclear Receptor Subfamily 1, Group F, Member 3; D018168:Receptors, Retinoic Acid; D011988:Receptors, Thyroid Hormone; C539901:Rorc protein, mouse; D050796:STAT3 Transcription Factor; C494087:Stat3 protein, mouse; D050822:Cytokine Receptor gp130