title: Interplay between CD45RA+ regulatory T cells and TNF-alpha in the regulation of human Th17 differentiation.
abstract: The balance between effector CD4(+) T cells secreting IL-17 (T(h)17) and regulatory T cells (Treg) plays an important role in autoimmune disorders that include rheumatoid arthritis (RA) and Crohn's disease. Tumor necrosis factor (TNF)-alpha is a key pro-inflammatory cytokine that contributes to disease pathogenesis. We investigated the interplay between CD45RA(+) Treg and TNF-alpha in the regulation of human T(h)17 differentiation. We found that CD45RA(+) Treg promoted while TNF-alpha inhibited naive CD4(+) T-cell differentiation into IL-17 and CCL20 co-expressing T(h)17 cells without influencing their IL-22 release. Unexpectedly, CD45RA(+) Treg depletion abrogated TNF-alpha suppressive function. Finally, dendritic cell-derived TNF-alpha suppressed the development of IL-17(+)CCL20(+) expressing T(h)17 cells. In conclusion, CD45RA(+) Treg positively governs human T(h)17 development, which is impaired by TNF-alpha. We propose that TNF-alpha may represent a negative feedback mechanism to control IL-17/CCL20- but not IL-22-associated autoimmune pathologies.
authors.affiliation: Immunoregulation Laboratory, Centre de Recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), University of Montreal, Montreal, Quebec, Canada.
authors.forename: Nobuyasu
authors.initials: N
authors.lastname: Baba
authors.forename: Manuel
authors.initials: M
authors.lastname: Rubio
authors.forename: Marika
authors.initials: M
authors.lastname: Sarfati
mesh_terms: D001327:Autoimmune Diseases / Q000276:immunology*; D002454:Cell Differentiation; D002478:Cells, Cultured; D054418:Chemokine CCL20 / Q000378:metabolism; D003713:Dendritic Cells / Q000276:immunology / Q000378:metabolism; D006801:Humans; D020381:Interleukin-17 / Q000096:biosynthesis; D007378:Interleukins / Q000096:biosynthesis; D017493:Leukocyte Common Antigens / Q000096:biosynthesis / Q000276:immunology*; D016176:T-Lymphocyte Subsets / Q000276:immunology* / Q000378:metabolism; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology* / Q000378:metabolism; D050378:T-Lymphocytes, Regulatory / Q000276:immunology* / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000276:immunology*; D000097043:Interleukin-22
chemical_list: D054418:Chemokine CCL20; D020381:Interleukin-17; D007378:Interleukins; D017493:Leukocyte Common Antigens; D014409:Tumor Necrosis Factor-alpha; D000097043:Interleukin-22; C108355:CCL20 protein, human