20
views
0
recommends
+1 Recommend
0 collections
    0
    shares
      • Record: found
      • Abstract: found
      • Article: not found

      The dichotomous nature of T helper 17 cells

      ,
      Nature Reviews Immunology
      Springer Nature

      Read this article at

      ScienceOpenPublisherPubMed
      Bookmark
          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

          Abstract

          T helper 17 (TH17) cells have a well-known role in immune pathology, but they also have protective and homeostatic roles. A detailed understanding of their plasticity and how their opposing functions are regulated is crucial for enabling the therapeutic targeting of TH17 cells in disease settings.

          Related collections

          Most cited references52

          • Record: found
          • Abstract: found
          • Article: not found

          Gut-residing segmented filamentous bacteria drive autoimmune arthritis via T helper 17 cells.

          Commensal microbes can have a substantial impact on autoimmune disorders, but the underlying molecular and cellular mechanisms remain largely unexplored. We report that autoimmune arthritis was strongly attenuated in the K/BxN mouse model under germ-free (GF) conditions, accompanied by reductions in serum autoantibody titers, splenic autoantibody-secreting cells, germinal centers, and the splenic T helper 17 (Th17) cell population. Neutralization of interleukin-17 prevented arthritis development in specific-pathogen-free K/BxN mice resulting from a direct effect of this cytokine on B cells to inhibit germinal center formation. The systemic deficiencies of the GF animals reflected a loss of Th17 cells from the small intestinal lamina propria. Introduction of a single gut-residing species, segmented filamentous bacteria, into GF animals reinstated the lamina propria Th17 cell compartment and production of autoantibodies, and arthritis rapidly ensued. Thus, a single commensal microbe, via its ability to promote a specific Th cell subset, can drive an autoimmune disease. Copyright 2010 Elsevier Inc. All rights reserved.
            Bookmark
            • Record: found
            • Abstract: found
            • Article: not found

            Generation of Pathogenic Th17 Cells in the Absence of TGF-β Signaling

            CD4+ T cells that selectively produce interleukin (IL)-17, are critical for host defense and autoimmunity 1–4 . Crucial for T helper17 (Th17) cells in vivo 5,6 , IL-23 has been thought to be incapable of driving initial differentiation. Rather, IL-6 and transforming growth factor (TGF)-β1 have been argued to be the factors responsible for initiating specification 7–10 . Herein, we show that Th17 differentiation can occur in the absence of TGF-β signaling. Neither IL-6 nor IL-23 alone efficiently generated Th17 cells; however, these cytokines in combination with IL-1β effectively induced IL-17 production in naïve precursors, independently of TGF-β. Epigenetic modification of the Il17a/Il17f and Rorc promoters proceeded without TGF-β1, allowing the generation of cells that co-expressed Rorγt and T-bet. T-bet+ Rorγt+ Th17 cells are generated in vivo during experimental allergic encephalomyelitis (EAE), and adoptively transferred Th17 cells generated with IL-23 without TGF-β1 were pathogenic in this disease model. These data suggest an alternative mode for Th17 differentiation. Consistent with genetic data linking IL23R with autoimmunity, our findings re-emphasize the importance of IL-23 and therefore have may have therapeutic implications.
              Bookmark
              • Record: found
              • Abstract: found
              • Article: not found

              Proinflammatory T-cell responses to gut microbiota promote experimental autoimmune encephalomyelitis.

              Although the effects of commensal bacteria on intestinal immune development seem to be profound, it remains speculative whether the gut microbiota influences extraintestinal biological functions. Multiple sclerosis (MS) is a devastating autoimmune disease leading to progressive deterioration of neurological function. Although the cause of MS is unknown, microorganisms seem to be important for the onset and/or progression of disease. However, it is unclear how microbial colonization, either symbiotic or infectious, affects autoimmunity. Herein, we investigate a role for the microbiota during the induction of experimental autoimmune encephalomyelitis (EAE), an animal model for MS. Mice maintained under germ-free conditions develop significantly attenuated EAE compared with conventionally colonized mice. Germ-free animals, induced for EAE, produce lower levels of the proinflammatory cytokines IFN-γ and IL-17A in both the intestine and spinal cord but display a reciprocal increase in CD4(+)CD25(+)Foxp3(+) regulatory T cells (Tregs). Mechanistically, we show that gut dendritic cells from germ-free animals are reduced in the ability to stimulate proinflammatory T cell responses. Intestinal colonization with segmented filamentous bacteria (SFB) is known to promote IL-17 production in the gut; here, we show that SFBs also induced IL-17A-producing CD4(+) T cells (Th17) in the CNS. Remarkably, germ-free animals harboring SFBs alone developed EAE, showing that gut bacteria can affect neurologic inflammation. These findings reveal that the intestinal microbiota profoundly impacts the balance between pro- and antiinflammatory immune responses during EAE and suggest that modulation of gut bacteria may provide therapeutic targets for extraintestinal inflammatory diseases such as MS.
                Bookmark

                Author and article information

                Journal
                Nature Reviews Immunology
                Nat Rev Immunol
                Springer Nature
                1474-1733
                1474-1741
                May 30 2017
                May 30 2017
                :
                :
                Article
                10.1038/nri.2017.50
                28555673
                578ef40a-13e3-401d-9a3f-03e44bef5923
                © 2017
                History

                Comments

                Comment on this article