Abstract
The T helper (Th) cell subsets are characterized by the type of cytokines produced and the master transcription factor expressed. Th1 cells participate in cell-mediated immunity, whereas Th2 cells promote humoral immunity. Furthermore, the two subsets can control each other. Thereby, Th1-Th2 balance offered a key paradigm in understanding the induction and regulation of immune pathology in autoimmune and other diseases. However, over the past decade, Th17 cells producing interleukin-17 (IL-17) have emerged as the major pathogenic T cell subset in many pathological conditions that were previously attributed to Th1 cells. In addition, the role of CD4. +. CD25. +. T regulatory cells (Treg) in controlling the activity of Th17 and other T cell subsets has increasingly been realized. Thereby, examination of the Th17/Treg balance in the course of autoimmune diseases has significantly advanced our understanding of the pathogenesis of these disorders. The differentiation of Th17 and Treg cells from naïve T cells is inter-related and controlled in part by the cytokine milieu. For example, transforming growth factor β (TGFβ) is required for Treg induction, whereas the same cytokine in the presence of IL-6 (or IL-1) promotes the differentiation of Th17. Furthermore, IL-23 plays a role in the maintenance of Th17. Accordingly, novel therapeutic approaches are being developed to target IL-23/IL-17 as well as to modulate the Th17/Treg balance in favor of immune regulation to control autoimmunity.
Original language | English (US) |
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Pages (from-to) | 54-61 |
Number of pages | 8 |
Journal | Cytokine |
Volume | 74 |
Issue number | 1 |
DOIs | |
State | Published - Jul 1 2015 |
Bibliographical note
Funding Information:This work was supported by R01 AT004321 (KDM) and F31 AT007278 (BA) from NIH/NCCAM.
Keywords
- Arthritis
- Interleukin-17
- Interleukin-23
- Regulatory T cell
- T helper 17