Th17 and autoimmune diseases

Abstract

naive CD4+ T helper cells can be induced to differentiate towards different subsets according to thelocal cytokine milieu. When the growth factor (TGF)-β and IL-6 are present, naive CD4+ T helper cells alwaysdifferentiate into Th17----a new T cell subset which is characterized by the expression of specific transcriptionfactor orphan nuclear receptor (ROR)-γt. There is considerable evidence for the importance of Th17 in the de-velopment and progression of inflammatory and autoimmune diseases. In contrast, CD4+ CD25+ Foxp3+ regula-tory T cells(Treg) have anti-inflammatory properties and can cause quiescence of autoimmune diseases. As aresult, it can be proposed that the immune response towards Th17 or Th1 may be responsible for the develop-ment and progression of inflammatory and autoimmune diseases in humans. Blocking critical cytokines in vivosuch as IL-17、IL-6 may result in a new balance between Th1 ,Th17 and Treg,which will induce the quiescenceof inflammatory and autoimmune diseases. Key words: Th17 ; Interleukin-17 ; Autoimmune diseases