Induced Foxp3(+) regulatory T cells: a potential new weapon to treat autoimmune and inflammatory diseases?

Abstract

Foxp3(+) T regulatory cells (Tregs) consisting of natural and induced Treg subsets play a crucial role in the maintenance of immune homeostasis against self-antigen. The actions designed to correct defects in numbers or functions of Tregs may be therapeutic in the treatment of autoimmune diseases. While recent studies demonstrated that natural Tregs are instable and dysfunctional in the inflammatory condition, induced Tregs (iTregs) may have a different feature. Here we review the progress of iTregs, particularly focus on their stability and function in the established autoimmune diseases. The advantage of iTregs as therapeutics used under inflammatory conditions is highlighted. Proper generation and manipulation of iTregs used for cellular therapy may provide a promise for the treatment of many autoimmune and inflammatory diseases.

Figure 1

Multi-effects of TGF-β on regulatory and effector T cells. TGF-β inhibits the differentiation, proliferation, and function of various immune cells, including Th1, Th2, and Tfh cells. TGF-β also promotes iTreg, Th17, and Th9 cell differentiation depending upon the cytokine environment. Additionally, TGF-β inhibits maturation and function of other immune cells such as CD8⁺ CTLs, NK cells, DCs, and macrophages.