The effects of TGF-ßs on immune responses.

ABSTRACT

Transforming growth factor (TGF)-ß family is a cytokine family with various biological processes and forms a highly homologous group of three mammalian isoforms, TGF-ß1, TGF-ß2, and TGF-ß3. Most of the attention on TGF-ß family in immunology has been mainly focused on TGF-ß1 in that TGF-ß1 induces anti-inflammatory regulatory T cells (Treg), and inflammatory T helper 17 (Th17) cells in combination with interleukin-6. Although little attention has been focused on the immunological roles of TGF-ß2 and TGF-ß3, the function of TGF-ß3 for maintaining immunological homeostasis has recently been identified such as the induction of Th17 cells and direct regulatory effects on humoral immunity. TGF-ß1 and TGF-ß3 shares similar anti-inflammatory or pro-inflammatory functions, but exhibits significantly different effects on fibrosis and chondrogenesis. For the clinical application of TGF-ßs, the mechanisms by which each TGF-ß isoform regulates immunity has to be elucidated. In this review, we provide an overview of the effects, cellular targets, and therapeutic potential of TGF-ßs on immune responses and autoimmune diseases.