Susceptibility and resistance of human autoimmune T cell activation to the immunoregulatory effects of transforming growth factor (TGF) β1, β2 and β1.2

The transforming growth factors type beta (TGF-beta) regulate immune responses by suppressing a variety of leukocyte functions. Using a panel of human autoimmune T cell lines specific for the acetylcholine receptor (AchR) we investigated the immunoregulatory effects of TGF-beta 1, TGF-beta 2, and TGF-beta 1.2. The cytokines have identical effects inhibiting activation of most T line cells and the activation-dependent changes in interleukin-2 (IL-2) receptor and T cell receptor expression. IL-2-dependent growth was not modulated by TGF-beta. However, autoimmune T cell lines specific for AchR differ in their susceptibility to TGF-beta and some are completely refractory. Resistance of autoimmune T cell activation to immunosuppressive cytokines might be an element in the development of chronic autoimmune disease.