Pleiotropic effects of transforming growth factor-beta on cells of the immune system.

It is now apparent that the TGF-beta has potent immunoregulatory properties. Although most reports have described the immunosuppressive activities of TGF-beta, recent evidence supports the concept that TGF-beta can have both inhibitory and stimulatory actions. The delivery of sufficient quantities of TGF-beta has proven beneficial in several disease models such as allograft rejection and autoimmunity. Moreover, the increased levels of TGF-beta found in several disease states associated with immunosuppression suggests that inhibitors of TGF-beta may be clinically useful in some diseases. Thus, TGF-beta or antagonists to TGF-beta have exciting potential for use in treating or preventing several diseases (Table 6).