PROTECTIVE EFFECT OF TRANSFORMING GROWTH FACTOR-BETA-1 ON EXPERIMENTAL AUTOIMMUNE-DISEASES IN MICE

Interleukin 1 (IL-1) and tumor necrosis factor-alpha are thought to contribute to the inflammatory response associated with autoimmune diseases. Transforming growth factor beta-1 (TGF-beta-1) counteracts many effects of these cytokines and has various immunosuppressive properties. In the present study, it is shown that microgram amounts of TGF-beta-1, injected daily for 1-2 weeks, protect against collagen-induced arthritis (CIA) and relapsing experimental allergic encephalomyelitis (REAE), the animal models for rheumatoid arthritis and multiple sclerosis, respectively. When administered during induction of the disease, TGF-beta-1 prevents CIA but only delays the onset of REAE by 2-3 days. However, when administered during a remission, TGF-beta-1 prevents the occurrence of relapses in REAE. The results suggest that TGF-beta-1 has powerful anti-inflammatory effects, mimicking in some respects the beneficial effects of immunosuppressive drugs in these experimental models of autoimmune disease, but without discernable adverse effects.