IMMUNOREGULATORY EFFECTS OF TRANSFORMING GROWTH-FACTOR-BETA IN A PROLONGED PERIOD OF CULTURE

It is well known that transforming growth factor-β (TGF-β) strikingly inhibits numerous immune functions in short-term cultures. In this study we investigated the effects of TGF-β on the immune responses of murine spleen cells in a prolonged period of culture. The addition of exogenous TGF-β (0.1 ng/ml) inhibited the proliferation of Con A- or LPS-stimulated spleen cells, polyclonal IgM and IgG antibody production, and NK cell activity during 4 days of the initial culture and subsequently enhanced their responses on Day 10. The augmented polyclonal IgM and IgG responses in murine spleen cells induced by LPS and TGF-β on Day 10 were suppressed by the secondary addition of TGF-β on Day 6. These results suggest that TGF-β acts as an immuno-regulator in prolonged period responses by immunoactivators. © 1992.