Effect of TGF‐β1 on the ebv‐induced transformation of human lymphocyte cultures

Abstract

We tested the effect of TGF-beta 1 on the EBV-induced activation and immortalization of human B lymphocytes. In lymphocyte cultures of EBV-seropositive individuals, T cells can inhibit the EBV-induced transformation of B cells. We found that in the presence of TGF-beta 1 the transformation was more efficient, due to the inhibition of this function. TGF-beta 1 inhibited the EBV-induced proliferation of purified B-cell cultures. Its effect was strongest when added at the beginning of the culture. Added later, the inhibition gradually decreased and was lost by the 4th day. After 10 to 14 days, in the cultures initiated with TGF-beta 1, the number of cells was higher and they formed larger aggregates as compared with control cultures. Thus, TGF-beta 1 modifies EBV-induced transformation in a complex way. It inhibits the activation of B cells but does not affect those already activated. Once they acquire the immortalized state, the B cells are even stimulated by TGF-beta 1.