Comparison between the in vitro activities of in vivo-induced hapten-specific suppressor cells and supernatants of a hapten-specific suppressor hybridoma.

A trinitrophenyl (TNP)-specific suppressor hybridoma was obtained by fusing hapten-binding spleen cells (SC) of BALB/c mice 1 week after intravenous (iv) injection of TNP-modified syngeneic lymphocytes with the AKR lymphoma BW5147. The suppressive activity of supernatants from one clone (TNP-44) was compared with that of in vivo-induced TNP-specific suppressor cells. Both the TNP-specific suppressor cells (TsTNP) and the TNP-44 were hapten binding and hapten specific. They suppressed the functional activity of TNP-haptenized T as well as B cells. TNP-44 supernatant also inhibited the proliferation of TNP-modified cells. Using native target cells, both TNP-44 supernatant and the in vivo-induced suppressor cells suppressed the anti-TNP B-cell response to TNP-bound T-dependent soluble or cellular antigens, but not to TNP-lipopolysaccharide (LPS). Furthermore, the function of TNP-specific helper T cells (THTNP) was impaired in the presence of TSTNP or supernatant from TNP-44. From these observations it was concluded that both the TSTNP and a TNP-specific factor derived from a suppressor hybridoma function via an antigen bridge at the TH or at the TH-dependent B-cell subset.