Helper and suppressor T-cells regulating killer cells of EB virus infected cells

Using an in-vitro human lymphocyte system, a study was performed to determine whether helper T-cells and suppressor T-cells control the generation of killer cells against autologous B-cells transformed by Epstein-Barr (EB) virus. When T-cells were treated with mitomycin C and reacted in the presence of macrophages with target cells bearing HLA-DR, helper T-cells were induced but suppressor T-cells were not. In contrast, when T-cells were reacted in the absence of macrophages to target cells lacking HLA-DR, suppressor T-cells but not helper T-cells were induced. The culture supernatant of the T-cells which showed suppressor activity also suppressed the generation of killer cells. The thus-induced suppressor T-cells also suppressed the HLA incompatible allogeneic killer cells which were directed against autologous B-cells transformed by EB virus and also autologous killer cells directed against allogeneic target cells. These observations indicated that there is no HLA restriction between the suppressor T-cells and the killer cells and the suppression is antigen nonspecific.