Preferential generation of killer or helper T-lymphocyte activity directed to the tumour-associated transplantation antigens.

Induction of killer and helper T-cell activities towards transplantation antigens of two tumour cell lines was analysed in the allogeneic and syngeneic host combinations. The lymphoid cells from C57BL/6 mice immunized with allogeneic viable or mitomycin C-treated X-5563 plasmacytoma cells derived from C3H/He mice revealed both killer and helper T-cell activities against alloantigens, whereas cells from mice immunized with tumour cells killed by a freezing and thawing procedure revealed predominantly helper T-cell activity. On the other hand, when C3H/He mice were immunized with viable syngeneic X-5563 plasmacytoma or MM102 mammary tumour cells, the former generated preferentially killer T-cell activity, whereas the latter induced predominantly helper T-cell activity against tumour-associated transplantation antigens. Thus, immunization with transplantation antigen(s) does not always induce both helper and killer T-cell activities in parallel, but a certain antigenic system induces predominantly one type of T-cell response, thus indicating that two distinct subsets of helper and killer T cells against the transplantation antigen(s) can be raised independently without an absolute requirement of collaboration between these different T-cells subsets.