Proliferative responses of T cells from SJL----F1 and F1----SJL bone marrow chimeras to SJL lymphoma cells.

RCS tumor cells induce marked proliferation of syngeneic SJL T cells in vivo and in vitro. Certain F1 hybrids of SJL mice give high proliferative responses to gamma-RCS, while other F1 hybrids give low responses. SJL----"non-responder" F1 and "non-responder" F1----SJL semiallogeneic bone marrow chimeras were prepared to study how the host environment affects the ability of T cells to give a proliferative response to gamma-RCS. The results indicate that T cells educated in an SJL host become responsive to RCS cells, while T cells educated in an (SJL X BALB/c)F1 host become unresponsive. This finding applies to both thymus and lymph node T cells. The unresponsiveness in F1 mice is not due to suppressor cells, since added F1 cells do not affect the proliferative response of SJL cells to gamma-RCS. Instead, it appears that RCS-specific T cells are either deleted in (SJL X BALB/c)F1 mice, or expanded in SJL mice as they develop. These findings are discussed in relation to the specificity of the responding T cells, for LPS activated syngeneic B cell blasts as well as RCS cells, and to the presence of a "leaky" thymus barrier in SJL mice for B cells.