Proliferative responses of T cells from SJL → F 1, and F 1 → SJL bone marrow chimeras to SJL lymphoma cells

Abstract

RCS tumor cells induce marked proliferation of syngeneic SJL T cells in vivo and in vitro. Certain F 1 hybrids of SJL mice give high proliferative responses to γ-RCS, while other F 1 hybrids give low responses. SJL → “non-responder” F 1 and “non-responder” F 1 → 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 γ-RCS. The results indicate that T cells educated in an SJL host become responsive to RCS cells, while T cells educated in an (SJL × BALB/c)F 1 host become unresponsive. This finding applies to both thymus and lymph node T cells. The unresponsiveness in F 1 mice is not due to suppressor cells, since added F 1 cells do not affect the proliferative response of SJL cells to γ-RCS. Instead, it appears that RCS-specific T cells are either deleted in (SJL × BALB/c)F 1 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.