Graft-versus-host disease in murine bone marrow transplantation. II. Modulation of acute and chronic GVHD in mice receiving bone marrow allografts pretreated with immunosuppressive factor derived from a human T cell line.

BALB/c bone marrow treated with monoclonal anti-Thy 1.2 antibody and complement is unable to produce prolonged hemopoietic repopulation and survival when transplanted to lethally-irradiated allogeneic CBA recipient mice. Preincubation of the antibody treated bone marrow cells with an immunosuppressive factor (SAF) derived from a 6-thioguanine resistant cell line, itself derived from the human T cell line CEM, in contrast, allowed those bone marrow cells to produce a state of chimerism and long term survival. Parameters designed to gauge the degree of graft-versus-host reactivity (GVHR) in these animals suggested that acute GVHR was abolished with this procedure. Moreover, defining chronic GVHD as associated with abnormally high spontaneous proliferation of splenic cells, elevated anti-host mixed lymphocyte reactivity, or elevated serum immunoglobulin levels (in all cases when compared with the syngeneically repopulated BALB/c----BALB/c), our data suggest that preincubation with SAF modified chronic GVHD also.