Loss of stem cell function in the bone marrow of mice undergoing a graft-vs-host reaction

The injection of parental T cells into healthy Fl hybrid mice can result in severe immunologic abnormalities including immune deficiency in the recipients. To test whether stem cell function could also be affected in Fl mice undergoing a parental-induced graft-vs-host (GVH) reaction, T cell-depleted bone marrow from parentally-injected Fl mice was tested for stem cell proliferative and T cell differentiation capacity by transplantation of the bone marrow from GVH mice into lethally irradiated syngeneic Fl test recipients. Stem cell proliferative capacity was tested in the repopulating spleens of the test mice by an in vivo pulse with 125IUDR. A reduction was observed in the proliferative capacity of marrow from GVH mice. From 6-to-10 weeks after grafting the test recipients, their spleen cells were tested in vitro for mitogen stimulation and for the generation of cytotoxic T lymphocytes (CTL) responses to hapten-self and alloantigens. No mitogen nor CTL responses were detected in the spleens of test mice inoculated with marrow from GVH mice. These findings indicate that the GVH reaction can affect early stages in the development of the lympho-hematopoietic system