Transplantation of hamster xenogeneic tissue in syngeneic murine chimaeras

CBA mice exposed to an otherwise lethal dose of irradiation (1006 rads) were saved by the intravenous injection of suspensions of CBA bone marrow cells. Hamster kidney cells (BHK) were injected intraperitoneally into these mice at 1, 3, 7 and 14 days after irradiation and marrow injection. The injected cells survived and proliferated in the abdominal cavities of the mice. The cells invaded abdominal organs and the skeletal muscle of the body wall. Mice injected with BHK cells 24 hours after irradiation and marrow injection survived 11-23 days. Mice injected with BHK cells 14 days after irradiation and marrow injection survived for a significantly longer period than those injected at 1, 3 and 7 days.The CBA/CBA chimaera is thus more immunologically competent 14 days after its formation than at 1, 3 and 7 days in its ability to respond to the transplantation of xenogeneic cells.