Syngeneic Marrow Graft: Effect on Persistence of Preirradiation Immunity To Hymenolepis nana in Mice

Summary X-irradiated mice preimmunized to Hymenolepis nana were injected with either 1 million or 40 million syngeneic (bone-marrow cells from nonimmune mice or with 204 million rat marrow cells. Twenty-two days after irradiation the mice were given H. nana eggs. Infection rates were lowest in the animals injected with the larger number of syngeneic marrow cells; the mice implanted with rat marrow had the highest infection rates. We conclude that transplanted syngeneic marrow from nonimmune donors makes less severe (or prevents) a radiation-induced depression of acquired immunity.