Immune response to sheep red cells in AKR mouse leukemia.

Long-term administration of sheep red cells to AKR mice did not influence the development of spontaneous leukemia. In mice with transplanted leukemia there was an increase in numbers of spleen hemolytic plaque-forming cells (PFC) during the early leukemic phase, as compared to controls, and a marked decrease and final disappearance of PFC from all lymphoid organs in the late leukemic phase. This pattern was seen in both the primary and secondary immune responses.