RECURRENCE OF A TRANSPLANTED LEUKAEMIA IN MOUSE RADIATION CHIMAERAS RECEIVING ANTI-DONOR ISOIMMUNE SERUM

RF mice bearing a transplanted myeloid leukaemia were subjected to sublethal X-irradiation (530 rad) and were injected with 10 × 106 C57BL spleen cells, or 10-40 × 106 C57BL spleen cells and 30 × 106 C57BL bone marrow cells. At various intervals after irradiation and allogeneic cell injection (days 4-6, 6-8, 6-11, 6-17 and 26-38) the animals were treated with RF-anti-C57BL serum in amounts ranging from 0·3 ml to 4·0 ml. RF spleen and bone marrow cells and blood were occasionally injected as well. In non-leukaemic controls this treatment prevented, or postponed, death attributable to acute graft-vs-host reaction. In leukaemic animals receiving 10 × 106 C57BL spleen cells, treatment with antiserum and isogeneic cells resulted in recurrence of leukaemia. Higher doses of spleen cells invariably caused death from secondary disease in spite of the treatment with antiserum. It was not possible to adjust the timing of the treatment and the dose of spleen cells and antiserum relative to each other, in such a way that the graft-vs-host reaction elicited by spleen cells could eradicate the leukaemia without killing the host. © 1969.