POSSIBLE ROLE OF NK CELLS IN RADIATION LEUKEMOGENESIS: ADOPTIVE REPAIR OF NK DEFICIT OF FRACTIONALLY IRRADIATED MICE BY MARROW TRANSFUSION

Publisher Summary This chapter examines the possible role of natural killer (NK) cells in radiation leukemogenesis. The study described in the chapter investigated the effect of fractionated irradiation of C57BL/6 mice, with or without marrow transfusion, on NK cell activity and development of thymic lymphoma. Over a period of many months, C57BL/6 mice reared in the barrier sustained cesarean derived, SPF mouse colony, aged 4 to 6 weeks, half of each sex, were randomized into unirradiated age control groups and irradiated groups. The latter received 4 weekly exposures to 225R 137 Cs. Four to seven hours after the last exposure, half of the irradiated mice received 10 7 C57 bone marrow cells intravenously. Marrow-transfused, nontransfused and age-control mice were tested at intervals thereafter for spleen natural cell-mediated lysis of YAC-1 lymphoma target cells, by a 4 hour chromium release method, with or without 1 or 5 days prior intraperitoneal injection of the interferon inducers Poly l:C (PIC) or Coryne bacterium parvum (CP), respectively. Spleen NK cell activity was depressed by fractionated irradiation. Bone marrow transfusion after the last irradiation significantly increased NK cell activity by 1 week post transfusion, to essentially normal levels throughout the 8 weeks post transfusion.