ABSTRACT
Vaccination with modified lymphoma cells produced highly specific antisera in syngeneic murine hosts. These were C3H/HeJ anti-6C3HED and BALB/cJ anti-P1798. These antisera gave positive membrane immunofluorescence tests with the corresponding tumor cells as well as with drug-resistant cells derived from the parental line. Immune BALB/cJ, but not immune C3H/HeJ, antiserum was cytotoxic in the presence of complement. The antisera did not cross-react with the opposite tumor, Moloney virus-induced YAC lymphoma cells, or normal splenocytes from either mouse strain. Both immune and nonimmune sera gave a positive cytotoxic test with Gross virus-induced lymphoma cells, indicating exposure of all the animals to the virus. Mice periodically given booster injections served repeatedly as serum donors; BALB/cJ mice not boosted for 42 weeks after tumor rejection still had circulating anti-P1798 antibodies. Allogeneic C57BL/KsJ anti-P1798 gave immunofluorescence tests with P1798, 6C3HED and normal BALB/cJ lymphocytes; it was cytotoxic for P1798 but not for normal lymphocytes. After absorption with normal BALB/cJ tissues, the serum became highly specific for P1798 but lost it cytotoxicity. Syngeneic and absorbed allogeneic anti-P1798 inhibited fetal liver colony formation on the spleens of irradiated BALB/c mice, indicating reaction with fetal antigen, but 6C3H/HeJ anti-6C3HED did not give similar inhibition. The latter antiserum was used successfully for passive immunization as long as there was excess antibody; BALB/c anti-P1798 did not protect, while C57BL/KsJ anti-P1798 was only marginally protective.
Subject(s)
Antibody Specificity , Immune Sera , Lymphoma/immunology , Animals , Antibodies, Neoplasm , Cross Reactions , Cytotoxicity Tests, Immunologic , Fetus/immunology , Isoantibodies , Mice , Mice, Inbred BALB C/immunology , Mice, Inbred C3H/immunology , Mice, Inbred C57BL/immunologyABSTRACT
Bacterial endotoxin was administered with iodoacetamide-modified P1798 lymphoma cells to immunize syngenic BALB/cJ mice against this lymphoma to which they are naturally unresponsive. Three or four vaccinations with endotoxin (6.6 mug/injection) alone or the modified cells alone did not produce host resistance. A significant number (30 percent) of mice receiving both endotoxin and modified cells rejected a subsequent implant of viable tumor cells. Even those mice having progressive tumor growth exhibited prolonged survival. High doses of endotoxin given with the modified P1798 cells caused 70-75 percent of the mice to reject the tumor implants. When resistance developed, antibodies reacting with tumor cell membrane were demonstrable. These results indicate that B-lymphocyte stimulators can produce an effective immune response against lymphoma cells.
