Immunologic characteristics in relation to high and low leukemogenic activity of radiation leukemia virus variants. II. Analysis of the immune response.

Comparative analysis of immune responses induced by two variants of the radiation leukemia virus having high (A-RadLV) or low (D-RadLV) leukemogenic potential was performed. Effective immunization could be induced only with RadLV variants having low leukemogenic potential when injected into adult mice of specific strains, (D-RadLV in C57BL/6 mice and A-RadLV in (BALB/c X C57BL/6)F1 mice). Immunologic cross-reactivity among the RadLV variants and the leukemic cells induced by them was demonstrated in several systems. Transplantation resistance could be induced in certain strains against challenge of leukemic cells induced by both RadLV variants. Isoantisera, raised in the suitable strains, could neutralize effectively the leukemogenic activity of both A-RadLV and D-RadLV. Leukemic cells induced by each of the variants shared cell-surface antigens. Circulating anti-tumor antibodies, induced by both variants in the appropriate strains, lysed efficiently the target leukemic cells.