Antibody-induced loss of Friend virus leukemia cell surface antigens occurs during progression of erythroleukemia in F1 mice.

Abstract

Friend virus (FV)-induced leukemic spleen cells from (B10.A .times. A)F1 mice lost sensitivity to antibody-mediated lysis during progression of erythroleukemia. This was correlated with a 78% loss of FV-induced cell surface antigens as determined by quantitative absorption of cytotoxic antibodies and with a decreased percentage of leukemic spleen cells showing membrane immunofluorescence with anti-FV antibody. Antigen loss was observed only with virus-induced antigens, and was limited to antigens expressed on the cell surface. FV-induced antigens were regained when low-antigen leukemia cells from late stages of the leukemia were transferred to lethally irradiated nonimmune recipients, but not when these cells were transferred to hyperimmune lethally irradiated recipients. When high-antigen leukemic spleen cells from early stages of the erythroleukemia were transferred to hyperimmune irradiated recipients, antigen loss was induced. The immune response to virus-induced antigens appeared to be involved in causing the antigenic changes observed on leukemia cells in this system.