Progressive Loss of H-2 Antigens With Concomitant Increase of Cell-Surface Antigen(s) Determined by Moloney Leukemia Virus in Cultured Murine Lymphomas23

Two Moloney leukemia virus (MLV)-induced murine lymphomas (YCAB and YAC) and a spontaneous murine lymphoma (WL4) were serially propagated in the ascites form in syngeneic hosts. At intervals, culture lines were established and maintained as stationary suspension cultures for a few days to 3 years. In vitro lines derived from all 3 lymphomas had less H-2 antigens and more MLV-determined cell-surface antigen(s) than the corresponding in vivo lines in syngeneic hosts. This was shown by the sensitivity of the cells to complement-dependent, antibody-mediated cytolysis, indirect membrane immunofluorescence, and quantitative absorption tests. The antigenic changes took place progressively after explantation and were correlated with the number of cell generations in culture. The final cell densities of the culture lines were also correlated with the number of cell generations in culture; e.g., a sevenfold increase in the final cell density was observed in a long-established YCAB culture line, compared with a newly established line of the same tumor.