Studies on the Neutralization of the Oncogenicity of Friend, Moloney, and Rauscher Viruses1

Friend, Moloney, and Rauscher (FMR) viruses were in cubated with either normal serum or with sera from C57BL/6 mice immunized with syngeneic Friend, Moloney, or Rauscher virus-induced lymphomas. The mixtures were inoculated into newborn BALB/c mice, and the development of lymphomas was followed. The oncogenicity of all 3 viruses was effectively neutralized by each of the antisera. The results suggest that FM II viruses possess similar, if not identical, antigens. A spe cific rat anti-Gross serum was also active against the 3 viruses, suggesting the existence of a virion coat component antigenically shared by Gross virus and the FMR viruses. Finally, sera from C57BL/6 mice whose autochthonous Moloney sarcoma virusinduced tumors had regressed also neutralized the FMR viruses.