Synthesis of Sv40 Tumor Antigen During Replication of Simian Papovavirus (Sv40)

Hamsters bearing tumors induced either by simian papovavirus 40 (SV40) or by cells tranformed in vitro by the virus develop antibodies capable of detecting a new complement-fixing antigen in the transformed cells.1 Antibodies also develop for a new intranuclear antigen present in all cells transformed by SV40 and detected by the immunofluorescence technique.2, 3 It appears that the new antigens detected by complement-fixation and by immunofluorescence are similar or identical immunologically.4 The new tumor antigen is presumably under control of at least a portion of the virus genome, but some of the cell lines producing the antigen do not go on to synthesize infectious SV40.5 The present experiments, and those reported in the accompanying paper,6 were designed to determine whether cells susceptible to SV40 produced the tumor antigens in the course of the replication of the virus.