Immunological Identity of the Group-specific Antigen of Hamster-specific C-type Viruses and an Indigenous Hamster Virus

Abstract

SUMMARY Antisera prepared in guinea-pigs against a purified internal virion antigen of a hamster-specific C-type virus reacted with an ether-stable antigen derived from several hamster-specific viruses and an indigenous hamster virus. Reactions of iden- tity were obtained in immunodiffusion tests between all virus preparations while no reactions were obtained with uninfected cells and murine C-type virus prepara- tions. Guinea-pig antiserum to the murine C-type virus gs antigen did not react with any of the hamster virus preparations. This pattern of specificity was main- tained in complement-fixation tests. Based on these data and the envelope antigen identity of the hamster-specific sarcoma viruses established in the accompanying paper, these viruses, originally re- covered from hamster tumours induced by murine sarcoma viruses, are considered to be pseudotype sarcoma viruses possessing the antigens of the indigenous hamster C-type virus~and the sarcoma gene(s) of the original tumour inducing murine viruses. Our current preferred nomenclature for the hamster-specific viruses is based on these considerations.