On the antigenic structure of rous sarcoma

Summary

The following constituents were obtained in fractionating Rous' sarcoma: 1) supernatant fluid (60,000 g; 1.5–2 hours), which did not contain corpuscular biologically active virus; 2) doubly reprecipitated precipitate, provoking tumors in chickens in the 1∶500 titre. Purified specific precipitating antibodies were isolated from the precipitate formed by the specific Rous sarcoma antigen (supernatant fluid). Testing of these antibodies in reaction of precipitation in agar has demonstrated that they react with the supernatant fluid in the same way as with the Rous sarcoma extract and do not react with the doubly reprecipitated precipitate; they did not neutralize sarcoma virus. Consequently, specific precipitating antigen of Rous sarcoma is not a virus antigen and is evidently of tissue origin. Apart from the specific precipitating antibodies, the virus neutralizing antibodies were revealed in the Rous sarcoma antiserum. These antibodies neutralized the virus at the same titre, as the initial Rous sarcoma antisera. However, they did not react in precipitation reactions in agar with any of the fractions of the Rous sarcoma tissue.