The Immunological Basis For Non-infective Rous Sarcomas

Abstract

It has long been recognized that chicken tumors induced by Rous sarcoma virus (RSV) vary widely in the yield of infectious virus, there being some tumors which contain over 109 infectious units per gram and others with no detectable virus. The latter, which will be referred to as non-infective tumors, were studied by Duran-Reynals (Duran-Reynals and Freire, 1953; Freire and Duran-Reynals, 1953), who found that they occurred more commonly in adult chickens than in very young chicks, and that their frequency increased with the age of the tumor both in young and adult chickens. On the basis of these findings he proposed that the absence of virus from tumors was due to an immunological reaction by the host against the virus.