STUDIES ON GROUP-SPECIFIC ANTIGENS IN TUMOURS INDUCED WITH AVIAN TUMOUR VIRUSES IN RATS

Group‐specific complement‐fixing antigen (GS antigen) was studied by the complement‐fixation test in various avian and mammalian tumours, induced with the following strains of avian tumour virus (ATV): Schmidt‐Ruppin strain of Rous sarcoma virus (SR‐RSV), Prague strain of RSV (PR‐RSV), Fujinami sarcoma virus (FSV) and Bratislava 77 virus (B77V). All primary tumours induced in chicks by SR‐RSV, FSV and B77V, as well as all duck tumours induced with B77V, contained high titres of GS antigen when studied with high‐titre rabbit antiserum against purified GS antigen of avian myeloblastosis virus (AMV). In three out of six B77V‐induced rat tumours (two virus‐producing and one non‐virogenic) high titres of GS antigen were detected when examined with rabbit antiserum and with some rat sera obtained from tumour‐bearing animals. In three remaining B77V‐induced virogenic rat tumours (C21, C22 and C23), GS antigen was not detected with rabbit antiserum; however, sera obtained from these three tumour‐bearing rats contained high titres of GS antibodies when tested with different GS antigens. Positive results were obtained also with PR‐RSV‐induced virogenic rat tumour XC. However, all attempts to detect GS antigen in one SR‐RSV induced virogenic rat tumour (MRI) gave negative results. Possible heterogeneity of ATV‐induced GS antigen in mammalian tumours is discussed. Copyright © 1969 Wiley‐Liss, Inc., A Wiley Company