Studies on group‐specific antigens in tumours induced with avian tumour viruses in rats

Abstract

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 ( A T V ) : Schmidt-Ruppin strain of Rous sarcoma virus ( S R -R S V ) , Prague strain of R S V ( P R -R S V ) , Fujinami sarcoma virus ( F S V ) and Bratislava 77 virus (B77V). All primary tumours induced in chicks by S R -R S V , 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 ( A M V ) . 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 tumourbearing 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 X C . However, all attempts to detect GS antigen in one S R -R S V induced virogenic rat tumour ( M R I ) gave negative results. Possible heterogeneity of A TV-induced GSantigen in mammalian tumours is discussed.

Expression of viral protein P27 in avian sarcoma virus‐transformed mammalian cells and helper‐dependent rescue of rous sarcoma virus

“…These results are, in principle, in agreement with the previous observations made by Harris et a/. (1969) and Thurzo et al (1969) in some SR-RSV-induced rat tumours.…”

“…The ASV Bratislava 77 (B77)-producing rat cell clones RBIasc K7, K12, K22, K24 and the subclone K2S, were isolated from in vitro established cell lines which were derived from an RBI tumour (SimkoviE et al, 1969;PopoviE et al, 1970;Svoboda et al, 1972). The virus-producing tumour RBI was induced by inoculation of B77 virus into Wistar rats (Hlavayova et al, 1964).…”

“…Because of significant differences and fluctuations in the viral genome expression in B77 virus-producing mammalian cells (PopoviE et al, 1972;Svoboda et al, 1972;Thurzo et a[., 1969), the production of infectious B77 virus and gs antigen content were retested in four clones (RBIasc K7, K14, K22, K24) and the subclone K2S derived from RBI cells (Table I). All four clones and the subclone K2S released infectious B77 virus into culture medium.…”

Comparative study of RSV rescue from RSV‐transformed mammalian cells

“…Five days after inoculation Vesely et al (1966) Bauer andJanda (1967) RVA 2 Newborn C57BI/6 SRRSV in vivo + + + Koldovsky and Bubenik (1964) mice Koldovsky et al (1966) Bubenik and Bauer (1967 RVA. Newborn C3H SRRSV in vivo + Svoboda (1960Svoboda ( , 1961Svoboda ( , 1967 Wistar rat ) Thurzo et al (1969 the chickens were killed, the peritoneal cavities were washed with PBS and the fluid harvest was centrifuged for 10 min at 1,000 xg. The pelleted cells were washed several times with PBS and cell suspensions were used immediately in the experiments.…”

“…Chicken peritoneal macrophages were isolated by the intraperitoneal injection of 6-to 8-weekold Brown Leghorn chickens with 20 ml of sterile liquid paraffin oil. Five days after inoculation Svoboda (1960Svoboda ( , 1961Svoboda ( , 1967 Wistar rat ) Thurzo et al (1969 the chickens were killed, the peritoneal cavities were washed with PBS and the fluid harvest was centrifuged for 10 min at 1,000 xg. The pelleted cells were washed several times with PBS and cell suspensions were used immediately in the experiments.…”