Helper virus‐dependent RSV rescue from two lines of hamster cells transformed in vivo by XC RSV

Abstract

Newborn hamsters were inoculated with chicken sarcoma tissue produced by XC RSV which had been rescued by transfection from XC cells. Tumours with a latency of up to 20 months appeared in all inoculated hamsters. Three tumour cell lines were successfully established for in vitro growth and cloned. The virus was rescued from the PR RSH-9 cell line by cell fusion with chicken fibroblasts and from the other two lines (PR RSH-12 and PR RSH-14) and clones only if chicken fibroblasts used for fusion had been preinfected with a helper virus. The last two cell lines evidently harboured a functional env gene since the the synthesis of transforming virus started soon after they were found with 16Q cells producing defective BH-RSH(-) lacking the envelope glycoprotein. Produced viruses acquired subgroup C specificity of XC rsv originally used for transformation of these two cell lines. The nature of provirus alterations in PR RSH-12 and PR RSH-14 cells as well as the mechanisms underlying these changes are discussed.

Studies on the Structure and Organization of Avian Sarcoma Proviruses in the Rat XC Cell Line

“…is type II. Svoboda (1981) has also transformed chicken cells with virus rescued from XC cells and the transformed chicken cells are then injected into hamsters to induce tumours. Several different tumour cell lines have been established from these tumours.…”

“…7, lane 6). J. Svoboda and colleagues have also established several hamster tumour lines from tumours induced by injecting virus rescued from XC cells (Svoboda, 1981). In one such line, H9, again the 1.45 kb fragment was present, suggesting that the proviral DNA from XC cells contained the provirus with the new EeoRI site (Fig.…”

Characterization of Transforming Viruses Rescued from a Hamster Tumour Cell Line Harbouring the v-src Gene Flanked by Long Terminal Repeats

“…In E6, however, the band was about 3.7 kb in size. In all these lines, including RAV-l-infected as well as normal QEF cells, a slow migrating band of about 25 kb and another fragment of 1.1 kb were also evident, which were derived from endogenous c-src of QEF and 3' end of RAV-1, * Two x 106 BLEF seeded with indicated numbers of H-19 cells (irradiated with 7000 R using a 6°Co source) were fused the next day with polyethylene glycol and overlaid with medium containing 0.8 ~ agar (Svoboda, 1981). Number of foci is expressed as average of two dishes.…”