title: 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.
mesh_terms: D000818:Animals; D001358:Avian Sarcoma Viruses / Q000276:immunology*; D002459:Cell Fusion; D002460:Cell Line; D002472:Cell Transformation, Viral; D002645:Chickens; D002999:Clone Cells; D006224:Cricetinae; D008647:Mesocricetus; D009368:Neoplasm Transplantation; D001357:Sarcoma, Avian / Q000276:immunology*