Replication of Murine Sarcoma Virus-HARVEY (MSV-H) in Tissue Cultures of Virus-induced Sarcomas

Abstract

SUMMARY Sarcomas induced in I3 BALB/c mice, one Sprague-Dawley rat and five Syrian (golden) hamsters by the murine sarcoma viruS-HARVEY (MSV-H) were grown in cell culture and the cell lines maintained for a maximum of I94 days. The majority of the tumour lines formed three-dimensional colonies of densely packed cells which eventually broke free from the glass and floated in the medium. Infective MSV-H was obtained from the mouse and rat tumour cultures. Filtrates of the culture fluids induced typical MSV-H lesions when injected into newborn mice, and those from cultures maintained for 4 to 6 months were as effective as those from cultures maintained for shorter periods. The newborn mice receiving undiluted culture fluids rapidly developed sarcomas and erythroblastic splenomegaly, while reci- pients of limiting dilutions developed lymphocytic leukaemia which never appeared earlier than z months after injection. Thus, the MSV-H derived from cell cultures behaved in the same way as that derived from infected animals. However, hamster tumour-cell culture filtrates did not contain active MSV-rI when tested in mice, but one such filtrate induced typical sarcomas and other characteristic MSV-H lesions when injected into newborn hamsters.