Isolation of Human Amnion Cells transformed by Rescuable Murine Sarcoma Virus

Separation of sarcoma virus-specific and leukemia virus-specific genetic sequences of Moloney sarcoma virus.

“…The other form of Mo-SV, isolated in cell culture from the sarcoma-leukemia complex, was called the S+L-strain of Mo-SV (11). This form of Mo-SV was later found to contain, as a part of its genome, information which codes for the p30 protein of Moloney leukemia virus (12,14), and thus is referred to here as a p30 positive strain of Mo-SV (Mo-SV p30+). In past experiments each of these forms has been shown to be genetically stable (12), and each of these forms of Mo-SV is defective by itself for replication.…”

A p60 polypeptide in the feline leukemia virus pseudotype of Moloney sarcoma virus with murine leukemia virus p30 antigenic determinants.

“…Moloney sarcoma virus (MSV) isolates can express Moloney murine leukemia virus (MI-MuLV) p30 group specific antigens in transformed nonmurine cells that were not co-infected with M-MuLV (4)(5)(6)(7). AMSV rescued by various leukemia viruses from sarcoma positive, leukemia negative (S+L ) cells of several species can be used to produce S+L-cells in new species which again express MuLV p30 (4,5,7). Because of the apparent genetic stability of AIuLV p30 elxpression by this AISV genome in cells of many mammalian species in the absence of MuLV, it is assumed that the MSV genome itself contains the information for MuLV p30.…”

“…However, the feline leukemia virus (FeLV) complex of MISV(FeLV) is useful for this purpose since it is coated with the easily distinguishable heterologous FeLV helper (4,5,8) and infectious AISV is produced in 4- with a discontinuous buffer system containing sodium dodecyl sulfate (NaDodSO4) (15). Samples were subjected to electrophoresis for 16 hr at 50-100 V. Gels were stained with Coomassie blue and scanned at 550 nm on a Gilford 2400 spectrophotometer (Oberlin, Ohio) or sliced and assayed for radioactivity as described (16).…”

Characterization of non‐producer human cells induced by kirsten sarcoma virus

“…It has been reported that human amnion cells can be transformed by certain isolates of MSV to yield human sarcoma-positive, leukemia-negative (S L-) cells (Peebles et al, 1973).…”