The Pathogenesis of Tumors Induced by Helper Virus-Free Abelson Murine Leukemia Virus

Abstract

The Abelson murine leukemia virus (A-MuLV) rapidly induces pre-B cell lymphomas in susceptible mice (Risser et al., 1978) and transforms bone marrow lymphocytes in vitro (Rosenberg and Baltimore, 1976) when inoculated as a complex of virions containing A-MuLV genomes and Moloney MuLY (M-MuLV) genomes. Recently, we have analyzed the activity of helper virus-free A-MuLV pools harvested from supernatants of the psi2 retroviral packaging cell line which had been transfected with a cloned A-MuLV P160 provirus (Green et al., 1987a). The availability of helper virus-free A-MuLV has allowed us to follow the progression of transformed cells in vivo without the complications that result from virus replication (Green et al., 1987b; Whitlock et al., 1983). Individual transformed cells recovered from A-MuLV(psi2) -infected mice were analyzed molecularly and biologically to determine which properties correlate with the progression of the transformed cell to a fully malignant cell.