Characterization of cell lines derived from enlarged spleens induced in C57BL/6 mice by the variant BSB strain of Friend erythroleukemia virus

Abstract BSB is a variant strain of Friend vims selected for pathogenicity in C57BL/6 mice that are resistant to parental Friend virus strains by virtue of their homozygosity for the recessive Fv -2 r allele (Steeves et al., 1970, Int. J. Cancer 5, 346–356). Lines and clones of erythroleukemia cells could readily be established in culture from the enlarged spleens of BSB-infected Fv -2 r homozygotes. All lines expressed viral gene products and could be induced to express hemoglobin. Some lines produced infectious virus. In addition to the viral envelope-related proteins (gPr85, gp70, and gp52) detected by precipitation with goat anti-Rauscher gp70 antiserum from tumor cell lines induced by parental Friend virus strains, BSB-induced cell lines also expressed gp80, p52, and gp45 products precipitable with the same antiserum. A rat monoclonal antibody that recognizes an epitope of an aminoterminal region of gp52 (Wolff et al., 1982, J. Virol. 43, 472–481) also precipitated the gp80 and gp45 viral proteins. The data indicate that the BSB strain of Friend virus is oncogenic in Fu-2 r homozygotes. Transformation is correlated with the expression of an altered SFFV env -gene product.