Transmission of murine leukemia virus (Scripps) from parent to progeny mice: a comparison of assay systems.

Transmission of murine leukemia virus (MuLV) from parent to progeny C3H/St and C57BL/St mice was examined by four assay systems: 1) recovery of infectious NB-tropic MuLV from spleen cultures, 2) the radioimmunoassay for p30 antigenemia, 3) morphologic examination for lymphoma development, and 4) the indirect fluorescent antibody technique for antinuclear antibodies (ANA). Transmission of MuLV (Scripps) occurred in 90-100% of C3H/St and C57BL/St progeny nursed by mothers with p30 antigenemia. All assays except ANA were equally sensitive for the determination of MuLV transmission in C3H/St mice, but the incidence of transmission in C57BL/St mice was determined only by assays of their cultured spleens for MuLV. Incidences of ANA were increased in all generations of C57BL/St mice compared with controls; the route of transmission of MuLV (Scripps) was not a factor. Only C3H/St mice infected by virus transmitted from parent to progeny developed ANA. Infectious MuLV was invariably recovered from spleens cultured from mice with p30 antigenemia, which was present in all mice that developed lymphoma. NB-tropic MuLV was also recovered after prolonged cultivation from spleens of 75% of C57BL/St progeny mice that did not develop p30 antigenemia. These suggested that MuLV (Scripps) could exist either as a productive persistent or nonproductive latent infection in C57BL/St mice.