Prevalence of murine mammary tumor virus antibody and antigens in normal and tumor-bearing feral mice.

Approximately 20% of normal male and female feral mice (Mus musculus) from areas with populations having either high [Lake Casitas (LC) and La Puente] or low (Bouquet Canyon) spontaneous lymphoma incidence expressed murine mammary tumor virus (MuMTV) gp52 in specific tissues. Sera from a low percentage (6%) of mice from the same trapping areas contained precipitating antibody specific for MuMTV. Although moderate to high levels of MuMTV gp52 were expressed in mammary tumor tissues of 3 of 7 LC mice and 3 of 3 (C57BL/10ScSn X LC)F1 mice, the same animals showed no detectable MuMTV-precipitating antibody. Neither MuMTV antibody nor tumor-associated MuMTV gp52 was defected in 10 LC mice bearing lymphomas or in 5 LC mice bearing hepatomas. Low levels of MuMTV gp52 expression and MuMTV antibody were also detected in subspecies of M. musculus and in the more distantly related species M. cervicolar. Compared with normal and tumor-bearing inbred mice of high (C3H/HeN) and low (C3H/HeN foster-nursed on NIH Swiss) mammary tumor strains, normal and tumor-bearing feral mice express MuMTV gp52 and MuMTV-precipitating antibodies at low frequency.