Mechanisms of C-type viral leukemogenesis. I. Correlation of in vitro lymphocyte blastogenesis to viremia and leukemia.

Various inbred strains of mice respond immunologically to genetically transmitted ecotropic C-type viruses. Part of this response is T cell blastogenesis with type specificity for the viral envelope glycoprotein gp71. Of those nonviremic, nonleukemic strains, and F1 crosses examined, in which virus expression occurs early in life, gp71-specific blastogenic T cells were detected within the first 2 months of age and temporally preceded the development of a humoral immune response. However, in the viremic, highly leukemic strain of AKR mice, gp71-specific T cell blastogenesis in vitro was readily detectable throughout the preleukemic phase, the first 5 months of age. In appropriate F1 crosses and backcrosses, the persistent in vitro blastogenic response segregated with viremia and leukemia. These data suggest that in vivo T cell stimulation by endogenous viral gp71, caused by viremia, may contribute to virus-induced leukemogenesis in mice.