AKV MURINE LEUKEMIA-VIRUS ENHANCES LYMPHOMAGENESIS IN MYC-KAPPA TRANSGENIC AND IN WILD-TYPE MICE

The contribution of endogenous retroviruses to the multistep process o f lymphomagenesis was investigated in wild-type mice and in two differ ent myc-kappa transgenic mouse lines by infection with Akv. This retro virus is derived from the endogenous ecotropic provirus of the AKR mou se and was previously considered to be nonlymphomagenic. The mice of t he two myc-k transgenic lines are predisposed to B-cell lymphomagenesi s and were therefore considered to be more susceptible to Akv. For com parison, the same mouse strains were also infected with the exogenous Moloney murine leukemia virus (MoMuLV). Both MoMuLV and Akv increased the tumor incidence and shortened the tumor latency period in wild-typ e mice and in the transgenic mouse lines. The differences in pathogeni city, number of provirus integrations, and level of virus expression b etween MoMuLV and Akv indicate different mechanisms of lymphomagenesis : while MoMuLV induced tumors apparently by insertional mutagenesis in volving common integration sites similar to previous reports, the enha ncement of lymphomagenesis by Akv seems to be directed by other mechan isms. (C) 1995 Academic Press, Inc.