Murine leukemia virus infection in immunocompetent adult mice

The course of infection of a chronic murine leukemia virus (MuLV), E-55+, which induces thymic lymphoma/leukemia in 100% of mice infected as adults, was followed after inoculation of virus into adult mice which generate both cytotoxic T cell and neutralizing antibody responses (Blank 1976). DNA from the tissues of these infected mice was analyzed using a polymerase chain reaction assay to detect integrated provirus. Infection in adult immunocompetent BALB.K mice results in an acute phase characterized by a high number of cells containing provirus DNA followed by a period in which provirus DNA in most tissues reaches background levels until the development of thymic lymphoma/leukemia at 4-7 months. This pattern of infection is different from what has been observed in immunosuppressed mice in which levels of virus-infected cells remain high throughout the preleukemic and leukemic phases.