Mouse thymic virus (MTLV; murid herpesvirus 3) infection in athymic nude mice: evidence for a T lymphocyte requirement.

Mouse thymic virus (MTLV; murid herpesvirus 3) is a lymphotropic herpesvirus that cytolytically infects developing T lineage lymphocytes in the thymus of neonatal mice. MTLV establishes a persistent infection and can be recovered indefinitely from infected mice, but nothing is known about requirements for this persistent infection. In order to determine whether T lineage lymphocytes are required for infection, young adult athymic nude (nu/nu) mice and euthymic littermates were infected with MTLV and tested for virus shedding. Although euthymic littermates regularly shed virus, in the nude mice only about 20% of isolation attempts up to 100 days postinfection were positive. Blind passage yielded an additional three isolations out of 14 samples (21%). In addition, unlike many other herpesviruses, the virus did not replicate in a number of epithelial and fibroblastic cell lines that were tested. These data confirm that the virus is preferentially T lymphotropic and suggest that infection may require T lineage lymphocytes.