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 (nulnu) 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.