MURINE GAMMAHERPESVIRUS 68: A MODEL TO STUDY DISEASES OF MAN AND DOMESTIC ANIMALS

Abstract

The gamma herpesviruses are widely disseminated in nature causing infection and disease in man. Domestic animals including cattle, deer, sheep, horses and rodents. Murine gammaherpesvirus-68 is a natural pathogen of wild rodents. In Balb/c mice, it establishes a productive infection of epithelial cells of the lung alveoli, and a latent infection of B-Iymphocytes. As with other gammaherpesviruses, chronic infection of mice is associated with Iymphoproliferative disease (LPD) which ranges from mild to high grade lymphomas. In vitro. virus establishes persistent infection in murine myeloma B-cells in which viral DNA exists both in circular form, indicative of a latent infection and linear form, indicative of productive infection. Acyclovir can inhibit virus replication in vivo and in vitro but does not prevent latent infection in mice or reduce circular forms of viral DNA in persistently infected murine myeloma cells. CD8+ T cells are the major effector cells during acute infection. In contrast to the T-cell response which arises promptly to counter infection in the lung and spleen, antibody production (IgM) is first detectable only at 15 to 20 days. MHV-68 infection of mice provides a powerful model to study pathogenesis of gammaherpesviruses, in particular establishment and maintenance of latent infection and virus interaction with the immune system.