Theiler’s Murine Encephalomyelitis Virus Subgroup Strain-Specific

We compared infection of a murine macrophage-like cell line, J774-1, with two Theiler’s murine encepha-lomyelitis virus subgroup strains. The GDVII strain, which is highly virulent and produces acute polioen-cephalomyelitis in mice, did not actively replicate in J774-1 cells, although there was a significant inhibition in cellular protein synthesis. In contrast, the DA strain, which is less virulent and causes demyelination with a persistent virus infection, productively infected J774-1 cells; however, there was less virus produced than in BHK-21 cells, and there was little if any cellular protein shutoff. These in vitro data may provide some explanation for the biological activities that are observed between both subgroup strains. Theiler’s murine encephalomyelitis viruses (TMEV) belong to the picornavirus group and are divided into two subgroups on the basis of their different biological activities. GDVII sub-group strains cause acute fatal polioencephalomyelitis in mice without viral persistence or demyelination. In contrast, DA or TO subgroup strains produce chronic demyelination with a persistent virus infection in the spinal cords. This white-matter disease is used as an experimental model of the human demy