Copyright © 1992, American Society for Microbiology Theiler's Virus Replication in Brain Macrophages Cultured In Vitro

Infection of the mouse with Theiler's virus is one of the best animal models for the study of multiple sclerosis, a chronic demyelinating disease of the human central nervous system. The identification of the virus target cell(s) is fundamental to an understanding of the viral persistence as well as the inflammation and demyelination observed in the chronic phase of the disease. This paper reports that a small fraction of brain macrophages grown in vitro can be efficiently infected with Theiler's virus without significant cytolytic effect. Viral replication as well as continuous production of infectivity were observed in these cultures. Mice persistently infected with Theiler's virus, a murine picornavirus, present tissue lesions closely resembling those of multiple sclerosis (MS), a chronic demyelinating disease of the human central nervous system (CNS) (12, 25, 39). The cause of MS seems to be multifactorial (13, 23). Viral infections may play an important role in the onset of the disease (41). Therefore, study of the mechanisms leading to viral persistence and to demyelination in animal models is of importance for understanding the pathogenesis of MS. I