Activation of glial cells by human coronavirus OC43 infection.

Multiple sclerosis (MS) is an immune-mediated demyelinating disease that could be triggered by a viral infection. Coronaviruses induce an MS-like disease in rodents, are neuroinvasive in humans and can infect primary cultures of human astrocytes and microglia. Infection of the human astrocytic cell line U-373MG by the OC43 strain of human coronavirus caused an upregulation of IL-6, TNF-alpha, and MCP-1 mRNA expression. This virus also modulated the activity of matrix metalloproteinases-2 and -9 and augmented nitric oxide production in both U-373MG cells and the human microglial cell line CHME-5. Thus, a coronaviral infection of glial cells could lead to the production of inflammatory molecules that have been associated with central nervous system pathologies such as MS.