Experimental demyelination produced by the A59 strain of mouse hepatitis virus.

Intracerebral inoculation of 4- to 6-week-old C57BL/6 mice with the A59 strain of mouse hepatitis virus (MHV), a murine coronavirus, produced biphasic disease. Acute hepatitis and mild meningoencephalitis were followed by subacute spastic paralysis with demyelinating lesions in the brain and spinal cord as determined by Epon-embedded toluidine-blue-stained sections and by electronmicroscopy. MHV-A59 was cultured by plaque assay from the blood, brain, spinal cord, and liver of infected mice during the acute phase, but not in the chronic stage. MHV-A59 antigen was detected by immunofluorescence (IF) until 3 months postinfection (PI). Serum anti-MHV-A59 antibodies were detected from 7 days to 5 months PI. The induction of demyelination by MHV-A59 provides a suitable system to study virus-induced demyelination further.