FIG. 3.

Infection with variant MHV-JHM results in a demyelinating encephalomyelitis. The brain and spinal cord from a mouse infected with virus encoding variant epitope CSLWSGPHL were harvested at 21 days p.i. The sample was fixed in formalin and embedded in paraffin. (A) Five-micrometer sections were cut, processed, and stained with luxol fast blue in order to detect areas of demyelination. (B) Sections (5 to 10 μm) were prepared and analyzed for viral antigen by using antibody to the N protein as described in Materials and Methods. Sections were lightly stained with hematoxylin after processing. Viral antigen (asterisks) is detected in the white matter adjacent to an area of demyelination. Bar, 100 μm (A) and 50 μm (B).