CD4+ and CD8+ T cells are not major effectors of mouse hepatitis virus A59-induced demyelinating disease.

We examined murine hepatitis virus strain A59 (MHV-A59)-induced demyelinating disease in C57BL/6 mice which had previously been thymectomized at 25 days of age. Demyelination was observed in 51-96% of spinal cord quadrants examined 30 or 60 days post infection (dpi), indicating that neither an intact thymus nor thymic infection is a prerequisite to demyelination. Depletion of CD4+ or CD8+ T cells at 5, 7 or 10 dpi did not influence the extent of demyelination indicating that neither T cell subset is a major effector of demyelination. However, these findings do not exclude the possibility that T cells are involved in initiating demyelinating disease very early in infection.