Cyclophosphamide and rabbit anti mouse thymocyte serum were used to immunosuppress SJL/J mice infected with Theiler's mouse encephalomyelitis virus (TMEV) in order to delineate the potential mechanism(s) of virus induced cellular injury in this infection. Whereas both immunosuppressive agents produced a significant increase in mortality, this treatment had differing effects on the pathological involvement of gray and white matter structures in the central nervous system. The central nervous systems of immunosuppressed TMEV infected mice had increased microglial cell proliferation and neuronal necrosis, longer maintenance of high virus levels, and spread of virus antigen to involve the neocortex and hippocampal complex. These observations indicate that TMEV causes a cytolytic infection of neurons and possibly other cells in gray matter. In contrast, immunosuppression produced a dramatic reduction in mononuclear inflammatory cells in the leptomeninges and spinal cord white matter of infected mice and prevented demyelination. Further, virus antigen was not detected in the leptomeninges and white matter of immunosuppressed and infected mice. These findings suggest that demyelination in TMEV infection is immune mediated.
ASJC Scopus subject areas
- Infectious Diseases