H-2 Dd transgene suppresses Theiler's virus-induced demyelination in susceptible strains of mice.

Theiler's murine encephalomyelitis virus is a picornavirus which induces chronic immune-mediated central nervous system demyelination and virus persistence in susceptible strains of mice. Using murine strains with congeneic recombinant haplotypes, the H-2D region within the class I major histocompatibility complex has been shown to be important in determining susceptibility/resistance to chronic Theiler's murine encephalomyelitis virus infection. We examined the role of H-2D in demyelinating disease with the use of transgenic D8 mice (H-2Dd, resistant haplotype) crossed to susceptible B10.Q (H-2q) and B10.S (H-2s) mice. Expression of the H-2Dd transgene dramatically suppressed demyelination and reduced the number of virus-antigen positive cells in the spinal cord 45 days following infection. More complete protection was observed in transgenic B10.Q (D8+) mice than in transgenic B10.S (D8+) mice. These experiments support the hypothesis that the immunologic basis of resistance by H-2D is determined by effective antigen presentation which prevents virus persistence and subsequent demyelination.