ADOPTIVELY TRANSFERRED CD8(-LYMPHOCYTES PROVIDE PROTECTION AGAINST TMEV-INDUCED DEMYELINATING DISEASE IN BALB() T)C MICE/

On intracerebral infection with the BeAn strain of Theiler's murine en cephalomyelitis virus (TMEV), certain mouse strains develop a chronic demyelinating disease similar both clinically and pathologically to hu man multiple sclerosis. Other strains remain resistant. We previously established that differential susceptibility to this demyelinating dis ease exists among BALB/c substrains, with BALB/cAnNCr mice being susce ptible while BALB/cByJ mice are resistant. BALB/cByJ mice are rendered susceptible to TMEV-induced demyelination on exposure to low dose gam ma-irradiation before TMEV infection. BALB/cAnNCr and irradiated, infe cted BALB/cByJ animals are protected against TMEV-induced demyelinatio n by the transfer of a splenic population from TMEV-infected BALB/cByJ donors. Resistance to demyelination appears to be mediated by a CD8() radiosensitive population, which is induced on infection with TMEV a nd which must act early to establish resistance to TMEV-induced demyel ination.