Evidence for MHC gene control of lesion severity in experimental allergic encephalomyelitis of chickens.

Susceptibility to experimental allergic encephalomyelitis (EAE) was studied in two related inbred lines of chickens (lines G-B1 and G-B2) as well as their F2 generation offspring. MHC (B system) genotypes of G-B1 and G-B2 birds are B13/B13 and B6/B6, respectively. Sensitization with central nervous system (CNS) tissue failed to induce clinical symptoms in any of the birds. However, brain lesions typical for EAE were found to be significantly greater in line G-B1 birds than in line G-B2 birds. Evidence for MHC gene control of EAE brain lesion severity was found with F2 offspring. Mean lesion scores were lowest for B6/B6 birds, intermediate for B6/B13 birds, and highest for B13/B13 birds.