Quantitation of myelin oligodendrocyte glycoprotein and myelin basic protein in the thymus and central nervous system and its relationship to the clinicopathologic features of autoimmune encephalomyelitis

There is controversy whether the amount of autoantigens expressed in the thymus regulates negative selection of autoreactive T cells and determine susceptibility or resistance to experimental autoimmune encephalomyelitis (EAE). In the present study, we have addressed this issue by quantifying neuroantigens in the thymus of two EAE-susceptible (LEW and LEW.1AV1) and one EAE-resistant (BN) rat strains. We further examined whether amounts of neuroantigens in various parts of the central nervous system (CNS) affect the clinical course and lesion distribution of acute and chronic EAE. Real-time PCR and histologic analyses showed that there was no significant difference in the amount and distribution of myelin oligodendrocyte glycoprotein and myelin basic protein in the thymus and CNS among the three strains and that both acute and chronic EAE lesions in the CNS were preferentially distributed in the area where neuroantigens were abundantly present. These findings suggest that susceptibility or resistance to EAE is not regulated by the amount of the neuroantigens expressed in the thymus. Furthermore, the lesion distribution, but not the clinical course, of EAE is related to the neuroantigen expression in the CNS.