Experimental autoimmune encephalomyelitis: the antigen specificity of T lymphocytes determines the topography of lesions in the central and peripheral nervous system.

Recent studies on autoimmune encephalomyelitis and neuritis reveal that many different antigens of the central (CNS) and peripheral nervous system may become targets of an encephalitogenic T-cell response. The aim of this study was to determine the influence of T-cell specificity on the pathology of autoimmune-mediated inflammation in the nervous system. Autoimmune encephalomyelitis was induced by the adoptive transfer of CD4+ T-line cells specific for either myelin basic protein, myelin oligodendrocyte glycoprotein (MOG), myelin-associated glycoprotein, S100 beta, or glial fibrillary acidic protein. The severity of the inflammatory response was antigen- and dose-dependent. With the exception of MOG-specific T-line cells, all autoreactive T-cell lines induced inflammation in the CNS and peripheral nervous system. In the myelin-basic-protein-mediated model, the spinal cord was most severely affected with only minor inflammation in the forebrain. In contrast, both MOG- and myelin-associated-glycoprotein-specific T cells induced a far higher density of lesions in the periventricular and cerebellar white matter. S100 beta- and glial-fibrillary-acidic-protein-specific T cells mediated particularly severe inflammation in the gray matter. In addition to these topographic differences, antigen specificity also influenced the extent of both parenchymal inflammation and macrophage activation in the CNS. However, irrespective of the specificity or number of T cells transferred, the major neuropathologic correlate with disease severity was the absolute number of activated macrophages recruited into the CNS parenchyma (r = 0.9; p < 0.0001). This study suggests that differences in lesion distribution in multiple sclerosis patients may reflect differences in the antigen specificity of an encephalitogenic T-cell response.