Journal of neuroimmunology
-
Expression of Class I (HLA-ABC) and Class II (HLA-Dr; Ia) major histocompatibility (MHC) antigens on endothelial cells and astrocytes was investigated in multiple sclerosis (MS) lesions of variable disease activity and in normal central nervous system (CNS) using immunocytochemical techniques. Findings were correlated to lesion pathology and to the presence and distribution of T cells, T cell subsets, and interleukin-2 (IL-2) receptor-bearing cells. HLA-ABC was present on virtually all endothelial cells in normal and pathologic tissue samples. ⋯ Expression of HLA-ABC and Ia molecules on astrocytes in MS lesions could indicate their involvement in local presentation of antigen to cytotoxic (T8+) and helper/inducer (T4+) T cells, respectively. The observed distinct distribution patterns of HLA-ABC and Ia-positive astrocytes might suggest that cytotoxic T8+ cells are operative early during lesion development in MS. This could be followed by a more extensive Class II MHC-restricted helper T cell-mediated immune response which leads to selective destruction of myelin via activated macrophages.