Human oligodendrocytes are susceptible to cytolysis by major histocompatibility complex class I-restricted lymphocytes

The majority of human oligodendrocytes in enriched glial cell cultures expresses class I major histocompatibility complex (MHC) antigens. We used a 51Cr release assay to study the susceptibility of oligodendrocyte-enriched glial cells to MHC-restricted and non-restricted immune-mediated cytolysis. Mitogen-activated mononuclear cells induced significant lysis in a lectin-dependent cytotoxicity assay. Mononuclear cells allo-activated in a one-way mixed lymphocyte culture with E- cells from the glial cell donor induced a significantly higher degree of oligodendrocyte cytolysis than mononuclear cells activated with E- cells bearing MHC-class I antigens discordant with the glia. Cytolysis by alloactivated unfractionated lymphocytes and by purified CD8+ lymphocytes was reduced by an anti-class I antibody (W6/32). Our findings suggest that human oligodendrocytes can be susceptible targets for MHC class I-restricted lysis.