Epitope specificity of demyelinating monoclonal autoantibodies directed against the human myelin oligodendrocyte glycoprotein (MOG).

We describe the epitope specificity of a panel of ten demyelinating monoclonal antibodies (mAb) that recognise the extracellular immunoglobulin-like domain of human myelin oligodendrocyte glycoprotein (hMOG(lgd)). All the mAbs bind to the surface of MOG-transfected fibroblasts as assessed in vitro by FACS and immunocytochemistry but failed to recognise overlapping 15-mer MOG peptides when assessed by ELISA. However, increasing peptide length to 25 amino acids revealed that four mAbs recognised epitopes within the amino acid sequence 63-100 of human MOG. In contrast, a non-demyelinating MOG-specific mAb recognised MOG by both ELISA and Western blotting but failed to stain MOG transfected fibroblasts. These observations suggest that assays based on the use of MOG-transfected cell lines will differentiate between pathogenic and non-pathogenic MOG-specific antibody responses in experimental models and human diseases of the nervous system.