Ganglio-N-tetraosylceramide (asialo GM1), an antigen common to the brain and immune system: its localization in myelin.

Anti-brain antisera are known to contain several interesting antibodies showing immunological cross-reactions between the nervous and hematopoietic systems, suggesting the existence of antigens common to the two systems (common antigens). One of these is the glycosphingolipid asialo GM1 (ganglio-N-tetraosylceramide, GgOse4Cer), but its location in the nervous system is unknown. Therefore, the location of the brain antigen that reacts with anti-asialo GM1 antibody was examined. On immunohistochemical treatment of sections of mouse brain with purified anti-asialo GM1 IgG, the white matter was stained specifically. Because myelin is a major component of the white matter, neutral glycosphingolipids were prepared from the myelin fraction. On thin-layer chromatography, myelin glycosphingolipids gave a band with the same mobility as asialo GM1. This band was also stained immunochemically by the peroxidase anti-peroxidase procedure using anti-asialo GM1 IgG. The glycosphingolipid of this band gave the molar ratio of sugars expected for asialo GM1. From these results it was concluded that the glycosphingolipid asialo GM1 exists in myelin.