SPECIFICITY AND CROSS-REACTIVITY OF ANTI-GALACTOCEREBROSIDE ANTIBODIES

Anti-galactocerebroside (GalC) antibodies have been reported to inhibi t myelin formation, cause demyelination, and block HIV-I infection of neural cells. We examined the binding of 3 monoclonal and polyclonal a nti-GalC antibodies to a panel of purified glycolipids by ELISA and by an immunospot assay on nitrocellulose blots. All 3 antibodies bound s trongly to GM1 ganglioside, monogalactosyl diglyceride, and asialo-GM1 , and 2 of the antibodies bound to GD1b and psychosine. The anti-GalC antibodies also bound to 3 glycoprotein bands in human neuroblastoma c ells on Western blot, and binding to the proteins was abolished by pre -treatment with pronase or with periodate which oxidizes the terminal carbohydrate residues. These results indicate that anti-GalC antibodie s cross react with oligosaccharide determinants of other glycolipids a nd glycoproteins, and that these cross-reactivities may be responsible for some of the biological effects of the anti-GalC antibodies.