The CDw65 Monoclonal Antibodies VIM-8 and VIM-11 Bind to the Neutral Glycolipid V³FucnLc₈Cer

Abstract

At the IV^th and V^th Workshop on Human Leukocyte Differentiation Antigens a group of monoclonal antibodies recognizing myeloid cells was found to bind to the ganglioside X³-NeuAcVII³FucnLc₁₀Cer (VIM-2 dodecasaccharide). These antibodies were given the provisional cluster of differentiation designation CDw65. Three antibodies of this cluster (VIM-2, VIM-8, and VIM-11) have now been studied in detail at the molecular and the cellular level. Binding of VIM-2 is abolished after treatment of cells with Vibrio cholerae neuraminidase, whereas VIM-8 and VIM-11 show enhanced binding to neuraminidase-treated cells. We investigated binding of the three mAbs to glycolipid antigens with shorter carbohydrate chains. Distinct differences were observed in the binding of CDw65 antibodies to VIII³-NeuAcV³FucnLc₈Cer (VIM-2 decasaccharide). VIM-2 strongly bound to this antigen, whereas no binding was observed with the other two mAbs. Conversely, the asialoganglioside of the VIM-2 decasaccharide, V³FucnLc₈Cer, was not recognized by VIM-2, but this antigen bound strongly VIM-8 and VIM-11. Thus, VIM-2 and the other CDw65 antibodies represented two different antigen specificities.