Human red cell antigens

Abstract

The minor red cell sialoglycoproteins-.beta. and .gamma. (also known as glycophorin C)-are believed to be important to the structural integrity of red cells. The absence of sialoglycoproteins .alpha. and .delta., as seen in En(a-) and S-s-U-cells, respectively, results in cells with normal morphology, but the absence of sialoglycoproteins .beta. and .alpha.is associated with elliptocytosis. However, cellsthat lack Gerbich (Ge) antigens but have an abnormal sialoglycoprotein reactive with antibodies to .beta. have normal morphology. The authors used a monoclonal antibody specific for .beta. to explore the nature of this abnormal sialoglycoprotein and its interactions with other membrane proteins. The .beta.-like sialoglycoprotein of Ge-Yus-red cells apepars to react poorly with some antibodies due to steric hindrance by other molecules of sites normally available to immune agglutinins. This steric hindrance is not due to a single interaction with either sialoglycoprotein .alpha. or .delta. or band 3. Furthermore, steric hindrance by other molecules does not account for the lack of Ge antigens on these cells.