Partial characterization of the human erythrocyte receptor for rabbit haemorrhagic disease virus.

An important, well known property of the rabbit haemorrhagic disease virus is its ability to agglutinate human red blood cells. Accordingly, red cells from human adult donors were agglutinated despite their blood group ABO status, and treatments with proteases or glycosidases did not prevent agglutination. However, we discovered that the cells from human umbilical cords or foetuses were not agglutinated. In order to identify the viral receptor on human erythrocytes, glycolipids and glycoproteins from adult red cells were separated and tested for their potency in inhibiting agglutination. The bulk of the biological activity was associated with the highly glycosylated glycolipids (polyglycosylceramides), whereas a lower but significant activity was also associated with neutral glycolipids. No activity was found in the lipid-free sialoglycoprotein fractions. All these data strongly suggest that the RHDV receptor on human red cells corresponds to a development antigen which is not expressed on foetal cells and is mainly carried by glycolipids. Faint activity was also found in membranes from sheep red cells, suggesting that a similar glycolipid component is carried by these animal cells.