Aedes albopictus cells release a goose red blood cell agglutinin

The presence of a goose red blood cell (RBC) agglutinin (HA) in the culture medium of apparently uninfected Aedes albopictus cells raised the possibility of contamination by an arbovirus. The HA sedimented in sucrose gradients between 18S and 28S and had a buoyant density in sucrose of 1,23 g/cm3. The HA adsorbed to concanavalin A-Sepharose and could be eluted with alpha-methyl-D-mannoside. The apparent molecular weights of the eluted glycoproteins were estimated by PAGE to range from 17,000 to 45,000. Treatment of culture medium from A.albopictus cells with excess goose RBC removed both HA activity and a proportion of the proteins of molecular weight 25,000--35,000. The HA also bound to human group 'O' RBC, It was not possible to inhibit hemagglutination with a variety of anti-arbovirus antisera. These data do not support the hypothesis that the HA is associated with an inapparent arbovirus infection of A.albopictus cells.