Immunological Properties of Purified Mumps Virus Glycoproteins

Abstract

SUMMARY Egg-grown mumps virus was used for purification of the glycoproteins of the virus. The two glycoproteins were separated by filtration on DEAE-Bio-Gel A columns and were used for preparation of rabbit hyperimmune sera. Antibodies directed against the large (mol. wt. 75 × 103) and small (mol. wt. 61 × 103) glycoprotein were immunologically distinct. Antiserum directed against the large glycoprotein inhibited haemagglutination, neuraminidase activity and virus infectivity, whereas antiserum against the small glycoprotein inhibited haemolysis, but not haemagglutination, neuraminidase activity or virus infectivity. It is concluded that mumps virus contains two glycoproteins on the envelope which are equivalent to the HN and F glycoproteins described for other paramyxoviruses. Antibody activities of rabbit hyperimmune sera against untreated, Tween 80-ether and formalin treated purified virions were compared with those of sera against purified glycoproteins. In analogy with results obtained in studies on Sendai virus, these sera contained antibodies against both glycoprotein structures, but antibodies against the small glycoprotein blocking haemolysis could not be demonstrated. The effect of formalin treatment on the two glycoprotein structures was studied in mixed haemadsorption experiments. Formalin treatment of mumps virus infected Vero cells resulted in destruction of the surface antigen of the small glycoprotein, whereas the surface antigen of the large glycoprotein was only moderately affected.