Canine herpesvirus 47 kD and mutated 41 kD glycoproteins are responsible for hemagglutination.

Monoclonal antibodies (MoAbs) were used to identify the hemagglutinin of canine herpesvirus (CHV). The inhibition of viral hemagglutination (HA) activity was observed with MoAbs against 41 kD glycoprotein, while no hemagglutination-inhibition (HI) activity was observed with those against 145/112 kD and 80 kD glycoproteins, suggesting that the 41 kD glycoprotein is the hemagglutinin of plaque-selected virus of CHV YP11 strain used as immunogen for MoAb production. All of the HI MoAbs also showed HI activities against HA antigens which were prepared from cells infected with other CHV strains, namely, F-205 V and Glasgow CHV2 reference strains, eight Japanese isolates, and the original YP11 strain. However, on immunoblotting analysis, a 47 kD protein band was detected in these strains by the HI MoAbs. These data suggest that the 47 kD glycoprotein is the common molecule of the hemagglutinin among CHV strains and the plaque-selected virus of YP11 strain appears to be a mutant whose molecular weight of the hemagglutinin changed into 41 kD.