CHARACTERIZATION OF CANINE HERPESVIRUS GLYCOPROTEIN-D (HEMAGGLUTININ)

Glycoprotein D (go) of canine herpesvirus (CHV) YP2 strain was express ed in COS-7 and insect (Spodoptera frugiperda; Sf9) cells. The gDs exp ressed in COS-7 and Sf9 cells reacted with a panel of monoclonal antib odies (MAbs) against CHV go (hemagglutinin) and an MAb 25C9 against fe line herpesvirus type 1 (FHV-1) go by indirect immunofluorescence assa y, and possessed a molecular weight (MW) of approximately 51-55 and 41 -46 kilodalton (kDa), respectively, when examined by immunoblot analys is. After treatment with tunicamycin, the MW of the go expressed in Sf 9 cells became approximately 37 kDa. By hemadsorption (HAD) tests usin g canine or (RBC), COS-7 cells expressing CHV go adsorbed only canine RBC, but not feline RBC, whereas control COS-7 cells expressing FHV-1 go adsorbed feline RBC, but not canine RBC. By hemagglutination (HA) t ests, lysates of Sf9 cells expressing CHV go agglutinated canine RBC, but not feline RBC. These HA and HAD activities were inhibited by HA-i nhibition MAbs against CHV go. Control lysates of Sf9 cells expressing FHV-1 go agglutinated only feline RBC. Serum from mice inoculated wit h lysates of Sf9 cells expressing CHV gD possessed a high titer of vir us-neutralizing activities against CHV infection. These results indica ted that CHV go is structurally similar to FHV-1 go, but is functional ly different from FHV-1 gD.