Characterization of Canine Herpesvirus Glycoprotein D (Hemagglutinin).

Abstract

ABSTRACT. Glycoprotein D (gD) of canine herpesvirus (CHV) YP2 strain was expressed in COS-7 and insect (Spodoptera frugiperda; Sf9) cells. The gDs expressed in COS-7 and Sf9 cells reacted with a panel of monoclonal antibodies (MAbs) against CHV gD (hemagglutinin) and an MAb 25C9 against feline herpesvirus type 1 (FHV-1) gD by indirect immunofluorescence assay, and possessed a molecular weight (MW) of approximately 51-55 and 41-46 kilodalton (kDa), respectively, when examined by immunoblot analysis. After treatment with tunicamycin, the MW of the gD expressed in Sf9 cells became approximately 37 kDa. By hemadsorption (HAD) tests using canine or feline red blood cells (RBC), COS-7 cells expressing CHV gD adsorbed only canine RBC, but not feline RBC, whereas control COS-7 cells expressing FHV-1 gD adsorbed feline RBC, but not canine RBC. By hemagglutination (HA) tests, lysates of Sf9 cells expressing CHV gD agglutinated canine RBC, but not feline RBC. These HA and HAD activities were inhibited by HA-inhibition MAbs against CHV gD. Control lysates of Sf9 cells expressing FHV-1 gD agglutinated only feline RBC. Serum from mice inoculated with lysates of Sf9 cells expressing CHV gD possessed a high titer of virus-neutralizing activities against CHV infection. These results indicated that CHV gD is structurally similar to FHV-1 gD, but is functionally different from FHV-1 gD. -KEY WORDS : canine herpesvirus, feline herpesvirus type 1, glycoprotein D, hemagglutinin.

Adhesion of Insect Cells Expressing the Feline Herpesvirus Type 1 Hemagglutinin(gD) to Feline Cell Lines.

“…canine RBC [15,19]. These interactions between gD and RBCs from the respective hosts might correlate with the host range of herpesvirus infection.…”

“…Similarly, the host range of CHV is also very narrow [4]. A 47 kDa glycoprotein of CHV being responsible for HA was encoded by CHV gD gene [15,24], and cross-reacted with FHV-1 gD by an MAb 25C9 against FHV-1 gD [12]. This MAb possessed inhibition activities against both HAs by FHV-1 gD and CHV gp47 [12].…”

Properties and Functions of Feline Herpesvirus Type 1 Glycoproteins.

“…The virus grows exclusively in cell types of only canine origin such as primary canine kidney cell cultures and Madin-Darby canine kidney (MDCK) cell line [6,10,62,78]. CHV gD adsorbs to canine RBC, not to feline RBC [47]. Although a common epitope is demonstrated between FHV-1 and CHV gDs by an MAb, which has a complement-independent VN activity to both viruses [36], different HA properties between these two gDs provide a notion that the gD may regulate the narrow host range of each virus at the cell-receptor levels.…”

Role of One N-linked Oligosaccharide Chain on Canine Herpesvirus gD in Its Biological Activity.

“…All CHV strains were grown in Madin-Darby canine kidney (MDCK) cells for extraction We reported previously that canine herpesvirus (CHV) gD agglutinated canine red blood cells (RBC) and that this hemagglutination (HA) activity was inhibited by monoclonal antibodies (MAbs) against CHV gD [16,24,25]. Similarly, we reported that gD of feline herpesvirus type 1 (FHV-1) agglutinated feline RBC and cells expressing the gD adsorbed the RBC [13,14].…”

“…One MAb 25C9 against FHV-1 gD recognized CHV gD by indirect immunofluorescence assay (IFA) and immunoblot analysis, and inhibited HA activity of CHV [12]. CHV gD agglutinates only canine RBC [16,19,24] while FHV-1 agglutinates only feline RBC [4,13,14,18]. The reason of these different HA activities has never been studied.…”