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

Abstract

ABSTRACT. The YP11mu strain of a plaque-selected canine herpesvirus (CHV) encoded a smaller molecular weight (MW) of gD than those of other strains including YP2 strain . When nucleotide sequence of the mutated gD of YP11mu strain (gD(YP11mu)) was compared with that of gDs of other CHV strains, gD(YP11mu) lacked 12 nucleotides encoding 4 amino acids, NKTI, including one predicted potential N-linked glycosylation site and no other change was found in other regions. When the gD(YP11mu) and gD of YP2 strain (gD(YP2)) expressed in COS-7 and insect (Spodoptera frugiperda; Sf9) cells were compared each other, both gDs reacted with a panel of monoclonal antibodies (MAbs) against CHV gD by indirect immunofluorescence analysis and the gD (YP11mu) in the virus penetration process remains to be further analyzed.Xuan et al. [25] reported that one plaque-selected CHV, YP11mu strain, possessed a smaller molecular weight (MW) of gD than those of other strains including YP2 strain. However its HA activity and reactivity with antibodies against CHV were similar to those of other strains. Therefore, it seems that mutation in the gD of YP11mu strain does not affect biological activities of the gD. By genetical analysis of this mutation, it is expected to obtain further information on functional region of gD.In this communication, we identified the mutated region on the gD of YP11mu strain and expressed the gD in COS-7 and insect (Spodoptera frugiperda; Sf9) cells. The CHV gD expressed in COS-7 cells specifically adsorbed canine RBC and extracts of CHV gD expressed in Sf9 cells agglutinated canine RBC. Further, antibodies raised in mice immunized with recombinant CHV gDs neutralized CHV infection in vitro. MATERIALS AND METHODS Viruses and cells:Three isolates from our laboratory, YP2, YP11, and the plaque-selected YP11 (YP11mu) [25], two isolates from other laboratories, GCH-1 and Pirene [29], and two reference strains, F-205V and Glasgow CHV2 of CHV were used in this study. All CHV strains were grown in Madin-Darby canine kidney (MDCK) cells for extraction

The expression and serological reactivity of recombinant canine herpesvirus 1 glycoprotein D

“…It is considered a structure indispensable for the virus replication cycle during attachment and subsequent penetration into a permissive cell, as could be deduced from analogy in other alphaherpesviruses (Ligas et al 1988;Rauh et al 1991). Glycoprotein D is also responsible for induction of neutralizing antibodies due to the presence of neutralizing epitopes (Maeda et al 1997). Also in other herpesvirus infections, gD was successfully used as antigen in diagnostic tests (Meskhat et al 2012;Fuentealba et al 2014).…”

“…virus neutralization test, indirect immunofluorescent test) are based on whole virus particles as antigen, however, the use of more sensitive immunoenzymatic tests (ELISA) requires the use of purified recombinant virus proteins. Based on the similarity with other herpesviruses and as shown by experimental data, glycoprotein D (gD) of CHV-1 induces immune response in infected animals and also bears several neutralizing epitopes (Xuan et al 1991;Maeda et al 1997) and can thus represent suitable antigen for serological testing.…”