Antigenic characterization of bovine ephemeral fever rhabdovirus G and GNS glycoproteins expressed from recombinant baculoviruses

Abstract

Recombinant baculoviruses expressing the BEFV envelope glycoprotein G and non-structural glycoprotein G(NS) were constructed. The G protein expressed in insect cells was located on the cell surface and induced spontaneous cell fusion at mildly acidic pH. The expressed G protein reacted with MAbs to continuous and conformational neutralization sites (G1, G2, G3b and G4), but not to conformational site G3a. The expressed G(NS) protein was also located on the cell surface but did not exhibit fusogenic activity. The G(NS) protein reacted with polyclonal antiserum produced from vaccinia-virus-expressed recombinant G(NS) but did not react with G protein antibodies. A His(6)-tagged, soluble form of the G protein was expressed and purified by Ni(2+)-NTA chromatography. The purified G protein reacted with BEFV-neutralizing MAbs to all continuous and conformational antigenic sites. The highly protective characteristics of the native BEFV G protein suggest that the secreted, baculovirus-expressed product may be a useful vaccine antigen.

Assessment of the molecular epidemiology of bovine ephemeral fever in Turkey

“…While one of the sites (G1) reacts only with anti-BeFV antibodies, the others (G2 -G4) show crossreactivity with sera against other related viruses (CYBINSkI et al, 1990;CYBINSkI et al, 1992;JOhaL et al, 2008;kONGSUWaN et al, 1998). the composition of these regions in the G gene sequences of the 2012-BEFVs differed from that of other field viruses from the 1985 and 2008 outbreaks in turkey.…”

“…Glycoprotein G, which is one of the nonstructural proteins of the virus includes four distinct antigenic sites (G1 -G4) on its surface, and is considered the major neutralising and protective antigen of BeFV (JOhaL et al, 2008;UreN et al, 1984). While one of the sites (G1) reacts only with anti-BeFV antibodies, the others (G2 -G4) show crossreactivity with sera against other related viruses (CYBINSkI et al, 1990;CYBINSkI et al, 1992;JOhaL et al, 2008;kONGSUWaN et al, 1998).…”

Expression of the G1 epitope of bovine ephemeral fever virus G glycoprotein in eukaryotic cells

“…The expressed G1 protein in a prokaryotic system, E. coli, had appropriate reaction activity and specificity with an anti-BEFV serum in immunoblot analysis (Zheng et al, 2007a;Beygi Nassiri et al, 2016). Johal et al (2008) showed that the expressed BEFV glycoprotein G by recombinant baculoviruses reacted with BEFV-neutralising monoclonal antibodies (MAbs) to all continuous and conformational antigenic sites and may be a useful vaccine antigen. Vaccinated rabbits and cattle with recombinant vaccinia viruses expressing the glycoprotein G developed high level of antibodies which neutralised BEFV in either mammalian or insect cells (Uren et al, 1994;Hertig et al, 1996).…”

“…The BEFV G glycoprotein is the target of virus neutralising antibodies (Cybinski et al, 1992;Uren et al, 1994). In addition, the highly protective characteristics of the native BEFV G protein suggest that its recombinant expressed product may be a useful vaccine antigen (Johal et al, 2008). Accordingly, recombinant or DNA vaccine based on G protein may be an appropriate alternative for current vaccines (Uren et al, 1994).…”

Immunogenicity of transmembrane deleted-G protein of bovine ephemeral fever virus (BEFV) expressed in insect cells

“…BEFV G protein comprises an N-terminal signal peptide (amino acid 1-12), a C-terminal transmembrane domain, and a cytoplasmic tail (amino acids 522-623). The native BEFV G protein present on the virion is 81 kDa but the recombinant G protein expressed in insect cells appears to be either 76 or 71 kDa (7). Four antigenic sites on the G protein (G1-G4) were well characterized by sequence analysis and protein mapping using specific monoclonal antibodies (7)(8)(9).…”