Production, purification and characterization of polyclonal antibody against the truncated gK of the duck enteritis virus

Duck virus enteritis (DVE) is an acute, contagious herpesvirus infection of ducks, geese, and swans, characterized by vascular damage, tissue hemorrhages, digestive mucosal eruptions, lesions of lymphoid organs, and degenerative changes in parenchymatous organs [1-5]. The causative agent of DVE is duck enteritis virus(DEV), composing of a linear, double-stranded DNA genome with 64.3% guanine-plus-cytosine content, which is higher than any other reported avian herpesvirus in the Alpha-herpesvirinae subfamily[6]. In duck-producing areas of the world where the diseases has been reported, DEV has produced significant economic losses in domestic and wild waterfowl due to mortality, condemnations, and decreased egg production[7].With the purpose of decreasing economic losses in the commercial duck industry, studying gK of DEV may be a new method for preferably preventing and curing this disease. Because glycoproteins are the major antigens recognized by the infected host's immune system and play an important role in mediating target cell infection, cellular entry of free viruses, and the maturation or egress of the virus [8,9]. Glycoprotein K is one of the major glycoproteins encoded by the DEV-gK gene, which is located in the unique long region of the DEV genome. Additionally, gK is capable of inducing a protective immune response in vivo and is responsible for viral binding to the cellular receptor [10,11].Although the disease has been reported in 1926, there was little information known about the functions of DEV-gK. To investigate the functions and characteristics of gK gene as well as gK, the full-length gK gene (fgK) and truncated gK gene (tgK) expression plasmid were constructed[11], only the tgK expressed efficiently in prokaryotic system (Figure 1, lane4). The recombinant tgK protein was purified by immobilized metal affinity chromatography (IMAC) and showed in (Figure 1, lane5).Then, the purified tgK was used to produce polyclonal antibody. Preimmune serum was c