Development and characterization of a potential diagnostic monoclonal antibody against capsid protein VP1 of the chicken anemia virus

Abstract

Chicken anemia virus (CAV) is an important viral pathogen that causes anemia and severe immunodeficiency syndrome in chickens worldwide. In this study, a potential diagnostic monoclonal antibody against the CAV VP1 protein was developed which can precisely recognize the CAV antigen for diagnostic and virus recovery purposes. The VP1 gene of CAV encoding the N-terminus-deleted VP1 protein, VP1Nd129, was cloned into an Escherichia ( E. ) coli expression vector. After isopropyl-β-D-thiogalactopyronoside induction, VP1Nd129 protein was shown to be successfully expressed in the E. coli . By performing an enzyme-linked immunoabsorbent assay using two coating antigens, purified VP1Nd129 and CAV-infected liver tissue lysate, E3 monoclonal antibody (mAb) was found to have higher reactivity against VP1 protein than the other positive clones according to the result of limiting dilution method from 64 clones. Using immunohistochemistry, the presence of the VP1-specific mAb, E3, was confirmed using CAV-infected liver and thymus tissues as positive-infected samples. Additionally, CAV particle purification was also performed using an immunoaffinity column containing E3 mAb. The monoclonal E3 mAb developed in this study will not only be very useful for detecting CAV infection and performing histopathology studies of infected chickens, but may also be used to purify CAV particles in the future.

Characterization of mAbs to chicken anemia virus and epitope mapping on its viral protein, VP1

“…Although several mAbs against CAV or recombinant VP1 proteins have been developed (Chandratilleke et al, 1991;Lien et al, 2012;McNulty et al, 1990), there is nonetheless a lack of important information related to the antigenicity of VP1, especially with respect to neutralizing epitopes. We identified the neutralizing epitopes on VP1.…”

“…In another study, eight mAbs were generated but lacked virus-neutralizing activity (Chandratilleke et al, 1991). Recently, one VP1-specific mAb was established by immunization of mice with truncated recombinant VP1; however, its virus-neutralizing activity was not evaluated (Lien et al, 2012). Thus, the neutralizing epitopes of CAV remain poorly understood.…”

Identification of nuclear localization signal and nuclear export signal of VP1 from the chicken anemia virus and effects on VP2 shuttling in cells

“…This finding was subsequently proved by analysis of VP1–VP2 protein–protein interaction [16]. In spite of this finding, the possible functional domain of VP1, especially in terms of the cellular localization, is not well understood, although some researchers have demonstrated the subcellular distribution of VP1 in cells using transient protein expression and immunofluorescence assays [11, 22]. The N-terminus of VP1 has been reported to possess a cell-penetrating activity [23].…”

Molecular Characterization of Isolated Chicken Infectious Anemia Viruses in Central China

“…The genome of CIAV is single-stranded, circular, negative-stranded covalently closed DNA, of ~2 kb, which contains three partially overlapping open reading frames (ORF) encoding VP1, VP2 and VP3, respectively [2]. VP1 represents the nucleocapsid protein of CIAV and is the main immunogen, which encodes an arginine-rich polypeptide with a molecular weight of approximately 50 KDa [3]. VP2 is an auxiliary scaffold protein required for CIAV assembly, which helps VP1 to form the correct conformation [4], and both VP1 and VP2 can cooperate with each other to induce an immune response.…”