Cloning and Expression of VP3 Gene of Infectious Bursal Disease Virus in E. coli and Purification of the Recombinant Protein

Infectious bursal disease or Gumboro, is a highly contagious viral disease of poultry which causes economic losses in the poultry industry, worldwide. Following infection, the first antibodies are produced against the structural VP3 protein of the Infectious bursal disease virus (IBDV); therefore, VP3 is a suitable antigen for use in ELISA. Given the difficulty of purifying native VP3 from IBDV or virus-infected cells, recombinant VP3 expressed in E. coli can be considered for this purpose. This study was performed with the aim of cloning the VP3 gene of D78 vaccine strain of the virus in pMal-C2X plasmid (a prokaryotic expression plasmid) and the expression and purification of the recombinant protein. Thus, VP3 gene was amplified by RT-PCR and cloned in plasmid pMal-C2X, after digestion with appropriate restriction enzymes. After sequencing to ensure the successful cloning of the gene, the expression of recombinant protein was confirmed by SDS-PAGE. In the following, the recombinant protein was purified using amylose resin chromatography column. Evaluation of the recombinant VP3 protein in immunoblotting showed that the produced protein was antigenically active. Considering the high efficiency of protein production in this system, the expressed protein is a good candidate for the design of ELISA to measure antibody titers against infectious bursal disease virus (IBDV).