Expression, purification and glycosylation analysis of chicken infectious bursal disease virus VP2 in yeast

Infectious bursal disease (IBD)، a highly contagious and devastating disease in young chicken، is caused by infectious bursal disease virus (IBDV). To improve the immunogenicity of recombinant IBDV subunit vaccine، an attempt was made to find a new way to prepare IBD vaccine containing glycosylated mVP2 antigen. Firstly، IBDV mVP2 gene (with a nucleic acid sequence encoding B cell epitope of IBDV (KFDQML) in the 5′-end of the VP2، with a nucleic acid sequence encoding B cell epitope of IBDV (LASP) and (His) 6-tag in the 3′-end of the VP2) was cloned. Secondly، IBDV mVP2 protein was expressed in the methylotrophic yeast Pichia pastoris which can secret glycosylated protein. The recombinant mVP protein could be stained pink with periodic acid-schiff reagents (PAS)، which showed that mVP2 was glycosylated. Finally، IBDV mVP2 protein was purified with His-Trap (1 mL) affinity chromatography. These results indicate that glycosylated IBDV VP2 protein modified with epitope peptides can be expressed in Pichia pastoris، which lay the groundwork for the development of a recombinant infectious bursal disease vaccine with high immunogenicity.