Diffusion precipitation reaction using recombinant vp2 protein of infectious bursal disease virus

Infectious bursal disease (IBD) is a highly contagious, immunosuppressive viral disease of young birds that causes significant economic losses to the poultry industry worldwide. Vaccination is the most important measure to control IBD. Vector vaccines against this disease (Vaxxitek HVT + IBD, VECTORMUNE® HVT-IBD) are used more and more often in industrial poultry farming. Their peculiarity is the synthesis of VP2 protein of IBD virus, which is the main protective antigen in this disease. Unfortunately, in the Russian Federation there are no domestic kits for the determination of postvaccinal antibody titers for these vaccines, so the development of domestic serologic kits for the VP2 protein of IBD virus is an urgent area of research today. The aim of the present work was to investigate the specificity of recombinant VP2 protein synthesized in a bacterial expression system in diffusion precipitation reaction (DPR). As a result of this research, Escherichia coli strains that synthesize full-length VP2 protein at a concentration of 90 μg/mL were obtained on the basis of FSBEI HE SPbSUVM and FSBEI HE SPbSU. This protein was used as antigen in RDP in diagnostic dilution 1:8 with positive serum of 10 Lohmann Brown cross chickens with antibody titer for IBD virus in ELISA (1:10 000). The precipitation bands in agar gel were shown and the synthesized VP2 protein was found to be specific. The data obtained indicate the effective use of recombinant antigens as components of diagnostic kits.