Adjuvanticity of sliver nanoparticles with Infectious bursal disease virus VP2 protein and its effect on humoral immune response in chickens

Abstract

The present study was conducted to decipher the effect of silver nanoparticles conjugated marker recombinant VP2 immunogen of Infectious bursal disease virus on humoral immune response in chickens. The hypervariable VP2 gene segment of field Infectious bursal disease virus, consisting of major and minor hydrophilic loops, was amplified using reverse transcription-polymerase chain reaction. The gene segment of size 664 bp was cloned into pGEM-T Easy plasmid followed by subcloning into pET32a plasmid vector. Truncated recombinant VP2 protein (rVP2, 19 kDa) was expressed in a prokaryotic expression system using Escherichia coli BL32DE3 cells. The rVP2 protein showed reactivity with specific anti VP2 chicken antibodies. The results of Western blot revealed its utility in serological diagnosis. The recombinant antigen was tested for immunogenic potential by vaccinating the chickens with and without silver nanoparticles. The rVP2 protein blended with adjuvant grade montanide oil showed a highly significant rise in serum IgY titers. The titers induced by rVP2 protein mixed with montanide oil were non-significant when compared with titers induced by the conventional vaccines. The IgY response was highly significant in chickens vaccinated with rVP2 protein blended with montanide oil and silver nanoparticles than in chickens vaccinated with conventional vaccines or rVP2 protein. The results represent Infectious bursal disease virus rVP2 protein as a promising candidate for the DIVA vaccine and sero-diagnostic tool. For the first time, the current study elucidated the adjuvanticity effect of silver nanoparticles on avian Infectious bursal disease virus rVP2 vaccine potency.