An immunoinformatic assay to design bio adjuvanted vaccine against infectious bursal disease virus

Objectives: Infectious bursal disease virus (IBDV) causes highly contagious and economically important immunosuppressive disease in young chickens worldwide. The control of infectious bursal disease (IBD) depends mainly on vaccination with inactivated and live attenuated viruses and strict hygiene management of poultry farms, but the disease continues to pose an important threat to the commercial poultry industry. Recently, second-generation vaccines based on expression of VP2 in various vectors have been developed as new strategies for vaccination against IBD. A series of the vaccines were made using different adjuvant to examine their immunogenicity. In this study we explore the idea of using TLR7 as bio adjuvant to stimulate immune responses against IBDV. Materials and Methods: The TLR7 nucleotide sequences of Homo sapiens, Mus musculus, and Gallus gallus deposited in NCBI databases were downloaded. Eight conserved TLR7 motifs were found among them following alignment of the related sequences. Each of the TLR7 motif was fused to IBDV VP2 fragment and VP2/TLR7-1 to -8 constructs were designed. By using in silico analysis include physicochemical properties determination, protein structures prediction, antigenic site determination, and evaluation of model quality, one of the chimeric proteins was subjected to introduce as vaccine candidate. Results and conclusion: The results indicate that some TLR7 motifs can be potentially used as bio adjuvant for induction of immune responses against IBDV. It is necessary in future study to determine the potential role of the peptide in induction of immunity against IBDV infection in chicken.,