基于免疫信息学分析设计牛呼吸道合胞体病毒多表位疫苗OA

[Objective]This study aimed to design a multi-epitope peptide vaccine targeting the F and G proteins of Bovine respiratory syncytial virus(BRSV)using immunoinformatics methods,with the aim of effectively activating T cell and B cell immune responses.[Method]Based on the antigen sequences of F and G proteins,B cell epitopes,cytotoxic T lymphocyte(CTL)epitopes,and helper T lymphocyte(HTL)epitopes were screened using bioinformatics analysis software,taking into account parameters such as antigenicity,allergenicity,and toxicity of each epitope.The selected B cell epitopes,CTL epitopes and HTL epitopes were connected using KK,AAY and GPGPG linkers,respectively.An adjuvant of β-defensin peptide 3 was added to the N-terminal of the constructed sequence,and a 6×His tag was added to the C-terminal.Protein-protein molecular docking was performed between the constructed vaccine protein sequence and Toll-like receptor 3(TLR3)and TLR4 using computational methods.The docking result with the largest cluster was selected for molecular dynamics(MD)simulation.Computer-based immune simulation,codon optimization and computer cloning were also conducted.[Result]A total of 5 B cell epitopes,7 CTL epitopes and 4 HTL epitopes were screened from the F and G antigens.The vaccine construct had good affinity and stability with the TLR3 and TLR4 models throughout the simulation period.Immune analysis of the vaccine demonstrated that it could significantly induce the production of various antibodies such as IgG and IgM,and also increase the levels of various cytokines.Through codon optimization,the GC content of the vaccine was 49.25%and the codon adaptation index(CAI)reached 1,indicating the potential for high expression in prokaryotic expression system.The vaccine was inserted into the Bam H Ⅰ and Xho Ⅰ restriction enzyme sites of the prokaryotic expression vector pET-28a(+),generating a complete cloning construct with a sequence length of 930 bp.[Conclusion]The multi-epitope vaccine designed in this study had the potential to induce strong T cell and B cell responses,and provided theoretical basis and data support for the development of BRSV multi-epitope vaccines.