B/Yamagata 系流感病毒血凝素 (HA) 蛋白疫苗的筛选研究.

Objective: To screen the recombinant hemagglutinin (HA) protein with high expression level and hemagglutinin inhibitory activity for B/Yamagata influenza virus. Methods: Based on the HA of B/Singapore/INFTT-16-0610/2016, the peptide sequences of GCN4pLL trimerization motif, GCN4pLL-cysteine, and GCN4pLL-the sequences from C-terminus of lamprey variable lymphocyte receptor (VLR)-B antibodies were fused to C-terminus of HA ectodomain, to obtain HA mutant genes BY-T, BY-LLc, and BY-PLc. They were inserted into pFastBac1 separately and expressed using baculovirus expression vector system. After expression identification, Strep-Tactin affinity chromatography purification was performed to purify the mutant proteins followed by identification of the degree of oligomerization and hemagglutination activity of the purified mutant proteins. Anti-HA Ig G titer and hemagglutination inhibition (HAI) antibody titer in sera of mice immunized with HA mutants were detected. Results: All HA mutants were effectively expressed. The BY-T mutant had the highest expression level, was easy to purify, had good purity, and existed in a polymeric form. The expression levels of BY-LLc and BY-PLc are secondary and exist in a highly polymerization form. The hemagglutination activities of the three HA mutant proteins were comparable, and all of them could effectively induce anti-HA Ig G and HAI antibodies. Conclusion: The HA protein ectodomain mutant fused with oligomeric motif GCN4pLL at the C-terminus is easy to purify and has hemagglutination activity, which can induce anti-HA Ig G and HAI antibodies in mice. The results provide a reference for the development strategy of recombinant protein vaccines against influenza virus B/Yamagata lineage. [ABSTRACT FROM AUTHOR]