禽流感病毒H5/H7亚型M2e-VLPs候选疫苗制备及其免疫原性研究OA

[Objective]This study aimed to prepare virus-like particle(VLP)candidate vaccines based on the extracellular domain of avian influenza virus M2 protein(M2e)and analyze their immunogenicity.[Methods]The M2e sequences from predominant strains of H5 and H7 subtypes were fused with the gene encoding bacteriophage AP205 VLPs to construct the prokaryotic expression recombinant plasmids pET21a-AP205-4M2eH5 and pET21a-AP205-6M2eH5H7.Following induced expression and purification,the recombinant proteins AP205-4M2eH5 and AP205-6M2eH5H7 were obtained.Mice were immunized with doses of 50 μg and 100 μg,respectively.Serum levels of specific antibodies,proliferation of T lymphocyte subsets,and expression of Th1-and Th2-related cytokines were measured on days 10,21,and 28 of post-immunization.[Result](1)The soluble recombinant proteins AP205-4M2eH5 and AP205-6M2eH5H7 were successfully obtained,and AP205-4M2eH5 was capable of self-assem-bling into VLPs.(2)Immunization with AP205-4M2eH5 and AP205-6M2eH5H7 significantly induced dose-dependent production of anti-M2e specific IgG antibodies,Th1 cytokines(IFN-γ,TNF-α,IL-2),and Th2 cytokines(IL-4,IL-10)in mouse sera,showing a dose-dependent effect.Significant proliferation of CD3+CD4+T and CD3+CD8+T lymphocyte subsets was observed in the peripheral blood of mice immunized with AP205-4M2eH5.For AP205-6M2eH5H7 immunization,only the high-dose group showed a significant increase in CD3+CD4+T and CD3+CD8+T cells.[Conclusion]Both AP205-4M2eH5 and AP205-6M2eH5H7 demonstrate good immunogenicity.Among these,the 4M2eH5 presented on the surface of AP205 VLPs provides a reference for developing a univer-sal candidate vaccine against the avian influenza H5 subtype.