表达PEDV RBD结构域的重组仙台病毒构建及其免疫原性评价OA

To construct a recombinant Sendai virus(SeV)expressing the receptor-binding domain(RBD)of porcine epidemic diarrhea virus(PEDV)and evaluate its immunogenicity,we designed a sequence-optimized PEDV spike(S)gene RBD domain(amino acids 507-757)engineered to contain four pairs of intramolecular disulfide bonds,referred to as RBD(8C).The optimized gene fragment was inserted into a SeV vector to generate the recombinant plasmid pBe-loBAC-SeV-PE-RBD(8C)-3Flag.Following virus rescue and characterization of its biological properties,the recombinant virus was used to immunize mice.PEDV-specific IgG and IgA antibody levels in serum and bronchoalveolar lavage fluid(BALF),serum neutralizing antibody titers,as well as T lymphocyte proliferation and T cell subset activation in lymph-oid tissues,were evaluated.The results demonstrated that the recombinant SeV specifically expressed the RBD(8C)pro-tein and exhibited a growth curve similar to that of wild-type SeV.Immunization with the recombinant virus effectively in-duced PEDV-specific IgG,IgA,and neutralizing antibodies in mice,significantly promoted PEDV-specific T cell prolifer-ation,and increased the proportions of CD4+and CD8+T cells in spleen and lymph nodes.In conclusion,the recombinant virus induced robust humoral,cellular,and mucosal immune responses in mice,providing experimental evidence to sup-port the development and optimization of PEDV vaccines.