Construction of a protozoan infection therapeutic vaccine development platform technology using antigen-displaying baculovirus

本研究为新孢子病成分疫苗的研制奠定了基础。在家蚕中成功表达和纯化了5种候选抗原。构建家蚕核型多角体病毒(BmNPV)携带犬新孢子虫抗原(NcSAG1、NcSRS2和NcMIC3)的颗粒免疫小鼠。与IgG1相比，NcSAG1-BmNPV颗粒免疫小鼠主要产生抗原特异性的IgG2a，并且诱导干扰素-γ占主导地位，表明NcSAG1-BmNPV颗粒能在小鼠体内诱导Th1免疫应答。半定量聚合酶链式反应分析显示，从家蚕中提纯的每个抗原显示的BmNPV颗粒免疫小鼠，部分地保护了小鼠免受犬脑新城疫的感染。这些结果表明，从家蚕中提纯的展示抗原的BmNPV颗粒可以为新一代犬新城疫疫苗提供一种替代方法。

In this study, we build the foundation of component vaccine development of neosporosis. Five candidate antigens were successfully expressed and purified in silkworm. Bombyx mori nucleopolyhedrovirus (BmNPV) particles displaying Neospora caninum antigens (NcSAG1, NcSRS2 and NcMIC3) purified from silkworm larvae were constructed to vaccinate mice against N. caninum. Antigen-specific IgG2a was predominantly produced in mice by immunization with NcSAG1-displaying BmNPV particles compared to IgG1, and induction of IFN-gamma was dominant, indicating that antigen-displaying BmNPV particles can elicit a Th1 immune response in mice. Semi-quantitative PCR analysis revealed that immunization with each antigen-displaying BmNPV particle purified from silkworms partially protected mice from cerebral N. caninum infection. These results suggest that antigen-displaying BmNPV particles purified from silkworms can provide an alternative method of a new generation of N. caninum vaccines.