The E2 envelope protein is the main protective antigen of classical swine fever virus (CSFV). Importantly, gram-positive enhancer matrix (GEM) particles can work as an immunostimulant and/or carrier system to improve the immune effect of antigens. In this study, the artificially designed E2-Spy was expressed and glycosylated in Pichia pastoris, and subsequently conjugated with SpyCatcher-PA which was expressed in Escherichia coli. The conjugated E2-Spy-PA was displayed on the surface of GEM particles, generating the E2-Spy-PA-GEM complex. Blocking ELISA analysis and neutralization assays showed that both E2-Spy and E2-Spy-PA-GEM complexes induced high levels of anti-CSFV antibodies in mice. Furthermore, statistical analyses indicated that the E2-Spy-PA-GEM complex exhibited enhanced immunogenicity compared with E2-Spy alone.

中文翻译：

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通过SpyTag / SpyCatcher系统在革兰氏阳性增强剂基质（GEM）颗粒上表面展示经典猪瘟病毒E2糖蛋白。

E2包膜蛋白是经典猪瘟病毒（CSFV）的主要保护性抗原。重要的是，革兰氏阳性增强剂基质（GEM）颗粒可以用作免疫刺激剂和/或载体系统，以改善抗原的免疫效果。在这项研究中，人工设计的E2-Spy在巴斯德毕赤酵母中表达并糖基化，随后与在大肠杆菌中表达的SpyCatcher-PA偶联。缀合的E2-Spy-PA显示在GEM颗粒的表面，生成E2-Spy-PA-GEM复合物。阻断ELISA分析和中和试验表明，E2-Spy和E2​​-Spy-PA-GEM复合物均可在小鼠中诱导高水平的抗CSFV抗体。此外，统计分析表明，与单独的E2-Spy相比，E2-Spy-PA-GEM复合物显示出增强的免疫原性。