文献类型： 外文期刊

作者： Li, Peng-cheng ¹ ; Qiao, Xu-wen ¹ ; Zheng, Qi-sheng ¹ ; Hou, Ji-bo ¹ ;

作者机构： 1.Jiangsu Acad Agr Sci, Natl Res Ctr Engn & Technol Vet Biol, Nanjing 210014, Jiangsu, Peoples R China

关键词： Porcine circovirus type 2;Cap protein;Surface display;Lactococcus lactis;PCV2 subunit vaccine

期刊名称：VACCINE （ 影响因子：3.641； 五年影响因子：3.816 ）

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收录情况： SCI

摘要： The capsid (Cap) protein, an important immunoprotective protein of porcine circovirus type 2 (PCV2), was expressed on the cell surface of the Gram-positive food-grade bacterium, Lactococcus lactis. Cap protein was fused to the peptidoglycan binding domain (known as the protein anchor domain, PA) of the lactococcal AcmA cell-wall hydrolase. The Cap protein fusion was non-covalently rebound to the surface of non-genetically modified, non-living high-binder L. lactis cells (designated Gram-positive enhancer matrix (GEM) particles). Expression of the recombinant GEM-displaying capsid protein (GEM-PA-Cap) was verified by Western blotting and immunofluorescence and transmission electron microscopy assays. To evaluate the immunogenicity of the recombinant Cap protein (rCap), 20 PCV2-seronegative piglets were immunized with the GEM-PA-Cap subunit vaccine, GEM alone, or phosphate-buffered saline (PBS, challenge control and empty control). Each group consisted of five piglets. The results showed that the level of PCV2-specific antibodies in piglets immunized with the GEM-PA-Cap subunit vaccine was significantly higher than that of the piglets immunized with GEM alone or the control group at all the time points post-vaccination (P < 0.01). After challenge with the PCV2 wild-type strain, piglets that received the GEM-PA-Cap subunit vaccine showed significantly higher average daily weight gain (DWG) and shorter fever duration than the other two groups (P < 0.001). Furthermore, a significant reduction in the gross lung lesion scores and lymph node lesion scores was noted in the GEM-PA-Cap-immunized group compared with the scores of the GEM or PBS-treated group (P < 0.01). The results suggest that recombinant rCap displayed by L lactis GEM particles provided the piglets with significant immunoprotection from PCV2-associated disease. Thus, the novel GEM-PA-Cap subunit vaccine has potential to be considered an effective and safe candidate vaccine against PCV2 infection in piglets. (C) 2015 Published by Elsevier Ltd.