Nie Mincai, Yue Jianguo, Deng Yichao, Yang Shu, Zhu Ling, Xu Zhiwen
College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, Sichuan, China.
Chengdu Animal Disease Prevention and Control Center, Chengdu 610041, Sichuan, China.
Sheng Wu Gong Cheng Xue Bao. 2021 Aug 25;37(8):2779-2785. doi: 10.13345/j.cjb.200582.
To investigate whether the engineered Lactobacillus plantarum expressing the porcine epidemic diarrhea virus (PEDV) S1 gene can protect animals against PEDV, guinea pigs were fed with recombinant L. plantarum containing plasmid PVE5523-S1, with a dose of 2×10⁸ CFU/piece, three times a day, at 14 days intervals. Guinea pigs fed with wild type L. plantarum and the engineered L. plantarum containing empty plasmid pVE5523 were used as negative controls. For positive control, another group of guinea pigs were injected with live vaccine for porcine epidemic diarrhea and porcine infectious gastroenteritis (HB08+ZJ08) by intramuscular injection, with a dose of 0.2 mL/piece, three times a day, at 14 days intervals. Blood samples were collected from the hearts of the four groups of guinea pigs at 0 d, 7 d, 14 d, 24 d, 31 d, 41 d and 48 d, respectively, and serum samples were isolated for antibody detection and neutralization test analysis by enzyme-linked immunosorbent assay (ELISA). The spleens of guinea pigs were also aseptically collected to perform spleen cells proliferation assay. The results showed that the engineered bacteria could stimulate the production of secretory antibody sIgA and specific neutralizing antibody, and stimulate the increase of IL-4 and IFN-γ, as well as the proliferation of spleen cells. These results indicated that the engineered L. plantarum containing PEDV S1 induced specific immunity toward PEDV in guinea pigs, which laid a foundation for subsequent oral vaccine development.
为研究表达猪流行性腹泻病毒（PEDV）S1基因的工程化植物乳杆菌能否保护动物抵御PEDV，给豚鼠喂食含质粒PVE5523 - S1的重组植物乳杆菌，剂量为2×10⁸CFU/只，每天3次，间隔14天。将喂食野生型植物乳杆菌和含空质粒pVE5523的工程化植物乳杆菌的豚鼠作为阴性对照。作为阳性对照，另一组豚鼠通过肌肉注射接种猪流行性腹泻和猪传染性胃肠炎活疫苗（HB08 + ZJ08），剂量为0.2 mL/只，每天3次，间隔14天。分别在0天、7天、14天、24天、31天、41天和48天从四组豚鼠心脏采集血样，分离血清样本，通过酶联免疫吸附测定（ELISA）进行抗体检测和中和试验分析。还无菌采集豚鼠脾脏进行脾细胞增殖试验。结果表明，工程菌能刺激分泌型抗体sIgA和特异性中和抗体的产生，刺激IL - 4和IFN - γ升高以及脾细胞增殖。这些结果表明，含PEDV S1的工程化植物乳杆菌在豚鼠中诱导了针对PEDV的特异性免疫，为后续口服疫苗开发奠定了基础。
