Evaluation of the Immunogenicity in Mice Orally Immunized with Recombinant <i>Lactobacillus casei</i> Expressing Porcine Epidemic Diarrhea Virus S1 Protein
Ya Xiao,
Xiaona Wang,
Yue Li,
Fengsai Li,
Haiyuan Zhao,
Yilan Shao,
Liu Zhang,
Guojie Ding,
Jiaxuan Li,
Yanping Jiang,
Wen Cui,
Zhifu Shan,
Han Zhou,
Li Wang,
Xinyuan Qiao,
Lijie Tang,
Yijing Li
Affiliations
Ya Xiao
College of Veterinary Medicine, Northeast Agricultural University, Harbin 150030, China
Xiaona Wang
College of Veterinary Medicine, Northeast Agricultural University, Harbin 150030, China
Yue Li
College of Veterinary Medicine, Northeast Agricultural University, Harbin 150030, China
Fengsai Li
College of Veterinary Medicine, Northeast Agricultural University, Harbin 150030, China
Haiyuan Zhao
Jiangsu Hanswine Food Co., Ltd., Ma’anshan 151700, China
Yilan Shao
College of Veterinary Medicine, Northeast Agricultural University, Harbin 150030, China
Liu Zhang
College of Veterinary Medicine, Northeast Agricultural University, Harbin 150030, China
Guojie Ding
Harbin Vikeses Biological Technology Co., Ltd., Harbin 150030, China
Jiaxuan Li
College of Veterinary Medicine, Northeast Agricultural University, Harbin 150030, China
Yanping Jiang
College of Veterinary Medicine, Northeast Agricultural University, Harbin 150030, China
Wen Cui
College of Veterinary Medicine, Northeast Agricultural University, Harbin 150030, China
Zhifu Shan
College of Veterinary Medicine, Northeast Agricultural University, Harbin 150030, China
Han Zhou
College of Veterinary Medicine, Northeast Agricultural University, Harbin 150030, China
Li Wang
College of Veterinary Medicine, Northeast Agricultural University, Harbin 150030, China
Xinyuan Qiao
College of Veterinary Medicine, Northeast Agricultural University, Harbin 150030, China
Lijie Tang
College of Veterinary Medicine, Northeast Agricultural University, Harbin 150030, China
Yijing Li
College of Veterinary Medicine, Northeast Agricultural University, Harbin 150030, China
Porcine epidemic diarrhea (PED), characterized by diarrhea, vomiting, and dehydration, is an acute enteric infectious disease of pigs. The disease is caused by porcine epidemic diarrhea virus (PEDV), which infects the intestinal mucosal surface. Therefore, mucosal immunization through the oral route is an effective method of immunization. Lactic acid bacteria, which are acid resistant and bile-salt resistant and improve mucosal immunity, are ideal carriers for oral vaccines. The S1 glycoprotein of PEDV mediates binding of the virus with cell receptors and induces neutralizing antibodies against the virus. Therefore, we reversely screened the recombinant strain pPG-SD-S1/Δupp ATCC 393 expressing PEDV S1 glycoprotein by Lactobacillus casei deficient in upp genotype (Δupp ATCC 393). Mice were orally immunized three times with the recombinant bacteria that had been identified for expression, and the changes of anti-PEDV IgG and secreted immunoglobulin A levels were observed over 70 days. The results indicated that the antibody levels notably increased after oral administration of recombinant bacteria. The detection of extracellular cytokines on the 42nd day after immunization indicated high levels of humoral and cellular immune responses in mice. The above results demonstrate that pPG-SD-S1/Δupp ATCC 393 has great potential as an oral vaccine against PEDV.
