A novel food-grade lactococcal expression system and its use for secretion and delivery of an oral vaccine antigen

作者：Zhang, Rongguang; Qiao, Dan; Peng, Xiaoyan; Duan, Guangcai^*; Shi, Qingfeng; Zhang, Linghan; Wang, Chen; Liang, Wenjuan; Chen, Shuaiyin; Fan, Qingtang

来源：Journal of Chemical Technology and Biotechnology, 2018, 93(6): 1655-1660.

DOI：10.1002/jctb.5536

• Lactococcus lactis
• food-grade
• secretory expression
• oral vaccine
• Helicobacter pylori

BACKGROUND: Food-grade bacterial expression systems are relatively rare, and increasing evidence indicates that subcellular location of antigens in bacterial vector vaccines may markedly affect the immune efficacy.
RESULTS: This study developed a novel food-grade secretory expression system for heterologous protein production and oral vaccine delivery. Furthermore, by using the expression system, an engineered L. lactis strain secreting H. pylori UreB was constructed, and used to vaccinate SPF BALB/c mice. As results, the UreB expressed in L. lactis was detected in both cell lysates and culture supernatant of the engineered strain, constituting roughly 50% of the culture supernatant proteins, and recognized by mouse anti-H. pylori sera. Oral vaccination with the engineered L. lactis produced a significantly elevated anti-UreB serum antibody level in mice (P < 0.05).
CONCLUSION: These data show a novel food-grade L. lactis secretory expression system, which may have distinct potential impact on edible and medicinal protein production and oral vaccine development. Moreover, this is the first report on secretory expression of a H. pylori antigen via using a food-grade lactococcal expression system, and the engineered strain secreting UreB can be a hopeful H. pylori vaccine candidate.

• 出版日期2018-6
• 单位郑州大学