文献类型：期刊文献

英文题名：Balanced role of T3SS and T6SS in contribution to the full virulence of Edwardsiella piscicida

作者：Hu, Tianjian[1];Chen, Ran[1];Zhang, Lingzhi[1];Wang, Zhuang[1];Yang, Dahai[1,2];Zhang, Yuanxing[1,2,3];Liu, Xiaohong[1,2];Liu, Qin[1,2,3]

机构：[1]East China Univ Sci & Technol, State Key Lab Bioreactor Engn, Shanghai 200237, Peoples R China;[2]Shanghai Engn Res Ctr Maricultured Anim Vaccines, Shanghai 200237, Peoples R China;[3]Shanghai Collaborat Innovat Ctr Biomfg, Shanghai 200237, Peoples R China

年份：2019

卷号：93

起止页码：871

外文期刊名：FISH & SHELLFISH IMMUNOLOGY

收录：;WOS:【SCI-EXPANDED(收录号:WOS:000488998300096)】；

基金：This work was supported by the NSFC grants 31472308 and 31622059 to Q.L., and The Fundamental Research Funds for The Central Universities.

语种：英文

外文关键词：Edwardsiella piscicida; Infection; Live attenuated vaccine; T3SS; T6SS

摘要：Edwardsiella piscicida is an important pathogen that infects a wide range of hosts, from fish to human. Its infection leads to extensive losses in a diverse array of commercially important fish, like Japanese flounder, turbot, and tilapia. During the infection, type III secretion system (T3SS) and type VI secretion system (T6SS) of E. piscicida play significant roles, but how T3SS and T6SS cooperatively contribute to its virulence is still unknown. In this study, we first examined the roles of T3SS and T6SS in different processes during E. piscicida infection of host cells, and revealed that T3SS of E. piscicida is responsible for promoting bacterial invasion, the following intracellular replication and inducing cell death in host cells, while T6SS restrains E. piscicida intracellular replication and cell death in J774A.1 cells, which suggested that T3SS and T6SS antagonistically concert E. piscicida infection. Furthermore, we found an significant decrease in transcription level of IL-1 beta in zebrafish kidney infected with T3SS mutant and an drastically increase in transcription level of TNF-alpha infected with T6SS mutant when compared with the wild-type. Interestingly, both T3SS and T6SS mutants showed significant attenuated virulence in the zebrafish infection model when compared with the wild-type. Finally, considering the cooperative role of T3SS and T6SS, we generated a mutant strain WED Delta T6SS based on the existing live attenuated vaccine (LAV) WED which showed improved vaccine safety and comparable immune protection. Therefore, WED Delta T6SS could be used as an optimized LAV in the future. Taken together, this work suggested a bilateral role of T3SS and T6SS which respectively act as spear and shield during E. piscicida infection, together contribute to E. piscicida virulence.