VscO, a putative T3SS chaperone escort of Vibrio alginolyticus, contributes to virulence in fish and is a target for vaccine development

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• 作者：Zejun Zhou ; Huanying Pang ; Yu Ding ; Jia Cai ; Yucong Huang ; Jichang Jian ; Zaohe Wu
• 关键词：Vibrio alginolyticus ; Type III secretion system ; vscO mutant ; Recombinant VscO ; Protective immunity
• 刊名：Fish & Shellfish Immunology
• 出版年：2013
• 出版时间：November, 2013
• 年：2013
• 卷：35
• 期：5
• 页码：1523-1531
• 全文大小：1073 K

文摘

Type III secretion system (T3SS) in Vibrio alginolyticus is essential for its pathogenesis. VscO's homologous proteins FliJ, InvI and YscO have been suggested to be putative chaperone escorts although its function in V. alginolyticus is unclear. To investigate the physiological role of VscO, a mutant strain of V. alginolyticus with an in-frame deletion of the vscO gene was constructed in the present study. One finding was that the mRNA expression levels of SycD, VopB and VopD proteins decreased in the ¦¤vscO mutant. In addition, the ¦¤vscO mutant showed an attenuated swarming ability and a ten-fold decrease in the virulence to fish. However, the ¦¤vscO mutant showed no difference in the biofilm formation and ECPase activity. Complementation of the mutant strain with the vscO gene could restore the phenotypes of the wild-type strain. Finally, the recombinant VscO protein caused a high antibody titer and an effective protection against lethal challenge with the wild-type strain V. alginolyticus. These results indicated that VscO protein has a specific role in the pathogenesis of V. alginolyticus and it may be a candidate antigen for development of a subunit vaccine against vibriosis.