Type III Secretion in the Melioidosis Pathogen Burkholderia pseudomallei

Frontiers in Cellular and Infection Microbiology

Stevens, Joanne M.¹  Vander Broek, Charles W.¹ 

[1] The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Midlothian, United Kingdom

关键词: T3SS;    effector;    translocator;    Burkholderia pseudomallei;    Melioidosis;   

DOI  :  10.3389/fcimb.2017.00255

学科分类：生物科学（综合）

来源: Frontiers

【 摘 要 】

Burkholderia pseudomallei is a Gram-negative intracellular pathogen and the causative agent of melioidosis, a severe disease of both humans and animals. Melioidosis is an emerging disease which is predicted to be vastly under-reported. Type III Secretion Systems (T3SSs) are critical virulence factors in Gram negative pathogens of plants and animals. The genome of B. pseudomallei encodes three T3SSs. T3SS-1 and -2, of which little is known, are homologous to Hrp2 secretion systems of the plant pathogens Ralstonia and Xanthomonas. T3SS-3 is better characterised and is homologous to the Inv/Mxi-Spa secretion systems of Salmonella spp. and Shigella flexneri respectively. Upon entry to the host cell, B. pseudomallei requires T3SS-3 for efficient escape from the endosome. T3SS-3 is also required for full virulence in both hamster and murine models of infection. The regulatory cascade which controls T3SS-3 expression and the secretome of T3SS-3 have been described, as well as the effect of mutations of some of the structural proteins. Yet only a few effector proteins have been functionally characterised to date and very little work has been carried out to understand the hierarchy of assembly, secretion and temporal regulation of T3SS-3. This review aims to frame current knowledge of B. pseudomallei T3SSs in the context of other well characterised model T3SSs, particularly those of Salmonella and Shigella.

【 授权许可】

CC BY