MPL36, a major plasminogen (PLG) receptor in pathogenic Leptospira, has an essential role during infection.
MPL36, a major plasminogen (PLG) receptor in pathogenic Leptospira, has an essential role during infection.
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DOI：
10.1371/journal.ppat.1011313
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发表时间：
2023-07
期刊：
影响因子：
6.7
通讯作者：
中科院分区：
文献类型：
--
作者：
钩端螺旋体病是一种全球分布的人畜共患病，由钩端螺旋体属致病性螺旋体引起。细菌外膜蛋白(OMP)，特别是具有表面暴露区域的OMP，在病原菌的传播和毒力机制中起着至关重要的作用。在这里，我们鉴定了钩端螺旋体膜蛋白L36(MPL36)，它是一种罕见的具有C末端孢子形成相关(Spor)结构域的脂蛋白A(RLPA)同源物，是致病钩端螺旋体的一个重要毒力因子。我们的结果证实了MPL36在感染过程中是表面暴露和表达的。利用重组MPL36(RMPL36)，我们也证实了先前的发现，即其与纤溶酶原(PLG)的结合能力由蛋白质C-末端的赖氨酸残基决定，具有将结合的PLG转化为活性纤溶酶的能力。利用Koch的分子假设，我们确定mpl36的一个突变体具有降低的PLG结合能力，导致黏附和移位MDCK细胞单层的能力降低。利用重组蛋白和突变菌株，我们确定了MPL36结合的纤溶酶(PLA)能够降解纤维蛋白原。最后，我们的mpl36突变体在急性钩端螺旋体病的仓鼠模型中具有显著的减弱表型。我们的数据表明，MPL36是致病性钩端螺旋体中主要的PLG结合蛋白，在感染过程中对病原体附着和与宿主组织相互作用的能力至关重要。MPL36的特性有助于扩大探索PLG毒力的细菌病原体的领域，推进缩小有关钩端螺旋体发病机制的知识差距的目标，同时为改善这种重要的人畜共患被忽视疾病的诊断和预防提供了一个新的潜在候选者。作为其多样化毒力机制的一部分，细菌病原体与人类纤溶酶原(PLG)结合，为它们提供一个促进侵袭、传播和毒力的蛋白分解平台。钩端螺旋体病是世界范围内发病率和死亡率最高的人畜共患病。鉴于气候变化和社会不平等的影响，这种被忽视的疾病的负担将继续增加，这是疾病的重要驱动因素。此外，关于钩端螺旋体发病机制的知识差距对敏感诊断工具和有效预防方法的开发产生了负面影响。以往的研究表明，作为钩端螺旋体病的病原体，致病性钩端螺旋体可以通过不同的候选蛋白与PLG相互作用。在这项工作中，我们鉴定了这些候选蛋白之一，膜蛋白L36(MPL36)，作为主要的钩端螺旋体纤溶酶原结合蛋白。利用转基因突变体，在体内和体外实验中，我们提供了证据表明，MPL36可以结合PLG，促进与宿主细胞的黏附和随后的易位，并通过将结合的PLG转化为聚乳酸来降解纤维蛋白原，从而对钩端螺旋体的毒力至关重要。这项工作有助于探索PLG以提高其毒力的细菌病原体的增长领域，同时突出了有关钩端螺旋体发病机制的重要新知识。在继续努力改进这一重要的人畜共患病的诊断和预防方面，MPL36是一个有待探索的重要候选者。
Leptospirosis, a zoonosis with worldwide distribution, is caused by pathogenic spirochetes belonging to the genus Leptospira. Bacterial outer membrane proteins (OMPs), particularly those with surface-exposed regions, play crucial roles in pathogen dissemination and virulence mechanisms. Here we characterized the leptospiral Membrane Protein L36 (MPL36), a rare lipoprotein A (RlpA) homolog with a C-terminal Sporulation related (SPOR) domain, as an important virulence factor in pathogenic Leptospira. Our results confirmed that MPL36 is surface exposed and expressed during infection. Using recombinant MPL36 (rMPL36) we also confirmed previous findings of its high plasminogen (PLG)-binding ability determined by lysine residues of the C-terminal region of the protein, with ability to convert bound-PLG to active plasmin. Using Koch’s molecular postulates, we determined that a mutant of mpl36 has a reduced PLG-binding ability, leading to a decreased capacity to adhere and translocate MDCK cell monolayers. Using recombinant protein and mutant strains, we determined that the MPL36-bound plasmin (PLA) can degrade fibrinogen. Finally, our mpl36 mutant had a significant attenuated phenotype in the hamster model for acute leptospirosis. Our data indicates that MPL36 is the major PLG binding protein in pathogenic Leptospira, and crucial to the pathogen’s ability to attach and interact with host tissues during infection. The MPL36 characterization contributes to the expanding field of bacterial pathogens that explore PLG for their virulence, advancing the goal to close the knowledge gap regarding leptospiral pathogenesis while offering a novel potential candidate to improve diagnostic and prevention of this important zoonotic neglected disease. As part of their diverse virulence machinery, bacterial pathogens bind to human plasminogen (PLG) providing them with a proteolytic platform that promotes invasiveness, dissemination, and virulence. Leptospirosis is the leading zoonotic disease in morbidity and mortality worldwide. The burden of this neglected disease will continue to raise given the effects of climate change and social inequality, important drivers of disease. Furthermore, the gap of knowledge regarding leptospiral pathogenesis has negatively impacted the development of sensitive diagnostic tools and effective prevention methods. Previous studies have shown that pathogenic Leptospira, the causative agent of leptospirosis, can interact with PLG through different protein candidates. In this work, we characterized one of those candidates, Membrane Protein L36 (MPL36), as the main leptospiral plasminogen binding protein. Using genetically modified mutants, in vivo, and in vitro assays we provided evidence that MPL36 can bound PLG, promotes adherence to host cells and subsequent translocation, and degrades fibrinogen by converting bound-PLG to PLA, thus essential to leptospiral virulence. This work contributes to the growing field of bacterial pathogens exploring PLG to increase their virulence, while highlighting important new knowledge on leptospiral pathogenesis. MPL36 is an important candidate to be explored on the continued effort to improve diagnostic and prevention of this important zoonotic disease.
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影响因子：
--
作者：
Vieira ML;Atzingen MV;Oliveira R;Mendes RS;Domingos RF;Vasconcellos SA;Nascimento AL
通讯作者：
Nascimento AL
影响因子：
6.7
作者：
Caimano MJ;Sivasankaran SK;Allard A;Hurley D;Hokamp K;Grassmann AA;Hinton JC;Nally JE
通讯作者：
Nally JE
影响因子：
5.7
作者：
Adhikarla H;Wunder EA Jr;Mechaly AE;Mehta S;Wang Z;Santos L;Bisht V;Diggle P;Murray G;Adler B;Lopez F;Townsend JP;Groisman E;Picardeau M;Buschiazzo A;Ko AI
通讯作者：
Ko AI
影响因子：
5.7
作者：
Daroz BB;Fernandes LGV;Cavenague MF;Kochi LT;Passalia FJ;Takahashi MB;Nascimento Filho EG;Teixeira AF;Nascimento ALTO
通讯作者：
Nascimento ALTO
影响因子：
64.8
作者：
Jumper J;Evans R;Pritzel A;Green T;Figurnov M;Ronneberger O;Tunyasuvunakool K;Bates R;Žídek A;Potapenko A;Bridgland A;Meyer C;Kohl SAA;Ballard AJ;Cowie A;Romera-Paredes B;Nikolov S;Jain R;Adler J;Back T;Petersen S;Reiman D;Clancy E;Zielinski M;Steinegger M;Pacholska M;Berghammer T;Bodenstein S;Silver D;Vinyals O;Senior AW;Kavukcuoglu K;Kohli P;Hassabis D
通讯作者：
Hassabis D