Heterologous production of the adhesin LIC13411 from pathogenic Leptospira facilitates binding of non-pathogenic Leptospira in vitro and in vivo.
Heterologous production of the adhesin LIC13411 from pathogenic Leptospira facilitates binding of non-pathogenic Leptospira in vitro and in vivo.
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DOI：
10.3389/fcimb.2022.917963
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发表时间：
2022
影响因子：
5.7
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中科院分区：
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钩端螺旋体病是全球范围内导致发病和死亡的一个重要病因。疾病严重程度不一，从无症状定植到广泛出血和多器官功能障碍。病原体钩端螺旋体属是一类人畜共患的革兰氏阴性螺旋体。发病机制中的一个重要步骤是细菌黏附素与宿主成分的结合。此前，我们实验室鉴定出问号钩端螺旋体的两种候选黏附素LIC11574和LIC13411，它们在体外可与血管内皮钙黏蛋白（VE - cadherin）结合。在当前研究中，我们证实了两株致病性问号钩端螺旋体破坏VE - cadherin定位的能力，VE - cadherin是一种对维持内皮细胞间连接很重要的蛋白质。纯化的MBP - LIC11574和MBP - LIC13411以一种类似于VE - cadherin的模式结合人皮肤微血管内皮细胞，但并不破坏VE - cadherin的定位。编码致病性钩端螺旋体候选黏附素的基因被克隆到一个过表达载体中，并导入非致病性双曲钩端螺旋体中，构建出功能获得性菌株，可产生LIC11574或LIC13411。通过Triton X - 114分级分离证实了蛋白质的产生以及其在外膜的定位。尽管这些菌株不破坏VE - cadherin的定位，但LIC13411的产生增加了非致病性钩端螺旋体与人内皮细胞的结合，且特异性地与VE - cadherin结合。在一个短期小鼠感染模型中，LIC13411的产生导致非病原体在肺、肝、肾和膀胱中的载量增加。这些数据证实了LIC13411作为钩端螺旋体属黏附素的作用，并表明其与病原体在多个器官中的播散有关。重要的是，抗黏附素疗法已被证明比传统抗生素有诸多优势。综上所述，这项工作为钩端螺旋体属的发病机制提供了新的见解，并确定LIC13411为一个潜在的预防和治疗靶点。
Leptospirosis is an important cause of morbidity and mortality worldwide. Disease severity ranges from asymptomatic colonization to widespread hemorrhage and multiorgan dysfunction. The causative agents, Leptospira spp., are zoonotic Gram-negative spirochetes. One important step in pathogenesis is binding of bacterial adhesins to host components. Previously our laboratory identified two L. interrogans candidate adhesins, LIC11574 and LIC13411, that bind to VE-cadherin in vitro. In the current study, we demonstrate the ability of two strains of pathogenic L. interrogans to disrupt the localization of VE-cadherin, a protein important to maintaining inter-endothelial junctions. Purified MBP-LIC11574 and MBP-LIC13411 bind human dermal microvascular endothelial cells in a pattern reminiscent of VE-cadherin, but do not disrupt VE-cadherin localization. Genes encoding the candidate adhesins from pathogenic Leptospira were cloned in an overexpression vector and introduced into non-pathogenic L. biflexa, creating gain-of-function strains producing LIC11574 or LIC13411. Protein production and localization to the outer membrane were confirmed by Triton X-114 fractionation. Although these strains do not disrupt VE-cadherin localization, production of LIC13411 increases binding of non-pathogenic Leptospira to human endothelial cells and specifically to VE-cadherin. In a short-term murine model of infection, LIC13411 production led to increased burdens of the non-pathogen in the lung, liver, kidney, and bladder. These data confirm the role of LIC13411 as an adhesin in Leptospira spp. and implicate it in dissemination to multiple organs. Importantly, anti-adhesin therapy has been shown to have many benefits over classical antibiotics. Taken together, this work provides novel insight into the pathogenesis of Leptospira spp. and identifies LIC13411 as a potential prophylactic and therapeutic target.