Identification of the interactome between fish plasma proteins and Edwardsiella tarda reveals tissue-specific strategies against bacterial infection

Elucidating the complex pathogen-host interaction is essential for a comprehensive understanding of how these remarkable agents invade their hosts and how the hosts defend against these invaders. During the infection, pathogens interact intensively with host to enable their survival, which can be revealed through their interactome. Edwardsiella tarda is a Gram-negative bacterial pathogen causing huge economic loss in aquaculture and a spectrum of intestinal and extraintestinal diseases in humans. E. tarda is an ideal model for host-pathogen investigation as it infects fish in three distinct steps: entering the host, circulating through the blood and establishing infection. We adopted a previous established proteomic approach that inactivated E. tarda cells and covalent crosslink fish plasma proteins were used to capture plasma proteins and bacterial outer membrane proteins, respectively. By the combinatorial use of proteomic and biochemical approaches, six plasma proteins and seven outer membrane proteins (OMPs) were identified. Interactions among these proteins were validated with protein-array, far-Western blotting and co-immunoprecipitation. At last, seventeen plasma protein-bacteria protein-protein interaction were confirmed to be involved in the interaction network, forming a complex interactome. Compared to our previous results, different host proteins were detected, whereas some of the bacterial proteins were similar, which indicates that hosts adopt tissue-specific strategies to cope with the same pathogen during infection. Thus, our results provide a robust demonstration of both bacterial initiators and host receptors or interacting proteins to further explore infection and anti-infective mechanisms between hosts and microbes. (C) 2016 Elsevier Ltd. All rights reserved.

阐明复杂的病原体 - 宿主相互作用对于全面理解这些非凡的病原体如何侵入宿主以及宿主如何抵御这些入侵者至关重要。在感染过程中，病原体与宿主强烈相互作用以实现其生存，这可通过它们的相互作用组揭示出来。迟缓爱德华氏菌是一种革兰氏阴性细菌病原体，在水产养殖中造成巨大的经济损失，并在人类中引起一系列肠道和肠道外疾病。迟缓爱德华氏菌是研究宿主 - 病原体的理想模型，因为它感染鱼类分为三个不同的步骤：进入宿主、在血液中循环以及建立感染。我们采用了先前建立的蛋白质组学方法，即灭活迟缓爱德华氏菌细胞，并用共价交联的鱼血浆蛋白分别捕获血浆蛋白和细菌外膜蛋白。通过蛋白质组学和生物化学方法的结合使用，鉴定出六种血浆蛋白和七种外膜蛋白（OMPs）。这些蛋白质之间的相互作用通过蛋白质阵列、远西方印迹和免疫共沉淀进行了验证。最后，确认有17种血浆蛋白 - 细菌蛋白 - 蛋白质相互作用参与相互作用网络，形成一个复杂的相互作用组。与我们之前的结果相比，检测到了不同的宿主蛋白，而一些细菌蛋白是相似的，这表明宿主在感染过程中采用组织特异性策略来应对相同的病原体。因此，我们的结果有力地展示了细菌起始因子以及宿主受体或相互作用蛋白，以进一步探索宿主和微生物之间的感染和抗感染机制。（C）2016爱思唯尔有限公司。保留所有权利。