Edwardsiella tarda evades serum killing by preventing complement activation via the alternative pathway
Edwardsiella tarda evades serum killing by preventing complement activation via the alternative pathway
复制标题
迟缓爱德华氏菌通过旁路途径阻止补体激活，从而逃避血清杀灭。
DOI：
10.1016/j.fsi.2014.12.037
复制
发表时间：
2015-04-01
影响因子：
4.7
通讯作者：
Li, Jun
中科院分区：
文献类型：
--
作者：
Li, Mo-fei;Sun, Li;Li, Jun
迟缓爱德华氏菌是一种革兰氏阴性细菌，宿主范围很广，包括各种养殖的鱼类和人类。迟发性埃希氏菌很早就知道能够在宿主血清中存活，但相关机制尚不清楚。在这项研究中，我们研究了一个基本问题，即迟发性埃希氏菌是否激活了血清补体。我们发现：(1)迟缓乳杆菌与牙槽鱼血清孵育后的存活率较高(87.6%)，但在有镁离子存在的情况下存活率略有下降；(2)迟缓乳杆菌孵育的血清具有较强的溶血和杀菌活性；(3)与补体敏感的实验室大肠杆菌菌株孵育的血清相比，迟缓乳杆菌的趋化活性明显降低；(4)与活的迟缓乳杆菌孵育的血清相比，热灭活的迟缓乳杆菌孵育的血清没有表现出明显的溶血能力。综上所述，这些结果首次表明，迟缓艾美耳球虫通过替代途径在很大程度上阻止补体激活而避开血清攻击，并且耐热表面结构可能在迟发艾美耳球虫逃避补体的过程中发挥重要作用。(C)2015爱思唯尔有限公司。保留所有权利。
Edwardsiella tarda is a Gram-negative bacterium with a broad host range that includes a wide variety of farmed fish as well as humans. E. tarda has long been known to be able to survive in host serum, but the relevant mechanism is unclear. In this study, we investigated the fundamental question, i.e. whether E. tarda activated serum complement or not. We found that (i) when incubated with flounder serum, E. tarda exhibited a high survival rate (87.6%), which was slightly but significantly reduced in the presence of Mg2+; (ii) E. tarda-incubated serum possessed strong hemolytic activity and bactericidal activity, (iii) compared to the serum incubated with a complement-sensitive laboratory Escherichia coli strain, E. tarda-incubated serum exhibited much less chemotactic activity, (iv) in contrast to the serum incubated with live E. tarda, the serum incubated with heat-inactivated E. tarda exhibited no apparent hemolytic capacity. Taken together, these results indicate for the first time that E. tarda circumvents serum attack by preventing, to a large extent, complement activation via the alternative pathway, and that heatlabile surface structures likely play an essential role in the complement evasion of E. tarda. (C) 2015 Elsevier Ltd. All rights reserved.