Expression of Immune-Related Genes of Ducks Infected with Avian Pathogenic Escherichia coli (APEC).
Expression of Immune-Related Genes of Ducks Infected with Avian Pathogenic Escherichia coli (APEC).
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禽致病性大肠埃希菌（APEC）感染鸭免疫相关基因的表达
DOI：
10.3389/fmicb.2016.00637
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发表时间：
2016
影响因子：
5.2
通讯作者：
Wei L
中科院分区：
文献类型：
--
作者：
Li R;Li N;Zhang J;Wang Y;Liu J;Cai Y;Chai T;Wei L
禽致病性大肠杆菌（APEC）可引起鸭的严重疾病，主要表现为肝炎周围炎、心包炎和气囊炎。虽然细菌分离和检测方法的研究已经报道，宿主对APEC感染的免疫反应仍然不清楚。因此，我们系统地研究了免疫相关基因的表达和细菌在感染鸭中的分布。结果表明，APEC可以在肝，脾和脑中快速复制，在感染后2天细菌含量最高。检测感染鸭肝、脾、脑组织中Toll样受体（Toll like receptor，TLRs）、禽β防御素（AvBD）和主要组织相容性复合体（major histocompatibility complex，MHC）的表达。TLR 2、TLR 4、TLR 5和TLR 15的表达模式不同，提示它们对APEC感染均有应答。在3天的测试期间，AvBD 2的表达在所有测试组织中上调，而AvBD 4、AvBD 5、AvBD 7和AvBD 9的表达下调，并且尽管MHC-I在所有测试日上调，但MHC-II显著下调。总的来说，我们的研究结果表明，APEC可以在短时间内在各种组织中复制，宿主免疫反应的激活始于感染开始。因此，这些研究结果澄清鸭APEC感染的免疫反应，并提供其发病机制的见解。
Avian pathogenic Escherichia coli (APEC) can cause severe disease in ducks, characterized by perihepatitis, pericarditis, and airsacculitis. Although the studies of bacteria isolation and methods of detection have been reported, host immune responses to APEC infection remain unclear. In response, we systemically examined the expression of immune-related genes and bacteria distribution in APEC-infected ducks. Results demonstrated that APEC can quickly replicate in the liver, spleen, and brain, with the highest bacteria content at 2 days post infection. The expression of toll-like receptors (TLRs), avian β-defensins (AvBDs) and major histocompatibility complex (MHC) were tested in the liver, spleen, and brain of infected ducks. TLR2, TLR4, TLR5, and TLR15 showed different expression patterns, which indicated that they all responded to APEC infection. The expression of AvBD2 was upregulated in all tested tissues during the 3 days of testing, whereas the expression of AvBD4, AvBD5, AvBD7, and AvBD9 were downregulated, and though MHC-I was upregulated on all test days, MHC-II was dramatically downregulated. Overall, our results suggest that APEC can replicate in various tissues in a short time, and the activation of host immune responses begins at onset of infection. These findings thus clarify duck immune responses to APEC infection and offer insights into its pathogenesis.