Coccidiosis is an infectious disease with large negative impact on the poultry industry worldwide. It is an enteric infection caused by unicellular Apicomplexan parasites of the genus Eimeria. The present study aimed to gain more knowledge about interactions between parasites and the host immune system during the early asexual replication phase of E. tenella in chicken caeca. For this purpose, chickens were experimentally infected with E. tenella oocysts, sacrificed on days 1–4 and 10 after infection and mRNA from caecal tissues was extracted and sequenced. Dual RNA-seq analysis revealed time-dependent changes in both host and parasite gene expression during the course of the infection. Chicken immune activation was detected from day 3 and onwards with the highest number of differentially expressed immune genes recorded on day 10. Among early (days 3–4) responses up-regulation of genes for matrix metalloproteinases, several chemokines, interferon (IFN)-γ along with IFN-stimulated genes GBP, IRF1 and RSAD2 were noted. Increased expression of genes with immune suppressive/regulatory effects, e.g. IL10, SOCS1, SOCS3, was also observed among early responses. For E. tenella a general up-regulation of genes involved in protein expression and energy metabolism as well as a general down-regulation genes for DNA and RNA processing were observed during the infection. Specific E. tenella genes with altered expression during the experiment include those for proteins in rhoptry and microneme organelles. The present study provides novel information on both the transcriptional activity of E. tenella during schizogony in ceacal tissue and of the local host responses to parasite invasion during this phase of infection. Results indicate a role for IFN-γ and IFN-stimulated genes in the innate defence against Eimeria replication.

中文翻译：

---

鸡原发性艾美球虫感染期间盲肠组织的双 RNA-seq 转录组分析

球虫病是一种传染病，对全世界的家禽业有很大的负面影响。它是由艾美球虫属的单细胞顶复门寄生虫引起的肠道感染。本研究旨在获得更多关于鸡盲肠中E.tenella早期无性复制阶段寄生虫与宿主免疫系统之间相互作用的知识。为此，鸡实验性地感染了球虫卵囊，在感染后第 1-4 天和第 10 天处死，从盲肠组织中提取 mRNA 并测序。双 RNA-seq 分析揭示了感染过程中宿主和寄生虫基因表达的时间依赖性变化。从第 3 天开始检测到鸡的免疫激活，第 10 天记录的差异表达免疫基因数量最多。在基质金属蛋白酶基因的早期（第 3-4 天）反应上调中，注意到了几种趋化因子、干扰素 (IFN)-γ 以及 IFN 刺激基因 GBP、IRF1 和 RSAD2。在早期反应中也观察到具有免疫抑制/调节作用的基因表达增加，例如 IL10、SOCS1、SOCS3。对于 E. tenella，在感染期间观察到涉及蛋白质表达和能量代谢的基因的普遍上调以及 DNA 和 RNA 加工的一般下调基因。在实验过程中表达改变的特定 E. tenella 基因包括菱形和微线体细胞器中的蛋白质。本研究提供了关于大肠杆菌转录活性的新信息。盲肠组织裂殖体中的tenella，以及在这个感染阶段对寄生虫入侵的局部宿主反应。结果表明 IFN-γ 和 IFN 刺激基因在先天防御艾美球虫复制中的作用。