Table 1_RNA sequencing reveals dynamic expression of genes related to innate immune responses in canine small intestinal epithelial cells induced by Echinococcus granulosus protoscoleces.xlsx

BackgroundDogs are definitive hosts of Echinococcus granulosus, with the small intestine being the only site of parasitic infections. However, the immunomodulatory processes that occur during interactions between E. granulosus and its definitive host remain unclear. Therefore, this study aimed to evaluate gene transcription patterns in canine small intestinal epithelial cells (CIECs) following stimulation by E. granulosus protoscoleces (PSCs). Particularly, this study investigated the roles of pattern recognition receptors (PRRs), involved in recognizing pathogen-associated molecular patterns (PAMPs) and mediating the host innate immune response to the tapeworm E. granulosus.
MethodsRNA sequencing (RNA-seq) was used to examine gene transcription patterns in CIECs following stimulation with PSCs for 12 and 24 h. The potential roles of differentially expressed (DE) genes were inferred through Gene Ontology (GO) enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses.
ResultsRNA-seq analysis identified 78,206,492–90,548,214 clean reads in 12 RNA samples. This included six samples stimulated with PSCs for 12 h (PSC1_12h–PSC3_12h) and 24 h (PSC1_24h–PSC3_24h) and six corresponding control samples (PBS1_12h–PBS3_12h and PBS1_24h–PBS3_24h). In the PSC_12h vs. PBS_12h and PSC_24h vs. PBS_24h groups, 3,520 (2,359 upregulated and 1,161 downregulated) and 3,287 (1765 upregulated and 1,522 downregulated) DEgenes were identified, respectively. The expression of 45 PRRs genes was upregulated in the PSC_12h and PSC_24h groups compared to those in the control groups, including 4 Toll-like receptors (TLRs), 4C-type lectin receptors (CLRs), 3 NOD-like receptors (NLRs), 17 G protein-coupled receptors (GPCRs), 4 scavenger receptors (SRs), and 13 leucine-rich repeat-containing proteins (LRRCs). GO enrichment and KEGG analyses revealed that these DEgenes were mainly involved in the regulation of host immune response processes and molecules. These included antigen processing and presentation, Th17, PI3K-Akt, Th1, and Th2 cell differentiation, neutrophil extracellular trap formation, NOD- and Toll-like receptors, TNF, intestinal immune network for IgA production and IL-17 signaling pathway. Furthermore, the identified DEgenes were involved in the regulation of signaling molecules and interaction (e.g., cell adhesion molecules and ECM-receptor interaction).
ConclusionThese preliminary findings provide novel perspectives on the host innate immune response to E. granulosus PSC stimulation, with a focus on the involvement of E. granulosus-specific PRRs in host defense mechanisms against infection.

研究背景
犬是细粒棘球绦虫（Echinococcus granulosus）的终宿主，其小肠是该寄生虫唯一的寄生部位。然而，细粒棘球绦虫与其终宿主互作过程中发生的免疫调节机制仍未明确。因此，本研究旨在评估细粒棘球绦虫原头蚴（PSCs）刺激后犬小肠上皮细胞（CIECs）的基因转录模式。本研究重点探究了模式识别受体（PRRs）在其中的作用——这类受体可识别病原体相关分子模式（PAMPs），并介导宿主针对该绦虫的固有免疫应答。

研究方法
本研究采用RNA测序（RNA-seq）技术，分析细粒棘球绦虫原头蚴分别刺激CIECs 12 h与24 h后的基因转录模式。通过基因本体（GO）富集分析与京都基因与基因组百科全书（KEGG）通路分析，对差异表达（DE）基因的潜在功能进行推断。

研究结果
RNA-seq分析在12份RNA样本中共获得78206492~90548214条清洁读段。其中包含6份经原头蚴刺激12 h的样本（PSC1_12h–PSC3_12h）、6份刺激24 h的样本（PSC1_24h–PSC3_24h），以及6份对应的对照样本（PBS1_12h–PBS3_12h与PBS1_24h–PBS3_24h）。在PSC_12h vs. PBS_12h与PSC_24h vs. PBS_24h两组比较中，分别鉴定出3520个（2359个上调、1161个下调）与3287个（1765个上调、1522个下调）差异表达基因。与对照组相比，PSC_12h与PSC_24h组中共45个模式识别受体基因表达上调，其中包括4个Toll样受体（TLRs）、4个C型凝集素受体（CLRs）、3个NOD样受体（NLRs）、17个G蛋白偶联受体（GPCRs）、4个清道夫受体（SRs）以及13个富含亮氨酸重复序列蛋白（LRRCs）。GO富集与KEGG通路分析结果显示，这些差异表达基因主要参与宿主免疫应答过程与分子调控，涵盖抗原加工与呈递、Th17/PI3K-Akt/Th1/Th2细胞分化、中性粒细胞胞外陷阱形成、NOD样与Toll样受体通路、肿瘤坏死因子（TNF）通路、IgA产生肠道免疫网络以及IL-17信号通路等。此外，鉴定出的差异表达基因还参与信号分子与相互作用的调控，例如细胞黏附分子及细胞外基质-受体相互作用通路。

研究结论
本研究的初步发现为宿主针对细粒棘球绦虫原头蚴刺激的固有免疫应答提供了新的研究视角，重点揭示了细粒棘球绦虫特异性模式识别受体在宿主抗感染防御机制中的作用。