Intestinal Epithelial Cells and the Microbiome Undergo Swift Reprogramming at the Inception of Colonic Citrobacter rodentium Infection
Intestinal Epithelial Cells and the Microbiome Undergo Swift Reprogramming at the Inception of Colonic Citrobacter rodentium Infection
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DOI：
10.1128/mbio.00062-19
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发表时间：
2019-03-01
期刊：
影响因子：
6.4
通讯作者：
Frankel, Gad
中科院分区：
文献类型：
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作者：
Hopkins, Eve G. D.;Roumeliotis, Theodoros I.;Frankel, Gad
我们使用小鼠附着和消失（A/E）病原体啮齿柠檬酸杆菌，其模拟人类A/E病原体肠致病性大肠杆菌和肠出血性大肠杆菌。大肠杆菌（EPEC和EHEC），以暂时解决体内感染期间肠上皮细胞（IEC）对微生物组的反应和变化。我们发现宿主在感染后的前3天（DPI）没有反应，当C。啮齿动物居住在盲肠中。相比之下，在4 DPI时，即结肠定植当天，尽管只有零星粘附到隐窝顶端，但我们观察到细胞周期和DNA修复过程的强烈上调，这与隐窝Ki 67阳性复制区的扩张有关，以及多种代谢过程（包括三羧酸[TCA]循环和氧化磷酸化）的下调。此外，我们观察到在早期感染期间杯状和深隐窝分泌细胞的急剧消耗以及IEC中胆固醇稳态的非典型调节，同时上调胆固醇生物合成（例如，3-羟基-3-甲基戊二酰-辅酶A还原酶[Hmgcr]），输入（例如，低密度脂蛋白受体[Ldlr]），和外排（例如，AbcA1）。我们还检测了IEC中的白细胞介素22（IL-22）应答（例如，Reg 3 γ），这与粘膜表面上的细菌性肠杆菌科细菌的大量繁殖同时发生。这些结果揭示了宿主-病原体-微生物组相互作用的新范式，首次表明检测少量病原菌会引发IEC组成和功能的快速内在变化，同时粘膜相关微生物组也会发生显著变化，这与先天免疫反应平行。啮齿动物是一种广泛使用的结肠感染模型，并且一直是细菌发病机制和粘膜免疫学领域基础发现的主要工具。尽管广泛的研究探讨急性C。虽然我们对啮齿动物感染的早期阶段的了解仍然相对不详细。为此，我们应用多组学方法来解决早期感染期间宿主和微生物组的时间变化。出乎意料的是，我们发现在结肠感染当天，宿主肠上皮细胞和微生物组都发生了立即和戏剧性的反应。我们的研究表明，在结肠中检测到病原体后，上皮细胞中胆固醇和碳代谢的变化立即被诱导，这与构成微生物组的主要兼性厌氧菌的转变相对应。这项研究有助于我们了解疾病的发病机制和屏障调节机制，这是开发针对肠上皮的新疗法所必需的。
We used the mouse attaching and effacing (A/E) pathogen Citrobacter rodentium, which models the human A/E pathogens enteropathogenic Escherichia coli and enterohemorrhagic E. coli (EPEC and EHEC), to temporally resolve intestinal epithelial cell (IEC) responses and changes to the microbiome during in vivo infection. We found the host to be unresponsive during the first 3 days postinfection (DPI), when C. rodentium resides in the caecum. In contrast, at 4 DPI, the day of colonic colonization, despite only sporadic adhesion to the apex of the crypt, we observed robust upregulation of cell cycle and DNA repair processes, which were associated with expansion of the crypt Ki67-positive replicative zone, and downregulation of multiple metabolic processes (including the tricarboxylic acid [TCA] cycle and oxidative phosphorylation). Moreover, we observed dramatic depletion of goblet and deep crypt secretory cells and an atypical regulation of cholesterol homeostasis in IECs during early infection, with simultaneous upregulation of cholesterol biogenesis (e.g., 3-hydroxy-3-methylglutaryl-coenzyme A reductase [Hmgcr]), import (e.g., low-density lipoprotein receptor [Ldlr]), and efflux (e.g., AbcA1). We also detected interleukin 22 (IL-22) responses in IECs (e.g., Reg3 gamma) on the day of colonic colonization, which occurred concomitantly with a bloom of commensal Enterobacteriaceae on the mucosal surface. These results unravel a new paradigm in host-pathogen-microbiome interactions, showing for the first time that sensing a small number of pathogenic bacteria triggers swift intrinsic changes to the IEC composition and function, in tandem with significant changes to the mucosa-associated microbiome, which parallel innate immune responses.IMPORTANCE The mouse pathogen C. rodentium is a widely used model for colonic infection and has been a major tool in fundamental discoveries in the fields of bacterial pathogenesis and mucosal immunology. Despite extensive studies probing acute C. rodentium infection, our understanding of the early stages preceding the infection climax remains relatively undetailed. To this end, we apply a multiomics approach to resolve temporal changes to the host and microbiome during early infection. Unexpectedly, we found immediate and dramatic responses occurring on the day of colonic infection, both in the host intestinal epithelial cells and in the microbiome. Our study suggests changes in cholesterol and carbon metabolism in epithelial cells are instantly induced upon pathogen detection in the colon, corresponding with a shift to primarily facultative anaerobes constituting the microbiome. This study contributes to our knowledge of disease pathogenesis and mechanisms of barrier regulation, which is required for development of novel therapeutics targeting the intestinal epithelium.