Karve Sayali S, Pradhan Suman, Ward Doyle V, Weiss Alison A
Department of Molecular Genetics, Biochemistry, and Microbiology, University of Cincinnati, Cincinnati, Ohio, United States of America.
Center for Microbiome Research and Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America.
PLoS One. 2017 Jun 14;12(6):e0178966. doi: 10.1371/journal.pone.0178966. eCollection 2017.
Infection with Shiga toxin (Stx) producing Escherichia coli O157:H7 can cause the potentially fatal complication hemolytic uremic syndrome, and currently only supportive therapy is available. Lack of suitable animal models has hindered study of this disease. Induced human intestinal organoids (iHIOs), generated by in vitro differentiation of pluripotent stem cells, represent differentiated human intestinal tissue. We show that iHIOs with addition of human neutrophils can model E. coli intestinal infection and innate cellular responses. Commensal and O157:H7 introduced into the iHIO lumen replicated rapidly achieving high numbers. Commensal E. coli did not cause damage, and were completely contained within the lumen, suggesting defenses, such as mucus production, can constrain non-pathogenic strains. Some O157:H7 initially co-localized with cellular actin. Loss of actin and epithelial integrity was observed after 4 hours. O157:H7 grew as filaments, consistent with activation of the bacterial SOS stress response. SOS is induced by reactive oxygen species (ROS), and O157:H7 infection increased ROS production. Transcriptional profiling (RNAseq) demonstrated that both commensal and O157:H7 upregulated genes associated with gastrointestinal maturation, while infection with O157:H7 upregulated inflammatory responses, including interleukin 8 (IL-8). IL-8 is associated with neutrophil recruitment, and infection with O157:H7 resulted in recruitment of human neutrophils into the iHIO tissue.
感染产志贺毒素（Stx）的大肠杆菌O157:H7可导致潜在致命并发症溶血尿毒综合征，目前仅有支持性治疗方法。缺乏合适的动物模型阻碍了对该疾病的研究。由多能干细胞体外分化产生的诱导性人肠道类器官（iHIOs）代表分化的人肠道组织。我们发现，添加人中性粒细胞的iHIOs可模拟大肠杆菌肠道感染及先天性细胞反应。引入iHIO管腔的共生菌和O157:H7迅速繁殖，数量增多。共生大肠杆菌未造成损伤，且完全局限于管腔内，这表明诸如黏液产生等防御机制可限制非致病菌株。一些O157:H7最初与细胞肌动蛋白共定位。4小时后观察到肌动蛋白和上皮完整性丧失。O157:H7呈丝状生长，这与细菌SOS应激反应的激活一致。SOS由活性氧（ROS）诱导，O157:H7感染会增加ROS产生。转录谱分析（RNAseq）表明，共生菌和O157:H7均上调了与胃肠道成熟相关的基因，而O157:H7感染上调了包括白细胞介素8（IL-8）在内的炎症反应。IL-8与中性粒细胞募集有关，O157:H7感染导致人中性粒细胞募集到iHIO组织中。
