PDF(Pubmed)
Abstract：
Extracellular vesicles (EVs) recently emerged as important players in the pathophysiology of parasitic infections. While the protist parasite Giardia duodenalis can produce EVs, their role in giardiasis remains obscure. Giardia can disrupt gut microbiota biofilms and transform commensal bacteria into invasive pathobionts at sites devoid of colonizing trophozoites via unknown mechanisms. We hypothesized that Giardia EVs could modify gut bacterial behaviour via a novel mode of trans-kingdom communication. Our findings indicate that Giardia EVs exert bacteriostatic effects on Escherichia coli HB101 and Enterobacter cloacae TW1, increasing their swimming motility. Giardia EVs also decreased the biofilm-forming ability of E. coli HB101 but not by E. cloacae TW1, supporting the hypothesis that these effects are, at least in part, bacteria-selective. E. coli HB101 and E. cloacae TW1 exhibited increased adhesion/invasion onto small intestine epithelial cells when exposed to Giardia EVs. EVs labelled with PKH67 revealed colocalization with E. coli HB101 and E. cloacae TW1 bacterial cells. Small RNA sequencing revealed a high abundance of ribosomal RNA (rRNA)- and transfer RNA (tRNA)-derived small RNAs, short-interfering RNAs (siRNAs) and micro-RNAs (miRNAs) within Giardia EVs. Proteomic analysis of EVs uncovered the presence of RNA chaperones and heat shock proteins that can facilitate the thermal stability of EVs and its sRNA cargo, as well as protein-modifying enzymes. In vitro, RNase heat-treatment assays showed that total RNAs in EVs, but not proteins, are responsible for modulating bacterial swimming motility and biofilm formation. G. duodenalis small RNAs of EVs, but not proteins, were responsible for the increased bacterial adhesion to intestinal epithelial cells induced upon exposure to Giardia EVs. Together, the findings indicate that Giardia EVs contain a heat-stable, RNase-sensitive cargo that can trigger the development of pathobiont characteristics in Enterobacteria, depicting a novel trans-kingdom cross-talk in the gut.
摘要：
细胞外囊泡（EV）最近成为寄生虫感染病理生理学中的重要参与者。虽然原生寄生虫十二指肠贾第鞭毛虫可以产生电动汽车，它们在贾第鞭毛虫病中的作用仍然不清楚。贾第鞭毛虫可以破坏肠道微生物群生物膜，并通过未知的机制将共生细菌转化为在没有定植滋养体的部位的侵袭性病原体。我们假设贾第虫EV可以通过一种新型的跨王国交流模式来改变肠道细菌行为。我们的发现表明，贾第鞭毛虫EV对大肠杆菌HB101和阴沟肠杆菌TW1具有抑菌作用，从而增加了它们的游泳运动能力。贾第虫EV还降低了大肠杆菌HB101的生物膜形成能力，但不降低阴沟肠杆菌TW1的生物膜形成能力，支持以下假设：至少在某种程度上,细菌选择性。大肠杆菌HB101和阴沟肠杆菌TW1在暴露于贾第虫EV时表现出对小肠上皮细胞的粘附/侵袭增加。用PKH67标记的EV显示与大肠杆菌HB101和阴沟肠杆菌TW1细菌细胞共定位。小RNA测序显示了高丰度的核糖体RNA（rRNA）和转移RNA（tRNA）衍生的小RNA，贾第鞭毛虫电动汽车内的短干扰RNA(siRNA)和微RNA(miRNA)。电动汽车的蛋白质组学分析揭示了RNA伴侣和热休克蛋白的存在，这些蛋白可以促进电动汽车及其sRNA货物的热稳定性，以及蛋白质修饰酶。体外，RNase热处理实验表明，电动汽车中的总RNA，但不是蛋白质，负责调节细菌游泳运动和生物膜形成。电动汽车的十二指肠小RNA，但不是蛋白质，是导致暴露于贾第虫EV后诱导的细菌与肠上皮细胞粘附增加的原因。一起,研究结果表明，贾第虫电动汽车含有热稳定的，RNase敏感的货物，可以触发肠杆菌的病理生物学特征的发展，描绘了肠道中的一种新颖的跨王国相声。
