Modelling Candida albicans infection of the human gut using human intestinal organoid cultures

白念珠菌被认为是人类最主要的真菌共生菌和病原体。白色念珠菌非常适合在健康的哺乳动物宿主中共生，但当宿主出现免疫缺陷、微生物失调和上皮损伤时，就会发生发病。人类肠道上皮细胞对白色念珠菌感染的敏感性还不是很清楚。肠道管腔因素，如饮食衍生和微生物代谢产物释放到管腔微环境中，很可能是易感性的驱动因素。目前，研究不得不依赖于小鼠模型或人类上皮细胞系；然而，这些并不能完全模仿人类的肠道。在这个项目中，将使用人类来源的肠道有机化合物，取代使用的小鼠模型。肠道对真菌感染的易感性的一个潜在因素是一种强有力的肠道毒素，即常见的真菌毒素食品污染物脱氧雪腐镰刀菌烯醇(DON)。DON针对人上皮细胞系和猪肠道外植体的肠道上皮屏障完整性和促炎信号。此外，在体外和体内，DON暴露都能促进肠道细菌易位和沙门氏菌和大肠杆菌等病原菌的全身感染。本项目旨在进一步发展我们的人源性肠道器官模型，以研究白色念珠菌与人肠道的相互作用，并阐明霉菌毒素DON对人肠道上皮细胞对白色念珠菌感染的易感性的影响。目的：1.建立肠道类器官模型，研究白色念珠菌与人肠道上皮细胞的相互作用。研究白色念珠菌对肠道屏障功能和促炎反应的影响。研究饮食来源的肠道真菌毒素(脱氧雪腐镰刀菌烯醇，DON)对白念珠菌上皮细胞反应的影响。方法：该项目将利用人类来源的肠道器官培养来评估白色念珠菌的肠道粘连和感染，并探索DON的潜在影响。将建立宿主-真菌共培养，并通过跨上皮电阻值、屏障蛋白表达和细胞因子释放的诱导来评估肠道功能。

Candida albicans is recognised as the most prominent fungal commensal and pathogen of humans. C. albicans is perfectly adapted for commensalism in healthy mammalian hosts, but pathogenesis occurs when hosts develop immunodeficiency, microbial dysbiosis and epithelial damage. Susceptibility of the human intestinal epithelium to C. albicans infection is not well understood. It is likely that intestinal luminal factors, such as diet-derived and microbial metabolites released into the luminal microenvironment, act as drivers of susceptibility. At present, studies have had to rely upon mouse models or human epithelial cell lines; however, these do not completely mimic the human gut. In this project human-derived intestinal organoids will be utilised, REPLACING use of mouse models. One potential contributor to intestinal susceptibility to fungal infection is a potent intestinal toxin, the common mycotoxin food contaminant deoxynivalenol (DON). DON targets intestinal epithelial barrier integrity and pro-inflammatory signalling in human epithelial cell lines and pig intestinal explants. Furthermore, DON exposure has been shown to facilitate intestinal bacterial translocation and systemic infection by pathogenic bacteria such as Salmonella and E. coli in vitro and in vivo. This project aims to further develop our human-derived intestinal organoid model to investigate interactions of C. albicans with the human gut and to elucidate the effect of the mycotoxin DON on the susceptibility of the human intestinal epithelium to C. albicans infection. Aims:1. Develop intestinal organoids model to study the interaction of C. albicans with human gut epithelium.2. Study the effect of C. albicans on intestinal barrier function and pro-inflammatory responses.3. Investigate the effect of a diet-derived intestinal mycotoxin (deoxynivalenol, DON) on epithelial responses to C. albicans.Methodology:The project will utilise human-derived intestinal organoid cultures to assess the intestinal adhesion and infection of C. albicans and to explore the potential effects of DON. Host-fungal co-cultures will be established and intestinal function will be assessed as using trans epithelial electrical resistance, barrier protein expression and induction of cytokine release.