Lymphothrombosis in gut health and disease

项目摘要 与其他地方的淋巴系统不同，胃肠道中的淋巴系统转运吸收的脂质， 对肠道微生物组中数十亿细菌的免疫监视。这种特殊功能被认为 需要独特的遗传和分子特征，但很少有这样的专门特征已被确定。 我们的初步研究使用了一种新的PAR 1-Tango转基因小鼠品系来证明高凝血酶活性 特别是在肠道的淋巴管中，这一发现与内皮抗- 血栓调节蛋白（THBD）和内皮蛋白C受体（EPCR）在肠道特异性表达 淋巴管内皮细胞（LECs）。在THBD或EPCR的诱导型、全局LEC缺失后，我们观察到， 纤维蛋白血栓形成，特别是在胃肠道疾病中，与来自肠道的淋巴液流量减少有关， 通过抗生素治疗逆转表型以减少肠道细菌。我们还检测到纤维蛋白血栓形成， 野生型动物在被肠道细菌病原体沙门氏菌或 耶尔森氏菌这些研究确定了一种新的体内凝血机制，淋巴血栓形成， 肠淋巴管，并且必须由肠LEC调节以维持正常的肠淋巴功能。的 该提案的目标将使用新的分子和遗传工具，以（i）充分定义 （ii）测试GI淋巴血栓形成是否以及如何与 肠道微生物群，和（iii）确定胃肠道感染期间肠道淋巴血栓形成的作用。我们预测， 研究将揭示血管系统外血栓形成的一种新机制， 并且在健康和疾病的肠道代谢中具有重要的功能作用。

Project Summary Unlike lymphatics elsewhere, the lymphatic system in the GI tract transports absorbed lipids and enables immune surveillance of the billions of bacteria in the gut microbiome. Such specialized functions are thought to require unique genetic and molecular characteristics, but few such specialized features have been identified. Our preliminary studies use a new line of PAR1-Tango transgenic mice to demonstrate high thrombin activity specifically in the lymphatic vessels of the gut, a finding consistent with high expression of the endothelial anti- thrombotic proteins thrombomodulin (THBD) and endothelial protein C receptor (EPCR) specifically in gut lymphatic endothelial cells (LECs). Following inducible, global LEC deletion of THBD or EPCR, we observe fibrin thrombus formation specifically in GI lymphatics that is associated with reduced lymph flow from the gut, phenotypes reversed by antibiotic treatment to reduce gut bacteria. We also detect fibrin thrombus formation in the gut lymphatics of wild-type animals following infection by the enteric bacterial pathogens Salmonella or Yersinia. These studies identify a new in vivo clotting mechanism, lymphothrombosis, that is highly specific for gut lymphatic vessels and that must be regulated by gut LECs to maintain normal gut lymphatic function. The aims of this proposal will use novel molecular and genetic tools to (i) fully define the process of lymphothrombosis in the gut lymphatic vasculature, (ii) test whether and how GI lymphothrombosis is linked to gut microbiota, and (iii) determine the role of gut lymphothrombosis during GI infection. We predict that these studies will reveal a novel mechanism of thrombosis outside of the blood vascular system that plays a unique and functionally important role in gut lymphatics in both health and disease.