枯否细胞在大片形吸虫实验性感染小鼠诱导“炎-癌”进程的作用及其相关信号通路的研究

Fascioliasis is known as an important world-wide parasitic zoonosis. The excretory-secreted products of Fasciola gigantica (FgESP) has found to induce alternative activation of macrophage ex vivo, that could be an important factor for the immunoescape process of this parasite. However, the mechanism about how F.gigantica modulate the immunoregulation in vivo is still unclear. The aims of this study is to reveal the function and potential mechanism of kupffer cell during F.gigantica infection and its tumorgenesis possibility, to screen genes as early warning signs for F.gigantica-related cancer of liver or bile duct, and the potential mechanism of signal transduction and regulation, then finally provide knowledge and theory to support veterinary or medical research on anti-fascioliasis therapy or drug development in future. The methodology of this study includes: investigating the dynamic changes of biological and immunological functions of mice kupffer cells against F.gigantica in vivo and in vitro, and discussing the importance of kupffer cell during fascioliasis, as well as the interrelationships between kupffer cell, liver injury and tumorgenesis.

片形吸虫病是全球流行的重要人兽共患蠕虫病。大片形吸虫分泌排泄产物（FgESP）被发现能在体外诱导巨噬细胞的替代激活，对虫体免疫逃避起重要作用，但片形吸虫如何通过巨噬细胞诱导免疫调控的机制尚不明确。本项目拟基于小鼠-大片形吸虫感染模型和枯否细胞体外刺激模型，从基因、蛋白、细胞、组织病理学多方面研究枯否细胞在宿主急性和慢性感染期的生物学和免疫学特征的变化，探讨枯否细胞在大片形吸虫感染建立的重要性及其与肝损伤进程、“炎-癌”转变的内在联系，并对这些关键分子进行验证。旨在发现枯否细胞在大片形吸虫感染进程中的作用机制和组织发生癌症转化的可能性，发现一些该虫诱导的早期肝胆癌症具有预警作用的指示基因，以及信号传导和调控机制，为动物与人抗片形吸虫感染、抗肿瘤的策略和药物研发提供知识积累和理论支持。

研究枯否细胞（KC）在大片形吸虫感染建立及其参与肝脏病理损伤和进程发挥的作用，探讨大片形吸虫（Fg）及其分泌排泄产物（FgESP）介导KC/巨噬细胞TLR通路，有助于发现KC参与Fg感染病程的机制和致癌风险。本研究通过氯化钆体内耗竭的方式验证了KC对Fg感染和炎症病变的重要性。体外试验表明Fg童虫（NEJ）短暂作用可致KC或巨噬细胞M2型极化，促凋亡基因表达上调。FgESP 刺激可使巨噬细胞TLR1、3、7、8、MyD88、NF-κB表达上调，抑制FgESP中的LPS、酶蛋白则使MyD88、NF-κB、TRIF表达降低。小鼠感染Fg后肝脏发生持续炎症和氧化应激，促/抑纤维化、细胞增殖相关基因表达上调，TLR1、6、7、8、9基因在不同阶段表达上调，TRIF表达随病程升高。上述结果提示TLR通路呈动态变化。此外，筛选到Ki67、Caspase-3/9等多个 “炎-癌”进程相关基因可用于预测大片形吸虫潜在致癌风险。本研究为研究片形吸虫感染的“炎-癌”关系奠定了基础。