炎症性肠病（IBD）包括克罗恩病(CD)和溃疡性结肠炎(UC)，长期影响患者生活质量，复发率高。近年来我国IBD病例快速增长，但由于病因未明，目前尚无治愈方法。作为Th的镜像细胞，新近发现的固有淋巴细胞（ILC）受到广泛关注。其在肠道免疫中发挥重要作用，并是IBD中相关炎症因子的重要来源。研究表明，ILC2、3在IBD的炎症起始、维持、炎性细胞招募及下游获得性免疫激活中分别具有重要作用。目前，ILC分子机制研究主要集中于转录因子对其发育的影响，而相关其在肠道中的功能调控却知之甚少。干扰素调节因子IRF4在Th细胞分化及功能有重要作用，但其在肠道ILC中的分子机制还未见报道。本项目将构建IRF4条件性基因敲除小鼠来分析其对ILC发育和功能的影响，并通过建立IBD疾病小鼠模型和研究IBD患者肠道标本数据，从分子机制上阐明肠道固有层淋巴细胞在炎症性肠病中所发挥功能，进而为IBD治疗提供新的思路。

Inflammatory bowel disease (IBD), mainly including Crohn's disease (CD) and ulcerative tcolitis (UC), has high recurrence and a long-term affection of life quality. In recent years, there`s a rapidly increase of IBD cases in China. However, the exact cause remains unknown, which blocks the way to recovery.As the innate mirror image of T help cell, newly indentified ILCs are highly concerned. It is a necessary innate lymphocyte in intestinal immunity, and an important source of pro-inflammatory cytokines in IBD. Reports showed that ILC2, ILC3 ,which are major source of type 2 cytokines and IL-17 distinctly, play a key role in the initiation and maintenance of inflammation in UC and CD respectively.Now, the research of molecular mechanism in ILC transcription factors mainly focus on the influence of development, thus, very little is known about its regulatory function of ILC in gut. Though the Interferon regulator factor 4 (IRF4) is essential in the differentiation and cytokine production of T help cell, the molecular mechanism in intestinal ILC has not been report yet..Our project will generate IRF4 conditional knockout mice with strains such as hCD2cre mice to evaluate its influence of development and function in ILC, to illustrate the function of intestinal ILC through mice model of IBD. Also, with IBD patients intestinal sample data analyzing, we can provide new idea and method for IBD treatment.