Development of novel therapy targeting innate immunity for Crohn's disease

克罗恩病（CD）是一种累及胃肠道的慢性炎症过程，以不连续和跨壁炎症为特征。虽然CD的病因尚不完全清楚，但越来越多的证据表明，局部免疫系统的失调在CD的发病机制中起着关键作用。来自人类和实验性小鼠结肠炎模型的研究表明，在CD中，局部免疫反应倾向于主要是T辅助细胞1型（Th1），并通过局部释放肿瘤坏死因子(TNF)-α、白细胞介素(IL)-12和IL-18等细胞因子来反映。在本研究中，我们试图建立从肠系膜淋巴结（MLN）中纯化树突状细胞的方法，并分析人CD的肠系膜淋巴结中的免疫级联反应。我们建立了从MLN中纯化树突状细胞的方法，采用密度梯度离心和CD3^+、CD11b^+和CD16^+细胞，然后用CD4^+进行阳性分离。从MLN中获得的细胞分析显示，与溃疡性结肠炎和对照组相比，CD MLN中DC1的比例增加，CD MLN中的CD4+ T淋巴细胞显示Th1谱。此外，我们试图通过使用IL-10缺陷（IL-10-/-）小鼠结肠炎模型来阐明巨噬细胞在肠道炎症中的作用，并证明肠道巨噬细胞异常分化亚群在th1显性慢性结肠炎中发挥关键作用，通过过量产生IL-12和IL-23来响应细菌。这些数据为IL-10-/-小鼠结肠炎发生过程中肠道巨噬细胞与肠道菌群的关系提供了新的见解。

Crohn's disease (CD) is a chronic inflammatory process involving the gastrointestinal tract, characterized by discontinuous and transmural inflammation. Although the etiology of CD is not fully understood, accumulating evidence suggests that dysregulation of the local immune system is pivotal in the pathogenesis of CD. Studies from humans and experimental murine colitis models indicate that in CD, the local immune response tends to be predominantly T helper cell type 1 (Th1) and is reflected by local release of cytokines such as tumor necrosis factor (TNF)-α, interleukin (IL)-12, and IL-18. However, it has not been elucidated what triggers the Th1 immune response in CD. In the present study, we attempted to establish the purification of dendritic cells from mesenteric lymph nodes (MLN) and to analyze the immune cascade in the mesenteric lymph nodes of human CD.We established the purification of dendritic cells from MLN by density gradient centrifugation and immunomagnetic depletion of CD3^+,CD11b^+ and CD16^+cells followed by positive isolation with CD4^+. The analysis of cells obtained from MLNs revealed that the proportion of DC1 was increased in the MLN of CD compared to ulcerative colitis and control and that CD4+ T lymphocytes from the MLN of CD show a Th1 profile.Furthermore, we tried to elucidate the roles of macrophages in intestinal inflammation by using an IL-10-deficient (IL-10-/-) mouse colitis model, and demonstrated that abnormally differentiated subsets of intestinal macrophage play a key role in Th1-dominant chronic colitis through excess production of IL-12 and IL-23 in response to bacteria. These data provide new insights into the intestinal macrophages to gut flora relationship in the development of colitis in IL-10-/- mice.