Tec kinase ITK-dependent signaling pathways in the resolution of inflammation in ulcerative colitis

我们对Itk和Itk相互作用蛋白的初步研究是在SFB1181的最后一个资助期完成的。我们发现Tec激酶ITK调节IBD和实验性结肠炎中t细胞细胞因子的产生，从而维持粘膜炎症并随后阻止疾病愈合。有趣的是，ITK信号在UC而非CD患者中被激活，并阻止T细胞凋亡，以及诱导T细胞特异性细胞因子。此外，ITK是免疫抑制药物CsA的靶点，用于UC的临床治疗。UC和CD中ITK信号通路激活不同的原因以及衔接蛋白或信号分子在ITK信号通路中的作用有待进一步研究。在本项目中，我们旨在进一步了解ZAP70、Lck和TIM1/3分子在粘膜炎症中对ITK表达和功能的调控作用，以及对T细胞特异性细胞因子产生的调控作用。此外，我们将研究这些蛋白在UC患者大队列以及慢性肠道炎症小鼠模型中的表达。我们将使用转基因小鼠（完全和t细胞特异性缺失）来研究这些蛋白质在体内急性和慢性肠道炎症中的功能作用。此外，我们将使用中和抗体、siRNA或TIM3配体（如半乳糖凝集素-9）调节实验性结肠炎中ZAP70、Lck和TIM1/3的功能。在转化实验中，我们将在细胞培养中测试ZAP70、ITK、Lck和TIM1/3特异性抑制剂对UC患者粘膜T细胞活化的影响。最后，我们将使用T细胞/肠道类器官培养以及组织切片培养来确定这些抑制剂的作用，以研究ITK通路依赖的细胞因子产生和屏障功能的调节。综上所述，这些研究应该为ITK通路在控制炎症反应中的功能作用提供新的见解，并为溃疡性结肠炎的治疗提供新的治疗方法。

Our initial studies on Itk and Itk-interacting proteins were obtained in the last funding period of the SFB1181. We found that the Tec kinase ITK regulates T-cell cytokine production in IBD and experimental colitis, thereby maintaining mucosal inflammation and subsequently preventing disease healing. Interestingly, ITK signalling was activated in UC but not CD patients, and prevented T cell apoptosis as, well as inducing T cell specific cytokines. Furthermore, ITK is a target of the immunosuppressive drug CsA, which is used for clinical therapy of UC. The reason for the different activation of the ITK signalling pathway in UC and CD as well as the role of adaptor proteins or signalling molecules in the ITK signalling pathway needs further investigation. In this project, we aim to gain further insights into the regulatory role of the molecules ZAP70, Lck and TIM1/3 in controlling ITK expression and function in mucosal inflammation, as well as in controlling the production of T cell-specific cytokines. In addition, we will investigate the expression of these proteins in large cohorts of UC patients as well as in mouse models of chronic intestinal inflammation. We will use genetically modified mice (complete and T-cell specific deletion) for these proteins to study their functional role in acute and chronic intestinal inflammation in vivo. Moreover, we will modulate the function of ZAP70, Lck and TIM1/3 in experimental colitis using neutralising antibodies, siRNA or TIM3 ligands, such as galectin-9. In translational experiments, we will test the effect of specific inhibitors of ZAP70, ITK, Lck and TIM1/3 on the activation of mucosal T cells derived from UC patients in cell cultures. Finally, we will determine the effects of these inhibitors using T cell/intestinal organoid cultures as well as tissue section cultures to investigate ITK pathway-dependent regulation of cytokine production and barrier function. Taken together, these studies should provide new insights into the functional role of the ITK pathway in controlling the inflammatory response and lead to novel therapeutic approaches for the treatment of ulcerative colitis.