Lymphocyte Trafficking by Chemokines/Adhesion Molecules in Crohn's Disease

描述(由申请人提供)： 肿瘤坏死因子阻断治疗克罗恩病(CD)的成功导致了对其他生物疗法的系统研究。不幸的是，这些新疗法(如IL-10、IL-11阻断)的有效性受到了限制。因此，针对其他途径的慢性肠炎的替代生物疗法必须在CD中进行评估。我们认为，由于淋巴细胞黏附级联中的冗余，需要同时阻断两个或两个以上的肠道归巢黏附分子和/或趋化因子(即L-选择素、β7整合素、MAdCAM-1和CCR9)。因此，我们的中心假设是，通过靶向黏附分子/趋化因子的特定组合来干扰淋巴细胞的运输将导致慢性回肠炎在CD的TNFdeltaARE小鼠模型中的改善。 为了解决这一假设，我们提出了以下具体目标： 1.确定慢性小肠炎条件下淋巴细胞黏附级联的冗余。利用免疫组织化学、聚合酶链式反应、流式细胞仪和活体显微镜，我们将剖析慢性回肠炎中淋巴细胞迁移的途径，并确定支持淋巴细胞黏附和迁移的分子。 2.探讨肠归巢黏附分子/趋化因子在慢性回肠炎发病中的作用。我们将使TNFdeltaARE小鼠和TNFdeltaARE/Beta7-/-小鼠回交到缺乏L-选择素和CCR9的小鼠。 3.评价联合阻断黏附分子/趋化因子治疗慢性回肠炎的疗效。为了这个翻译目的，我们将使用特定的功能阻断单抗的组合，这些抗体可能会改善目前已经在临床试验中的抗α4或α4β7整合素阻断策略(即Natalizumab，MLN02)的有效性。 这项建议旨在为首席调查员提供各种实验室技术方面的丰富经验，如具体目标所列。两位专门研究粘膜免疫学(FC)和黏附分子(KFL)的导师的优势，以及实验所需的所有设备、试剂和小鼠品系的可用性，是我们机构独一无二的。这些经验将与严格的实验室和课堂教学计划相辅相成。鉴于人类CD和我们的小鼠模型中肿瘤坏死因子诱导的慢性回肠炎的相似之处，拟议的研究也可能为治疗这种毁灭性疾病的新的生物靶点提供重要的线索。

DESCRIPTION (provided by applicant): The success of TNF blockade for the treatment of Crohn's disease (CD) has lead to the systematic study of other biological therapies. Unfortunately, the usefulness of these newer therapies (e.g. IL-10, IL-11 blockade) has been limited. Therefore, alternative biological therapies that target other pathways of chronic intestinal inflammation must be evaluated in CD. We propose that due to redundancies in the lymphocyte adhesion cascade, simultaneous blockade of two or more gut-homing adhesion molecules and/or chemokines (i.e. L-selectin, beta7integrin, MAdCAM-1 and CCR9) will be required. Therefore, our central hypothesis is that interference with lymphocyte trafficking by targeting specific combinations of adhesion molecules/chemokines will result in amelioration of chronic ileitis in the TNFdeltaARE murine model of CD. To address this hypothesis we propose the following specific aims: 1. To identify redundancies of the lymphocyte adhesion cascade under conditions of chronic small intestinal inflammation. Using immunohistochemistry, PCR, flow cytometry and intravital microscopy we will dissect the pathways of lymphocyte trafficking in chronic ileitis and identify the molecules that support lymphocyte adhesion and migration. 2. To assess the role of gut-homing adhesion molecule/chemokines on the development of chronic ileitis. We will backcross TNFdeltaARE mice and TNFdeltaARE/beta7-/- mice to mice deficient for L-selectin and CCR9. 3. To evaluate the effectiveness of combinatorial blockade of adhesion molecules/chemokines for the treatment of established chronic ileitis. For this translational aim, we will use combinations of specific function-blocking monoclonal antibodies that may improve the effectiveness of current anti-alpha4- or alpha4beta7- integrin blockade strategies (i.e. Natalizumab, MLN02), already in clinical trials. This proposal is designed to provide the principal investigator with extensive experience in a variety of laboratory techniques, as listed on the specific aims. The strengths of 2 mentors that specialize in mucosal immunology (FC) and adhesion molecules (KFL), as well as the availability of all equipment, reagents and mouse strains required for the experiments is unique to our institution. These experiences will be complemented by a rigorous program of laboratory and classroom instruction. Given the similarities between human CD and the TNF-induced chronic ileitis in our mouse model, the proposed studies could also provide important leads for novel biological targets to treat this devastating disease.