MUCOSAL T-CELLS IN EARLY&LATE PEDIATRIC CROHN'S DISEASE

提案(改编自申请人的摘要)：这个项目的总体目标 项目是从功能和表型上表征肠道粘膜T细胞 在新发病和长期克罗恩病(CD)的儿童中，以及 利用这些信息指导裁谈会新战略的制定 诊断、患者情况和早期医疗干预。CD是一种 胃肠道的终生慢性炎症性破坏 在青少年和年轻人中最常被诊断的一种疾病。 由于CD的病因仍未确定，诊断依赖于 在x线、内窥镜检查中发现的破坏性粘膜改变的鉴别 和/或组织组织学。最近的临床试验表明，早期 免疫调节剂治疗可改善CD的临床结局 儿童，但早期医疗干预可能会因诊断滞后而受阻 长达18个月。基础调查也显示出显著的差异 存在于“早期”和“晚期”之间的细胞和分子机制 肠道的慢性炎症，进一步强调了 在诊断时和长期存在的CD中都进行了调查。 在过去的四年里，调查人员进行了系统的 儿童内窥镜活检黏膜T细胞分离的研究 CD以及非炎症性肠病(IBD)炎症和 正常对照组。他们定义了T细胞体外生长的独特模式 和对白介素2(IL-2)反应的增殖，其中CD，粘膜T- 细胞在体外生长显著增强(J.PEDS，133：675- 81,1998)。最近对粘膜T细胞表型的流式细胞仪分析 免疫记忆标记物(CD45RA、CD45RO)和归巢(L- 选择素)区分慢性炎症的“早期”和“晚期” CD儿童。因此，这项提议的中心假设是： 粘膜T细胞功能和表型的鉴定将允许 及时诊断，并将其分为“早期”和“晚期”两个阶段 儿童CD的慢性炎症。这一假设将通过以下方式进行检验 以下三个具体目标。目标1是粘膜的特征 T细胞体外生长在CD早期诊断中的应用 对高危儿童进行验证、纵向跟踪和评估。目标2 是早期粘膜T细胞表型和功能的特征 分析粘膜T细胞亚群和细胞因子的产生。 目的3是评估早期免疫调节治疗对临床的影响。 新发病例的预后及其与粘膜T细胞表型和功能的相关性 对确诊的CD患者进行了24个月的纵向随访。因此，K23 指导以患者为导向的临床研究职业发展奖将不会 仅定义了免疫致病的基本领域 儿童CD的面积，它还将允许申请者获得关键的 执行高水平翻译所需的培训和专业知识 研究。

PROPOSAL (Adapted from the applicant's abstract): The overall goal of this project is to functionally and phenotypically characterize gut mucosal T-cells in children with new onset as well as longstanding Crohn's disease (CD), and use this information in guiding the development of new strategies for CD diagnosis, patient substratification and early medical intervention. CD is a devastating lifelong chronic inflammatory destruction of the gastrointestional tract that is most frequently diagnosed in adolescents and young adults. Because the cause of CD remains undefined, diagnosis relies on the identification of destructive mucosal changes identified on x-ray, endoscopy and/or tissue histology. Recent clinical trials suggest that early immunomodulator therapy results in an improved clinical outcome in CD children, but early medical intervention may be hindered by a lag in diagnosis of up to 18 months. Basic investigation also suggests significant differences exist in cellular and molecular mechanisms between "early" and "late" phases of chronic inflammation in the intestine, further emphasizing the need for investigation both at the time of diagnosis as well as in longstanding CD. Over the past four years, the investigators have conducted a systematic investigation of mucosal T-cells isolated from endoscopic biopsies in children with CD as well as non-inflammatory bowel disease (IBD) inflammation and normal controls. They have defined unique patterns of in vitro T-cell growth and proliferation in response to interleukin-2 (IL-2), where CD, mucosal T- cells demonstrate significantly enhanced in vitro growth (J. Peds., 133: 675- 81, 1998). Recent flow cytometric analysis of mucosal T-cell phenotype has shown that markers of immunologic memory (CD45RA, CD45RO) and homing (L- selectin) differentiate "early" and "late" phases of chronic inflammation in CD children. Thus, the central hypothesis of this proposal is: Characterization of mucosal T-cell function and phenotype will allow for prompt diagnosis as well as substratification into "early" and "late" phases of chronic inflammation in pediatric CD. This hypothesis will be tested with the following three specific aims. Aim 1 is the characterization of mucosal T-cell in vitro growth in the early diagnosis of CD, with cross-sectional validation, longitudinal follow-up, and evaluation of children at risk. Aim 2 is the characterization of mucosal T-cell phenotype and function during early and late CD with analysis of mucosal T-cell subsets and cytokine production. Aim 3 is to assess the impact of early immunomodulatory therapy on clinical outcome and correlate with mucosal T-cell phenotype and function in newly diagnosed CD patients over a 24-month longitudinal follow-up. Thus, the K23 Mentored Patient-Oriented Clinical Research Career Development Award will not only define fundamental areas of immunopathogenesis in the under-researched area of pediatric CD, it will also allow the applicant to obtain critical training and expertise required to perform high caliber translational research.