Immunoregulatory Defects In Inflammatory Bowel Disease

炎症性肠病的免疫调节缺陷

• 批准号: 6674046
• 负责人: WARREN STROBER
• 金额: --
• 依托单位: NATIONAL INSTITUTE OF ALLERGY AND INFECTIOUS DISEASES
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/6674046
• 关键词: Crohn's disease; T cell receptor; confocal scanning microscopy; cytokine; enzyme linked immunosorbent assay; flow cytometry; helper T lymphocyte; human subject; immunopathology; immunoregulation; inflammatory bowel diseases; interferon gamma; interleukin 10; interleukin 12; intestinal mucosa; laboratory mouse; mucosal immunity; patient oriented research; tissue /cell culture; transforming growth factors

Project 1: Defined Th1 responses causing intestinal inflammation such as that occurring in SJL/J mice with TNBS-colitis offer an excellent opportunity to identify genetic loci (and ultimately defined genes) that are responsible for the colitis. This approach is facilitated by the fact that there is enormous mouse strain variability in susceptibility to TNBS-colitis: SJL/J mice and C57BL/10 mice are highly susceptible whereas C25BL/6 mice are highly resistant. Accordingly, we conducted an extensive genome-wide linkage analysis in F2 progeny of SJL/J and C57BL/6 mice by identifying susceptible and resistant progeny and then correlating that with multiple chromosomal markers associated with the two strains. This analysis led to the identification of two susceptibility loci, one on chromosome 9 and one on chromosome 11 called TNBS1 and TNBS2 respectively. Furthermore, while TNBS was strongly associated with disease in male mice, it was relatively weakly associated with disease in females. Conversely, while TNBS was strongly associated with disease in female mice, it was not associated with disease in male mice. However, further analysis of resistant male mice negative for TNBS1 revealed an association with TNBS2; thus, both male and female mice have a susceptibility locus on chromosome 11. Recognizing that locus on chromosome 11 contains the IL-12 gene, we conducted futher studies to identify IL-12 response abnormalities that might also map to this locus. Accordingly, we administered IP LPS to SJL/J and C57BL/6 mice and showed that whereas IL-12 p40 production induced by the LPS was equivalent in the two strains, the amount of IL-12 p70 was vastly greater in the SJL/J strain than in the C57BL/6 strain. We then conducted further genome-analysis to map this difference in responses and found that the ability to mount a high IL-12 p70 response mapped to the SJL/J chromosome 11 allele. Thus, these data were strongly suggestive that a genetic abnormality involving the IL-12 gene is partly responsible for susceptibility to TNBS-colitis. This conclusion was also supported by the fact that male C57BL/10 mice whose genome is 99% identical to that of C57BL/6 mice and differs largely at the chromosome 11 susceptibility region, is also susceptible to TNBS-colitis and mounts a high LPS-induced IL-12 p70 response. Finally, it is important to note that a human chromosome region on human chromosome 5 (5q33-34) syntenic to the TNBS2 on chromosome 11 has been linked to human Crohn?s disease: on this basis, TNBS2 may have relevance to the human disease.

项目1：定义的TH1反应引起了肠道炎症，例如在SJL/J小鼠中使用TNBS-Colisis发生的反应，这为鉴定遗传基因座（并最终定义的基因）提供了极好的机会，这些机会是导致结肠炎的。这种方法的易感性易于TNBS-Colisis：SJL/J小鼠和C57BL/10小鼠具有高度易感性，而C25BL/6小鼠具有高度抗性。因此，我们通过鉴定易感和抗性后代，然后将其与与两种菌株相关的多个染色体标记相关联，在SJL/J和C57BL/6小鼠的F2后代进行了广泛的全基因组连接分析。该分析导致了两个易感基因座的鉴定，一个分别在9号染色体上，一个在11号染色体上分别称为TNBS1和TNBS2。此外，尽管TNB与雄性小鼠的疾病密切相关，但它与女性疾病相对较弱。相反，虽然TNB与雌性小鼠的疾病密切相关，但与雄性小鼠无关。但是，对TNB1阴性的抗性男性小鼠的进一步分析显示，TNBS2有关联。因此，雄性和雌性小鼠在11号染色体上均具有易感性基因座。认识到11号染色体上的基因座包含IL-12基因，我们进行了FUTHER研究以识别可能也可能映射到该基因座的IL-12反应异常。因此，我们将IP LPS施加到SJL/J和C57BL/6小鼠中，表明LPS诱导的IL-12 p40产生在两种菌株中相当于SJL/J菌株的IL-12 p70的量要大得多。然后，我们进行了进一步的基因组分析以绘制这种反应差异，并发现将映射到SJL/J染色体11等位基因的高IL-12 p70响应的能力。因此，这些数据强烈暗示涉及IL-12基因的遗传异常是对TNBS-验证炎的易感性的部分原因。这一结论也得到了以下事实的支持：雄性C57BL/10小鼠的基因组与C57BL/6小鼠的基因组相同，并且在很大程度上在11号染色体易感性区域不同，也容易受到TNBS-Colitis的影响，并且具有高LPS诱导的IL-12 P70响应。最后，重要的是要注意，人类染色体上的人类染色体区域5（5q33-34）与TNBS2染色体11上的TNBS2同步与人类Crohn的疾病有关：在此基础上，TNBS2可能与人类疾病有相关的关系。