Agonism of DR3 for Enhanced Treg Cell Function in IBD

项目摘要 炎症性肠病（IBD）中的免疫介导的慢性炎症导致发作， 需要患者接受终身生物治疗。最近，在IBD疾病管理方面的努力已经取得了进展。 重点关注基于调节性T（Treg）细胞的治疗作为传统治疗的替代方案的潜力。Treg 细胞限制了对外来抗原和自身抗原的炎症反应， 在暴露于免疫刺激物时，有效抑制效应物TdR（eTdR）。尤其是那些 产生免疫抑制细胞因子白细胞介素10（IL-10），在人类和 鼠结肠炎然而，诱导和功能性增强这一亚群的信号还没有得到很好的理解， 这主要是因为它们的数量有限，并且没有合适的协议来区分它们， 体外在这里，我们已经确定了一个信号，增强扩增和维持IL-10+ eT细胞在体内， 和体外培养。死亡受体3（DR 3或TNFRSF 25）是肿瘤坏死因子受体超家族（TNFRSF） 由活化的T细胞组成性表达的成员，并且已发现其增强和抑制 免疫反应。我们已经发现，用DR 3激动剂抗体（aDR 3）治疗， 特异性地增强IL-10+ eT细胞的增殖和细胞存活。此外，治疗大大扩展 许多组织中的Treg细胞总数，但影响在肠道中最为深远。据我们所知， aDR 3扩增IL-10产生eT细胞的情况尚未被描述。该提案将决定 DR 3信号传导诱导肠TdR增加的机制（Aim 1），以及aDR 3 作为治疗结肠炎的治疗剂（目的2）。我们将利用一种新的缺乏DR 3的转基因小鼠模型， 特别是在THP中，以了解DR 3信号传导在肠Treg功能中的作用， 状态和发炎的结肠。通过使用我们的IL-10和Foxp 3双报告小鼠，我们将能够分层 通过IL-10能力，这将使我们能够表征DR 3 差异增强Treg细胞亚群。我们的中心假设是DR 3信号的作用是双重的， 它：（1）引发Treg细胞的效应表型;和（2）制定影响eTreg的特定程序 生存稳定和功能了解这种途径如何增强Treg细胞功能将具有广泛的- 不仅在IBD领域，而且在许多免疫介导的疾病的管理中也具有重要意义。 疾病

PROJECT SUMMARY The immune-mediated, chronic inflammation in inflammatory bowel disease (IBD) leads to flares that often require patients to be treated with life-long biologic therapy. Recently, efforts in IBD disease management have focused on the potential of regulatory T (Treg) cell-based therapy as an alternative to traditional treatments. Treg cells limit inflammatory responses to both foreign and self-antigens and can become further differentiated into potently suppressive effector Tregs (eTregs) upon exposure to immune stimuli. eTregs, especially those that produce the immunosuppressive cytokine interleukin 10 (IL-10), play a critical, mitigating role in both human and murine colitis. However, the signals that induce and functionally enhance this subset are not well understood, largely because they are limited in number and there have been no suitable protocols to differentiate them in vitro. Here, we have identified a signal that enhances the expansion and maintenance of IL-10+ eTregs in vivo and in vitro. Death receptor 3 (DR3 or TNFRSF25) is a tumor necrosis factor receptor superfamily (TNFRSF) member that is constitutively expressed by activated T cells and has been found to both enhance and suppress the immune response. We have found that treatment with an agonist antibody to DR3 (aDR3) significantly enhances the proliferation and cell survival specifically of IL-10+ eTregs. Additionally, treatment greatly expands total Treg cells in many tissues, but the effect is most profound in the intestine. To our knowledge, the observation that aDR3 expands IL-10 producing eTregs has not yet been described. This proposal will determine the mechanisms by which DR3 signaling induces increased intestinal Tregs (Aim 1), as well as the potential of aDR3 as a therapeutic in the treatment of colitis (Aim 2). We will utilize a novel transgenic mouse model that lacks DR3 specifically in Tregs to understand the role that DR3 signaling plays in intestinal Treg function in both the steady state and in the inflamed colon. By using our IL-10 and Foxp3 dual reporter mouse, we will be able to stratify Treg populations by IL-10 competency, which will allow us to characterize the mechanisms by which DR3 differentially enhances Treg cell subsets. Our central hypothesis is that the effect of DR3 signaling is two-fold in that it: (1) primes Treg cells for an effector phenotype; and (2) enacts a specific program that impacts eTreg survival, stability, and function. Understanding how this pathway augments Treg cell function will have broad- reaching implications not only in the field of IBD, but also in the management of a number of immune-mediated diseases.