Alloreactive and autoreactive immune-mediated mechanisms of impaired epithelial regeneration in the GI tract

肠道干细胞(ISCs)在免疫介导的胃肠道反应中被靶向和耗尽的程度。 肠道(Gl)损伤和免疫系统在调节ISC介导的再生中的作用很差 明白了。同样，虽然已知T细胞可以迁移到肠道，但它们在肠道中的特殊定位 在介导疾病时，组织和接近ISC间隔的情况在很大程度上是未知的。在协作中 与NIDDK赞助的肠道干细胞联盟一起，这项提议组建了一个多学科的团队 为了阐明免疫系统如何在肠道损伤和死亡过程中影响ISC间隔区 重建，以及评估克服这种损害和促进受伤人员康复的方法 上皮组织。我们的初步发现表明，ISCs及其调节再生的能力在 移植物抗宿主病(GVHD)引起的同种异体反应性损伤和调节性T细胞的自身反应性损伤 耗竭，免疫细胞和肠道类器官共培养可以用来建模和机械地 剖析这些过程。我们还发现白介素22(IL-22)是一种重要的免疫信号 系统增强ISC介导的损伤后再生。针对以下问题开发新的初步数据 评论家评论指出，我们的自身免疫模型反映了GVHD与效应器T细胞的急性激活 GI归巢分子的上调，活化的T细胞渗入胃肠道，并减少 IL-22治疗后的上皮损伤。F-652是Generon公司开发的一种新型重组人白细胞介素22二聚体，已经 在体内促进间质干细胞恢复和上皮再生的翻译潜力。其他新数据 证明我们的3D成像方法可以量化ISCs的丢失、ISC的特定侵袭 GVHD中血管整合素配体的定位。新的机械数据表明 MAdCAM-1阻断特异性地抑制T细胞的隐窝侵袭并保护ISCs，表明这一途径是 是ISC损伤的重要调节因素，而不仅仅是整个肠道迁移。 我们将检验以下假设：1)T细胞募集到ISC隔室，ISCs耗尽，和ISCs丢失 它们的再生能力是免疫介导的胃肠道上皮损伤的共同特征，2)IL-2 22给药可保护ISCs，促进损伤后再生。ISC的功能和损耗将是 用自身反应和同种异体反应实验方法进行评估，利用体内小鼠模型 小鼠和人肠道器官的系统自身免疫和移植物抗宿主病及体外培养 与UMC Utrecht的合作，他们的有机生物库，以及他们先进的ISC专业知识。IL-22治疗将 被评价为促进ISC功能的上皮靶向再生免疫疗法。目前还没有治疗方法 目前正在加速胃肠道免疫病理的恢复。这个项目将导致一个机械化的 了解ISC间隔和免疫系统之间的基本相互作用，打开了一个 通过保护ISCs和增强再生来治疗炎症性胃肠道疾病的新方向。

The extent to which intestinal stem cells (ISCs) are targeted and depleted during immune-mediated gastro- intestinal (Gl) damage and the role of the immune system in regulating ISC-mediated regeneration are poorly understood. Likewise, while T cells are known to migrate to the intestines, their specific localization within the tissue and proximity to the ISC compartment when mediating disease are largely unknown. In collaboration with the NIDDK-sponsored Intestinal Stem Cell Consortium, this proposal assembles a multi-disciplinary team to elucidate how the immune system can influence the ISC compartment during intestinal damage and regeneration, as well as to evaluate approaches to overcome such damage and promote recovery of injured epithelium. Our preliminary findings indicate that ISCs and their ability to mediate regeneration are lost during both alloreactive injury from graft vs. host disease (GVHD) and autoreactive injury from regulatory T cell depletion, and that co-cultures of immune cells and gut organoids can be used to model and mechanistically dissect these processes. We have also found that Interleukin-22 (IL-22) is an important signal from the immune system augmenting ISC-mediated regeneration after injury. New preliminary data developed in response to reviewer comments indicate that our autoimmunity model mirrors GVHD with acute activation of effector T cells and upregulation of GI homing molecules, infiltration of the GI tract with activated T cells, and reduced epithelial damage after IL-22 treatment. F-652, a novel rhIL-22 dimer developed by Generon Corp., has translational potential to promote ISC recovery and epithelial regeneration in vivo. Additional new data demonstrate that our 3-D imaging approach can quantify loss of ISCs, specific invasion of the ISC compartment, and localization of vascular integrin ligands in GVHD. New mechanistic data indicate that MAdCAM-1 blockade specifically inhibits T cell crypt invasion and protects ISCs, indicating this pathway to be an important regulator of ISC injury, and not just overall gut migration. We will test the hypotheses that 1) T cell recruitment to the ISC compartment, depletion of ISCs, and loss of their regenerative capacity are common features of immune-mediated epithelial injury in the GI tract and 2) IL- 22 administration can protect ISCs and promote regeneration after damage. ISC function and depletion will be evaluated with autoreactive and alloreactive experimental approaches, utilizing in vivo mouse models of systemic autoimmunity and GVHD as well as ex vivo cultures of mouse and human intestinal organoids in collaboration with UMC Utrecht, their organoid biobank, and their advanced ISC expertise. IL-22 treatment will be evaluated as an epithelial-targeted regenerative immunotherapy promoting ISC function. No therapy exists currently to accelerate GI recovery from immunopathology. This project will lead to a mechanistic understanding of fundamental interactions between the ISC compartment and the immune system, opening a new direction for treatment of inflammatory GI diseases by protecting ISCs and augmenting regeneration.