Inflammatory Cytokine Networks in Gastrointestinal Tract Graft Versus Host Disease

项目总结 移植物抗宿主病(GVHD)是与异基因移植相关的主要并发症。 造血干细胞移植。对胃肠道(GI)的损害 急性移植物抗宿主病是一种特别严重的事件，会导致严重的发病率和死亡率。 促炎性细胞因子在肠道移植物抗宿主病的病理生理学中起着关键作用，在一定程度上， 通过激活捐赠者的T细胞群，从而导致组织损伤。在预赛中 研究表明，GM-CSF是一种关键的细胞因子，在肿瘤的发生、发展中起重要作用。 胃肠道急性移植物抗宿主病的病理生理学研究这项提案的目标是定义 GM-CSF影响免疫的先天和适应性臂的机制 系统在移植物抗宿主病期间在这个组织部位引起炎症。我们的总体假设是 GM-CSF在胃肠道诱导促炎环境，而这 这种影响可归因于致病髓系细胞群体的招募和 同种异体反应性供者T细胞反应增强。对特定目标1的研究将 描述对GM-CSF信号有反应的固有细胞群，并定义 特异性GM-CSF反应细胞在介导胃肠道损伤中的作用 急性移植物抗宿主病。为了解决这个问题，我们将使用新型Csf2rbfl/fl小鼠，在这些小鼠中，高水平的 GM-CSF受体的亲和力β链具有侧翼的lox p位点，这将允许髓系 当与适当的特定血统的CRE动物繁殖时，细胞特异性缺失。实验在 特定目标2将定义GM-CSF影响T细胞介导的机制途径 免疫系统中的炎症和调节功能，从而调节严重程度 胃肠道中的GVHD。具体来说，我们将确定GM-CSF是否会诱导IL-23的产生 通过胃肠道供体来源的APC，检查CD4+T细胞来源的GM-CSF是否促进 供体来源的APC在结肠中间接提呈同种异体抗原，并确定GM-1的作用 脑脊液在移植物抗宿主病中调节T细胞亚群重建中的作用。具体的研究 AIM 3将确定CD4+GM-CSF+T细胞是否代表稳定的T细胞谱系，即 受白介素7(IL-7)信号调节。为了解决这个问题，我们将构建一部小说 GM-CSF命运报告鼠，将允许我们命运图谱免疫细胞群产生 GM-CSF，并确定其对IL-7的反应。这项提议的总体目标是发展 对胃肠道内移植物抗宿主病的病理生理学和调节的新见解 减少异基因造血干细胞移植中这一并发症的临床相关策略的发展 并改善血癌患者的预后。

PROJECT SUMMARY Graft versus host disease (GVHD) is the major complication associated with allogeneic hematopoietic stem cell transplantation (HSCT). Damage to the gastrointestinal (GI) tract from acute GVHD is a particularly serious event leading to significant morbidity and mortality. Proinflammatory cytokines play a critical role in the pathophysiology of intestinal GVHD, in part, by activating donor T cell populations which subsequently induce tissue damage. In preliminary studies, we have identified GM-CSF as a pivotal cytokine which plays an important role in the pathophysiology of acute GVHD in the GI tract. The goal of this proposal is to define the mechanistic pathways by which GM-CSF affects the innate and adaptive arms of the immune system to induce inflammation in this tissue site during GVHD. Our overall hypothesis is that GM-CSF induces a proinflammatory environment in the GI tract, and that this effect is attributable to the recruitment of pathogenic myeloid cell populations and the augmentation of alloreactive donor T cell responses. Studies in Specific Aim 1 will characterize the innate cell populations that are responsive to GM-CSF signaling and define the functional role of specific GM-CSF-responsive cells in mediating damage in the GI tract during acute GVHD. To address this question, we will employ novel Csf2rbfl/fl mice in which the high affinity beta chain of the GM-CSF receptor has flanking lox p sites, which will allow for myeloid cell-specific deletion when bred with appropriate lineage-specific Cre animals. Experiments in Specific Aim 2 will define mechanistic pathways by which GM-CSF affects T cell-mediated inflammatory and regulatory functions in the immune system, and thereby modulates the severity of GVHD in the GI tract. Specifically, we will determine whether GM-CSF elicits IL-23 production by donor-derived APCs in the GI tract, examine whether CD4+ T cell-derived GM-CSF promotes indirect alloantigen presentation by donor-derived APCs in the colon, and define the role of GM- CSF in the reconstitution of the regulatory T cell compartment during GVHD. Studies in Specific Aim 3 will determine whether CD4+ GM-CSF+ T cells represent a stable T cell lineage that is regulated by interleukin 7 (IL-7) signaling. To address this question, we will construct a novel GM-CSF fate reporter mouse that will allow us to fate map immune cell populations that produce GM-CSF and define their response to IL-7. The overall objective of this proposal is to develop new insights into the pathophysiology and regulation of GVHD within the GI tract that will foster the development of clinically relevant strategies to mitigate this complication in allogeneic HSCT recipients and improve outcomes in patients with blood cancers.