Developing novel therapies to improve blood stem cell transplantation outcomes

项目总结 急性移植物抗宿主病(AGVHD)是异基因造血系统常见的致死性并发症 干细胞移植(allo-HSCT)：供者T细胞通过分泌 炎性细胞因子(肿瘤坏死因子-α和干扰素-γ)和/或诱导直接细胞毒性细胞反应。尽管最近 尽管取得了进展，但aGVHD仍然是一个主要的临床问题，强调了进一步阐明其 然后开发新的治疗策略的机制。在这项提案中，我们正在调查上皮细胞 生长因子样蛋白7(EGFL7)作为aGVHD的潜在调节剂。Egfl7是一种内皮细胞抑制因子 激活在血管生成中起着重要的生理作用。最近，它也被记录在案 EGFL7通过抑制血管内皮细胞活化在调节炎症中发挥重要作用 对炎性细胞因子如肿瘤坏死因子-α的反应。EGFL7对内皮细胞活化的抑制作用 导致ICAM-1、VCAM和E-选择素等细胞黏附分子表达减少， 结果减少了炎症细胞对靶组织的黏附和外渗。根据这些数据， 我们假设，allo-HSCT后升高EGFL7水平将通过以下方式减轻aGVHD的严重程度 干扰T细胞向靶组织的迁移。我们的初步数据显示，治疗 在两种不同的aGVHD小鼠模型中应用重组EGFL7(REGFL7)可降低aGVHD的严重程度和 与对照组相比，异基因移植后受体小鼠的存活率提高，而不影响 移植物抗白血病(GVL)效应。此外，我们还表明，rEGFL7治疗会导致更高的 异基因造血干细胞移植后受体小鼠胸腺细胞、T、B细胞和树突状细胞总的来说，我们的初步数据支持 EGFL7在调节aGVHD中的作用。在这项提案中，我们想通过以下方式剖析这些机制 哪个EGFL7调节aGVHD和对免疫BM重建的影响并进行临床前研究 应用rEGFL7预防和治疗aGVHD我们正计划通过以下方式实现这些目标 具体目标1：剖析EGFL7调节aGVHD和 对免疫重建的影响。在这个目标中，我们将系统地评估内皮细胞的激活状态 EGFL7治疗后aGVHD小鼠模型的T细胞表型。此外，我们还将探讨是否 Egfl7对T细胞功能和肠道干细胞有任何直接影响。最后，我们将调查EGFL7 对免疫重建的影响。具体目标2：使用rEGFL7进行临床前研究 预防和治疗aGVHD的治疗。在这个目标中，我们想要进行初步的毒理学、药代动力学 并进行药效学研究，以选择预防和治疗aGVHD的最佳剂量和方案。此外, 我们想要研究rEGFL7治疗在激素难治性aGVHD小鼠模型中是否有效。 影响：将EGFL7确定为治疗GVHD的新疗法将主要受益于接受异基因移植的患者。 造血干细胞移植治疗恶性血液病。

PROJECT SUMMARY Acute Graft-versus-host disease (aGVHD) is a frequent and lethal complication of allogeneic hematopoietic stem cell transplantation (allo-HSCT) in which donor T cells destroy HLA mismatched host tissues by secreting inflammatory cytokines (TNF-α and IFN-γ) and/or inducing direct cytotoxic cellular responses. Despite recent advances, aGVHD still remains a major clinical problem, underscoring the need to elucidate further its mechanisms to then develop novel therapeutic strategies. In this proposal, we are investigating epithelial growth factor like 7 (EGFL7) as a potential modulator of aGVHD. EGFL7 is a repressor of endothelial cell activation which plays an important physiological role in angiogenesis. Recently, it has also been documented that EGFL7 plays a significant role in regulating inflammation by repressing endothelial cell activation in response to the inflammatory cytokines such as TNF-α. The repression of endothelial cell activation by EGFL7 results in reduced expression of cellular adhesion molecules such as ICAM-1, VCAM, and E-Selectin, which results in reduced adhesion and extravasation of inflammatory cells into target tissues. Based on these data, we hypothesized that increasing EGFL7 levels after allo-HSCT will diminish the severity of aGVHD by interfering with the migration of T cells to the target tissues. Our preliminary data showed that treatment with recombinant EGFL7 (rEGFL7) in two different murine models of aGVHD decreases aGVHD severity and improves survival in recipient mice after allogeneic transplantation with respect to controls without affecting graft versus leukemia (GVL) effect. Furthermore, we showed that rEGFL7 treatment results in higher thymocytes, T, B and dendritic cells in recipient mice after allo-HSCT. Overall, our preliminary data support a role for EGFL7 in the modulation of aGVHD. In this proposal, we would like to dissect the mechanisms by which EGFL7 modulates aGVHD and impact on immune BM reconstitution and to perform preclinical studies using rEGFL7 as a therapy to prevent and treat aGVHD. We are planning to achieve these goals by performing the following aims: Specific Aim 1: To dissect the mechanisms by which EGFL7 modulates aGVHD and impact on immune reconstitution. In this aim, we will systematically assess endothelial cell activation status and T cell phenotypes in murine models of aGVHD after EGFL7 therapy. Furthermore, we will explore whether EGFL7 has any direct effects on T cell function and intestinal stem cells. Last, we will investigate the EGFL7 effects on immune reconstitution. Specific Aim 2: To perform preclinical studies using rEGFL7 as a therapy to prevent and treat aGVHD. In this aim, we would like to perform initial toxicology, pharmacokinetics and pharmacodynamic studies to select the best dose and schedule to prevent and treat aGVHD. In addition, we would like to investigate whether rEGFL7 therapy is effective in a steroid refractory aGVHD murine model. Impact: The identification of EGFL7 as new therapy for GVHD will benefit primarily patients undergoing allo- HSCT to cure hematologic malignancies.