Developing novel therapies to improve blood stem cell transplantation outcomes

项目摘要 急性移植物抗宿主病（acute Graft-versus-host disease，aGVHD）是一种常见的、致死性的异基因造血干细胞移植并发症。 干细胞移植（allo-HSCT），其中供体T细胞通过分泌 炎性细胞因子（TNF-α和IFN-γ）和/或诱导直接的细胞毒性细胞应答。尽管最近 尽管取得了进展，aGVHD仍然是一个主要的临床问题，强调需要进一步阐明其 然后开发新的治疗策略。在这项提案中，我们正在研究上皮细胞 生长因子样7（EGFL 7）作为aGVHD的潜在调节剂。EGFL 7是内皮细胞的阻遏物 活化，其在血管生成中起重要的生理作用。最近，也有文献记载 EGFL 7通过抑制内皮细胞活化在调节炎症中起重要作用， 对炎性细胞因子如TNF-α的反应。EGFL 7对内皮细胞活化的抑制作用 导致细胞粘附分子如ICAM-1、VCAM和E-选择素的表达减少， 导致炎性细胞向靶组织的粘附和外渗减少。根据这些数据， 我们假设allo-HSCT后EGFL 7水平的增加会降低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， 在两种不同的aGVHD鼠模型中，重组EGFL 7（rEGFL 7）降低了aGVHD的严重程度， 相对于对照，在同种异体移植后提高受体小鼠的存活率， 移植物抗白血病（GVL）效应。此外，我们发现rEGFL 7治疗导致更高的 异基因造血干细胞移植后受体小鼠胸腺细胞、T、B细胞和树突状细胞的变化。总体而言，我们的初步数据支持 EGFL 7在aGVHD调节中的作用。在本提案中，我们希望通过以下方式剖析这些机制： EGFL 7调节aGVHD并影响免疫BM重建，并进行临床前研究 使用rEGFL 7作为预防和治疗aGVHD的疗法。我们计划通过执行这些目标， 具体目的1：剖析EGFL 7调节aGVHD的机制， 影响免疫重建。在这个目标中，我们将系统地评估内皮细胞活化状态 和EGFL 7治疗后aGVHD鼠模型中的T细胞表型。此外，我们还将探讨 EGFL 7对T细胞功能和肠道干细胞有任何直接影响。最后，我们将研究EGFL 7 对免疫重建的影响具体目标2：使用rEGFL 7作为药物进行临床前研究。 预防和治疗aGVHD的方法。为此，我们希望进行初步毒理学、药代动力学 以及药效学研究，以选择预防和治疗aGVHD的最佳剂量和方案。此外，本发明还提供了一种方法， 我们想研究rEGFL 7疗法在类固醇难治性aGVHD鼠模型中是否有效。 影响：EGFL 7作为GVHD新疗法的鉴定将主要使接受同种异体移植的患者受益。 HSCT治疗血液系统恶性肿瘤。

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.