Targeted conditioning to maximize prenatal HSC engraftment for SCD

针对性调节以最大限度地提高 SCD 的产前 HSC 植入

• 批准号: 10654382
• 负责人: Graca Duarte Almeida-Porada
• 金额: $ 71.66万
• 依托单位: WAKE FOREST UNIVERSITY HEALTH SCIENCES
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-07-01 至 2027-06-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10654382
• 关键词: ALCAM gene; Achievement; Acute; Acute Disease; Adult; Allogenic; Animal Model; Animals; B-Lymphocytes; Biological Models; Birth; Blood; CD34 gene; Cell Separation; Cells; Characteristics; Child; Chronic; Chronic Disease; Clinical; Clustered Regularly Interspaced Short Palindromic Repeats; Communities; Development; Dipeptidyl-Peptidase IV; Disease; Disease model; Electrophoresis; Engraftment; Exhibits; Fetal Development; Fetal Hemoglobin; Fetal Sheep; Fetus; Genes; Genetic Diseases; Goals; Head; Hematological Disease; Hematopoietic Cell Growth Factors; Hematopoietic Stem Cell Transplantation; Hematopoietic Stem Cell subsets; Hematopoietic stem cells; Hemoglobin; Hemoglobinopathies; Homing; Human; IL2RG gene; Immune; Incidence; Infant; Infection; Inherited; Intervention; Life; Medical; Modeling; Monitor; Mus; Mutation; NCAM1 gene; Natural Killer Cells; Nature; Other Genetics; Pain; Patients; Pattern; Peptide Hydrolases; Phenotype; Play; Population Study; Procedures; Proto-Oncogene Protein c-kit; Resistance; Resources; Risk; Role; Sheep; Sheep Diseases; Sickle Cell; Sickle Cell Anemia; Solubility; Stroke; Stromal Cell-Derived Factor 1; Symptoms; T-Lymphocyte; Testing; Therapeutic; Time; Treatment Efficacy; World Health Organization; acute chest syndrome; antibody conjugate; beta Globin; clinically relevant; compliance behavior; conditioning; curative treatments; disease phenotype; economic implication; efficacy testing; fetal; fetal immunity; human disease; in utero; in utero transplantation; infancy; knock-down; lung injury; novel; novel strategies; novel therapeutic intervention; novel therapeutics; prenatal; sheep model; sickle cell crisis; sickling; side effect; small hairpin RNA; somatic cell nuclear transfer; statistics; stem cell engraftment; stressor; success; therapeutic evaluation; translational model

PROJECT ABSTRACT: Treatment of genetic disorders by in utero transplantation (IUTx) has safely been performed for decades in humans. The first IUTx cure, in the US, used hematopoietic stem cells (HSC) and corrected a child with X-SCID. Since this groundbreaking moment >25 yrs. ago, >50 patients have now been treated with this procedure for 14 different genetic disorders. However, for reasons that are still not well understood, full therapeutic success has only been achieved in X-SCID patients. Thus, a better understanding of the mechanisms by which HSC engraftment is hindered after IUTx is required, so that strategies can be developed to achieve therapeutic levels of HSC engraftment in other genetic disorders, such as hemoglobinopathies, that could benefit from IUTx. We and others have identified several characteristics of the developing fetus that may negatively impact its ability to serve as an amenable HSC recipient. Among these factors are competition from highly proliferative host HSC, more significant fetal immune barriers than initially known, and the degree of maturity and receptivity of nascent BM niches required for engraftment of donor (adult) HSC. Here, using fetal sheep as a model, we propose to: (Aim1) define the nature of, and overcome, the barriers to engraftment by using non-genotoxic conditioning to dissect the role that niche availability, host HSC competition, and fetal immunity play in the engraftment of adult donor HSC following IUTx, and (Aim 2) determine the impact of the phenotype and functionality of the donor HSC on the levels of engraftment following IUTx. We hope that, upon completion of these first 2 Aims, we will not only have identified the mechanisms involved in resistance to HSC engraftment, but we will also have achieved a minimum target of 20-25% HSC engraftment, which would allow IUTX to become a viable therapeutic approach for hemoglobinopathies. Among these, sickle cell disease (SCD) is the most common inherited blood disorder in the US, and one of the diseases that could benefit from IUTx, since even though the fetus is protected from sickling by the presence of fetal hemoglobin (Hb), clinical manifestations of SCD start during early infancy, placing the child at risk of complications such as stroke, splenic crisis, pain episodes, life-threatening infections, and episodes of acute chest syndrome, which can cause permanent lung damage. Of direct relevance to SCD, sheep exhibit the same developmental pattern of fetal to adult Hb switching as humans. Recently, using CRISPR/ Cas editing and subsequent somatic cell nuclear transfer, we produced SCD sheep with a disease phenotype mirroring that of human patients, displaying sickled cells in blood smears, positive Hb solubility test, and HbS detected by Hb electrophoresis. In Aim 3, we propose to validate the sheep SCD model by monitoring the animals over time, determining the stressors that induce sickle cell crises, and defining acute and chronic disease complications. In addition, we will test the therapeutic efficacy of IUTx for treating/curing SCD. Upon completion, we hope these studies will contribute to the development of novel strategies to achieve curative levels of HSC engraftment after IUTX and will validate a highly clinically relevant model for the SCD community in general.

项目摘要： 几十年来，通过子宫内移植 (IUTx) 治疗遗传性疾病已安全进行。 人类。第一个 IUTx 疗法在美国使用造血干细胞 (HSC) 并纠正了一名患有 X-SCID 的儿童。 自这一开创性时刻以来已经超过 25 年了。此前，超过 50 名患者已接受该手术治疗 14 年 不同的遗传疾病。然而，由于尚不清楚的原因，治疗已取得完全成功 仅在 X-SCID 患者中实现。因此，更好地了解 HSC 的机制 需要 IUTx 后，植入会受到阻碍，因此可以制定策略以达到治疗水平 其他遗传性疾病（例如血红蛋白病）中 HSC 移植的研究可能会受益于 IUTx。我们 和其他人已经确定了发育中胎儿的几个特征，这些特征可能对其能力产生负面影响 作为一个顺从的 HSC 接受者。这些因素包括来自高度增殖的宿主 HSC 的竞争， 胎儿免疫屏障比最初已知的更显着，以及新生婴儿的成熟程度和接受能力 供体（成人）HSC 植入所需的 BM 龛位。在此，以胎羊为模型，我们建议： （目标 1）通过使用非基因毒性调节来定义植入障碍的性质并克服这些障碍 剖析生态位可用性、宿主 HSC 竞争和胎儿免疫在成人植入中所起的作用 IUTx 后的供体 HSC，并（目标 2）确定供体表型和功能的影响 HSC 关于 IUTx 后的植入水平。我们希望，在完成这前两个目标后，我们将 我们不仅已经确定了与 HSC 植入抵抗有关的机制，而且我们还将 实现了 20-25% HSC 植入的最低目标，这将使 IUTX 成为一种可行的治疗方法 血红蛋白病的治疗方法。其中，镰状细胞病（SCD）是最常见的遗传性血液病 在美国，这种疾病是可以从 IUTx 中受益的疾病之一，因为即使胎儿受到保护 由于存在胎儿血红蛋白 (Hb)，SCD 的临床表现在婴儿早期就开始出现， 让孩子面临中风、脾危象、疼痛发作、危及生命的感染等并发症的风险， 以及急性胸部综合征的发作，这可能导致永久性肺损伤。与 SCD 直接相关， 绵羊表现出与人类相同的胎儿到成人血红蛋白转换的发育模式。最近，利用 CRISPR/ Cas编辑和随后的体细胞核移植，我们生产了具有疾病表型的SCD羊 反映人类患者的情况，在血涂片中显示镰状细胞、血红蛋白溶解度测试和 HbS 呈阳性 通过Hb电泳检测。在目标 3 中，我们建议通过监测绵羊 SCD 模型来验证 随着时间的推移，对动物进行分析，确定诱发镰状细胞危机的压力源，并定义急性和慢性疾病 并发症。此外，我们还将测试IUTx治疗/治愈SCD的疗效。完成后， 我们希望这些研究将有助于制定新策略以达到 HSC 的治疗水平 IUTX 后的植入，将为 SCD 群体验证一个高度临床相关的模型。