Fetal Tolerance, Chimerism and Sickle Cell Disease ( Translational Study )

子宫内造血干细胞移植（IUHSCTx）是治疗卵巢癌的一种有前途的方法。 包括血红蛋白病在内的血液系统疾病。然而，在缺乏选择优势的情况下， 在正常细胞中，IUHSCTx的临床和实验努力通常导致有限的或不可检测的 植入，表明在造血竞争中存在植入的主要障碍。 收件人。本项目的长期目标是克服这些障碍，开发临床适用的 将植入增加到治疗水平的策略，以允许IUHSCTx的临床扩展到治疗 镰状细胞病（SCD）。我们已经开发了三种基于IUHSCTx的小鼠模型 诱导供体特异性耐受以产生高水平的混合造血嵌合体，跨越完整的MHC屏障， 不使用骨髓消融或免疫抑制。在这个应用程序中，我们计划利用捐助者的具体 耐受性，以创造高水平的嵌合体，使用既定的和新的战略，在多个模型！ 血红蛋白病，并确定什么水平的嵌合体是需要治愈SCD。具体目标是 建议：1）通过产前联合移植建立IUHSC移植后高水平的混合嵌合体 供体来源的HSC和免疫调节细胞群体的数量。特异性供体细胞 将在产前与HSC共移植群体以产生供体细胞的竞争优势。2)到 通过策略建立血红蛋白病受者IUHSCTx后的高水平混合性溶血 基于产前耐受诱导，以促进出生后使用非清髓性增强嵌合体 接近。在常规SCD中通过IUHSC Tx实现的有限混合嵌合体将被转换 通过非毒性治疗方案使供者出生后达到高水平或完全嵌合体。3)在非清髓的 SCD小鼠模型，什么水平的混合嵌合体足以防止镰状化 与SCD相关的危象和器官损伤法师。在小鼠体内产生不同水平的混合嵌合体的能力 结合SCD的表型和功能测定的鼠SCD模型应该允许以下问题： 嵌合体水平是完全治疗SCD所必需的。本建议中的研究包括 旨在测试改善SCD IUHSCTx后植入的策略，并将指导后续研究， 大型动物模型。

In utero hematopoietic stem cell transplantation (IUHSCTx) is a promising approach for the treatment of a varlet)' of hematologic disorders including the hemoglobinopathies. However, in the absence of a selective advantage for normal cells, clinical and experimental efforts at IUHSCTx have generally resulted in limited or no detectable engraftment, suggesting the existence of major barriers to engraftment in the hematopoietically competitive recipient. The long-term objective of this project is to overcome these barriers and develop clinically applicable strategies to increase engraftment to therapeutic levels to allow clinical expansion of IUHSCTx to the treatment of Sickle Cell Disease(SCD). We have developed three approaches in the mouse model based on IUHSCTx induced donor specific tolerance to create high level mixed hematopoietic chimerism, across full MHC barriers, without the use of myeloablation or immunosuppression. In this application we plan to exploit donor specific tolerance to create high level chimerism, using established and new strategies, in mufine models of ! hemoglobinopathy and to determine what levels of chimerism is required to cure SCD. The specific aims of this proposal are: 1) To establish high level mixed chimerism after IUHSCTx by the prenatal cotransplantation of donor derived HSC and immanomodnlatory cell populations. Specific donor cell populations will be cotransplanted with HSC prenatally to create a competitive advantage for donor cells. 2) To establish high level mixed ehimerism after IUHSCTx in the hemoglobinopathy recipient by strategies based on prenatal tolerance induction to facilitate postnatal enhancement of chimerism using nonmyeloablative approaches. Limited mixed chimerismachieved by IUHSCTx in routine SCD will be converted to high level or co,_lplete donor chimerism after birth by non-toxic regimens. 3) To establish in a nonmyeloablated murine model of SCD, what level of mixed chimerism is sufficient to prevent sickling crises and organ d_mage associated with SCD. The ability to create various levels of mixed chimerism in the murine SCD model combined with phenotypic and functional assays of SCD should allow the question of what level of chimerism is necessary to completely treat SCD to be addressed. The studies in this proposal are designed to test strategies to improve engraftment after IUHSCTx for SCD and will direct subsequent studies in a large animal model.