Clinical Grade Cultured Rare Red Blood Cells as Reagents and Future Transfusion Support

 描述（由申请人提供）：慢性贫血输血治疗的一个主要问题是，与大多数献血者为白色欧洲人相比，亚洲和非洲背景人群的血型抗原遗传多样性程度较高。红细胞上的这些多态性抗原导致同种免疫的高发生率和这些患者血清中多种抗体的存在。鉴定这些抗体的特异性并确定它们是自身抗体还是同种抗体对于提供相容性血液至关重要。本申请的主要目标是利用通过扩增造血干细胞和造血祖细胞体外生产培养红细胞（cRBC）的进展，与稀有血型遗传表征的进展一致，开发试剂cRBC，以鉴定高流行供体抗原的临床显著抗体的存在。试剂cRBC将促进高度同种免疫多次输血患者的抗体鉴定，并简化和标准化检测。 我们设计了一个由6名具有罕见血型表型的供体组成的小组，该小组足以解决在具有自身抗体和同种抗体的患者中观察到的大多数抗体鉴定问题，并且可以用于输注由于缺乏适当的稀有血液而目前无法输注的患者。在目标1中，我们提出开发新的培养方法，以通过顺序扩增HSC、HPC和成红细胞区室来扩增从外周血收集的或从iPSC分化的造血细胞。我们还建议从这6个供体中产生诱导多能干细胞，并设计一种O，Rh无效的iPSC系，其可用作试剂红细胞，并可用作输血的“通用”细胞。 从外周血或从iPSC产生的cRBC上的表面抗原的表达尚未被广泛表征。在目标2中，我们建议将cRBC与来自同一供体的天然红细胞进行比较，以确定它们是否适合作为试剂细胞和用于输血。我们将重点关注cRBC在传统血库检测中的抗原谱、基因型、储存稳定性和性能。 重要的是，我们将生产的试剂cRBC是同种免疫患者输血短缺的相同细胞。因此，我们拟进行的方法开发和质量检测将为生产足量的稀有cRBC用于挽救生命的输血治疗铺平道路，并确定第一个特定应用，即试剂红细胞的生产，以及第一个人类适应症，即在没有其他选择的情况下为SCD患者提供输血支持。

 DESCRIPTION (provided by applicant): A major problem for transfusion therapy for chronic anemia is the high degree of genetic diversity in blood group antigens in people of Asian and African backgrounds compared to white Europeans, who are the majority of blood donors. These polymorphic antigens on RBCs contribute to the high incidence of allo-immunization and presence of multiple antibodies in the serum of these patients. Identifying the specificity of thes antibodies and determining if they are auto- or allo- antibodies is critical for providing compatibe blood. The major goal of this application is to take advantage of the progress that has been made in the in vitro production of cultured red blood cells (cRBCs) by expansion of hematopoietic stem cells and hematopoietic progenitor cells, coincident with the progress made in the genetic characterization of rare blood groups, to develop reagent cRBCs to identify the presence of clinically significant antibodies to high prevalence donor antigens. Reagent cRBCs will facilitate antibody identification in highly allo-immunized multiply transfused patients, and streamline and standardize testing. We have designed a panel of 6 donors with rare blood group phenotypes that are sufficient to resolve most antibody identification problems seen in patients who have auto- and allo-antibodies, and that could be used to transfuse patients who currently cannot be transfused because of shortage of appropriate rare blood. In Aim 1, we propose to develop new culture methods to expand hematopoietic cells collected from peripheral blood or differentiated from iPSCs by sequential amplification of the HSC, HPC and erythroblast compartments. We also propose to generate induce-pluripotent stem cells from these 6 donors and to engineer a group O, Rh null line of iPSCs that are useful as reagent red cells and that could be used as "universal" cells for transfusion. Expression of surface antigens on cRBCs produced from peripheral blood or from iPSCs has not been extensively characterized. In Aim 2, we propose to compare cRBCs to native red blood cells from the same donor to determine if they would be suitable as reagent cells and for transfusion. We will focus on the antigenic profiles, the genotypes, the storage stability, and the performance of cRBCs in traditional blood bank assays. Importantly, the reagent cRBCs that we will produce are the same cells that are in short supply for transfusion of allo-immunized patients. The method development and the quality testing that we propose to perform will therefore pave the way to the production of sufficient amounts of rare cRBCs for life saving transfusion therapies and define the first specific application, production of reagent red cells, and the first human indication, transfusion support for SCD patients without other options.