Recombinant TAT-BMI-1 fusion protein induces ex vivo expansion of human umbilical cord blood-derived hematopoietic stem cells.
Recombinant TAT-BMI-1 fusion protein induces ex vivo expansion of human umbilical cord blood-derived hematopoietic stem cells.
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DOI：
10.18632/oncotarget.15156
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发表时间：
2017-07-04
期刊：
影响因子：
--
通讯作者：
Morrone G
中科院分区：
文献类型：
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作者：
Codispoti B;Rinaldo N;Chiarella E;Lupia M;Spoleti CB;Marafioti MG;Aloisio A;Scicchitano S;Giordano M;Nappo G;Lucchino V;Moore MAS;Zhou P;Mesuraca M;Bond HM;Morrone G
造血干细胞（HSC）移植是治疗多种疾病的成熟方法。 HSC 通常源自细胞因子诱导动员后的骨髓或外周血。脐带血 (CB) 是一种颇具吸引力的 HSC 替代来源，但单个 CB 单位的数量较少限制了其应用。安全体外扩增 CB 衍生的 HSC (CB-HSC) 的策略的可用性可能允许扩大这些细胞在成年患者中的使用，并避免植入不足或造血恢复延迟的风险。在这里，我们描述了一种基于 CB-HSC 短暂暴露于重组 TAT-BMI-1 嵌合蛋白的体外扩增系统。 BMI-1 属于表观遗传修饰因子 Polycomb 家族，被认为是 HSC 自我更新的中央调节因子。细菌产生的重组TAT-BMI-1能够通过与BMI-1共价连接的HIV TAT衍生蛋白转导肽进入靶细胞，并保留其生物活性。重复添加 10 nM 纯化的 TAT-BMI-1 处理 CB-CD34+ 细胞 3 天，显着增强了总细胞扩增以及培养物中原始造血祖细胞的扩增。重要的是，TAT-BMI-1 处理的 CB-CD34+ 细胞在免疫功能低下小鼠的初次和二次异种移植中显示出持续较高的多谱系长期再增殖活性。因此，重组 TAT-BMI-1 可能代表一种新的、有效的试剂，用于离体扩增 CB-HSC 以达到治疗目的。
Transplantation of hematopoietic stem cells (HSCs) is a well-established therapeutic approach for numerous disorders. HSCs are typically derived from bone marrow or peripheral blood after cytokine-induced mobilization. Umbilical cord blood (CB) represents an appealing alternative HSC source, but the small amounts of the individual CB units have limited its applications. The availability of strategies for safe ex vivo expansion of CB-derived HSCs (CB-HSCs) may allow to extend the use of these cells in adult patients and to avoid the risk of insufficient engraftment or delayed hematopoietic recovery. Here we describe a system for the ex vivo expansion of CB-HSCs based on their transient exposure to a recombinant TAT-BMI-1 chimeric protein. BMI-1 belongs to the Polycomb family of epigenetic modifiers and is recognized as a central regulator of HSC self-renewal. Recombinant TAT-BMI-1 produced in bacteria was able to enter the target cells via the HIV TAT-derived protein transduction peptide covalently attached to BMI-1, and conserved its biological activity. Treatment of CB-CD34+ cells for 3 days with repeated addition of 10 nM purified TAT-BMI-1 significantly enhanced total cell expansion as well as that of primitive hematopoietic progenitors in culture. Importantly, TAT-BMI-1-treated CB-CD34+ cells displayed a consistently higher rate of multi-lineage long-term repopulating activity in primary and secondary xenotransplants in immunocompromised mice. Thus, recombinant TAT-BMI-1 may represent a novel, effective reagent for ex vivo expansion of CB-HSC for therapeutic purposes.