Ex Vivo Culture of Umbilical Cord Blood Stem Cells for Adult Transplantation

描述（由申请方提供）：本提案的总体目标是描述体外无血清培养条件，以扩增来自冻存脐带血细胞的CD 34+细胞至支持其在成人移植环境中使用的水平。脐带血用于成人移植的缺点已被归因于脐带血中的长期移植细胞/造血干细胞太少。本文中提出的研究表明，可以基于1）开发临床级无血清培养基来避免该问题，所述临床级无血清培养基特别指定用于源自脐带血的CD 34+细胞的离体扩增，2）使用临床级血清将来自冷冻保存的脐带血的CD 34+细胞成功扩增至足以支持成人移植的水平-具有早期作用细胞因子、Flt-3配体、干细胞因子、血小板生成素和白细胞介素6的游离培养基，和3）这些离体培养的CD 34+细胞在用于人造血的胎羊模型中长期移植的能力。I期里程碑将是重复和扩展这些初始研究，并评估这些培养的CD 34+细胞在更多动物中的长期移植能力，并评价更长的培养期。这些关键结果将形成II期提案的基础，以确定1）长期移植细胞是否在这些离体无血清培养条件下扩增或维持，2）确定产生高质量长期移植细胞的最佳培养期，以及3）评价其他细胞因子与上述细胞因子平台的组合。扩增长期移植细胞的能力在成人移植环境中是无价的。这项建议的努力将产生临床相关数据的最佳条件下使用冷冻保存的脐带血成人移植。.本提案衍生的产品将支持来自冻存脐带血的CD 34+细胞的离体培养，并维持这些细胞的长期移植能力。由于脐带血具有很少的长期移植细胞/造血干细胞，它只能用于婴儿移植，而不是成人移植。开发支持长期移植细胞扩增的无血清临床级培养系统的能力将促进这些细胞在成人移植中的临床应用。

DESCRIPTION (provided by applicant): The overall goal of this proposal is to delineate the ex vivo serum-free culture conditions to expand CD34+ cells derived from cryopreserved umbilical cord blood cells to levels that will support its use in the adult transplant setting. The disadvantage of umbilical cord blood for adult transplants has been attributed to having too few long-term engrafting cells/hematopoietic stem cells in the cord blood. Studies presented herein suggest that this problem can be circumvented based on 1) the development of a clinical grade serum-free medium designated especially for the ex vivo expansion of CD 34+ cells derived from cord blood, 2) the successful expansion of CD 34+ cells from cryopreserved umbilical cord blood to levels adequate to support adult transplantation using the clinical grade serum-free medium with the early acting cytokines, Flt-3 ligand, stem cell factor, thrombopoietin, and Interleukin 6, and 3) the ability of these ex vivo cultured CD 34+ cells to engraft long-term in the fetal sheep model for human hematopoiesis. The Phase I milestone will be to repeat and extended these initial studies and assess the long-term engrafting ability of these cultured CD 34+ cells in increased numbers of animals and evaluate longer culture periods. These critical results will form the basis of the Phase II proposal to determine if 1) the long-term engrafting cells are being expanded or maintained under these ex vivo serum-free culture conditions, 2) define the optimal culture period yielding high quality long-term engrafting cells, and 3) evaluate other cytokines in combination with the above cytokine platform. The ability to expand the long-term engrafting cells would be invaluable in the adult transplant setting. The efforts from this proposal will yield clinically relevant data on the optimal conditions necessary for use of cryopreserved cord blood for adult transplantation. . The products derived form this proposal will support the ex vivo culture of CD34+ cells derived from cryopreserved umbilical cord blood and the maintenance of these cells ability to engraft long-term. Since cord blood has few long-term engrafting cells /hematopoietic stem cells it can only be used for infant transplantation, not adult transplantation. The ability to develop a serum-free clinical grade culture system that will support the expansion of the long-term engrafting cells will facilitate the clinical use of these cells in adult transplants.