Novel humanized mouse model developed from cord blood CD34 positive HSC and autologous iPS cell derived thymus

项目总结/摘要 人源化小鼠，即，免疫缺陷小鼠，其通过以下方式支持人类免疫系统的发育： 与人造血干细胞（HSC）的移植在临床前已经变得越来越重要 工具.然而，NSG小鼠的HSC移植导致H2限制性人T细胞的发育， 不能适当地与自体人HLA表达、抗原呈递细胞和B细胞相互作用， 外围。已经产生了NSG-HLA转基因小鼠来解决这个问题，但是HLA的库 特异性仅限于那些表达的和H2限制性的人T细胞继续产生， 小鼠胸腺人源化NSG小鼠中最强大的免疫系统是使用胎儿组织产生的， 骨髓/肝脏/胸腺模型。BLT模型的使用允许人T细胞在人T细胞上发育。 自体胸腺，并产生强大的HLA限制性人类免疫系统。然而，一些人类T 细胞仍然在鼠胸腺中发育，并且是H2限制性的，混淆了实验的解释。在 此外，使用人胎儿组织来产生人源化小鼠是复杂的，因为其有限的可用性， 是因为对组织获取的担忧为了提供基于胎儿组织的模型的替代方案， 我们建议利用通过人类细胞因子转基因杂交开发的新的无胸腺NSG小鼠品系， NSG小鼠与我们的无胸腺NSG-Foxn 1 null（裸）小鼠原种以及通过CRISPR/Cas直接靶向Foxn 1， 我们新的表达人类造血生长因子的NSG股票。我们将使用脐带血 iPS细胞产生人类胸腺结构，支持HLA限制性人类T细胞的体内发育 来源于自体脐带血HSC的细胞。对于这个多PI，多学科团队项目，我们建议 三个目的：1）生成并验证支持最佳植入的免疫缺陷小鼠的新模型， 在不存在鼠胸腺的情况下，人胸腺组织的HSC和功能; 2）产生并验证人 由iPS细胞产生的胸腺上皮和类器官; 3）比较产生的人类免疫系统 在我们的新模型与BLT模型。我们的建议利用强大的新技术， 创建人源化小鼠的新模型，并建立在我们超过25年的生成，验证， 分享新的人源化小鼠模型。我们相信，我们的创新方法，结合我们的 多学科协作团队将确保开发这种急需的临床前模型， 人源化小鼠，其不依赖于使用人胎儿组织。而且舒尔茨医生在杰克逊酒店 实验室，这些小鼠模型将被开发，促进他们的快速分配给科学 社区和独特的定位，我们实现本计划宣布的既定目标。

PROJECT SUMMARY/ABSTRACT Humanized mice, i.e., immunodeficient mice that support the development of human immune systems by engraftment with human hematopoietic stem cells (HSCs) have become increasingly important preclinical tools. However, HSC engraftment of NSG mice results in the development of H2-restricted human T cells that cannot interact appropriately with autologous human HLA-expressing, antigen-presenting cells and B cells in the periphery. NSG-HLA transgenic mice have been generated to address this, but the repertoire of HLA specificities is restricted to only those expressed and H2-restricted human T cells continue to be generated in the murine thymus. The most robust immune system in humanized NSG mice is created using fetal tissues, the BLT (bone marrow/liver/thymus) model. Use of the BLT model permits human T cell development on an autologous thymus and generates robust HLA-restricted human immune systems. However, some human T cells still develop in the murine thymus and are H2-restricted, confounding interpretation of the experiments. In addition, the use of human fetal tissue to create humanized mice is complicated by its limited availability and by concerns surrounding procurement of the tissues. To provide an alternative to fetal tissue-based models, we propose to utilize novel athymic NSG mouse strains developed by crosses of human cytokine trangenic NSG mice with our athymic NSG-Foxn1null (nude) mouse stock and by CRISPR/Cas targeting Foxn1 directly in our new NSG stocks expressing human hematopoietic growth factors. We will use umbilical cord blood-derived iPS cells to create human thymus structures that will support in vivo development of HLA-restricted human T cells derived from autologous cord blood HSCs. For this multi-PI, multi-disciplinary team project, we propose three Aims: 1) Generate and validate new models of immunodeficient mice that support optimal engraftment of HSCs and function of human thymic tissues in the absence of murine thymus; 2) Generate and validate human thymic epithelium and organoids generated from iPS cells; 3) Compare the human immune system generated in our new models with the BLT model. Our proposal takes advantage of powerful new technologies for creating new models of humanized mice, and builds on our >25 year track record for generating, validating, and sharing novel models of humanized mice. We believe that our innovative approaches, combined with our multi-disciplinary collaborative team will ensure the development of this much-needed preclinical model of humanized mice that does not rely on use of human fetal tissues. Furthermore, Dr. Shultz is at The Jackson Laboratory where these mouse models will be developed, facilitating their rapid distribution to the scientific community and uniquely positioning us to achieve the stated goals of this program announcement.