Modulation of spinal neurodegenerative diseases in swine by stem cell grafting

 描述(由申请人提供)：特定人类疾病的大型动物模型的发展和特征及其在临床前疗效和安全性研究中的有效利用，对于基于细胞替代的疗法成功地过渡到临床是至关重要的。根据所针对的疾病、细胞移植后存活的时间以及是否需要使用短暂或持续的免疫抑制，这些模型的常规使用与不同程度的技术/技术困难有关。除了使用大型动物模型时的一般考虑外，还存在特定的限制，这取决于要研究的病变器官系统和相关的功能损失。例如，在脊髓神经退行性疾病领域，仍然存在一些具体的挑战，包括：i)完全发育的截瘫表型的脊髓损伤动物的长期维持，ii)用于异种或异基因移植设计的可靠和安全的免疫抑制方案，以及iii)近交系动物的可用性，部分或完全MHC匹配的动物用于产生用于体内移植的同种或异基因神经前体细胞系(NSCs)。此外，细胞标记技术无法用于研究移植细胞在活体动物中存活/成熟的随时间的变化，以及在移植到单一动物受体后在不同产生的细胞群(例如，iPS来源的神经干细胞或胎儿组织来源的神经干细胞)中进行死后基因活性分析。这些方案/技术的开发对于优化和验证用于前瞻性人体试验的大型临床前模型和细胞衍生方案至关重要。通过使用完全或部分MHC相合的小型猪，我们首次提出了在幼稚的非免疫抑制或一过性免疫抑制的猪身上，已建立的猪iPS或胎儿组织来源的神经干细胞移植到腰髓后的存活、分化和基因活性的特征。其次，利用猪脊髓挫伤模型，确定同基因或异基因iPS和FT来源的神经干细胞脊髓移植后对运动功能恢复和相应移植细胞存活的治疗效果。

 DESCRIPTION (provided by applicant): The development and characterization of large animal models of specific human diseases and their effective utilization in preclinical efficacy and safety studies is essential for a successful transition of cell replacement- based therapies into clinic. Depending on the disease to be targeted, the duration of post-cell transplantation survival, and the need for use of transient or continuous immunosuppression, routine use of such models is associated with a variable degree of technical/technological difficulties. In addition to general consideration in using large animal models, specific limitations exist depending on the diseased organ system and associated functional loss to be studied. In the field of spinal neurodegenerative disorders, for example, several specific challenges remain, including: i) long-term maintenance of spinally injured animals with fully developed paraplegic phenotype, ii) reliable and safe immunosuppression protocols to be used in xenograft or allogeneic grafting design, and iii) the availability of inbred partially or fully MHC-matched animals for generation of isogeneic or allogeneic neural precursor lines (NSCs) to be used for in vivo grafting. In addition, cell labeling techniques which would permit to study time dependent changes in grafted cell survival/maturation in living animals and perform postmortem gene activity profiling in differentially generated cell populations (iPS-derived NSCs or fetal tissue-derived NSCs, for example) after grafting into a single animal recipient are not available. The development of these protocols/techniques is critical for optimization and validation of large preclinical models and cell derivation protocols to be used in perspective human trials. By using fully or partially MHC- matched miniature swine, we first propose to characterize the survival, differentiation and gene activity profile of established porcine iPS or fetal tissue-derived NSCs after grafting into the lumbar spinal cord in naïve non- immunosuppressed or transiently immunosuppressed swine. Second, using well characterized porcine model of spinal contusion injury, we will define the treatment effect after spinal grafting of isogeneic or allogeneic iPS an FT-derived NSCs on the recovery of motor function and corresponding grafted cell survival.