Strategies to promote Engraftment of Genetically Modified Hemopoietic

项目SUIVIMARY 某种形式的骨髓抑制对于移植的经过基因矫正的自体干细胞的有效和持久植入是必要的。温和的条件调节方案支持有效的植入，但不会让患者遭受不必要的毒性和风险，这是非常可取的，但这些方案尚未在大型动物或人类身上进行测试。在这个项目中，我们还建议在小鼠和灵长类临床前模型中研究两种这样的创新条件调节方案。建议的实验验证了这样一种假设，即低剂量辐射与抗体介导的干细胞功能损伤或干细胞动员剂的使用相结合，将促进基因校正的干细胞的植入。因此，低剂量辐射将在特定目标1与抗人c-kit治疗相结合，以减少干细胞/细胞祖细胞池，并在特定目标2与干细胞/祖细胞置换的动员剂相结合。辅助的 使用类似方案的初步实验将在小鼠身上进行，以提供指导和机制线索。由于不仅受体的调节对于增强植入是必要的，对供体细胞的创新治疗也是重要的。我们将在特定的目标3中解决这个问题。在这个特定的目标中，我们利用dmPGE2对体外孵育的小鼠或人类来源的细胞进行短期处理，并将它们移植到免疫抑制剂宿主(NOD/SCID)中。用dmPGE2处理前WVO的小鼠细胞和人类细胞的行为比较将在相同的免疫缺陷受体模型中进行，这也允许探讨机制问题。我们相信，这些实验的结果将对使用自体基因校正细胞的人类移植结果具有重要的临床意义。

PROJECT SUIVIMARY Some form of myelosuppression is necessary for effective and durable engraftment of transplanted genetically corrected autologous stem cells. Milder conditioning protocols which support efficient engraftment but do not subject patients to undue toxicity and risks are highly desirable, but these have not been tested in large animals or humans as yet. In this project we propose too investigate two such innovative conditioning regimens in murine and primate preclinical models. The proposed experiments test the hypothesis that low dose irradiation in combination with either Ab-mediated impairment of stem cell function or with the use of stem cell mobilizing agents will facilitate the engraftment of genetically corrected stem cells. Thus, low dose irradiation will be combined in Specific Aim 1 with anti-human c-kit treatment to reduce the stem/cell progenitor pool and in Specific Aim 2 with a mobilizing agent for displacement of stem/progenitor cells. Ancillary preliminary experiments using similar regimens will be conducted in mice to provide guidance and mechanistic clues. Since not only recipient conditioning is necessary for enhanced engraftment, innovative treatments of donor cells are also important. We will address this issue in Specific Aim 3. To enhance engraftment, in this Specific Aim we exploit short term treatment of in vitro incubated cells of murine or human origin with dmPGE2 and their transplantation in an immunodeticient host (NOD/SCID). Comparison of the behavior of murine vs. human cells treated ex wVo with dmPGE2 will be done in the same immunodeficient recipient model allowing also the approach of mechanistic issues. We believe that results from these experiments will have important clinical implications in transplantation outcomes in humans using autologous gene corrected cells.