Fas ligand+ cells to reduce transplant rejection

描述(申请人提供)：针对PAR-03-063(“NHLBI人类胚胎干细胞研究竞争性补充剂”)申请补充剂的目的是使我的实验室能够提高我正在进行的NHLBI拨款(R2.1 HL72229：“Fas配体*血细胞以减少移植排斥反应”)的现有目标，目前正在使用原代小鼠和人类淋巴造血干/祖细胞(HSCs)进行这项申请。我正在进行的资助的总体目标是研究慢病毒(LV)转导的HSCs或表达高水平Fas配体(FasL)的树突状细胞(DC)降低对同种异体抗原(Ag)的反应并增加同种异体(Allo)HSCs的植入的能力。在本提案的目标1-2中，我们建议在细胞免疫学和移植实验中研究这一点，并阐明同种异体免疫细胞中的凋亡途径。由于转导的FasL？HSCs在体内可能具有潜在的毒性，我们建议研究限制潜在的FasL毒性的技术。一种新的减少移植物排斥反应的FasL细胞治疗方法可能最终用于临床异基因血液和骨髓移植(BMT)。此外，稳定的淋巴细胞-造血嵌合体的实现有望为移植的同种异体器官产生耐受性，这在目标3中进行了探索。人类胚胎干细胞可以被操纵来产生血细胞，已经提出了HESC来源的HSCs的造血移植，并在小鼠身上进行了原理验证。由于免疫排斥是异基因hESCs(包括HESC来源的HSCs)临床应用的主要障碍，我们的下一个合乎逻辑的步骤是研究FasL转导的HESC来源的HSCs/DC是否会降低同种异体免疫反应。这种对HESC线路的使用显然在我们正在进行的赠款的目标和目的的范围内和合乎逻辑的延伸。事实上，我们在最初的申请中并没有提出这项建议，只是因为我们当时完全没有实际操作HESCs的经验，而HESC线路当时非常难以获得。在本补充应用中，涉及hESCs的实验限于特定目标2.2(假设2.2：FasL？HSCs及其后代将删除攻击同种异体反应性T细胞--在本补充中扩展以研究hESCs来源的“HSCs”)。

DESCRIPTION (provided by applicant): The purpose of this application for a supplement in response to PAR-03-063 ("NHLBI Competitive Supplements for Human Embryonic Stem Cell Research") is to enable my lab, which has little prior experience working with human embryonic stem cell (HESC) lines, to enhance our existing aims of my ongoing NHLBI grant (R2.1 HL72229: "Fas ligand* blood cells to reduce transplant rejection"), which is now being pursued using primary mouse and human lympho-hematopoietic stem-progenitor cells (HSCs). The overall goal of my ongoing grant is to investigate the ability of lentivirally (LV) transduced HSCs or dendritic cells (DCs) expressing high levels of Fas ligand (FasL) to reduce the response to alloantigen (Ag) and increase engraftment of allogeneic (allo) HSCs. In Aims 1-2 of this proposal, we proposed to investigate this in cellular immunology and transplant experiments, as well as to elucidate the apoptotic pathways in alloimmune cells. Since transduced FasL ¿ HSCs might potentially be toxic in vivo, we proposed to investigate technologies to limit potential FasL toxicity. A novel FasL ¿ cell therapy approach to reduce graft rejection might eventually be used in clinical allo blood and marrow transplantation (BMT). Furthermore, achievement of stable lympho-hematopoietic chimerism would be predicted to generate tolerance for transplanted allo organs, which is explored in Aim 3. HESCs can be manipulated to generate blood cells, and hematopoietic transplants of HESC-derived HSCs have been proposed with proof-of-principle illustrated in mice. Since immunologic rejection is a major barrier to use of allo HESCs (including HESC-derived HSCs) clinically, a next logical step for us is to investigate whether FasL transduced HESC-derived HSCs/DCs might reduce the alloimmune response. This use of HESC lines is clearly within the scope and a logical extension of the goals and objectives of our ongoing grant. Indeed, we did not propose this in the initial application only because we had absolutely no hands-on experience with HESCs at that time, and HESC lines were then extremely difficult to obtain. In this supplement application, the experiments involving HESCs are confined to Specific Aim 2.2 (Hypothesis 2.2: FasL ¿ HSCs and their progeny will delete attacking alloreactive effector T cells -- extended in this supplement to investigate HESCs-derived "HSCs").