Fas ligand+ cells to reduce transplant rejection

描述（由申请人提供）：本申请的目的是对PAR-03-063进行补充（“NHLBI人类胚胎干细胞研究竞争性补充”）是为了使我的实验室，这与人类胚胎干细胞（HESC）线之前几乎没有经验的工作，以加强我们的现有目标，我正在进行的NHLBI赠款（R2.1HL72229：“Fas配体 * 血细胞减少移植排斥”），目前正在使用原代小鼠和人淋巴造血干祖细胞（HSC）进行研究。 我正在进行的资助的总体目标是研究慢病毒（LV）转导的HSC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）HSC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对此进行研究，并阐明同种免疫细胞中的凋亡途径。由于转导的FasL？HSC在体内可能具有潜在毒性，因此我们建议研究限制潜在FasL毒性的技术。一种新的FasL细胞治疗方法，以减少移植排斥反应，最终可能会用于临床同种异体血液和骨髓移植（BMT）。此外，预期实现稳定的淋巴-造血嵌合体会产生对移植的同种异体器官的耐受性，这在目的3中进行了探索。可以操纵HESC以产生血细胞，并且已经提出了HESC衍生的HSC的造血移植，并在小鼠中说明了原理证明。由于免疫排斥是临床上使用同种异体HESC（包括HESC衍生的HSC）的主要障碍，因此我们的下一个合乎逻辑的步骤是研究FasL转导的HESC衍生的HSC/DC是否可能减少同种异体免疫应答。这种使用HESC线显然是我们正在进行的赠款的目标和目的的范围和逻辑延伸。事实上，我们在最初的申请中没有提出这一点，只是因为我们当时完全没有HESC的实践经验，而HESC系当时非常难以获得。在本补充申请中，涉及HESC的实验仅限于特异性目标2.2（假设2.2：FasL？HSC及其后代将删除攻击同种异体反应性效应T细胞-在本补充申请中扩展以研究HESC衍生的“HSC”）。

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").