ICAM1 gene inactivation protects against ischemic injury

所有的同种异体实体器官移植都会在体外保留一段时间。虽然这一体外阶段会导致不受欢迎的缺血性损伤，但它确实为集中和有效的基因转移提供了一个独特的窗口，可以提高移植物和受体的存活率。移植物功能延迟和原发无功能仍然是移植中的顽固性问题，并与慢性排斥反应导致的晚期移植物失败有关。缺血/再灌注损伤(IRI)是一种重要的抗原非依赖性因子，在这些临床实体的发病机制中起着重要作用。我们已经开发了一种嵌合表达载体，可以在原位产生丰富的反义/核酶调节分子，并已被证明有效。这项工作的目的是通过高效地将嵌合转基因导入同种异体移植物，为选择性灭活导致IRI的单个基因创造条件。黏附分子ICAM-1被选为开发这一基因治疗策略的模型靶基因，因为有令人信服的证据表明，它是导致IRI的一系列促炎介质的重要触发分子。我们的假设是，体外传递旨在产生抗ICAM-1调节分子的嵌合转基因将抑制内皮细胞中ICAM-I的表达，并消除或改善缺血器官的IRI。我们希望通过合理的方法设计嵌合结构并在体外进行测试，以期建立在同种异体移植中抑制ICAM-1和IRI途径中其他重要分子的要求和条件。病毒和非病毒方法都将被开发用于大鼠肾脏IRI模型，以传递有效的ICAM-1抑制转基因。由于这种抑制方法所基于的技术比以前采用的策略更有效和更特异，因此它具有作为一种强大的治疗剂和询问基因功能的替代遗传工具的巨大潜力。这项工作对通过体外基因转移选择性灭活同种异体移植物的基因功能具有重要意义。

All solid organ allografts are maintained for some period of time outside of the body. While unwelcome ischemic injury results from this ex vivo phase, it does offer a unique window for focused and efficient gene transfer that could improve graft and recipient survival. Delayed graft function and primary nonfunction remain recalcitrant problems in transplantation and have been associated with late graft failure due to chronic rejection. Ischemia/reperfusion injury (IRI) is an important antigen-independent factor that can contribute to the pathogenesis of these clinical entities. We have developed a chimeric expression vector that generates abundant antisense/ribozyme regulatory molecules in situ and has proven efficacy. The goal of this work is to establish the conditions for the selective inactivation of individual genes responsible for IRI through the efficient ex vivo delivery of our chimeric transgene into allografts. The adhesion molecule ICAM-1 has been chosen as a model target gene to develop this gene therapy strategy because there is compelling evidence that it is an important trigger molecule for cascades of proinflamatory mediators responsible for IRI. Our hypothesis is that the ex vivo delivery of a chimeric transgene designed to produce anti- ICAM-1 regulatory molecules will inhibit the expression of ICAM-I in endothelial cells and abrogate or ameliorate IRI in an ischemic organ. Using a rational approach to designing chimeric constructs and testing them in vitro, we hope to establish the requirements and conditions for inhibition of ICAM-1 and other important molecules in the IRI pathway in transplanted allografts. Both viral and nonviral approaches to delivering effective ICAM-1 inhibitory transgenes will be developed for use in a rat renal IRI model. Because this method of inhibition is based on technology that is more potent and specific than strategies previously employed, it possess great potential as both a powerful therapeutic agent and a surrogate genetic tool for interrogating gene function. This work has important implications for the selective inactivation of gene function in allografts through ex vivo gene transfer.