Generation of immunologically invisible organs through ex vivo MHC silencing to prevent rejection in a miniature swine lung transplantation model

通过离体 MHC 沉默生成免疫学上不可见的器官，以防止小型猪肺移植模型中的排斥反应

• 批准号: 396049657
• 负责人: Professorin Dr. Constanca Figueiredo
• 金额: --
• 依托单位: Institut für Transfusionsmedizin und Transplantat Engineering
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2018
• 资助国家: 德国
• 起止时间: 2017-12-31 至 2021-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/396049657?language=en
• 关键词: Generation; immunologically; invisible; organs; through

Currently, lung diseases occupy the rank 4 of the leading cause of death worldwide with an increasing prevalence and incidence. Lung transplantation is a highly successful therapy for patients with end-stage pulmonary disease, which is, however, hampered by frequent and early development of chronic rejection and high rate of opportunistic infections. Disparities between donor and recipient at the loci of the human leukocyte antigen (HLA) remain the main cause for immune rejection events and the need for strong immunosuppression. Previously, we have shown the feasibility to permanently suppress HLA expression in different cell and tissue types using RNA interference technology. Recently, we have shown in rat and mouse models that MHC-silenced cells are able to escape a humoral and cellular allogeneic immune rejection. The low MHC levels achieved using specific shRNAs allowed to prevent antibody-mediated, T- and NK-cell cytotoxicity. Hence, this project aims to reduce the immunogenicity of the lung by silencing MHC expression to improve graft survival after allogeneic transplantation. As the endothelium of a vascularized solid organ triggers and serves as the main target to the allogeneic immune response, we will focus on the downregulation of MHC class I and II expression on the lung endothelium during ex vivo lung perfusion (EVLP). A lentiviral vector will be used for the delivery of MHC-specific shRNA into the lung endothelial cells. Here, the protocol to achieve the permanent genetic engineering of the lung endothelium using the EVLP platform will be optimized. An established miniature swine lung transplantation model will be used to evaluate whether silencing SLA expression on the organ endothelium supports lung survival after allogeneic transplantation, by preventing acute and chronic rejection, even in the absence of immunosuppression. This interdisciplinary proposal has the potential to open a new horizon in the field of lung transplantation and a might be easily expanded to other solid organs.

目前，肺部疾病已成为世界范围内的第四大死因，其患病率和发病率均呈上升趋势。肺移植是治疗终末期肺部疾病的一种非常成功的治疗方法，然而，慢性排斥反应的频繁和早期发展以及机会性感染的高发生率阻碍了终末期肺部疾病的治疗。供者和受者在人类白细胞抗原(人类白细胞抗原)基因座上的差异仍然是免疫排斥事件和需要强有力的免疫抑制的主要原因。此前，我们已经证明了使用RNA干扰技术永久抑制不同细胞和组织类型的人类白细胞抗原表达的可行性。最近，我们在大鼠和小鼠模型中表明，MHC沉默的细胞能够逃避体液和细胞同种异体免疫排斥反应。低MHC水平使用特定的shRNA可以防止抗体介导的T细胞和NK细胞的细胞毒性。因此，本项目旨在通过沉默MHC的表达来降低肺的免疫原性，以提高异基因移植后的移植物存活率。由于血管化实体器官的内皮细胞是同种异体免疫反应的主要靶点，我们将重点关注体外肺灌流(EVLP)过程中肺内皮细胞MHC-I和MHC-II类表达的下调。慢病毒载体将被用于将MHC特异性shRNA运送到肺内皮细胞。在这里，利用EVLP平台实现肺内皮永久基因工程的方案将得到优化。一个已建立的小型猪肺移植模型将被用来评估即使在没有免疫抑制的情况下，沉默器官内皮细胞上的SLA表达是否通过防止急性和慢性排斥反应来支持同种异体移植后的肺存活。这一跨学科的建议有可能为肺移植领域开辟一个新的视野，并可能很容易扩展到其他实体器官。