Multitransgenic donor animals and new immunosuppressive strategies in preclinical experimental xenotransplantation models

HCD59、hDAF/siaGT、hTRAIL、人类白细胞抗原-E、人血栓调节蛋白和人血红素加氧酶-1转基因猪的建立为在体内探索克服迟发性异种移植排斥反应的新策略提供了可能性。进一步修饰供体器官(CTLA4-Ig，VIL-10)的效果将在以rAAV为载体的小鼠模型中进行研究。然后，将在同种异体心脏移植模型中研究rAAV介导的猪心脏基因转移。使用适当的体外灌流装置，将对项目II和III中产生的多重转基因和/或敲除的猪器官的治疗效果进行调查。此外，工作心脏模型允许对新靶点进行系统筛选，以克服急性血管排斥反应，方法是在接触人类血液后的不同时间点进行表达谱分析。在将转基因或多转基因猪心移植到灵长类动物体内的过程中，排斥反应和缺血再灌注损伤对微循环变化的影响将利用正交偏振光谱成像技术(OPSI)在体内进行可视化和量化。将使用环磷酰胺(减毒诱导疗法)、免疫吸附(GAS914)、抗人类白细胞抗原-DR抗体和他克莫司/西罗莫司的组合来研究新的免疫调节策略。

The generation of pigs transgenic for hCD59, hDAF/siaGT, hTRAIL, HLA-E, human thrombomodulin and human heme-oxygenase 1 offers the possibility to investigate new strategies to overcome delayed xenograft rejection in vivo. The effect of further modifications of the donor organs (CTLA4-Ig, vIL-10) will be investigated in a mouse model using rAAV as a vector. rAAV mediated gene transfer into porcine hearts will then be investigated in an allogeneic heart transplantation model. Using an appropriate ex-vivo perfusion set-up, multitransgenic and/or knock-out porcine organs generated in projects II and III will be investigated as to their therapeutic effectiveness. In addition, the working-heart model allows to perform a systematic screen for new targets to overcome acute vascular rejection by expression profiling at different time-points after exposure to human blood. During orthotopic transplantation of transgenic or multitransgenic pig hearts into primates the effects of both rejection and ischemia-reperfusion-injury on microcirculatory changes will be visualized and quantified in vivo using Orthogonal Polarization Spectral Imaging (OPSI). Novel immunomodulatory strategies will be investigated using a combination of cyclophosphamide (attenuated induction therapy), immunoadsorption (GAS914), anti HLA-DR antibodies and tacrolimus/ sirolimus.