Myeloid Specific Targeted Nanoimunotherapy for Organ Transplant Acceptance

总结 在缺乏慢性免疫抑制治疗的情况下诱导移植物接受仍然是一个难以捉摸的目标， 器官移植移植免疫学家历史上曾试图通过以下方法来防止器官排斥反应： 开发靶向抗原呈递（信号1）、共刺激（信号2） 和/或细胞因子产生（信号3）。虽然使用这些新的方法已经获得了有希望的结果， 尽管靶向适应性免疫应答的方法学，长期移植物存活率仍然不理想。 最近的数据表明，先天免疫系统（巨噬细胞）启动移植排斥反应。一致 通过这些观察，我们的实验室最近发现了一种新的途径， 排斥，这是由巨噬细胞的表观遗传重编程介导的。最近发现的 巨噬细胞的功能状态被定义为“训练的免疫”，并由免疫调节因子积极调节。 哺乳动物雷帕霉素靶蛋白（mTOR）。同时调节巨噬细胞的分化和功能 虽然它是一种引人注目的治疗方法，但其诱导免疫耐受的应用仍然存在。 未经临床研究。 我们推测，诱导移植物长期存活的失败可能部分是由于缺乏治疗性的免疫抑制剂。 体内靶向骨髓细胞的方案。因此，开发针对先天性免疫疗法 体内免疫细胞和防止训练的免疫代表了一种有前途的方法，以促进长期 同种异体移植物存活率。为此，我们开发了靶向骨髓的高密度脂蛋白（HDL）纳米生物制剂， 细胞在体内并通过钝化mTOR途径来调节训练的免疫力。我们观察到这些mTORi- HDL纳米生物制剂防止有氧糖酵解和炎症细胞因子的表观遗传修饰 生产（信号3）与训练的免疫力。为了提高治疗效果，我们开发了一种 第二抑制性CD 40-TRAF 6特异性纳米生物学CD 40 i-HDL，其防止共刺激（信号2）。 值得注意的是，短期联合mTORi-HDL和CD 40 i-HDL纳米免疫治疗方案导致了 在无毒性或慢性移植物血管病变迹象的情况下无限期移植物存活。具有 描述了训练的免疫力可以通过HDL纳米颗粒负调节，以促进对 在“幼稚”小鼠中移植，我们建议评估我们的联合纳米免疫疗法在 影响移植器官长期功能的两种情况：感染和异敏化。

SUMMARY Induction of graft acceptance in the absence of chronic immunosuppressive therapy remains an elusive goal in organ transplantation. Transplant immunologists have historically attempted to prevent organ rejection by developing novel therapeutic approaches that target antigen-presentation (signal 1), co-stimulation (signal 2) and/or cytokine production (signal 3). While promising results have been obtained using these novel methodologies that target the adaptive immune response, long-term graft survival rates remain suboptimal. Recent data demonstrates that the innate immune system (macrophages) initiate transplant rejection. In line with these observations, our laboratory has recently discovered a novel pathway that contributes to allograft rejection, which is mediated by epigenetic reprograming of macrophages. This recently discovered macrophage functional state has been defined as “trained immunity” and is positively regulated by the mammalian target of rapamycin (mTOR). While regulation of macrophage differentiation and function represents a compelling therapeutic approach, its application to induce immunological tolerance remains unexplored clinically. We hypothesize that failure to induce long-term allograft survival may be due, in part, to the lack of therapeutic protocols that target myeloid cells in vivo. Therefore, the development of an immunotherapy that targets innate immune cells in vivo and prevents trained immunity represents a promising approach to facilitate long-term allograft survival. To this aim, we developed high-density lipoprotein (HDL) nanobiologics that target myeloid cells in vivo and regulate trained immunity by blunting the mTOR pathway. We observed that these mTORi- HDL nanobiologics prevented aerobic glycolysis and epigenetic modifications underlying inflammatory cytokine production (signal 3) associated with trained immunity. To enhance therapeutic efficacy, we developed a second inhibitory CD40-TRAF6 specific nanobiologic CD40i-HDL that prevents co-stimulation (signal 2). Remarkably, a short-term combined mTORi-HDL and CD40i-HDL nanoimmunotherapy regimen resulted in indefinite allograft survival with no signs of toxicity or chronic allograft vasculopathy. Having described that trained immunity can be negatively regulated by HDL nanoparticles to promote tolerance for transplantation in "naïve" mice, we propose to evaluate the robustness of our combined nanoimmunotherapy in two settings that compromise the long-term function of the transplanted organ: infection and allosenstization.