Myeloid Specific Targeted Nanoimunotherapy for Organ Transplant Acceptance

摘要 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实现的目标 器官移植。移植免疫学家历来试图通过以下方法预防器官排斥反应 开发以抗原提呈(信号1)、共刺激(信号2)为靶点的新治疗方法 和/或细胞因子产生(信号3)。虽然使用这些新颖的技术已经取得了很有希望的结果 以适应性免疫反应为目标的方法，移植物的长期存活率仍然不是最优的。 最近的数据表明，先天性免疫系统(巨噬细胞)启动了移植排斥反应。排队 通过这些观察，我们的实验室最近发现了一种有助于同种异体移植的新途径。 排斥，这是由巨噬细胞的表观遗传重新编程所介导的。这是最近发现的 巨噬细胞的功能状态被定义为“训练有素的免疫”，并受到 雷帕霉素的哺乳动物靶标(MTOR)。而巨噬细胞分化和功能的调节 代表了一种引人注目的治疗方法，但它在诱导免疫耐受方面的应用仍然 临床上未被探索过的。 我们推测，未能诱导同种异体移植物的长期存活，部分原因可能是缺乏治疗。 以体内髓系细胞为靶点的方案。因此，针对先天的免疫疗法的发展 体内免疫细胞和防止训练有素的免疫是一种有希望的方法，以促进长期 同种异体移植物存活率。为此，我们开发了针对髓系细胞的高密度脂蛋白(Hdl)纳米生物制剂。 细胞在体内，并通过钝化mTOR途径调节训练性免疫。我们观察到这些mTORi- 高密度脂蛋白纳米生物制剂防止炎症细胞因子的有氧糖酵解和表观遗传修饰 产生(信号3)与训练有素的免疫力有关。为了提高治疗效果，我们开发了一种 第二，抑制CD40-TRAF6特定的纳米生物CD40i-高密度脂蛋白，防止共刺激(信号2)。 值得注意的是，一个短期的mTORi-高密度脂蛋白和CD40i-高密度脂蛋白纳米免疫疗法的结果是 同种异体肾无限期存活，无毒性或慢性同种异体血管病变迹象。拥有 描述了训练免疫可以被高密度脂蛋白纳米粒负向调节以促进对 在“幼稚”的小鼠身上移植，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是：感染和异体过敏。

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.