Using trained immunity-inhibiting nanobiologics to achieve tolerance of heart allografts in non-human primates

摘要--项目3 在非人灵长类动物(NHP)和人类中，通过结合 非清髓性预适应和供者骨髓移植导致一过性混合造血 嵌合体。然而，相同的方案未能在NHP心脏接受者中诱导耐受性。其原因是 这种免疫学的二分法尚不清楚，但阐明其潜在的机制可能会为新的策略提供依据。 实现耐受同种异体移植物的耐受性(目标1)。尽管同种异体心脏移植带来了免疫障碍，但我们 最近开发了一种新的方案，首次诱导了对完全MHC的长期耐受 食蟹猴不匹配的同种异体心脏移植。我们取得这一显著成果是通过将 供肾联合移植的暂时性混合嵌合体方案。供体肾脏的存在是 与减轻炎症和增强宿主调节机制有关。因为牺牲了一个肾 单纯实现同种异体心脏移植在人类心脏受体中的耐受性是站不住脚的，我们现在寻求一种有效的替代品 用于肾脏联合移植(目标2)。最近，我们的团队报告说，在器官移植之后， 同种异体移植物中的巨噬细胞表现出与训练的功能状态相关的明显的表观遗传学特征。 豁免权。经过训练的免疫已被确认为事实上的先天免疫记忆，其特征是代谢 以及先天免疫细胞的表观遗传变化，导致它们的高反应性。受过训练的巨噬细胞 具有增强炎症细胞因子反应和上调共刺激分子的作用，这 从而诱导更有效的适应性免疫反应。重要的是，我们的团队设计了一种髓系 选择性抑制训练免疫同时促进调节的细胞特异性纳米免疫疗法 该研究已在小鼠和最近的猴子体内实现了同种异体心脏移植物的长期存活。 基于这些发现，我们假设：1)训练免疫有助于心脏的耐受性。 2)训练有素的免疫抑制纳米疗法将产生一种抗炎/促炎症- 将促进心脏耐受的调节环境，而不需要肾脏联合移植。我们将测试 项目3中的这些假设。项目2中的小鼠研究将通过提供补充的、在- 心脏和肾移植受者训练性免疫的深度机制分析及新训练者的识别 免疫抑制靶点(由Core B开发)值得在NHP中测试。核心C将提供最先进的 分子分析和专业知识，以机械地确定1)如何诱导训练有素的免疫，2)作用 训练有素的免疫在耐受诱导中观察到的器官特异性差异中发挥了作用，以及3)我们的治疗方法 受过冲击训练的豁免权。我们预计，这些高度互动的项目将共同产生新的和 创新的治疗策略，以防止排斥反应和更有效地实现免疫耐受。如果 如果成功，这些研究可能会影响整个移植领域，并提供也可能 骨髓移植和自身免疫性疾病的换野。

SUMMARY – PROJECT 3 Kidney allograft tolerance has been achieved in nonhuman primates (NHPs) and humans by combining nonmyeloablative conditioning and donor bone marrow transplantation resulting in transient mixed hematopoietic chimerism. However, identical protocols have failed to induce tolerance in NHP heart recipients. The reason for this immunological dichotomy is unknown but elucidating its underlying mechanisms could inform new strategies for achieving tolerance of resistant allografts (Aim 1). Despite the immune barriers posed by heart allografts, we have recently developed a novel protocol that has, for the first time, induced long-term tolerance of fully MHC mismatched heart allografts in cynomolgus monkeys. We attained this remarkable result by combining a transient mixed chimerism protocol with donor kidney co-transplantation. The presence of the donor kidney was associated with diminished inflammation and enhanced host regulatory mechanisms. Since sacrificing a kidney allograft simply to achieve tolerance in human heart recipients is untenable, we now seek an effective substitute for kidney co-transplantation (Aim 2). Recently, our team reported that following organ transplantation, macrophages in the allograft display distinct epigenetic signatures associated with the functional state of trained immunity. Trained immunity has been identified as de facto innate immune memory characterized by metabolic and epigenetic changes in innate immune cells, resulting in their hyperresponsiveness. Trained macrophages have heightened inflammatory cytokine responses and upregulated costimulatory molecules, which consequently induce more potent adaptive immune responses. Importantly, our team has designed a myeloid cell-specific nanoimmunotherapy that selectively inhibits trained immunity while promoting regulatory mechanisms and has achieved long-term cardiac allograft survival in mice and, more recently, in monkeys. Based on these findings, we hypothesize that 1) trained immunity contributes to the tolerance resistance of heart versus kidney allografts, and 2) trained immunity-inhibiting nanotherapy will generate an anti-inflammatory/pro- regulatory milieu that will facilitate heart tolerance without the need for kidney co-transplantation. We will test these hypotheses in Project 3. Murine studies in Project 2 will guide Project 3 by providing complementary, in- depth mechanistic analyses of trained immunity in heart and kidney recipients and also identifying new trained immunity-inhibiting targets (developed by Core B) worthy of testing in NHPs. Core C will provide state-of-the-art molecular assays and expertise, to determine mechanistically 1) how trained immunity is induced, 2) the role trained immunity plays in the organ-specific differences observed in tolerance induction, and 3) how our therapies impact trained immunity. We anticipate that together, these highly interactive Projects will generate new and innovative therapeutic strategies to prevent rejection and more effectively achieve immune tolerance. If successful, these studies could impact the entire field of transplantation and provide insights that could also be field-changing for bone marrow transplantation and autoimmune disease.