Novel Approaches to Inducing Lung Allograft Tolerance in NHPs

项目摘要/摘要 超过40%的同种异体肺移植接受者在移植后五年内死亡，这表明有一种 迫切需要解决这些患者慢性免疫抑制(IS)的不足。实现 肺部受体的强健耐受状态将减少或消除主要的肺部特异性和药物相关因素。 这导致了这一令人沮丧的统计数据。异体肾移植在非人灵长类动物(NHP)中已获得耐受性 和人类通过使用非清髓性调节和供体骨髓移植的组合 导致一过性混合造血嵌合体。然而，相同的方案未能诱导对 同种异体肺移植受者。尽管同种异体肺移植对耐受诱导有抵抗力，但我们现在已经证明 第一次，在NHP接受者中达到持久的状态(在器官的寿命内)混合嵌合体导致 同种异体肺移植的长期、无IS存活。这一显著的结果是通过修改混合嵌合体而实现的 条件反射以增强宿主调节机制。虽然这是一个重大的进步，但这种修改后的混合嵌合体 该方案仅在MHC半相合的同种异体肺移植受者中成功，并与显著的 移植后淋巴增生性疾病(PTLD)、巨细胞病毒(CMV)感染的毒性； 辐射引起的骨髓抑制。我们现在的目标是通过产生一种 更安全、更有效的方案，能够诱导对无关的、完全不匹配的MHC的长期耐受 使用FDA批准或即将批准的药物的同种异体肺移植。这个节目的统一假设是，诱导 严格的同种异体肺移植受者的持久嵌合和长期耐受性将需要下一代混合细胞 嵌合体协议，增强系统和移植物内的适应性和固有调节机制。在项目1中， 我们将通过器官内注射α、IL-6R特异性和mTORi特异性纳米疗法来验证这一假设，以减少 IS相关并发症，阻断训练有素的免疫，促进移植物内调节。Bcl2抑制将被用来 促进持久的混合嵌合体，同时减少与全身照射(TBI)相关的毒性 骨髓抑制。这些研究将得到项目2的补充，该项目将使用以下工具测试我们的统一假设 基于抗体的调节、调节性T细胞(Treg)支持的免疫调节和基因调控的新策略 改良的Tregs，都准备好立即进行临床移植。由CORE协调的最先进的机械分析 A(分子免疫学核心，‘MIC’)将使在每个项目中获得的见解能够快速相互交织。我们 预计，这些高度互动的项目将共同产生一个或多个安全有效的耐用混合 嵌合体耐受方案在资助期结束前准备好进行临床试验。如果成功，这些研究 可以影响整个移植领域，并提供也可能改变骨髓领域的见解 移植和自身免疫性疾病。

PROJECT SUMMARY/ABSTRACT Over 40% of lung allograft recipients succumb within five years of being transplanted, making it clear that there is an urgent unmet need to address the inadequacies of chronic immunosuppression (IS) in these patients. Achieving a robust state of tolerance in lung recipients would reduce or eliminate the major lung-specific and drug-related factors that contribute to this dismal statistic. Tolerance of kidney allografts has been achieved in nonhuman primates (NHPs) and humans by using a combination of nonmyeloablative conditioning and donor bone marrow transplantation that results in transient mixed hematopoietic chimerism. However, identical protocols have failed to induce tolerance in recipients of lung allografts. Despite the resistance of lung allografts to tolerance induction, we have now shown for the first time, that achieving a state of durable (for the life of the organ) mixed chimerism in NHP recipients results in long-term, IS-free survival of lung allografts. This remarkable result was achieved by modifying the mixed chimerism conditioning to augment host regulatory mechanisms. While a significant advance, this modified mixed chimerism protocol was only successful in recipients of MHC haplo-matched lung allografts and was associated with significant toxicity in the form of posttransplant lymphoproliferative disease (PTLD), cytomegalovirus (CMV) infection, and radiation-induced myelosuppression. Our goal now is to render this breakthrough clinically applicable by generating a safer and more effective protocol that is capable of inducing long-term tolerance of unrelated, fully MHC mismatched lung allografts using FDA-approved or soon-to-be-approved drugs. This Program’s unifying hypothesis is that inducing durable chimerism and long-term tolerance in recipients of stringent lung allografts will require next-generation mixed chimerism protocols that augment systemic and intra-graft adaptive and innate regulatory mechanisms. In Project 1, we will test this hypothesis using intra-organ delivery of αIL-6R-specific and mTORi-specific nanotherapies to reduce IS-related complications, block trained immunity, and promote intra-graft regulation. Bcl-2 inhibition will be used to promote durable mixed chimerism while diminishing the toxicities related to total body irradiation (TBI)-driven myelosuppression. These studies will be complemented by Project 2, which will test our unifying hypothesis using novel strategies for antibody-based conditioning, regulatory T cells (Treg)-supportive immunomodulation, and gene- modified Tregs, all poised for immediate clinical translation. State-of-the-art mechanistic assays coordinated by Core A (The Molecular Immunology Core, ‘MIC’) will enable rapid cross-fertilization of insights gained in each project. We anticipate that together, these highly interactive projects will generate one or more safe and effective durable mixed chimerism tolerance protocols ready for clinical trials by the end of the funding period. 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.