Project 2: The New Era of Cellular Therapies For Lung Transplant Tolerance

项目总结/摘要 目前，肺移植物的半衰期短得令人无法接受，仅为6.7年，所有接受者都会遇到显著的并发症。 并发症，包括同种异体移植排斥和免疫抑制相关毒性。免疫耐受 为这些问题提供了最终的解决方案，并承诺终身接受移植物， 免疫抑制和/或至关重要的是，维持保护性免疫。虽然对肾脏的耐受性 已经在非人灵长类动物（NHP）和具有短暂混合嵌合体的人类中实现，相同的方案 到目前为止，肺部已经失败了。然而，重要的是，我们最近成功地诱导了持久的（即稳定的 在NHP肺移植过程中的混合嵌合体和耐受性，代表了一个重大进展。 然而，这第一次成功采用了非临床可用的药物，并赋予了移植后的高风险 淋巴组织增生性疾病（PTLD）。这些数据表明，持久的嵌合体为基础的肺移植耐受性， 这是可能的，但需要改进的策略，以重置受体免疫耐受，保持保护性 免疫力，并能够快速临床翻译。为了实现这些目标，项目2侧重于3个领域：1）开发 安全的、有针对性的骨髓预处理方案用于嵌合体诱导;（2）发现Treg支持的 （3）工程化最佳的基于CD 4 +/FoxP 3+调节性T细胞（Treg）的细胞免疫调节策略。 治疗，以增强和稳定基于嵌合体的免疫耐受。我们通过以下两项具体措施做到这一点： 目的：目的1：基于CD 45-抗体-药物-偶联物（ADC）的预处理和靶向免疫调节： 新时代的混合嵌合体诱导临床翻译。目标1包括3个目标：（1）测试 假设CD 45-ADC可以成功地产生骨髓和免疫空间。(2)为了验证Treg- 通过抗OX 40 L、CD 137-ADC或抗CD 154，支持性致耐受性免疫调节将成功诱导 持久的嵌合体跨越MHC屏障，并保持保护性免疫。(3)为了检验CD 45-ADC- 基于嵌合体和靶向免疫调节可以通过建立Treg- 支持性全身和移植物内环境。目的2：设计最佳Treg细胞疗法以增强 基于嵌合体的耐受性诱导。目标2包括3个目标，旨在优化Treg安全性/有效性 用于嵌合和耐受诱导。(1)为了检验OX 40 L-或CD 83-CAR-T细胞将更多表达的假设， 抑制性，并且将增强炎症信号传导的控制，抑制同种异体反应性， 稳定嵌合体。(2)为了检验以下假设，即经过碱基编辑以增强FOXP 3表达的TcR， 对钙调磷酸酶抑制剂、西罗莫司和/或类固醇具有抗性的患者在输注后将最大程度地持续和稳定。（三） 为了验证这一假设，即这些Tcls将通过增强Treg-1， 支持性全身和移植物内环境。这些目标旨在共同开发创新方法， 持久的嵌合体肺移植耐受性。

PROJECT SUMMARY / ABSTRACT The current half-life of a lung allograft is unacceptably short at just 6.7 years, and all recipients encounter significant complications, both from allograft rejection and from immunosuppression-associated toxicities. Immune tolerance provides the ultimate solution to these issues, with the promise of life-long graft acceptance without chronic immunosuppression, and, or critical importance, with maintenance of protective immunity. While tolerance to kidneys has been achieved in non-human primates (NHPs) and humans with transient mixed chimerism, the same protocols have thus far failed for lungs. Importantly, however, we have recently successfully induced durable (ie stable for the life of the transplant) mixed-chimerism and tolerance during NHP lung transplantation, representing a major advance. However, this first success employed non-clinically available agents and conferred a high risk of post- transplant lymphoproliferative disorder (PTLD). These data suggest that durable chimerism-based lung transplant tolerance is possible, but that improved strategies are needed, to reset recipient immunity towards tolerance, preserve protective immunity, and enable rapid clinical translation. To address these goals, Project 2 focuses on 3 areas: 1) Developing safe, targeted bone marrow conditioning regimens for chimerism-induction; (2) Discovering Treg-supportive immunomodulation strategies; and (3) Engineering optimal CD4+/FoxP3+ regulatory T cell (Treg)- based cellular therapies, to enhance and stabilize chimerism-based immune tolerance. We do so through the following two Specific Aims: Aim 1: CD45-antibody-drug-conjugate (ADC)-based conditioning and targeted immunomodulation: the new era of mixed-chimerism induction for clinical translation. Aim 1 encompasses 3 Objectives: (1) To test the hypothesis that a CD45-ADC can successfully create marrow and immune space. (2) To test the hypothesis that Treg- supportive, tolerogenic immunomodulation, through anti-OX40L, CD137-ADC, or anti- CD154, will successfully induce durable chimerism across MHC barriers and maintain protective immunity. (3) To test the hypothesis that CD45-ADC- based chimerism and targeted immune modulation can induce lung allograft tolerance by establishing a Treg- supportive systemic and intragraft environment. Aim 2: Engineering an optimal Treg cellular therapy to augment chimerism-based tolerance induction. Aim 2 encompasses 3 Objectives designed to optimize Treg safety/efficacy for chimerism- and tolerance-induction. (1) To test the hypothesis that OX40L- or CD83-CAR-Tregs will be more suppressive than unmodified Treg, and will enhance control of inflammatory signaling, inhibit alloreactivity, and stabilize chimerism. (2) To test the hypothesis that Tregs that are base-edited to enforce FOXP3 expression and be resistant to calcineurin inhibitors, sirolimus, and/or steroids, will be maximally persistent and stable after infusion. (3) To test the hypothesis that these Tregs will optimize chimerism- based lung allograft tolerance, by reinforcing a Treg- supportive systemic and intragraft environment. Together, these Aims are designed to develop innovative approaches for durable chimerism-based lung transplant tolerance.