Requirements and mechanisms of alloantigen-induced cardiac allograft survival by cDC1s

项目摘要/摘要 心脏移植是目前治疗晚期心力衰竭的唯一方法，因此， 全球进行的移植手术继续增加。外科技术的进展和可获得性 免疫抑制显著提高了患者的存活率，但多年后就不能这么说了。 移植。免疫介导的病理，如慢性同种异体血管病变导致移植物失败和 长期使用免疫抑制药物导致的显著发病率，包括肾功能不全、糖尿病、 和恶性，继续被患者体验到。因此，改进的战略，以促进生存 同种异体心脏移植是必要的。 大量研究试图确定导致心脏移植排斥反应的细胞因子和 宽容。在排斥的背景下，获得性免疫反应已经出现了主导作用，特别是 CD4+和CD8+T细胞。重要的是，T细胞不是单独的表演者，而是需要由 抗原提呈细胞，主要是树突状细胞(DC)。曾经被认为是同质人口的DC 现在被认为是其独特的个体发育和功能角色，决定了DC亚集的特性。 传统的DC-1细胞(cDC-1)是免疫反应的强大介质，已被证明是 这对促进中央容忍至关重要。目前还没有关于cDC1s在固体器官中的亚组特定作用的研究 已经进行了移植，我们对CDC1s在外周免疫耐受中的理解仍停留在其 婴儿期。重要的是，我的初步数据表明，CDC1s在供者诱导的耐受策略中是必要的。 这会导致同种异体心脏移植物长期存活。 利用输注供体抗原和共刺激阻断(COB)的耐受策略产生长期效果 同种异体心脏移植在小鼠和非人类灵长类动物模型中的存活，尽管关于暴露于 供体同种异体抗原影响耐受诱导。这项提议假设在捐赠者诱导的 耐受策略，cDC1亚集是促进外周免疫所必需的 通过处理同种异体抗原对心脏移植的低反应性，调节 表面标记表达和代谢转录重编程。这一假设将得到检验。 使用cDC1缺失和异位心脏移植的小鼠模型，同时进行功能性(触诊， 超声心动图)和细胞(流式细胞术、组织学)分析。此外，单细胞转录组学 体内异体和异体输注COB后的脾DC与体外实验相结合将 帮助揭示促进耐受性同种异体特异性反应的cDC1特异性编程。因此，拟议的 研究将确定增强免疫耐受性和改善同种异体心脏移植物存活率的靶向途径。

PROJECT SUMMARY/ABSTRACT Heart transplantation is currently the only treatment for advanced stage heart failure and as such, the volume of transplants performed globally continues to increase. Advances in surgical technique and available immunosuppression have improved patient survival acutely, however the same cannot be said years after transplantation. Immune mediated pathologies such as chronic allograft vasculopathy result in graft failure and significant morbidity from prolonged use of immunosuppressant medication including renal dysfunction, diabetes, and malignancy, continue to be experienced by patients. Therefore, improved strategies to promote survival of the cardiac allograft are necessary. A great deal of research has sought to identify the cellular actors responsible for cardiac allograft rejection and tolerance. In the setting of rejection, the adaptive immune response has emerged in a leading role, specifically CD4+ and CD8+ T cells. Importantly, T cells are not solo performers but instead require instruction provided by antigen presenting cells, predominantly dendritic cells (DCs). Once considered a homogenous population, DCs are now recognized for their distinct ontogeny and functional roles which determine DC subset identity. Conventional DC 1 cells (cDC1s) are powerful mediators of the immune response and have been shown to be critical for the promotion of central tolerance. Yet no work on the subset specific role of cDC1s in solid organ transplantation has been performed and our understanding of cDC1s in peripheral tolerance remains in its infancy. Importantly, my preliminary data implicate cDC1s as necessary in donor-induced tolerization strategies that result in long term cardiac allograft survival. Tolerization strategies utilizing infused donor antigen and costimulation blockade (CoB) produce long term cardiac allograft survival in murine and nonhuman primate models, though little is known as to how exposure of donor alloantigen influences tolerance induction. This proposal hypothesizes that during a donor-induced tolerance strategy, the cDC1 subset is necessary to promote peripheral immunological hyporesponsiveness towards cardiac allografts through processing of alloantigen, modulation of surface marker expression, and metabolic transcriptional reprogramming. This hypothesis will be tested using mouse models of cDC1 deletion and heterotopic heart transplantation alongside functional (palpation, echocardiography) and cellular (flow cytometry, histology) analysis. Additionally, single-cell transcriptomics of splenic DCs after in vivo allo- and iso- infusion in the presence of CoB coupled with in vitro experimentation will help unveil cDC1 specific programming that promote a tolerogenic allospecific response. Thus, the proposed studies will identify targetable pathways to enhance immunologic tolerance and improve cardiac allograft survival.