Defining How Macrophage Allorecognition Impacts Tissue Repair After Transplantation

项目概要/摘要 心脏移植（HTx）后的慢性排斥反应（CR）是导致移植物长期存活的主要障碍， 在移植后10年（Tx），近50%的移植物排斥反应。驱动CR的因素是复杂的， 靶向淋巴细胞的免疫抑制方案不能防止进行性纤维化瘢痕形成和闭塞， 移植血管然而，一个已知的主角，CR的发展是长期的移植物缺血 再灌注损伤（IRI），其触发移植物浸润单核细胞的强烈早期炎症反应， 局部炎症信号。最近，已经确定单核细胞和巨噬细胞（MΦs）区分 通过配对免疫球蛋白样受体（PIR）从自身MHCI中识别非自身，并直接先天识别 PIR-A诱导的同种异体H2-Dd促进HTx排斥。MΦ是解决炎症所必需的，以促进 修复反应，重建移植物稳态，以保护器官功能，但如何MΦ同种异体抗原 识别形状或失调的移植修复是完全未知的。我测试了MΦ如何识别 自身或非自身协调它们的分化，并证明单源MΦ识别 同种异体材料将其局部转化为野生型Rag 2-/-γc-/-中的促炎性Ly 6chiCD 86 hi MΦ， Pira-/--Rag 2-/-γc-/ B6受体。我的初步数据进一步确定，重组H2-Dd促进亲- 骨髓来源的MΦs（BMDMΦs）中的炎性分化，并且再次没有差异 在野生型和Pira-/- BMDMΦ之间。因此，我检测了MΦ是否表达其他H2-Dd受体， 初步数据显示，阻断受体Ly 49 d可消除H2-Dd相关途径。最后我 确定了这种MΦ同种异体识别的功能后果，并表明MΦ暴露于同种异体， 但不是同源的，增强了它们对成纤维细胞的修复。因此，我的假设是，受体MΦ分化 由于Ly 49 d诱导的信号传导由供体H2-Dd MHCI触发， 修复和加速CR。我将通过解决以下具体目标来直接检验这个假设：1。 定义MΦ对非自身H2-Dd的识别如何塑造转录组和代谢组，以诱导前 炎性MΦ分化。2.确定防止MΦ非自身MHCI识别是否限制了IRI后的CR 心脏移植这些目标的完成将确定Ly 49 d是否是基本的MΦ同种异体识别受体， 定义介导促炎性MΦ分化为H2-Dd的途径。我还将精确地确定 MΦ对H2-Dd的识别放大了它们的促纤维化作用，如果消除MΦ对非自身MHCI的反应， CR以提供有效的移植物修复。对培训的贡献：本提案涉及一项广泛的培训计划， 阐明MΦ同种免疫反应，结合生物信息学和生物化学方面的高超指导。 总之，生成的数据将促进我在会议演讲和手稿方面的专业发展 准备.它进一步整合了我在为Tx患者开发临床靶点方面的兴趣，并提供了强大的 通过与世界知名的Tx研究人员合作，为我的学术生涯奠定了基础。

PROJECT SUMMARY/ABSTRACT Chronic rejection (CR) after heart transplant (HTx) is the principal barrier to long-term graft survival that results in nearly 50% graft rejection after 10 years post-transplant (Tx). The factors driving CR are complex, as current immunosuppressive regimes targeting lymphocytes fail to prevent progressive fibrotic scarring and occlusion of graft vasculature. However, a known protagonist to the development of CR is prolonged graft ischemia reperfusion injury (IRI) that triggers robust early inflammatory responses of graft infiltrating monocytes that react to local inflammatory signals. Recently, it was established that monocytes and macrophages (MΦs) distinguish non-self from self MHCI via paired-immunoglobulin-like receptors (PIRs), and direct innate recognition of allogeneic H2-Dd by PIR-A promoted HTx rejection. MΦs are essential for resolving inflammation to promote reparative responses that re-establishes graft homeostasis to preserve organ function, yet how MΦ alloantigen recognition shapes or dysregulates the repair of grafts is completely unknown. I tested how MΦ recognition of self or non-self coordinates their differentiation and demonstrated that mono-derived MΦ recognition of allogeneic materials locally transforms them into pro-inflammatory Ly6chiCD86hi MΦs in wildtype, Rag2-/-γc-/-, and Pira-/--Rag2-/-γc-/ B6 recipients-. My preliminary data further settled that recombinant H2-Dd promotes pro- inflammatory differentiation in bone marrow-derived MΦs (BMDMΦs) and there were again no differences between wildtype and Pira-/- BMDMΦs. Therefore, I tested whether MΦs express other H2-Dd receptors and my preliminary data shows that blocking the receptor Ly49d extinguished H2-Dd-associated pathways. Lastly, I determined the functional consequences of this MΦ allorecognition, and show that MΦ exposure to allogeneic, but not syngeneic, amplifies their repair of fibroblasts. Therefore, my hypothesis is that recipient MΦs differentiate into a pro-fibrotic subset due to Ly49d-induced signaling triggered by donor H2-Dd MHCI leading to dysregulated repair and accelerated CR. I will directly test this hypothesis by addressing the following Specific Aims: 1. Define how MΦ recognition of non-self H2-Dd shapes the transcriptome and metabolome to induce pro- inflammatory MΦ differentiation. 2. Determine if preventing MΦ non-self MHCI recognition limits CR after IRI in heart grafts. Completion of these aims will establish if Ly49d is a fundamental MΦ allorecognition receptor and define pathways mediating pro-inflammatory MΦ differentiation to H2-Dd. I will also precisely determine whether MΦ recognition of H2-Dd amplifies their pro-fibrotic roles, and if abolishing MΦ responses to non-self MHCI limits CR to deliver effective graft repair. Contribution to Training: This proposal entails an extensive training plan to elucidate MΦ alloimmune responses combined with superb mentorship in bioinformatics and biochemistry. Together, the generated data will foster my professional development for conference talks and manuscript preparation. It further integrates my interests in developing clinical targets for Tx patients and provides strong foundations for my academic career by collaborating with world-renowned Tx researchers.