Adenosine A2 Receptors and Imaging of Inflammation in Lung Reperfusion Injury

项目摘要 缺血-再灌注损伤（IRI）是导致原发性移植物功能障碍（PGD）的一个重要原因。 肺移植后早期死亡的主要原因。目前的临床方法， 诊断PGD仅限于胸部X线检查、CT和功能检查，其中没有一项 专门针对急性炎症或免疫细胞活化; 肺IRI。FDG-PET成像通常在临床上用作炎症的指示， 中性粒细胞活性;然而，FDG-PET是非特异性的成像一般代谢 活动本提案的主要目标是开发新的细胞特异性SPECT 影像学方法提供敏感和早期诊断IRI后肺 移植使用肺IRI的小鼠模型，Aim 1将验证三种新的 用于肺IRI的SPECT成像的分子探针：靶向甲酰基的99 mTc-cFLFLF 活化中性粒细胞上的肽受体，靶向活化的，前 炎性M1巨噬细胞和99 mTc标记的抗甘露糖受体纳米抗体 其靶点是交替激活的抗炎M2巨噬细胞。我们假设 靶向M1巨噬细胞将提供IRI的最早诊断， PGD的表现，同时靶向M2巨噬细胞将允许提供信息 通过免疫抑制作用评估IRI的消退。SPECT成像 将与FDG-PET成像进行比较。Aim 2将使用SPECT成像 监测对腺苷受体靶向治疗的反应， 衰减IRI。腺苷A2 A受体（A2 AR）激动和/或 A2 BR的拮抗作用将集中在肺泡上皮细胞A2 BR的机制 将确定拮抗剂介导的IRI保护作用。目标3将翻译我们的 结果临床相关，大型动物肺移植模型，通过确定是否 SPECT显像可早期诊断猪移植肺IRI 肺成功完成我们的提案可能会导致这些翻译 新的成像方法的临床设置的目标是提供一个有效的，非- 早期诊断IRI的侵入性方法，以便进行快速、靶向治疗 预防PGD的干预措施，从而改善肺部的短期和长期结果 移植接受者

Project Summary Ischemia-reperfusion injury (IRI), which leads to primary graft dysfunction (PGD), is a major source of early mortality after lung transplantation. Current clinical methods to diagnose PGD are limited to chest x-ray, CT, and functional tests, none of which specifically address acute inflammation or immune cell activation; key components of lung IRI. FDG-PET imaging is often used clinically as an indication of inflammation and neutrophil activity; however, FDG-PET is non-specific by imaging general metabolic activity. The primary objective of this proposal is to develop novel, cell-specific SPECT imaging methods to provide sensitive and early diagnosis of IRI after lung transplantation. Using a murine model of lung IRI, Aim 1 will validate three novel molecular probes for SPECT imaging of lung IRI: 99mTc-cFLFLF that targets formyl peptide receptor on activated neutrophils, 99mTc-EC20 that targets activated, pro- inflammatory M1 macrophages, and 99mTc-labeled anti-mannose receptor Nanobodies that target alternatively activated, anti-inflammatory M2 macrophages. We hypothesize that targeting of M1 macrophages will provide the earliest diagnosis of IRI prior to manifestation of PGD while targeting of M2 macrophages will allow informative assessment of the resolution of IRI via immunosuppressive actions. SPECT imaging with these probes will be compared to FDG-PET imaging. Aim 2 will use SPECT imaging in mice to monitor the response to adenosine receptor-targeted therapies aimed at attenuating IRI. Attenuation of IRI by adenosine A2A receptor (A2AR) agonism and/or A2BR antagonism will be focused on, and alveolar epithelial mechanisms for A2BR antagonist-mediated protection from IRI will be determined. Aim 3 will translate our results to a clinically relevant, large animal lung transplant model by determining if SPECT imaging will provide early diagnosis of lung IRI after transplantation of porcine lungs. The successful completion of our proposal could result in translation of these novel imaging methods to the clinical setting with the goal of providing an effective, non- invasive means for early diagnosis of IRI in order to permit rapid, targeted therapeutic interventions to prevent PGD and thus improve short- and long-term outcomes in lung transplant recipients.