Multi-modal rescue of pulmonary NRF2-insufficiency after burn and burn + inhalation injury to regulate innate immune dysfunction

总结 美国烧伤协会估计，每年约有3,500人死于烧伤。有 吸入性损伤对烧伤患者的发病率和死亡率有多种影响， 因为它导致对机会性细菌感染的易感性增加以及相关的发病率， mortality.临床需求的三个方面与这个临床问题相关：1）我们缺乏预测风险的能力， 感染，2）我们不了解感染风险的机制，3）我们无法恢复患者的 免疫系统在损伤后保持稳态，以能够充分控制感染因子。总体目标 本申请的目的是描述负责以下不受控制的炎症循环的机制： 烧伤，以完善预测模型，患者的结果和完善治疗方法，以恢复免疫 体内平衡，从而降低对感染的易感性并预防相关的发病率和死亡率。 我们和其他人已经在人体样本和小鼠模型中证明，烧伤和烧伤+吸入（B+I） 损伤产生许多损伤相关分子模式（DAMP）的局部和全身释放。 DAMP通过关键的免疫调节剂促进相互作用，例如哺乳动物雷帕霉素靶标（mTOR）， 诱导活性氧（ROS）、炎性细胞因子和趋化因子，导致组织损伤 和免疫细胞募集。免疫稳态通常至少部分地通过转录因子来恢复 核因子-红细胞样蛋白-2相关因子（NRF 2）。我们的初步数据表明，Nrf 2-/-敲除小鼠 在B+I损伤后有很高的死亡率。然而，我们的初步数据也表明， 在野生型小鼠中，免疫细胞NRF 2蛋白翻译在B+I后迅速增加，但它不易位到 原子核因此，我们假设烧伤和B+I损伤后NRF 2介导的稳态不足， 但是NRF 2途径的药理学激活具有减少急性免疫功能障碍的潜力。 使用我们的烧伤和B+I损伤的临床前模型，我们将定义急性免疫损伤的NRF 2特异性机制。 烧伤或B+I损伤后的功能障碍，并在我们的高容量研究中验证了人类队列中的这些发现。 烧伤中心。此外，我们将利用微粒技术开发和表征NRF 2驱动的治疗。 来改善损伤后的免疫功能障碍正如我们所理解的，对烧伤和B+I的反应是多因素的， 我们将利用这项技术将联合收割机NRF 2激活与第二种方法结合起来，并抑制mTOR， 一种新的多模式治疗方法。这些方法的有效性将使用我们的预- 烧伤和B+I临床模型。我们有能力成功完成这项提案， 我们填补现有的知识空白，改善烧伤和B+I患者的长期结局。

SUMMARY The American Burn Association estimates that there are ~3,500 deaths each year from burn injuries. There are multiple influences on morbidity and mortality in burn patients, with inhalation injury among the most significant as it leads to increased susceptibility to opportunistic bacterial infections and the associated morbidity and mortality. A trifecta of clinical need is associated with this clinical problem: 1) we lack the ability to predict risk of infection, 2) we do not understand the mechanism of infectious risk, and 3) we are unable to restore a patient’s immune system to homeostasis after injury to enable adequate control of infectious agents. The overall objective of this application is to delineate mechanisms responsible for the cycle of uncontrolled inflammation following burn-injury to refine prediction models patient outcomes and to refine therapeutic approaches to restore immune homeostasis, thus decreasing susceptibility to infection and preventing the associated morbidity and mortality. We and others have demonstrated in human samples and mouse models that burn and burn + inhalation (B+I) injury generates the local and systemic release of numerous Damage-Associated Molecular Patterns (DAMPs). DAMPs promote interactions, via key immune regulators, such as mammalian Target of Rapamycin (mTOR) to induce reactive oxygen species (ROS), inflammatory cytokines, and chemokines which results in tissue damage and immune cell recruitment. Immune homeostasis is normally restored at least in part by the transcription factor Nuclear Factor-Erythroid-2-Related Factor (NRF2). Our preliminary data demonstrate that Nrf2-/- knockout mice have profound mortality after B+I injury. However, our preliminary data also demonstrate that while pulmonary immune cell NRF2 protein translation is rapidly increased after B+I in wildtype mice, it is not translocated to the nucleus. Thus, we hypothesize that the NRF2-mediated homeostasis following burn and B+I injury is insufficient, but that pharmacological activation of the NRF2 pathway has the potential to reduce acute immune dysfunction. Using our pre-clinical models of burn and B+I injury, we will define NRF2-specific mechanisms of acute immune dysfunction following burn or B+I injury and validate these findings in human cohorts within in our high-volume burn center. In addition, we will utilize microparticle technology to develop and characterize NRF2-driven therapy to improve post-injury immune dysfunction. As we appreciate that the response to burn and B+I is multifactorial, we will leverage this technology to combine NRF2 activation with a second approach and inhibit mTOR to provide a novel multimodal therapeutic approach. The efficacy of these approaches will be evaluated using our pre- clinical models of burn and B+I. We are uniquely poised to successful complete this proposal which will allow us to fill the existing knowledge gaps and improve long-term outcomes of burn and B+I patients.