Targeting macrophages to reduce the combined injury effects of radiation and virus exposure

项目摘要/摘要：肿瘤性肺放射治疗(RT)或 骨髓移植的TBI条件反射。炎性细胞因子的持续产生，巨噬细胞调节失调 激活和永久ROS的产生被认为是这些事件的分子介体。SARS-CoV-2- 确诊患者出现下呼吸道疾病、呼吸困难和外周纤维化，以及 从重新招募的免疫细胞产生促炎细胞因子；提示肺部的事件 容易感染SARS-CoV-2，高龄和合并症也被确定为易感条件。 因此，高剂量RT和病毒感染都促进了肺内的促炎微环境， 巨噬细胞群的募集和细胞因子信号转导；提示其机制的共性 肺纤维化涉及一场“细胞因子风暴”。为了支持这一点，我们报告了初步数据，肺- 靶向RT，单独或与脑损伤合并，增加甲型流感病毒的死亡率和纤维化(HKx31(H3N2)) 并加剧了辐射敏感器官的感染风险。因为当地的微环境变化 和先天免疫细胞招募有关，我们现在假设肺辐射会产生长期的- 肺部微环境的长期变化，影响对呼吸道病毒病原体的免疫反应。 我们将调查导致长期肺损伤的即时(24小时)机械相互作用(26周) 使用3D精密肺切割法，由联合暴露于局部肺RT和病毒引起，反之亦然 切片和鼠标模型。总体目标是开发基于分子的保护/缓解策略。 目的1.1：探讨C57BL/6和C3H小鼠预先接受肺照射和剂量依赖性照射对小鼠肺损伤的影响。 引起肺损伤，影响对流感病毒和小鼠冠状病毒感染的敏感性和易感性 用来模拟SARS-CoV-2感染的菌株。此外，为了研究持续性或潜伏性肺损伤是如何从第一次 侮辱通过改变两次侮辱之间的时间间隔来影响对第二次侮辱的敏感性。 目的1.2：研究病毒感染和病毒诱导的细胞因子风暴如何改变肺的放射敏感性，以及 放射性肺炎和纤维化的时间进展。老化的小鼠也将被用来 确定与年龄和体重相关的共同发病因素如何加剧合并肺损伤的风险。 目标1.3：使用人类3D肺切片培养来研究病毒感染如何改变RT诱导的机制 DNA DSB修复，以及对细胞致死性的影响。 目的2：确定抗氧化剂AEOL-10150是否能减轻肺部的炎症和/或氧化应激 和NaI，或阻止肺组织部位浸润性巨噬细胞的异常募集和激活 通过靶向CD200受体的损伤，将降低辐射和病毒联合暴露的风险。 这些研究将具有重要意义，因为它们模拟了辐射损伤和病毒之间的关系 在肺中的传染性，并提供了分子靶向缓解RT和联合病毒损伤的可能性。

PROJECT SUMMARY/ABSTRACT: Pneumonitis and fibrosis occur after oncologic lung radiotherapy (RT) or TBI conditioning for BMT. The sustained production of inflammatory cytokines, dysregulated macrophage activation and perpetual ROS generation are considered molecular mediators of these events. SARS-CoV-2- confirmed patients experience lower respiratory tract illness, dyspnea and peripheral fibrosis, along with production of proinflammatory cytokines from recruited immune cells; events that indicate the lungs are susceptible to SARS-CoV-2 infection, with old age and comorbidities also identified as predisposing conditions. Therefore, both high-dose RT and viral infection promote proinflammatory microenvironments in the lung, the recruitment of macrophage populations and cytokine signaling; suggesting a commonality to mechanisms of pulmonary fibrosis that involve a ‘cytokine storm’. In support of this, we reported preliminary data that lung- targeted RT, alone or combined with TBI, increased mortality and fibrosis from influenza virus A (HKx31 (H3N2)) and exacerbated infection risks in radiation-sensitive organs. Since both local microenvironmental alterations and innate immune cell recruitment were implicated, we now hypothesize that lung radiation produces long- term changes in the lung microenvironment that affect immune responses to respiratory viral pathogens. We will investigate the immediate (<24h) mechanistic interactions responsible for long-term lung injury (>26 wks) caused by combined exposures to focal lung RT followed by virus, and vice versa, using 3D precision cut lung slices and mouse models. The overall goal is to develop molecular-based protective/mitigating strategies. Aim 1.1: To investigate how prior lung irradiation of C57BL/6 and C3H mice, and dose-dependent radiation- induced lung injury, affects sensitivity and susceptibility to virus infection using Influenza and murine corona viral strains to model SARS-CoV-2 infection. Also, to investigate how persistent or latent lung injury from the first insult impacts the sensitivity to the second insult by varying the time interval between the two insults. Aim 1.2: To investigate how viral infection and the viral-induced ‘cytokine storm’ alters lung radiosensitivity, and the temporal progression through radiation-induced pneumonitis and fibrosis. Aged mice will also be used to determine how age- and weight-related co-morbidity factors exacerbate the risk for combined pulmonary injury. Aim 1.3: Use human 3D lung slice cultures to investigate how viral infection alters mechanisms of RT-induced DNA DSB repair, and the impact on cell lethality. Aim 2: To determine if mitigating inflammation and/or oxidative stress in the lungs with antioxidants AEOL-10150 and NaI, or preventing the aberrant recruitment and activation of infiltrating macrophages at sites of pulmonary injury by targeting the CD200 receptor, will mitigate risks for combined radiation and viral exposures. These studies will be significant because they model the relationship between radiation damage and viral infectivity in the lung, and offer the potential for molecular-targeted mitigation for RT and combined viral injury.