Digital pathology for defining myeloid cell-mediated lung injury during acute SARS CoV-2 Infection in hamsters

项目摘要 巨噬细胞和中性粒细胞与SARS CoV-2在人和非人类灵长类动物中的发病有关 但在仓鼠模型中，它们在SARS CoV-2病理中的作用尚不清楚。我们假设 髓系细胞可以被靶向治疗以改善新冠肺炎的结果，我们将在 新冠肺炎感染仓鼠模型。仓鼠模型是新冠肺炎的一个容易驯服的小动物模型 在人类中模拟严重的临床疾病，研究设计、组织和评估时间点的差异限制 结果的跨机构比较和结果的再现性。我们建议对图像进行定量分析 可用于有效地监测免疫细胞的渗透并确定疾病进展的机制 仓鼠模型，但临床疾病的病理相关性有待建立。更广泛地说，有一个 需要对SARS CoV-2感染动物模型中的定量病理终点进行标准化 基准研究质量，改进跨机构数据比较，验证蜂窝目标，并评估 治疗效果使针对SARS CoV-2的潜在药物可以迅速进步。我们将使用量化 图像分析探讨抗体依赖等髓系组织损伤机制 疾病增强(ADE)和PI3K炎症途径。使用叙利亚仓鼠模型和数字 我们将评估在SARS冠状病毒中髓系细胞群对疾病病理的相对贡献 2感染，探讨髓系细胞介导的肺损伤机制。我们将开发图像分析工具来 在SARS仓鼠模型中定量炎性浸润物并确定临床疾病的病理相关性 冠状病毒2型感染。我们将进行滴定研究，以确定与临床相关的病理终点 疾病和病毒载量，以更好地了解该模型中的疫苗和治疗结果。我们还将定义 用优化图像研究SARS CoV-2感染仓鼠的髓系组织损伤机制 分析工具集。我们将探讨亚治疗性单抗(MAb)治疗和非保护性水平的 疫苗诱导的中和抗体建立评估IAD的病理指标并使用PI3K-γ 目前处于实体瘤第二阶段临床试验的抑制剂，以确定髓系细胞转运是否可以 通过抑制PI3K-γ通路进行调节。经过验证和标准化的定量图像的开发 与仓鼠临床和病毒学控制相关的分析终点将更快地推进 开发SARS CoV-2治疗和预防药物的临床药物和疫苗疗效试验。这些 工具也可以用来探索新冠肺炎疾病的病理机制。 1

Project Summary Macrophages and neutrophils are implicated in SARS CoV-2 pathogenesis in people and non-human primates but their contribution to SARS CoV-2 pathology in the hamster model is poorly defined. We hypothesize that myeloid cells can be targeted therapeutically to improve COVID-19 outcomes and we will explore this in the hamster model of COVID-19 infection. The hamster model is a tractable small animal model for COVID-19 that models severe clinical disease in humans yet, variations in study design, tissue and time-points assessed limit cross-institutional comparison of results and result reproducibility. We propose that quantitative image analysis can be used to effectively monitor immune cell infiltrates and define mechanisms of disease progression in the hamster model, but pathologic correlates of clinical disease need to be established. More broadly, there is a need to standardize quantitative pathologic endpoints in animal models of SARS CoV-2 infection in order to benchmark study quality, improve cross-institutional comparison of data, validate cellular targets, and assess therapeutic efficacy such that potential drugs for SARS CoV-2 can rapidly advance. We will use quantitative image analysis to explore mechanisms of myeloid mediated tissue damage such as antibody dependent enhancement of disease (ADE) and the PI3K inflammatory pathway. Using the Syrian hamster model and digital pathology we will assess the relative contribution of myeloid cell populations to disease pathology in SARS CoV- 2 infection and explore mechanisms of myeloid-mediated lung damage. We will develop image analysis tools to quantify inflammatory infiltrates and define pathologic correlates of clinical disease in the hamster model of SARS CoV-2 infection. We will perform titration studies to establish pathologic endpoints that correlate with clinical disease and viral load to better understand vaccine and therapeutic outcomes in this model. We will also define mechanisms of myeloid-mediated tissue damage in SARS CoV-2 infected hamsters using an optimized image analysis toolset. We will explore subtherapeutic monoclonal Ab (MAb) treatment and non-protective levels of vaccine-induced neutralizing antibodies to establish pathologic metrics for assessing iADE and use a PI3K-γ inhibitor currently in Phase II clinical trials for solid tumors, to determine whether myeloid cell trafficking can be modulated by inhibiting the PI3K-γ pathway. Development of validated and standardized quantitative image analysis end-points that correlate with clinical and virologic control in hamsters will more rapidly advance pre- clinical drug and vaccine efficacy trials for development of SARS CoV-2 therapeutics and preventives. These tools can also be used to explore pathologic mechanisms of disease in COVID-19. 1