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参与SARS CoV-2在人类和非人类灵长类动物中的发病机制 但它们在仓鼠模型中对SARS CoV-2病理学的作用尚不清楚。我们假设 骨髓细胞可以在治疗上靶向改善COVID-19的结果，我们将在 COVID-19感染的仓鼠模型。仓鼠模型是一种易于处理的COVID-19小动物模型， 在人类中模拟严重的临床疾病，研究设计、组织和时间点的变化评估限制 结果的跨机构比较和结果再现性。我们建议定量图像分析 可用于有效监测免疫细胞浸润，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需要建立。更广泛地说， 需要标准化SARS CoV-2感染动物模型的定量病理终点， 基准研究质量，改善数据的跨机构比较，验证细胞靶点，并评估 因此，SARS CoV-2的潜在药物可以迅速发展。我们将使用定量 图像分析探讨骨髓介导组织损伤机制 疾病增强（ADE）和PI 3 K炎症通路。使用叙利亚仓鼠模型和数字 我们将评估骨髓细胞群体对SARS CoV疾病病理学的相对贡献， 2感染，探讨骨髓介导的肺损伤机制。我们将开发图像分析工具， 在SARS仓鼠模型中定量炎性浸润并确定临床疾病的病理相关性 CoV-2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 利用优化图像研究SARS CoV-2感染仓鼠骨髓介导的组织损伤机制 分析工具集。我们将探讨亚治疗性单克隆抗体（MAb）治疗和非保护性水平的 疫苗诱导的中和抗体，以建立评估iADE的病理指标，并使用PI 3 K-γ 抑制剂目前在实体瘤的II期临床试验中，以确定髓系细胞运输是否可以 通过抑制PI 3 K-γ途径调节。开发经验证和标准化的定量图像 与仓鼠的临床和病毒学控制相关的分析终点将更快地提前， 临床药物和疫苗有效性试验，用于开发SARS CoV-2治疗和预防药物。这些 工具也可用于探索COVID-19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