A Regulatory T Cell Notch4 Switch Governs Lung Inflammation in Viral Infections
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ABSTRACT: Coronavirus disease 2019 (Covid19), caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is associated with lung inflammation and respiratory failure. In a prospective multi-country cohort of Covid19 patients, we found that increased Notch4 expression on circulating Treg cells was associated with increased disease severity, predicted mortality, and declined upon recovery. Deletion of Notch4 in Treg cells or therapy with anti-Notch4 antibodies in conventional and humanized mice suppressed the dysregulated innate immune response and rescued disease morbidity and mortality induced by a synthetic analogue of viral RNA or by the influenza H1N1 virus in an amphiregulin-dependent manner. Notably, amphiregulin production declined in Covid19 subjects as a function of disease severity and Notch4 expression. These results identify Notch4 as an immune regulatory switch that licenses virus-induced lung inflammation by altering Treg cell-mediated tissue repair. They also suggest Notch4 as a therapeutic target in Covid19 and other respiratory viral infections.
Project description:The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the etiological pathogen of coronavirus disease 2019 (COVID-19), a highly contagious disease, spreading quickly and threatening global public health. The symptoms of the disease vary from mild reactions to severe respiratory distress or even fatal outcomes probably due to the different status of innate immunity which is the first line to combat the virus. Here in the study, we unveiled the underlying transcriptional patterns of peripheral blood mononuclear cells (PBMCs) using SARS-CoV-2 infected patients with different severity and outcome. Through systemic analysis, an anti-microbe peptide, α-defensin-1 (DEFA1) was identified to be elevated in both plasma and PBMCs in COVID19 patients, and the function and mechanism is studied.
Project description:Coronavirus disease 2019 (COVID-19) is associated with significant morbidity and mortality, albeit with considerable heterogeneity among affected individuals. Emerging evidence points towards an important role of preexisting host factors, such as a deregulated inflammatory response at the time of infection. Here, we demonstrate the negative impact of clonal hematopoiesis, a prevalent clonal disorder of ageing individuals, on COVID-19-related cytokine release severity and mortality. In this study we perform single cell RNA sequencing of PBMCs from COVID19 patients and patients with clonal hematopoiesis.
Project description:Coronavirus disease 2019 (COVID-19) is associated with significant morbidity and mortality, albeit with considerable heterogeneity among affected individuals. Emerging evidence points towards an important role of preexisting host factors, such as a deregulated inflammatory response at the time of infection. Here, we demonstrate the negative impact of clonal hematopoiesis, a prevalent clonal disorder of ageing individuals, on COVID-19-related cytokine release severity and mortality. In this study we perform Multiome single cell sequencing of PBMCs from COVID19 patients and patients with clonal hematopoiesis.
Project description:Coronavirus disease 2019 (COVID-19) is associated with significant morbidity and mortality, albeit with considerable heterogeneity among affected individuals. Emerging evidence points towards an important role of preexisting host factors, such as a deregulated inflammatory response at the time of infection. Here, we demonstrate the negative impact of clonal hematopoiesis, a prevalent clonal disorder of ageing individuals, on COVID-19-related cytokine release severity and mortality. In this study we perform use the Illumina MethylationEPIC array to quantify methylation levels in PBMCs from COVID19 patients and patients with clonal hematopoiesis.
Project description:Elucidating the mechanisms that sustain asthmatic inflammation is critical for precision therapies. We found that IL-6 and STAT3-dependent upregulation of Notch4 on Iung tissue regulatory T (Treg) cells is necessary for allergens and particulate matter pollutants to promote airway inflammation. Notch4 subverted Treg cells into TH2 and TH17 effector T (Teff) cells by Wnt and Hippo pathway-dependent mechanisms. Wnt activation induced GDF15 expression in Treg cells, which activated group 2 innate lymphoid cells (ILC2) to provide a feed-forward mechanism for aggravated inflammation. Notch4, Wnt and Hippo were upregulated on circulating Treg cells of asthmatics as a function of disease severity, in association with reduced Treg cell-mediated suppression. Our studies thus identify Notch4-mediated immune tolerance subversion as a fundamental mechanism that licenses tissue inflammation in asthma.
Project description:Coagulopathy is a hallmark finding in patients infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and is associated with an increased risk of death from venous and arterial thromboembolic complications. SARS-CoV-2 infection can lead to microvascular thrombosis that contributes to acute lung injury and respiratory failure. The molecular mechanisms leading to thrombosis in Coronavirus disease 2019 (COVID19) patients are poorly understood. Here, we study a role of the procoagulant neutrophil extracellular traps (NETs)/Factor XII (FXII) axis in COVID19-associated thromboembolism.
Project description:Coagulopathy is a hallmark finding in patients infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and is associated with an increased risk of death from venous and arterial thromboembolic complications. SARS-CoV-2 infection can lead to microvascular thrombosis that contributes to acute lung injury and respiratory failure. The molecular mechanisms leading to thrombosis in Coronavirus disease 2019 (COVID19) patients are poorly understood. Here, we study a role of the procoagulant neutrophil extracellular traps (NETs)/Factor XII (FXII) axis in COVID19-associated thromboembolism.
Project description:High-resolution mass spectrometry and the parallel quantitative evaluation of thousands of proteins has been used to characterise the proteomes of peripheral blood neutrophils from >200 individuals. This work has comprehensively mapped neutrophil molecular changes associated with mild versus severe COVID19 and identified significant quantitative changes in more than 1700 proteins in neutrophils from patients hospitalised with COVID19 versus patients with non-COVID19 acute respiratory infections. The study identifies neutrophil protein signatures associated with COVID19 disease severity. The data also show that alterations in neutrophil proteomes can persist in fully recovered patients and identify distinct neutrophil proteomes in recovered versus non recovered patients. Our study provides novel insights into neutrophil responses during acute COVID-19 and reveal that altered neutrophil phenotypes persist in convalescent COVID19 infections.
Project description:Mass Spectrometry identifies temporal changes and hallmarks of Delayed Recovery in the COVID19 Neutrophil proteomes MTD project_description High-resolution mass spectrometry and the parallel quantitative evaluation of thousands of proteins has been used to characterise the proteomes of peripheral blood neutrophils from >200 individuals. This work has comprehensively mapped neutrophil molecular changes associated with mild versus severe COVID19 and identified significant quantitative changes in more than 1700 proteins in neutrophils from patients hospitalised with COVID19 versus patients with non-COVID19 acute respiratory infections. The study identifies neutrophil protein signatures associated with COVID19 disease severity. The data also show that alterations in neutrophil proteomes can persist in fully recovered patients and identify distinct neutrophil proteomes in recovered versus non recovered patients. Our study provides novel insights into neutrophil responses during acute COVID-19 and reveal that altered neutrophil phenotypes persist in convalescent COVID19 infections.
Project description:A hyperinflammatory response to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection gravely worsens the clinical progression of coronavirus disease 2019 (COVID-19). Although the undesirable effects of inflammasome activation have been correlated to the severity of COVID-19, the mechanisms of this process in the asymptomatic infection and disease progression have not yet been clearly elucidated. Our results indicate potential preventive targets for COVID-19 disease development and progression.