Post by Nadica (She/Her) on Jul 19, 2024 5:02:10 GMT
Comparative single-cell analysis reveals IFN-γ as a driver of respiratory sequelae after acute COVID-19 - Published July 17, 2024
Editor’s summary
The term “Long Covid” covers a myriad of symptoms that a person may experience after an acute infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and is also referred to as postacute sequelae of SARS-CoV-2 (PASC). The specific drivers of these symptoms are unclear, complicating the development of therapeutics for those suffering from this condition. Here, Li et al. used comparative analysis to interrogate a potential driver of respiratory PASC, one of the most debilitating types of PASC. The authors found that humans with respiratory PASC had evidence of an enhanced monocyte-derived macrophage response in their bronchoalveolar lavage fluid. A similar phenotype was observed in aged C57BL/6 mice infected with mouse-adapted SARS-CoV-2. This phenotype in mice could be reduced by anti–interferon-γ (anti–IFN-γ) treatment initiated after the resolution of acute disease, suggesting that the IFN-γ signaling pathway may represent a potential therapeutic target for humans. —Courtney Malo
Abstract
Postacute sequelae of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection (PASC) represent an urgent public health challenge and are estimated to affect more than 60 million individuals globally. Although a growing body of evidence suggests that dysregulated immune reactions may be linked with PASC symptoms, most investigations have primarily centered around blood-based studies, with few focusing on samples derived from affected tissues. Furthermore, clinical studies alone often provide correlative insights rather than causal mechanisms. Thus, it is essential to compare clinical samples with relevant animal models and conduct functional experiments to understand the etiology of PASC. In this study, we comprehensively compared bronchoalveolar lavage fluid single-cell RNA sequencing data derived from clinical PASC samples and a mouse model of PASC. This revealed a pro-fibrotic monocyte-derived macrophage response in respiratory PASC, as well as abnormal interactions between pulmonary macrophages and respiratory resident T cells, in both humans and mice. Interferon-γ (IFN-γ) emerged as a key node mediating the immune anomalies in respiratory PASC. Neutralizing IFN-γ after the resolution of acute SARS-CoV-2 infection reduced lung inflammation and tissue fibrosis in mice. Together, our study underscores the importance of performing comparative analysis to understand the cause of PASC and suggests that the IFN-γ signaling axis might represent a therapeutic target.
Editor’s summary
The term “Long Covid” covers a myriad of symptoms that a person may experience after an acute infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and is also referred to as postacute sequelae of SARS-CoV-2 (PASC). The specific drivers of these symptoms are unclear, complicating the development of therapeutics for those suffering from this condition. Here, Li et al. used comparative analysis to interrogate a potential driver of respiratory PASC, one of the most debilitating types of PASC. The authors found that humans with respiratory PASC had evidence of an enhanced monocyte-derived macrophage response in their bronchoalveolar lavage fluid. A similar phenotype was observed in aged C57BL/6 mice infected with mouse-adapted SARS-CoV-2. This phenotype in mice could be reduced by anti–interferon-γ (anti–IFN-γ) treatment initiated after the resolution of acute disease, suggesting that the IFN-γ signaling pathway may represent a potential therapeutic target for humans. —Courtney Malo
Abstract
Postacute sequelae of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection (PASC) represent an urgent public health challenge and are estimated to affect more than 60 million individuals globally. Although a growing body of evidence suggests that dysregulated immune reactions may be linked with PASC symptoms, most investigations have primarily centered around blood-based studies, with few focusing on samples derived from affected tissues. Furthermore, clinical studies alone often provide correlative insights rather than causal mechanisms. Thus, it is essential to compare clinical samples with relevant animal models and conduct functional experiments to understand the etiology of PASC. In this study, we comprehensively compared bronchoalveolar lavage fluid single-cell RNA sequencing data derived from clinical PASC samples and a mouse model of PASC. This revealed a pro-fibrotic monocyte-derived macrophage response in respiratory PASC, as well as abnormal interactions between pulmonary macrophages and respiratory resident T cells, in both humans and mice. Interferon-γ (IFN-γ) emerged as a key node mediating the immune anomalies in respiratory PASC. Neutralizing IFN-γ after the resolution of acute SARS-CoV-2 infection reduced lung inflammation and tissue fibrosis in mice. Together, our study underscores the importance of performing comparative analysis to understand the cause of PASC and suggests that the IFN-γ signaling axis might represent a therapeutic target.