Subject(s)
COVID-19 Drug Treatment , Macrophages, Alveolar , Dexamethasone/pharmacology , Humans , SARS-CoV-2ABSTRACT
Exploring the cross-talk between the immune system and advanced biomaterials to treat SARS-CoV-2 infection is a promising strategy. Here, we show that ACE2-overexpressing A549 cell-derived microparticles (AO-MPs) are a potential therapeutic agent against SARS-CoV-2 infection. Intranasally administered AO-MPs dexterously navigate the anatomical and biological features of the lungs to enter the alveoli and are taken up by alveolar macrophages (AMs). Then, AO-MPs increase the endosomal pH but decrease the lysosomal pH in AMs, thus escorting bound SARS-CoV-2 from phago-endosomes to lysosomes for degradation. This pH regulation is attributable to oxidized cholesterol, which is enriched in AO-MPs and translocated to endosomal membranes, thus interfering with proton pumps and impairing endosomal acidification. In addition to promoting viral degradation, AO-MPs also inhibit the proinflammatory phenotype of AMs, leading to increased treatment efficacy in a SARS-CoV-2-infected mouse model without side effects. These findings highlight the potential use of AO-MPs to treat SARS-CoV-2-infected patients and showcase the feasibility of MP therapies for combatting emerging respiratory viruses in the future.
Subject(s)
Angiotensin-Converting Enzyme 2/administration & dosage , Angiotensin-Converting Enzyme 2/metabolism , COVID-19/metabolism , COVID-19/therapy , Cell- and Tissue-Based Therapy/methods , Cell-Derived Microparticles/metabolism , Cholesterol/metabolism , Endosomes/chemistry , Macrophages, Alveolar/metabolism , SARS-CoV-2/metabolism , A549 Cells , Angiotensin-Converting Enzyme 2/genetics , Animals , COVID-19/virology , Chlorocebus aethiops , Disease Models, Animal , Female , Humans , Hydrogen-Ion Concentration , Lysosomes/chemistry , Mice , Mice, Inbred ICR , Mice, Transgenic , Oxidation-Reduction , RAW 264.7 Cells , Treatment Outcome , Vero CellsSubject(s)
Angiotensin-Converting Enzyme 2/metabolism , COVID-19/enzymology , Lung/enzymology , Receptors, Aryl Hydrocarbon/metabolism , SARS-CoV-2/pathogenicity , Angiotensin-Converting Enzyme 2/genetics , Animals , Basic Helix-Loop-Helix Transcription Factors , Binding Sites , COVID-19/genetics , COVID-19/virology , Cell Line , Disease Models, Animal , Host-Pathogen Interactions , Humans , Lung/virology , Macaca , Mice , Promoter Regions, Genetic , Receptors, Aryl Hydrocarbon/geneticsABSTRACT
Silent hypoxia has emerged as a unique feature of coronavirus disease 2019 (COVID-19). In this study, we show that mucins are accumulated in the bronchoalveolar lavage fluid (BALF) of COVID-19 patients and are upregulated in the lungs of severe respiratory syndrome coronavirus 2 (SARS-CoV-2)-infected mice and macaques. We find that induction of either interferon (IFN)-ß or IFN-γ upon SARS-CoV-2 infection results in activation of aryl hydrocarbon receptor (AhR) signaling through an IDO-Kyn-dependent pathway, leading to transcriptional upregulation of the expression of mucins, both the secreted and membrane-bound, in alveolar epithelial cells. Consequently, accumulated alveolar mucus affects the blood-gas barrier, thus inducing hypoxia and diminishing lung capacity, which can be reversed by blocking AhR activity. These findings potentially explain the silent hypoxia formation in COVID-19 patients, and suggest a possible intervention strategy by targeting the AhR pathway.