Prevalence and Mechanisms of Mucus Plugging in COVID-19 Lung Disease
Ontology highlight
ABSTRACT: Purpose: To investigate molecular mechanisms of SARS-CoV-2-induced mucin expression and synthesis and test candidate countermeasures. Methods: Bulk RNA-seq was performed on well-differentiated human bronchial epithelial (HBE) cell culture lysates with/without SARS-CoV-2 inoculation. Results: SARS-CoV-2-infected HBE cultures exhibited peak titers 3 days post inoculation, whereas induction of MUC5B/MUC5AC peaked 7-14 days post inoculation. Conclusions: SARS-CoV-2-infection to HBE culture causes mucus goblet cell metaplasia and increased expression of MUC5B-dominated mucin overproduction.
Project description:We use high-throughput sequencing to profile the response of oral commensal pathogen Streptococcus mutans to mucins protein polymers (human MUC5B mucins) and soluble mucin glycans (human MUC5B glycans and porcine MUC5AC glycans). We find that mucins and their glycans alter the regulation of dozens of S. mutans genes, specifically downregulating competence-associated quorum sensing genes. The transcriptional responses induced by MUC5B mucins, MUC5B glycans, and MUC5AC glycans are highly correlated.
Project description:Mucus accumulation is a key feature of respiratory diseases such as cystic fibrosis (CF) and chronic obstructive pulmonary disease (COPD). This is associated with goblet cell metaplasia and mucin overexpression, which can be induced by the increased activity of neutrophil elastase. The aim of the study was to characterization of mucus and epithelial cell proteomics in a porcine pancreatic elastase (PPE) mouse model of COPD/CF. The major proteins detected in mucus plugs obtained from PPE-treated mice included mucins Muc5ac and Muc5b, mucus-related proteins Clca1, Fcgbp, and Bpifb1. These proteins were upregulated in bronchoalveolar lavage (BAL) fluid and epithelial cells in mice exposed to elastase. Similar changes were found in BAL fluid of COPD patients.
Project description:We investigated the interactions of four distinct betacoronaviruses; HCoV-OC43, SARS-CoV, MERS-CoV, and SARS-CoV-2 within human bronchial epithelial (HBE) organoids using single-cell RNA sequencing (scRNA-seq) to comprehensively understand betacoronaviruses cellular tropism and the intricate interplay between these cells and the host's immune defense mechanisms.
Project description:The Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has had devastating impacts on our global society. Although vaccines and monoclonal antibody countermeasures have reduced the morbidity and mortality associated with SARS-CoV-2 infection, variants with constellations of mutations in the spike gene threaten their efficacy. Therefore, antiviral interventions that are resistant to further virus evolution may be needed. Here, we show IFN-λ protects against SARS-CoV-2 B.1.351 (Beta) and B.1.1529 (Omicron) variants in three strains of conventional and human ACE2 transgenic mice. Prophylaxis or therapy with nasally-delivered IFN-λ2 limited infection of historical or variant (B.1.351 and B.1.1.529) SARS-CoV-2 strains in both the upper and lower respiratory tracts without causing excessive inflammation. In the lung, IFN-λ was produced preferentially in epithelial cells and acted on radio-resistant cells to protect against of SARS-CoV-2 infection. Thus, inhaled IFN-λ may have promise as a treatment for evolving SARS-CoV-2 variants that develop resistance to antibody-based countermeasures.
Project description:To further investigate the underlying mechanisms of severe acute respiratory syndrome (SARS) pathogenesis and evaluate the therapeutic efficacy of potential drugs and vaccines it is necessary to use an animal model that is highly representative of the human condition in terms of respiratory anatomy, physiology and clinical sequelae. The ferret, Mustela putorius furo, supports SARS-CoV replication and displays many of the symptoms and pathological features seen in SARS-CoV-infected humans. We have recently established a SARS-CoV infection-challenge ferret platform for use in evaluating potential therapeutics to treat SARS. The main objective of the current study was to extend our previous results and identify early host immune responses upon infection and determine immune correlates of protection upon challenge with SARS-CoV in ferrets. Keywords: time course This study is a simple time course (58 day) examination of host responses in 35 SARS-CoV (TOR2) infected ferrets with the addition of a challenge inoculation of SARS CoV (TOR2) at day 29 post infection. Three mock-infected ferrets are included as negative controls. Due to the unavailability of ferret microarrays, Affymetrix Canine 2.0 oligonucleotide arrays were chosen following sequence analysis of our ferret cDNA library (~5000 clones) and demonstration of high levels of homology (>80%) between dog and ferret.
Project description:The COVID-19 pandemic prompted an unprecedented effort to develop effective countermeasures against SARS-CoV-2. While efficacious vaccines and certain therapeutic monoclonal antibodies are available, here, we report the development, cryo-EM structures and functional analyses of distinct potent monoclonal antibodies (mAbs) that neutralize SARS-CoV-2 and its variant B.1.351. We established a platform for rapid identification of highly potent and specific SARS-CoV-2-neutralizing antibodies by high-throughput B cell receptor single cell sequencing of spike receptor binding domain immunized animals. We identified two highly potent and specific SARS-CoV-2 neutralizing mAb clones that have single-digit nanomolar affinity and low-picomolar avidity. We also generated a bispecific antibody of these two lead clones. The lead monospecific and bispecific antibodies showed strong neutralization ability against prototypical SARS-CoV-2 and the highly contagious South African variant B.1.351 that post a further risk of reducing the efficacy of currently available therapeutic antibodies and vaccines. The lead mAbs showed potent in vivo efficacy against authentic SARS-CoV-2 in both prophylactic and therapeutic settings. We solved five cryo-EM structures at ~3 resolution of these neutralizing antibodies in complex with the ectodomain of the prefusion spike trimer, and revealed the molecular epitopes, binding patterns and conformations between the antibodies and spike RBD, which are distinct from existing antibodies. Our recently developed antibodies expand the repertoire of the toolbox of COVID-19 countermeasures against the SARS-CoV-2 pathogen and its emerging variants.
Project description:The dominant risk factor for the development of idiopathic pulmonary fibrosis (IPF) is a common variant in the promoter region of the airway mucin MUC5B, variant rs35705950. The MUC5B promoter variant enhances MUC5B expression in the terminal respiratory bronchiole, where it is normally absent. We pursued a spatial gene expression approach to understand how the MUC5B variant influences IPF in age-matched unaffected and IPF lung tissue specimens.
Project description:The ancestral sarbecovirus giving rise to SARS-CoV-2 is posited to have originated in bats. While SARS-CoV-2 causes asymptomatic to severe respiratory disease in humans, little is known about the biology, virus tropism, and immunity of SARS-CoV-2-like sarbecoviruses in bats. SARS-CoV-2 has been shown to infect multiple mammalian species, including various rodent species, non-human primates, and Egyptian fruit bats. Here, we investigate the Jamaican fruit bat (Artibeus jamaicensis) as a possible model species to study reservoir responses. SARS-CoV-2 can utilize Jamaican fruit bat ACE2 spike for entry in vitro. However, we find that SARS-CoV-2 Delta does not efficiently replicate in Jamaican fruit bats in vivo. We observe infectious virus in the lungs of only one animal on day 1 post inoculation and find no evidence for shedding or seroconversion. This is possibly due to host factors restricting virus egress after aborted replication. Furthermore, we observe no significant immune gene expression changes in the respiratory tract but do observe changes in the intestinal metabolome after inoculation. This suggests that, despite its broad host-range, SARS-CoV-2 is unable to infect all bat species and Jamaican fruit bats are not an appropriate model to study SARS-CoV-2 reservoir infection.
Project description:A recombinant SARS-CoV lacking the envelope (E) protein is attenuated in vivo. Here we report that E protein PDZ-binding motif (PBM), a domain involved in protein-protein interactions, is a major virulence determinant in vivo. Elimination of SARS-CoV E protein PBM by using reverse genetics led to attenuated viruses (SARS-CoV-mutPBM) and to a reduction in the deleterious exacerbate immune response triggered during infection with the parental virus (SARS-CoV-wt). Cellular protein syntenin bound E protein PBM during SARS-CoV infection. Syntenin activates p38 MAPK leading to overexpression of inflammatory cytokines, and we have shown that active p38 MAPK was reduced in lungs of mice infected with SARS-CoVs lacking E protein PBM (SARS-CoV-mutPBM) as compared with the parental virus (SARS-CoV-wt), leading to a decreased expression of inflammatory cytokines and to viral attenuation. Therefore, E protein PBM is a virulence factor that activates pathogenic immune response most likely by using syntenin as a mediator of p38 MAPK induced inflammation. Three biological replicates were independently hybridized (one channel per slide) for each sample type (SARS-CoV-wt, SARS-CoV-mutPBM, Mock). Slides were Sure Print G3 Agilent 8x60K Mouse (G4852A-028005)
Project description:For the assessment of host response dynamics to SARS-CoV and SARS-CoV-2 infections in human airway epithelial cells at ambient temperature corresponding to the upper or lower respiratory tract. We performed a temporal transcriptome analysis on human airway epithelial cell (hAEC) cultures infected with SARS-CoV and SARS-CoV-2, as well as uninfected hAEC cultures, incubated either at 33°C or 37°C. hAEC cultures were harvested at 24, 48 72, 96 hpi and processed for Bulk RNA Barcoding and sequencing (BRB-seq), which allows a rapid and sensitive genome-wide transcriptomic analysis in a highly multiplexed manner. Transcriptome data was obtained from a total of 7 biological donors for pairwise comparisons of SARS-CoV or SARS-CoV-2 virus-infected to unexposed hAEC cultures at respective time points and temperatures.