SARS-CoV-2 entry factors are highly expressed in nasal epithelial cells together with innate immune genes.
Ontology highlight
ABSTRACT:
SUBMITTER: Sungnak W
PROVIDER: S-EPMC8637938 | biostudies-literature |
REPOSITORIES: biostudies-literature
Similar Datasets
Project description:The SARS-CoV-2 coronavirus, the etiologic agent responsible for COVID-19 coronavirus disease, is a global threat. To better understand viral tropism, we assessed the RNA expression of the coronavirus receptor, ACE2, as well as the viral S protein priming protease TMPRSS2 thought to govern viral entry in single-cell RNA-sequencing (scRNA-seq) datasets from healthy individuals generated by the Human Cell Atlas consortium. We found that ACE2, as well as the protease TMPRSS2, are differentially expressed in respiratory and gut epithelial cells. In-depth analysis of epithelial cells in the respiratory tree reveals that nasal epithelial cells, specifically goblet/secretory cells and ciliated cells, display the highest ACE2 expression of all the epithelial cells analyzed. The skewed expression of viral receptors/entry-associated proteins towards the upper airway may be correlated with enhanced transmissivity. Finally, we showed that many of the top genes associated with ACE2 airway epithelial expression are innate immune-associated, antiviral genes, highly enriched in the nasal epithelial cells. This association with immune pathways might have clinical implications for the course of infection and viral pathology, and highlights the specific significance of nasal epithelia in viral infection. Our findings underscore the importance of the availability of the Human Cell Atlas as a reference dataset. In this instance, analysis of the compendium of data points to a particularly relevant role for nasal goblet and ciliated cells as early viral targets and potential reservoirs of SARS-CoV-2 infection. This, in turn, serves as a biological framework for dissecting viral transmission and developing clinical strategies for prevention and therapy.
| S-EPMC7280877 | biostudies-literature
Project description:BackgroundThe pathogenesis of COVID-19 emerges as complex, with multiple factors leading to injury of different organs. Some of the studies on aspects of SARS-CoV-2 cell entry and innate immunity have produced seemingly contradictory claims. In this situation, a comprehensive comparative analysis of a large number of related datasets from several studies could bring more clarity, which is imperative for therapy development.MethodsWe therefore performed a comprehensive comparative study, analyzing RNA-Seq data of infections with SARS-CoV-2, SARS-CoV and MERS-CoV, including data from different types of cells as well as COVID-19 patients. Using these data, we investigated viral entry routes and innate immune responses.Results and conclusionFirst, our analyses support the existence of cell entry mechanisms for SARS and SARS-CoV-2 other than the ACE2 route with evidence of inefficient infection of cells without expression of ACE2; expression of TMPRSS2/TPMRSS4 is unnecessary for efficient SARS-CoV-2 infection with evidence of efficient infection of A549 cells transduced with a vector expressing human ACE2. Second, we find that innate immune responses in terms of interferons and interferon simulated genes are strong in relevant cells, for example Calu3 cells, but vary markedly with cell type, virus dose, and virus type.
| S-EPMC8195239 | biostudies-literature
Project description:Durable cell-mediated immune responses require efficient innate immune signaling and the release of pro-inflammatory cytokines. How precisely mRNA vaccines trigger innate immune cells for shaping antigen specific adaptive immunity remains unknown. Here we show that SARS-CoV-2 mRNA vaccination primes human monocyte derived macrophages for activation of the NLRP3 inflammasome. Spike protein exposed macrophages undergo NLRP3 driven pyroptotic cell death and subsequently secrete mature interleukin-1β. These effects depend on activation of spleen tyrosine kinase (SYK) coupled to C-type lectin receptors. Using autologous co-cultures, we show that SYK and NLRP3 orchestrate macrophage driven activation of effector memory T cells. Furthermore, vaccination induced macrophage priming can be enhanced with repetitive antigen exposure providing a rationale for prime-boost concepts to augment innate immune signaling in SARS-CoV-2 vaccination. Collectively, these findings identify SYK as a regulatory node capable of differentiating between primed and unprimed macrophages, which modulate spike protein specific T cell responses.
| S-SCDT-EMM-2022-15888P | biostudies-other
Project description:Cell-intrinsic responses mounted in PBMCs during mild and severe COVID-19 differ quantitatively and qualitatively. Whether they are triggered by signals emitted by productively infected cells of the respiratory tract or result from physical interaction with virus particles, remains unclear. Here, we analyzed susceptibility and expression profiles of PBMCs from healthy donors upon ex vivo exposure to SARS-CoV and SARS-CoV-2. In line with the absence of detectable ACE2 receptor expression, human PBMCs were refractory to productive infection. RT-PCR experiments and single cell RNA-sequencing revealed JAK/STAT-dependent induction of interferon-stimulated genes (ISGs), but not pro-inflammatory cytokines. This SARS-CoV-2-specific response was most pronounced in monocytes. SARS-CoV-2-RNA-positive monocytes displayed a lower ISG signature as compared to bystander cells of the identical culture. This suggests a preferential invasion of cells with a low ISG base-line profile or delivery of a SARS-CoV-2-specific sensing antagonist upon efficient particle internalization. Together, non-productive physical interaction of PBMCs with SARS-CoV-2- and, to a much lesser extent, SARS-CoV particles stimulate JAK/STAT-dependent, monocyte-accentuated innate immune responses that resemble those detected in vivo in patients with mild COVID-19.
| S-SCDT-MSB-2022-10961 | biostudies-other
Project description:Recent studies have profiled the innate immune signatures in patients infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and suggest that cellular responses to viral challenge may affect disease severity. Yet the molecular events that underlie cellular recognition and response to SARS-CoV-2 infection remain to be elucidated. Here, we find that SARS-CoV-2 replication induces a delayed interferon (IFN) response in lung epithelial cells. By screening 16 putative sensors involved in sensing of RNA virus infection, we found that MDA5 and LGP2 primarily regulate IFN induction in response to SARS-CoV-2 infection. Further analyses revealed that viral intermediates specifically activate the IFN response through MDA5-mediated sensing. Additionally, we find that IRF3, IRF5, and NF-κB/p65 are the key transcription factors regulating the IFN response during SARS-CoV-2 infection. In summary, these findings provide critical insights into the molecular basis of the innate immune recognition and signaling response to SARS-CoV-2.
| S-EPMC7832566 | biostudies-literature
Project description:Most SARS-CoV-2 proteins are translated from subgenomic RNAs (sgRNAs). While the majority of these sgRNAs are monocistronic, some viral mRNAs encode more than one protein. One example is the ORF3a sgRNA that also encodes ORF3c, an enigmatic 41-amino acid peptide. Here, we show that ORF3c is expressed in SARS-CoV-2 infected cells and suppresses RIG-I- and MDA5-mediated IFN-β induction. ORF3c interacts with the signaling adaptor MAVS, induces its C-terminal cleavage and inhibits the interaction of RIG-I with MAVS. The immunosuppressive activity of ORF3c is conserved among members of the subgenus sarbecovirus, including SARS-CoV and coronaviruses isolated from bats. Notably, however, the SARS-CoV-2 delta and kappa variants harbor premature stop codons in ORF3c demonstrating that this reading frame is not essential for efficient viral replication in vivo and is likely compensated by other viral proteins. In agreement with this, disruption of ORF3c does not significantly affect SARS-CoV-2 replication in CaCo-2, CaLu-3 or Rhinolophus alcyone cells. In summary, we here identify ORF3c as an immune evasion factor of SARS-CoV-2 that suppresses innate sensing in infected cells.
| S-SCDT-10_15252-EMBR_202357137 | biostudies-other
Project description:The risk of developing severe COVID-19 rises dramatically with age. Schoolchildren are significantly less likely than older people to die from SARS-CoV-2 infection, but the molecular mechanisms underlying this age-dependence are unknown. In primary infections, innate immunity is critical due to the lack of immune memory. Children, in particular, have a significantly stronger interferon response due to a primed state of their airway epithelium. In single-cell transcriptomes of nasal turbinates, we find increased frequencies of immune cells and stronger cytokine-mediated interactions with epithelial cells, resulting in increased epithelial expression of viral sensors (RIG-I, MDA5) via IRF1. In vitro, adolescent PBMCs produce more cytokines, priming A549 cells for stronger interferon responses to SARS-CoV-2. Taken together, our findings suggest that increased numbers of immune cells in the airways of children and enhanced cytokine-based interactions with epithelial cells tune the set-point of the epithelial antiviral system. Our findings shed light on the molecular basis of children's remarkable resistance to COVID-19 and may suggest a novel concept for immunoprophylactic treatments.
| S-SCDT-10_15252-EMBR_202357912 | biostudies-other
Project description:BACKGROUNDInfluenza A virus (IAV) and SARS-CoV-2 are pandemic viruses causing millions of deaths, yet their clinical manifestations are distinctly different.METHODSWith the hypothesis that upper airway immune and epithelial cell responses are also distinct, we performed single-cell RNA sequencing (scRNA-Seq) on nasal wash cells freshly collected from adults with either acute COVID-19 or influenza or from healthy controls. We focused on major cell types and subtypes in a subset of donor samples.ResultsNasal wash cells were enriched for macrophages and neutrophils for both individuals with influenza and those with COVID-19 compared with healthy controls. Hillock-like epithelial cells, M2-like macrophages, and age-dependent B cells were enriched in COVID-19 samples. A global decrease in IFN-associated transcripts in neutrophils, macrophages, and epithelial cells was apparent in COVID-19 samples compared with influenza samples. The innate immune response to SARS-CoV-2 appears to be maintained in macrophages, despite evidence for limited epithelial cell immune sensing. Cell-to-cell interaction analyses revealed a decrease in epithelial cell interactions in COVID-19 and highlighted differences in macrophage-macrophage interactions for COVID-19 and influenza.ConclusionsOur study demonstrates that scRNA-Seq can define host and viral transcriptional activity at the site of infection and reveal distinct local epithelial and immune cell responses for COVID-19 and influenza that may contribute to their divergent disease courses.FundingMassachusetts Consortium on Pathogen Readiness, the Mathers Foundation, and the Department of Defense (W81XWH2110029) "COVID-19 Expansion for AIRe Program."
| S-EPMC8663782 | biostudies-literature
Project description:We performed single-cell RNA sequencing (scRNA-Seq) on nasal wash cells freshly collected from adults with COVID-19, influenza A, or no disease (healthy). Major cell types and subtypes were defined using cluster analysis and classic transcriptional markers.
2021-09-29 | GSE176269 | GEO
Project description:Severe acute respiratory syndrome-associated coronavirus (SARS-CoV) infection causes an immune-mediated disease. We have recently shown that SARS-CoV-induced epithelial Calu-3 cytokines could exacerbate and dampen host inflammatory and T cell responses, respectively, through modulating the functions of macrophages and dendritic cells, thereby suggesting that not only are lung epithelial cells the primary cells of SARS-CoV infection, but they also involve in initiating and orchestrating the host innate and adaptive immunity. Comprehensive evaluation of the complex epithelial signaling to SARS-CoV is, thus, crucial for paving the way to better understand SARS pathogenesis and develop the innovative therapeutics against SARS. Here, based on the microarray-based functional genomics, we reported that 2B4 cells, a clonal derivative of Calu-3 cells, elicited a temporal and spatial activation of nuclear factor (NF)kappaB, activator protein (AP)-1 (ATF2/c-Jun), and interferon regulatory factor (IRF)-3/-7 at 12-, 24-, and 48-hrs post infection (p.i.), respectively, resulting in the activation of many antiviral genes, including interferon (IFN)-β, -λs, SARS-related inflammatory mediators, and various IFN-stimulated genes (ISGs). While elevated responses of IFN-β and IFN-λs were not detected until 48-hrs p.i., as a consequence of a delayed IRF-3/-7 activation, we showed, for the first time, that both types of IFNs exerted previously under-described non-redundant, complementary, and/or synergistic effects on the epithelial defense against SARS-CoV. Collectively, our results highlight the molecular mechanisms of the sequential activation of virus- and IFN-dependent signaling of lung epithelial cells against SARS-CoV and identify novel cellular targets for future studies, aiming at advancing strategies against SARS. DNA microarrays were performed in the Molecular Genomics (MG) Core Facilities at UTMB. The detailed information about the procedures of microarray analysis has been posted on the MG Core Facilities website (genomics@scms.utmb.edu). To characterize the dynamic, spatial, and temporal changes of the gene expression induced by SARS-CoV, confluent 2B4 cells grown in T-75 flasks were infected with SARS-CoV (MOI=0.1) or remained uninfected (as control) for 12, 24, and 48hrs. Because 2B4 cells were also permissive to the productive infection of Dhori virus (DHOV), a member of the Orthomyxoviridae family within the Thogotovirus genus, resulting in robust responses of IFNs and other pro-inflammatory mediators, we also established parallel cultures of DHOV-infected 2B4 cells (MOI=0.1) for the comparative analysis of global gene expression elicited by SARS-CoV- versus DHOV-infected 2B4 cells. To meet the minimal number required for application of statistical algorithms, we performed the study in triplicate at each time point for mock-, SARS-CoV-, and DHOV-infected cultures, yielding a total of 27 arrays. Briefly, supernatants were harvested from differentially treated cultures at 12-, 24-, and 48-hrs p.i. for subsequent analyses of viral yields and cytokine profiling, whereas the cells were subjected to total RNA extraction by using an RNAqueous-4PCR kit and following the protocol recommended by the manufacturer (Ambion, Austin, TX). Purified RNA samples were sent to our core facility for conversion to cDNA, biotin-labeled, and hybridized to 27 Affymetrix Human Genome U133 Plus 2.0 âGene Chipsâ each of which contained 54,675 probe set identifiers representing more than ~47,400 transcripts that identify ~38,500 well-characterized genes, and various internal controls (Affymetrix, Santa Clara, CA). Mock-infected cells were compared to cells infected with SARS-CoV or DHOV at each time point.
2010-02-24 | E-GEOD-17400 | biostudies-arrayexpress