Type I and Type III IFN Restrict SARS-CoV-2 Infection of Human Airway Epithelial Cultures

ABSTRACTThe newly emerged human coronavirus, SARS-CoV-2, has caused a pandemic of respiratory illness. The innate immune response is critical for protection against Coronaviruses. However, little is known about the interplay between the innate immune system and SARS-CoV-2. Here, we modeled SARS-CoV-2 infection using primary human airway epithelial (pHAE) cultures, which are maintained in an air-liquid interface. We found that SARS-CoV-2 infects and replicates in pHAE cultures and is directionally released on the apical, but not basolateral surface. Transcriptional profiling studies found that infected pHAE cultures had a molecular signature dominated by pro-inflammatory cytokines and chemokine induction, including IL-6, TNFα, CXCL8. We also identified NF-κB and ATF4 transcription factors as key drivers of this pro-inflammatory cytokine response. Surprisingly, we observed a complete lack of a type I or III IFN induction during SARS-CoV-2 infection. Pre-treatment or post-treatment with type I and III IFNs dramatically reduced virus replication in pHAE cultures and this corresponded with an upregulation of antiviral effector genes. Our findings demonstrate that SARS-CoV-2 induces a strong pro-inflammatory cytokine response yet blocks the production of type I and III IFNs. Further, SARS-CoV-2 is sensitive to the effects of type I and III IFNs, demonstrating their potential utility as therapeutic options to treat COVID-19 patients.IMPORTANCEThe current pandemic of respiratory illness, COVID-19, is caused by a recently emerged coronavirus named SARS-CoV-2. This virus infects airway and lung cells causing fever, dry cough, and shortness of breath. Severe cases of COVID-19 can result in lung damage, low blood oxygen levels, and even death. As there are currently no vaccines or antivirals approved for use in humans, studies of the mechanisms of SARS-CoV-2 infection are urgently needed. SARS-CoV-2 infection of primary human airway epithelial cultures induces a strong pro-inflammatory cytokine response yet blocks the production of type I and III IFNs. Further, SARS-CoV-2 is sensitive to the effects of type I and III IFNs, demonstrating their potential utility as therapeutic options to treat COVID-19 patients.

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Type I and Type III Interferons Restrict SARS-CoV-2 Infection of Human Airway Epithelial Cultures

Journal of Virology ◽

10.1128/jvi.00985-20 ◽

2020 ◽

Vol 94 (19) ◽

Cited By ~ 19

Author(s):

Abigail Vanderheiden ◽

Philipp Ralfs ◽

Tatiana Chirkova ◽

Amit A. Upadhyay ◽

Matthew G. Zimmerman ◽

...

Keyword(s):

Proinflammatory Cytokine ◽

Respiratory Illness ◽

Model System ◽

Cytokine Response ◽

Molecular Signature ◽

Current Evidence ◽

Type I ◽

Airway Epithelial ◽

Type Iii ◽

Human Airway

ABSTRACT The newly emerged human coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has caused a pandemic of respiratory illness. Current evidence suggests that severe cases of SARS-CoV-2 are associated with a dysregulated immune response. However, little is known about how the innate immune system responds to SARS-CoV-2. In this study, we modeled SARS-CoV-2 infection using primary human airway epithelial (pHAE) cultures, which are maintained in an air-liquid interface. We found that SARS-CoV-2 infects and replicates in pHAE cultures and is directionally released on the apical, but not basolateral, surface. Transcriptional profiling studies found that infected pHAE cultures had a molecular signature dominated by proinflammatory cytokines and chemokine induction, including interleukin 6 (IL-6), tumor necrosis factor alpha (TNF-α), and CXCL8, and identified NF-κB and ATF-4 as key drivers of this proinflammatory cytokine response. Surprisingly, we observed a complete lack of a type I or III interferon (IFN) response to SARS-CoV-2 infection. However, pretreatment and posttreatment with type I and III IFNs significantly reduced virus replication in pHAE cultures that correlated with upregulation of antiviral effector genes. Combined, our findings demonstrate that SARS-CoV-2 does not trigger an IFN response but is sensitive to the effects of type I and III IFNs. Our studies demonstrate the utility of pHAE cultures to model SARS-CoV-2 infection and that both type I and III IFNs can serve as therapeutic options to treat COVID-19 patients. IMPORTANCE The current pandemic of respiratory illness, COVID-19, is caused by a recently emerged coronavirus named SARS-CoV-2. This virus infects airway and lung cells causing fever, dry cough, and shortness of breath. Severe cases of COVID-19 can result in lung damage, low blood oxygen levels, and even death. As there are currently no vaccines approved for use in humans, studies of the mechanisms of SARS-CoV-2 infection are urgently needed. Our research identifies an excellent system to model SARS-CoV-2 infection of the human airways that can be used to test various treatments. Analysis of infection in this model system found that human airway epithelial cell cultures induce a strong proinflammatory cytokine response yet block the production of type I and III IFNs to SARS-CoV-2. However, treatment of airway cultures with the immune molecules type I or type III interferon (IFN) was able to inhibit SARS-CoV-2 infection. Thus, our model system identified type I or type III IFN as potential antiviral treatments for COVID-19 patients.

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Human β‐defensin 3 binds to hemagglutinin B (rHagB), a non‐fimbrial adhesin from Porphyromonas gingivalis , and attenuates a pro‐inflammatory cytokine response

Immunology and Cell Biology ◽

10.1038/icb.2008.56 ◽

2008 ◽

Vol 86 (8) ◽

pp. 643-649 ◽

Cited By ~ 53

Author(s):

Lindsey C Pingel ◽

Karl G Kohlgraf ◽

Christopher J Hansen ◽

Christopher G Eastman ◽

Deborah E Dietrich ◽

...

Keyword(s):

Porphyromonas Gingivalis ◽

Inflammatory Cytokine ◽

Cytokine Response ◽

Inflammatory Cytokine Response ◽

Fimbrial Adhesin

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Alpha-1 antitrypsin inhibits TMPRSS2 protease activity and SARS-CoV-2 infection

Nature Communications ◽

10.1038/s41467-021-21972-0 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Lukas Wettstein ◽

Tatjana Weil ◽

Carina Conzelmann ◽

Janis A. Müller ◽

Rüdiger Groß ◽

...

Keyword(s):

Serine Protease ◽

Immune Defense ◽

Innate Immune ◽

Respiratory Pathogen ◽

The Novel ◽

Airway Epithelial ◽

Protein Library ◽

Epithelial Cultures ◽

Alpha 1 Antitrypsin ◽

Novel Coronavirus

AbstractSARS-CoV-2 is a respiratory pathogen and primarily infects the airway epithelium. As our knowledge about innate immune factors of the respiratory tract against SARS-CoV-2 is limited, we generated and screened a peptide/protein library derived from bronchoalveolar lavage for inhibitors of SARS-CoV-2 spike-driven entry. Analysis of antiviral fractions revealed the presence of α1-antitrypsin (α1AT), a highly abundant circulating serine protease inhibitor. Here, we report that α1AT inhibits SARS-CoV-2 entry at physiological concentrations and suppresses viral replication in cell lines and primary cells including human airway epithelial cultures. We further demonstrate that α1AT binds and inactivates the serine protease TMPRSS2, which enzymatically primes the SARS-CoV-2 spike protein for membrane fusion. Thus, the acute phase protein α1AT is an inhibitor of TMPRSS2 and SARS-CoV-2 entry, and may play an important role in the innate immune defense against the novel coronavirus. Our findings suggest that repurposing of α1AT-containing drugs has prospects for the therapy of COVID-19.

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