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1.
J Photochem Photobiol B ; 226: 112357, 2022 Jan.
Article in English | MEDLINE | ID: covidwho-1510060

ABSTRACT

Mitochondrial antiviral signaling (MAVS) protein mediates innate antiviral responses, including responses to certain coronaviruses such as severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). We have previously shown that ultraviolet-A (UVA) therapy can prevent virus-induced cell death in human ciliated tracheal epithelial cells (HTEpC) infected with coronavirus-229E (CoV-229E), and results in increased intracellular levels of MAVS. In this study, we explored the mechanisms by which UVA light can activate MAVS, and whether local UVA light application can activate MAVS at locations distant from the light source (e.g. via cell-to-cell communication). MAVS levels were compared in HTEpC exposed to 2 mW/cm2 narrow band (NB)-UVA for 20 min and in unexposed controls at 30-40% and at 100% confluency, and in unexposed HTEpC treated with supernatants or lysates from UVA-exposed cells or from unexposed controls. MAVS was also assessed in different sections of confluent monolayer plates where only one section was exposed to NB-UVA. Our results showed that UVA increases the expression of MAVS protein. Further, cells in a confluent monolayer exposed to UVA conferred an elevation in MAVS in cells adjacent to the exposed section, and also in cells in the most distant sections which were not exposed to UVA. In this study, human ciliated tracheal epithelial cells exposed to UVA demonstrate increased MAVS protein, and also appear to transmit this influence to confluent cells not exposed to UVA, likely via cell-cell signaling.


Subject(s)
Adaptor Proteins, Signal Transducing/metabolism , Adaptor Proteins, Signal Transducing/radiation effects , Ultraviolet Rays , Adaptor Proteins, Signal Transducing/immunology , COVID-19/immunology , COVID-19/radiotherapy , COVID-19/virology , Cell Communication/immunology , Cell Communication/radiation effects , Cells, Cultured , Epithelial Cells/immunology , Epithelial Cells/radiation effects , Host Microbial Interactions/immunology , Host Microbial Interactions/radiation effects , Humans , Immunity, Innate/radiation effects , Photobiology , SARS-CoV-2/immunology , SARS-CoV-2/pathogenicity , Signal Transduction/immunology , Signal Transduction/radiation effects , Trachea/cytology , Ultraviolet Therapy
2.
Int J Mol Sci ; 22(19)2021 Sep 30.
Article in English | MEDLINE | ID: covidwho-1444232

ABSTRACT

Natural or experimental infection of domestic cats and virus transmission from humans to captive predatory cats suggest that felids are highly susceptible to SARS-CoV-2 infection. However, it is unclear which cells and compartments of the respiratory tract are infected. To address this question, primary cell cultures derived from the nose, trachea, and lungs of cat and lion were inoculated with SARS-CoV-2. Strong viral replication was observed for nasal mucosa explants and tracheal air-liquid interface cultures, whereas replication in lung slices was less efficient. Infection was mainly restricted to epithelial cells and did not cause major pathological changes. Detection of high ACE2 levels in the nose and trachea but not lung further suggests that susceptibility of feline tissues to SARS-CoV-2 correlates with ACE2 expression. Collectively, this study demonstrates that SARS-CoV-2 can efficiently replicate in the feline upper respiratory tract ex vivo and thus highlights the risk of SARS-CoV-2 spillover from humans to felids.


Subject(s)
COVID-19/veterinary , Cats/virology , Lions/virology , Angiotensin-Converting Enzyme 2/analysis , Animals , COVID-19/transmission , COVID-19/virology , Cat Diseases/transmission , Cat Diseases/virology , Cells, Cultured , Disease Susceptibility , Humans , Lung/cytology , Lung/virology , Nose/cytology , Nose/virology , SARS-CoV-2/isolation & purification , Trachea/cytology , Trachea/virology
3.
Virulence ; 12(1): 1111-1121, 2021 12.
Article in English | MEDLINE | ID: covidwho-1243446

ABSTRACT

Coronaviruses and influenza viruses are circulating in humans and animals all over the world. Co-infection with these two viruses may aggravate clinical signs. However, the molecular mechanisms of co-infections by these two viruses are incompletely understood. In this study, we applied air-liquid interface (ALI) cultures of well-differentiated porcine tracheal epithelial cells (PTECs) to analyze the co-infection by a swine influenza virus (SIV, H3N2 subtype) and porcine respiratory coronavirus (PRCoV) at different time intervals. Our results revealed that in short-term intervals, prior infection by influenza virus caused complete inhibition of coronavirus infection, while in long-term intervals, some coronavirus replication was detectable. The influenza virus infection resulted in (i) an upregulation of porcine aminopeptidase N, the cellular receptor for PRCoV and (ii) in the induction of an innate immune response which was responsible for the inhibition of PRCoV replication. By contrast, prior infection by coronavirus only caused a slight inhibition of influenza virus replication. Taken together, the timing and the order of virus infection are important determinants in co-infections. This study is the first to show the impact of SIV and PRCoV co- and super-infection on the cellular level. Our results have implications also for human viruses, including potential co-infections by SARS-CoV-2 and seasonal influenza viruses.


Subject(s)
Epithelial Cells/virology , Influenza A Virus, H3N2 Subtype/physiology , Porcine Respiratory Coronavirus/physiology , Viral Interference , Animals , CD13 Antigens/metabolism , Cells, Cultured , Coinfection/virology , Coronavirus Infections/virology , Epithelial Cells/immunology , Epithelial Cells/metabolism , Epithelial Cells/pathology , Immunity, Innate , Orthomyxoviridae Infections/virology , Swine , Trachea/cytology , Virus Replication
4.
Methods Mol Biol ; 2203: 135-143, 2020.
Article in English | MEDLINE | ID: covidwho-761350

ABSTRACT

Several techniques are currently available to quickly and accurately quantify the number of virus particles in a sample, taking advantage of advanced technologies improving old techniques or generating new ones, generally relying on partial detection methods or structural analysis. Therefore, characterization of virus infectivity in a sample is often essential, and classical virological methods are extremely powerful in providing accurate results even in an old-fashioned way. In this chapter, we describe in detail the techniques routinely used to estimate the number of viable infectious coronavirus particles in a given sample. All these techniques are serial dilution assays, also known as titrations or end-point dilution assays (EPDA).


Subject(s)
Coronavirus/pathogenicity , Viral Plaque Assay/methods , Animals , Cells, Cultured , Coronavirus/growth & development , Infectious bronchitis virus/growth & development , Infectious bronchitis virus/pathogenicity , Trachea/cytology
5.
Respir Investig ; 58(3): 155-168, 2020 May.
Article in English | MEDLINE | ID: covidwho-154704

ABSTRACT

BACKGROUND: Coronavirus 229E (HCoV-229E), one of the causes of the common cold, exacerbates chronic obstructive pulmonary disease (COPD) and bronchial asthma. Long-acting muscarinic antagonists and ß2-agonists and inhaled corticosteroids inhibit the exacerbation of COPD and bronchial asthma caused by infection with viruses, including HCoV-229E. However, the effects of these drugs on HCoV-229E replication and infection-induced inflammation in the human airway are unknown. METHODS: Primary human nasal (HNE) and tracheal (HTE) epithelial cell cultures were infected with HCoV-229E. RESULTS: Pretreatment of HNE and HTE cells with glycopyrronium or formoterol decreased viral RNA levels and/or titers, the expression of the HCoV-229E receptor CD13, the number and fluorescence intensity of acidic endosomes where HCoV-229E RNA enters the cytoplasm, and the infection-induced production of cytokines, including IL-6, IL-8, and IFN-ß. Treatment of the cells with the CD13 inhibitor 2'2'-dipyridyl decreased viral titers. Pretreatment of the cells with a combination of three drugs (glycopyrronium, formoterol, and budesonide) exerted additive inhibitory effects on viral titers and cytokine production. Pretreatment of HNE cells with glycopyrronium or formoterol reduced the susceptibility to infection, and pretreatment with the three drugs inhibited activation of nuclear factor-kappa B p50 and p65 proteins. Pretreatment with formoterol increased cAMP levels and treatment with cAMP decreased viral titers, CD13 expression, and the fluorescence intensity of acidic endosomes. CONCLUSIONS: These findings suggest that glycopyrronium, formoterol, and a combination of glycopyrronium, formoterol, and budesonide inhibit HCoV-229E replication partly by inhibiting receptor expression and/or endosomal function and that these drugs modulate infection-induced inflammation in the airway.


Subject(s)
Adrenergic beta-2 Receptor Agonists/pharmacology , Budesonide/pharmacology , Coronavirus/physiology , Cytokines/metabolism , Epithelial Cells/metabolism , Epithelial Cells/virology , Formoterol Fumarate/pharmacology , Glycopyrrolate/pharmacology , Muscarinic Antagonists/pharmacology , Nasal Mucosa/cytology , Trachea/cytology , Virus Replication/drug effects , CD13 Antigens/metabolism , Cells, Cultured , Humans
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