Pediatric nasal epithelial cells are less permissive to SARS-CoV-2 replication compared to adult cells

AbstractRationaleYoung children (typically those <10 years old) are less susceptible to SARS-CoV-2 infection and symptoms compared to adults. However, the mechanisms that underlie these age-dependent differences remain to be determined and could inform future therapeutics for adults.ObjectiveTo contrast the infection dynamics of SARS-CoV-2 in primary nasal epithelial cells from adults and children.MethodsViral replication was quantified by plaque assay. The cellular transcriptome of infected and uninfected cells was assessed by RNA-seq. ACE2 and TMPRSS2 protein expression were quantified by Western Blot.Measurements and Main ResultsWe report significantly higher SARS-CoV-2 replication in adult compared to pediatric nasal epithelial cells. This was restricted to SARS-CoV-2 infection, as the same phenomenon was not observed with influenza virus infection. The differentiational SARS-CoV-2 replication dynamics were associated with an elevated type I and III interferon response, and a more pronounced inflammatory response in pediatric cells. No significant difference between the two age groups was observed in the protein levels of ACE2 and TMPRSS2.ConclusionsOur data suggest that the innate immune response of pediatric nasal epithelial cells, and not differential receptor expression, may contribute to the reported reduced SARS-COV-2 infection and symptoms reported amongst children.At a Glance CommentaryScientific Knowledge on the SubjectThere is now a growing body of evidence that children are less susceptible to SARS-CoV-2 infection compared to adults and if infected, children are more likely to develop an asymptomatic infection. The reasons for this remain unclear. In particular, the role of the pediatric nasal epithelium, the primary point of viral entry into the human host, in this differential susceptibility has yet to be investigated.What This Study Adds to the FieldOur study indicates that pediatric nasal epithelial cells produce a more vigorous anti-viral and pro-inflammatory response to SARS-CoV-2 compared to adult cells. This is associated with reduced SARS-CoV-2, but not influenza virus, replication in pediatric epithelial cells. We also show that on a protein level SARS-CoV-2 receptor expression on nasal epithelial cells is not significantly different between children and adults. These data provide an important insight into pediatric infections with SARS-CoV-2.

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PLASMACYTOID DENDRITIC CELLS FUNCTION IN HIV INFECTION

Clinical & Investigative Medicine ◽

10.25011/cim.v31i4.4808 ◽

2008 ◽

Vol 31 (4) ◽

pp. 13

Author(s):

Martin Hyrcza ◽

Mario Ostrowski ◽

Sandy Der

Keyword(s):

Dendritic Cells ◽

Influenza Virus ◽

Hiv Infection ◽

Gene Transcription ◽

Sendai Virus ◽

Plasmacytoid Dendritic Cells ◽

Type I Interferons ◽

Interferon Response ◽

Type I ◽

Type I Ifn

Plasmacytoid dendritic cells (pDCs) are innate immune cells able to produce large quantities of type I interferons (IFN) when activated. Human immunodeficiency virus (HIV)-infected patients show generalized immune dysfunction characterized in part by chronic interferon response. In this study we investigated the role of dendritic cells inactivating and maintaining this response. Specifically we compared the IFN geneactivity in pDCs in response to several viruses and TLR agonists. We hypothesized that 1) the pattern of IFN gene transcription would differ in pDCs treated with HIV than with other agents, and 2) that pDCs from patients from different stages of disease would respond differently to the stimulations. To test these hypotheses, we obtained pDCs from 15 HIV-infected and uninfected individuals and treated freshly isolated pDCs with either HIV (BAL strain), influenza virus (A/PR/8/34), Sendai virus (Cantell strain), TLR7 agonist(imiquimod), or TLR9 agonist (CpG-ODN) for 6h. Type I IFN gene transcription was monitored by real time qPCRfor IFNA1, A2, A5, A6, A8,A17, B1, and E1, and cytokine levels were assayed by Cytometric Bead Arrays forTNF?, IL6, IL8, IL10, IL1?, and IL12p70. pDC function as determined by these two assays showed no difference between HIV-infected and uninfected patients or between patients with early or chronic infection. Specifically, HIV did notinduce type I IFN gene expression, whereas influenza virus, Sendai virus and imiquimod did. Similarly, HIV failed to induce any cytokine release from pDCs in contrast to influenza virus, Sendai virus and imiquimod, which stimulatedrelease of TNF?, IL6, or IL8. Together these results suggest that the reaction of pDCs to HIV virus is quantitatively different from the response to agents such as virus, Sendai virus, and imiquimod. In addition, pDCs from HIV-infected persons have responses similar to pDCs from uninfected donors, suggesting, that the DC function may not be affected by HIV infection.

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Canine Influenza Virus is Mildly Restricted by Canine Tetherin Protein

Viruses ◽

10.3390/v10100565 ◽

2018 ◽

Vol 10 (10) ◽

pp. 565

Author(s):

Yun Zheng ◽

Xiangqi Hao ◽

Qingxu Zheng ◽

Xi Lin ◽

Xin Zhang ◽

...

Keyword(s):

Influenza Virus ◽

Transmembrane Domain ◽

Transmembrane Protein ◽

Cellular Damage ◽

Interferon Response ◽

Type I ◽

Canine Influenza Virus ◽

Immune Factor ◽

Canine Influenza ◽

The Impact

Tetherin (BST2/CD317/HM1.24) has emerged as a key host-cell ·defence molecule that acts by inhibiting the release and spread of diverse enveloped virions from infected cells. We analysed the biological features of canine tetherin and found it to be an unstable hydrophilic type I transmembrane protein with one transmembrane domain, no signal peptide, and multiple glycosylation and phosphorylation sites. Furthermore, the tissue expression profile of canine tetherin revealed that it was particularly abundant in immune organs. The canine tetherin gene contains an interferon response element sequence that can be regulated and expressed by canine IFN-α. A CCK-8 assay showed that canine tetherin was effective in helping mitigate cellular damage caused by canine influenza virus (CIV) infection. Additionally, we found that the overexpression of canine tetherin inhibited replication of the CIV and that interference with the canine tetherin gene enhanced CIV replication in cells. The impact of canine tetherin on CIV replication was mild. However, these results elucidate the role of the innate immune factor, canine tetherin, during CIV infection for the first time.

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Quantitative Proteome Analysis of Atg5-Deficient Mouse Embryonic Fibroblasts Reveals the Range of the Autophagy-Modulated Basal Cellular Proteome

mSystems ◽

10.1128/msystems.00481-19 ◽

2019 ◽

Vol 4 (6) ◽

Cited By ~ 1

Author(s):

Kiran Bala Sharma ◽

Manish Sharma ◽

Suruchi Aggarwal ◽

Amit Kumar Yadav ◽

Shinjini Bhatnagar ◽

...

Keyword(s):

Cell Adhesion ◽

Inflammatory Response ◽

Transforming Growth Factor ◽

Proteome Analysis ◽

Interferon Response ◽

Type I ◽

Mouse Embryonic Fibroblasts ◽

Embryonic Fibroblasts ◽

The Impact

ABSTRACT Basal autophagy is crucial for maintenance of cellular homeostasis. ATG5 is an essential protein for autophagosome formation, and its depletion has been extensively used as a tool to disrupt autophagy. Here, we characterize the impact of Atg5 deficiency on the cellular proteome of mouse embryonic fibroblasts (MEFs). Using a tandem mass tagging (TMT)-based quantitative proteomics analysis, we observe that 14% of identified proteins show dysregulated levels in atg5−/− MEFs. These proteins were distributed across diverse biological processes, such as cell adhesion, development, differentiation, transport, metabolism, and immune responses. Several of the upregulated proteins were receptors involved in transforming growth factor β (TGF-β) signaling, JAK-STAT signaling, junction adhesion, and interferon/cytokine-receptor interactions and were validated as autophagy substrates. Nearly equal numbers of proteins, including several lysosomal proteins and enzymes, were downregulated, suggesting a complex role of autophagy/ATG5 in regulating their levels. The atg5−/− MEFs had lower levels of key immune sensors and effectors, including Toll-like receptor 2 (TLR2), interferon regulatory factor 3 (IRF3), IRF7, MLKL, and STAT1/3/5/6, which were restored by reexpression of ATG5. While these cells could efficiently mount a type I interferon response to the double-stranded RNA (dsRNA) mimic poly(I·C), they were compromised in their inflammatory response to the bacterial pathogen-associated molecular patterns (PAMPs) lipopolysaccharide (LPS) and Pam3CSK4. Transcriptional activation and secretion of interleukin-6 (IL-6) in these cells could be recovered by ATG5 expression, supporting the role of autophagy in the TLR2-induced inflammatory response. This study provides a key resource for understanding the effect of autophagy/ATG5 deficiency on the fibroblast proteome. IMPORTANCE Autophagy performs housekeeping functions for cells and maintains a functional mode by degrading damaged proteins and organelles and providing energy under starvation conditions. The process is tightly regulated by the evolutionarily conserved Atg genes, of which Atg5 is one such crucial mediator. Here, we have done a comprehensive quantitative proteome analysis of mouse embryonic fibroblasts that lack a functional autophagy pathway (Atg5 knockout). We observe that 14% of the identified cellular proteome is remodeled, and several proteins distributed across diverse cellular processes with functions in signaling, cell adhesion, development, and immunity show either higher or lower levels under autophagy-deficient conditions. These cells have lower levels of crucial immune proteins that are required to mount a protective inflammatory response. This study will serve as a valuable resource to determine the role of autophagy in modulating specific protein levels in cells.

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Type-III interferon, not type-I, is the predominant interferon induced by respiratory viruses in nasal epithelial cells

Virus Research ◽

10.1016/j.virusres.2011.07.011 ◽

2011 ◽

Vol 160 (1-2) ◽

pp. 360-366 ◽

Cited By ~ 82

Author(s):

Tamaki Okabayashi ◽

Takashi Kojima ◽

Tomoyuki Masaki ◽

Shin-ichi Yokota ◽

Tadaatsu Imaizumi ◽

...

Keyword(s):

Epithelial Cells ◽

Respiratory Viruses ◽

Type I ◽

Nasal Epithelial Cells ◽

Type Iii ◽

Type Iii Interferon

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Knockout of IRF7 Highlights its Modulator Function of Host Response Against Avian Influenza Virus and the Involvement of MAPK and TOR Signaling Pathways in Chicken

Genes ◽

10.3390/genes11040385 ◽

2020 ◽

Vol 11 (4) ◽

pp. 385

Author(s):

Tae Hyun Kim ◽

Colin Kern ◽

Huaijun Zhou

Keyword(s):

Influenza Virus ◽

Avian Influenza ◽

Avian Influenza Virus ◽

Signaling Pathways ◽

Cell Lines ◽

Host Response ◽

Antiviral Response ◽

Influenza Viruses ◽

Interferon Response ◽

Type I

Interferon regulatory factor 7 (IRF7) is known as the master transcription factor of the type I interferon response in mammalian species along with IRF3. Yet birds only have IRF7, while they are missing IRF3, with a smaller repertoire of immune-related genes, which leads to a distinctive immune response in chickens compared to in mammals. In order to understand the functional role of IRF7 in the regulation of the antiviral response against avian influenza virus in chickens, we generated IRF7-/- chicken embryonic fibroblast (DF-1) cell lines and respective controls (IRF7wt) by utilizing the CRISPR/Cas9 (clustered regularly interspaced short palindromic repeats/CRISPR-associated protein 9) system. IRF7 knockout resulted in increased viral titers of low pathogenic avian influenza viruses. Further RNA-sequencing performed on H6N2-infected IRF7-/- and IRF7wt cell lines revealed that the deletion of IRF7 resulted in the significant down-regulation of antiviral effectors and the differential expression of genes in the MAPK (mitogen-activated protein kinase) and mTOR (mechanistic target of rapamycin) signaling pathways. Dynamic gene expression profiling of the host response between the wildtype and IRF7 knockout revealed potential signaling pathways involving AP1 (activator protein 1), NF-κB (nuclear factor kappa B) and inflammatory cytokines that may complement chicken IRF7. Our findings in this study provide novel insights that have not been reported previously, and lay a solid foundation for enhancing our understanding of the host antiviral response against the avian influenza virus in chickens.

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Generation and characterization of variants of NWS/G70C influenza virus after in vitro passage in 4-amino-Neu5Ac2en and 4-guanidino-Neu5Ac2en.

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.40.1.40 ◽

1996 ◽

Vol 40 (1) ◽

pp. 40-46 ◽

Cited By ~ 115

Author(s):

J L McKimm-Breschkin ◽

T J Blick ◽

A Sahasrabudhe ◽

T Tiong ◽

D Marshall ◽

...

Keyword(s):

Amino Acids ◽

Influenza Virus ◽

Receptor Binding ◽

Liquid Culture ◽

Plaque Assay ◽

Enoic Acid ◽

Cross Resistance ◽

Receptor Binding Site ◽

Significant Difference

The compounds 4-amino-Neu5Ac2en (5-acetylamino-2,6-anhydro-4-amino-3,4,5- trideoxy-D-glycerol-D-galacto-non-2-enoic acid) and 4-guanidino-Neu5Ac2en (5-acetylamino-2,6-anhydro-4-guanidino-3,4,5- trideoxy-D-glycerol-D-galacto-non-2-enoic acid), which selectively inhibit the influenza virus neuraminidase, have been tested in vitro for their ability to generate drug-resistant variants. NWS/G70C virus (H1N9) was cultured in each drug by limiting-dilution passaging. After five or six passages in either compound, there emerged viruses which had a reduced sensitivity to the inhibitors in cell culture. Variant viruses were up to 1,000-fold less sensitive in plaque assays, liquid culture, and a hemagglutination-elution assay. In addition, cross-resistance to both compounds was seen in all three assays. Some isolates demonstrated drug dependence with an increase in both size and number of plaques in a plaque assay and an increase in virus yield in liquid culture in the presence of inhibitors. No significant difference in neuraminidase enzyme activity was detected in vitro, and no sequence changes in the conserved sites of the neuraminidase were found. However, changes in conserved amino acids in the hemagglutinin were detected. These amino acids were associated with either the hemagglutinin receptor binding site, Thr-155, or the left edge of the receptor binding pocket, Val-223 and Arg-229. Hence, mutations at these sites could be expected to affect the affinity or specificity of the hemagglutinin binding. Compensating mutations resulting in a weakly binding hemagglutinin thus seem to be circumventing the inhibition of the neuraminidase by allowing the virus to be released from cells with less dependence on the neuraminidase.

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Toll-Like Receptor Expression and Induction of Type I and Type III Interferons in Primary Airway Epithelial Cells

Journal of Virology ◽

10.1128/jvi.01956-12 ◽

2013 ◽

Vol 87 (6) ◽

pp. 3261-3270 ◽

Cited By ~ 110

Author(s):

I. Ioannidis ◽

F. Ye ◽

B. McNally ◽

M. Willette ◽

E. Flano

Keyword(s):

Epithelial Cells ◽

Airway Epithelial Cells ◽

Receptor Expression ◽

Type I ◽

Airway Epithelial ◽

Toll Like Receptor ◽

Type Iii

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Ebola virus infection induces a type I interferon response and the shutdown of key liver functions in human iPSC-derived hepatocytes

10.21203/rs.3.rs-346554/v1 ◽

2021 ◽

Author(s):

Whitney Manhart ◽

Liliana Mancio ◽

Ellen Suder ◽

Carlos Villacorta-Martin ◽

Jonathan Lindstrom-Vautrin ◽

...

Keyword(s):

Inflammatory Response ◽

Ebola Virus ◽

Interferon Response ◽

Type I ◽

Interferon Signaling ◽

Liver Functions ◽

Ebov Infection ◽

Transcriptomic Changes ◽

Human Ipsc ◽

Ebola Virus Infection

Abstract Liver damage and an exacerbated inflammatory response are hallmarks of Ebola virus (EBOV) infection. Little is known about the intrinsic response to infection in human hepatocytes and their contribution to the observed inflammatory response. Here, we present an iPSC-derived hepatocyte platform to define the hepato-intrinsic response to EBOV infection. Transcriptomics analysis revealed a delayed host response with minimal transcriptomic changes at one day post infection (dpi) followed by a general downregulation of genes associated with hepatic functions and upregulation of interferon signaling at two and three dpi. Using RNA-FISH, we showed at single cell resolution that IFNβ and CXCL10 were mainly expressed in bystander cells or cells with weak EBOV mRNA signal intensity. We did not observe an inflammatory signature at any timepoint. In conclusion, iPSC-derived hepatocytes are an immune competent platform to study intrinsic responses to EBOV infection that have not been observed in EBOV-infected hepatocarcinoma cell lines.

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Heat-Not-Burn cigarette induces oxidative stress response in primary rat alveolar epithelial cells

PLoS ONE ◽

10.1371/journal.pone.0242789 ◽

2020 ◽

Vol 15 (11) ◽

pp. e0242789

Author(s):

Yoko Ito ◽

Kana Oshinden ◽

Naokata Kutsuzawa ◽

Chinatsu Kohno ◽

Sanae Isaki ◽

...

Keyword(s):

Oxidative Stress ◽

Stress Response ◽

Epithelial Cells ◽

Oxidative Stress Response ◽

Alveolar Epithelial Cells ◽

Target Cells ◽

Type I ◽

Alveolar Epithelial ◽

Significant Difference ◽

Different Types

There has been an increase in the usage of heat-not-burn (HNB) cigarette products. However, their effects on alveolar epithelial cells (AECs) remain unknown. AECs are the target cells of conventional cigarette smoking-related respiratory diseases such as chronic obstructive pulmonary disease, idiopathic pulmonary fibrosis and lung cancer whose pathogenesis involves oxidative stress. In this study, primary rat AECs were isolated, cultured and stimulated by HNB cigarette smoke extract (CSE). Our data indicate that rat AECs exposed to HNB CSE induced oxidative stress response genes (e.g. Hmox-1, Gsta1, Gsta3 and Nqo1). We also compared the oxidative stress response between two different types of AECs, alveolar type I-like (ATI-like) cells and type II (ATII) cells, and between two different types of cigarette, HNB cigarettes and conventional cigarettes. The expressions of Gsta1, Gsta3 and Nqo1 were higher in ATII cells than ATI-like cells in response to HNB and conventional cigarettes, but there was no significant difference in their expression levels between HNB cigarette and conventional cigarette. Taken together, our results suggest that HNB cigarettes have the similar potential as conventional cigarette products to induce oxidative stress response in AECs.

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