scholarly journals Cellular co-infection can modulate the efficiency of influenza A virus production and shape the interferon response

2019 ◽  
Author(s):  
Brigitte E. Martin ◽  
Jeremy D. Harris ◽  
Jiayi Sun ◽  
Katia Koelle ◽  
Christopher B. Brooke
Keyword(s):  
Influenza A Virus ◽  
Cell Lines ◽  
Influenza A ◽  
Mdck Cells ◽  
A549 Cells ◽  
Virus Production ◽  
Innate Immune ◽  
Type I ◽  
Functional Forms ◽  
A Cell

ABSTRACTDuring viral infection, the numbers of virions infecting individual cells can vary significantly over time and space. The functional consequences of this variation in cellular multiplicity of infection (MOI) remain poorly understood. Here, we rigorously quantify the phenotypic consequences of cellular MOI during influenza A virus (IAV) infection over a single round of replication in terms of cell death rates, viral output kinetics, interferon and antiviral effector gene transcription, and superinfection potential. By statistically fitting mathematical models to our data, we precisely define specific functional forms that quantitatively describe the modulation of these phenotypes by MOI at the single cell level. To determine the generality of these functional forms, we compare two distinct cell lines (MDCK cells and A549 cells), both infected with the H1N1 strain A/Puerto Rico/8/1934 (PR8). We find that a model assuming that infected cell death rates are independent of cellular MOI best fits the experimental data in both cell lines. We further observe that a model in which the rate and efficiency of virus production increase with cellular co-infection best fits our observations in MDCK cells, but not in A549 cells. In A549 cells, we also find that induction of type III interferon, but not type I interferon, is highly dependent on cellular MOI, especially at early timepoints. This finding identifies a role for cellular co-infection in shaping the innate immune response to IAV infection. Finally, we show that higher cellular MOI is associated with more potent superinfection exclusion, thus limiting the total number of virions capable of infecting a cell. Overall, this study suggests that the extent of cellular co-infection by influenza viruses may be a critical determinant of both viral production kinetics and cellular infection outcomes in a host cell type-dependent manner.AUTHOR SUMMARYDuring influenza A virus (IAV) infection, the number of virions to enter individual cells can be highly variable. Cellular co-infection appears to be common and plays an essential role in facilitating reassortment for IAV, yet little is known about how cellular co-infection influences infection outcomes at the cellular level. Here, we combine quantitative in vitro infection experiments with statistical model fitting to precisely define the phenotypic consequences of cellular co-infection in two cell lines. We reveal that cellular co-infection can increase and accelerate the efficiency of IAV production in a cell line-dependent fashion, identifying it as a potential determinant of viral replication kinetics. We also show that induction of type III, but not type I, interferon is highly dependent upon the number of virions that infect a given cell, implicating cellular co-infection as an important determinant of the host innate immune response to infection. Altogether, our findings show that cellular co-infection plays a crucial role in determining infection outcome. The integration of experimental and statistical modeling approaches detailed here represents a significant advance in the quantitative study of influenza virus infection and should aid ongoing efforts focused on the construction of mathematical models of IAV infection.

scholarly journals Hemagglutinin of Influenza A Virus Antagonizes Type I Interferon (IFN) Responses by Inducing Degradation of Type I IFN Receptor 1

2015 ◽  
Vol 90 (5) ◽  
pp. 2403-2417 ◽  
Author(s):  
Chuan Xia ◽  
Madhuvanthi Vijayan ◽  
Curtis J. Pritzl ◽  
Serge Y. Fuchs ◽  
Adrian B. McDermott ◽  
...  
Keyword(s):  
Signaling Pathway ◽  
Influenza A Virus ◽  
Influenza A ◽  
Type I Interferon ◽  
Innate Immune ◽  
Host Cells ◽  
Type I ◽  
Type I Ifn ◽  
Type I Ifns ◽  
Ha Protein

ABSTRACTInfluenza A virus (IAV) employs diverse strategies to circumvent type I interferon (IFN) responses, particularly by inhibiting the synthesis of type I IFNs. However, it is poorly understood if and how IAV regulates the type I IFN receptor (IFNAR)-mediated signaling mode. In this study, we demonstrate that IAV induces the degradation of IFNAR subunit 1 (IFNAR1) to attenuate the type I IFN-induced antiviral signaling pathway. Following infection, the level of IFNAR1 protein, but not mRNA, decreased. Indeed, IFNAR1 was phosphorylated and ubiquitinated by IAV infection, which resulted in IFNAR1 elimination. The transiently overexpressed IFNAR1 displayed antiviral activity by inhibiting virus replication. Importantly, the hemagglutinin (HA) protein of IAV was proved to trigger the ubiquitination of IFNAR1, diminishing the levels of IFNAR1. Further, influenza A viral HA1 subunit, but not HA2 subunit, downregulated IFNAR1. However, viral HA-mediated degradation of IFNAR1 was not caused by the endoplasmic reticulum (ER) stress response. IAV HA robustly reduced cellular sensitivity to type I IFNs, suppressing the activation of STAT1/STAT2 and induction of IFN-stimulated antiviral proteins. Taken together, our findings suggest that IAV HA causes IFNAR1 degradation, which in turn helps the virus escape the powerful innate immune system. Thus, the research elucidated an influenza viral mechanism for eluding the IFNAR signaling pathway, which could provide new insights into the interplay between influenza virus and host innate immunity.IMPORTANCEInfluenza A virus (IAV) infection causes significant morbidity and mortality worldwide and remains a major health concern. When triggered by influenza viral infection, host cells produce type I interferon (IFN) to block viral replication. Although IAV was shown to have diverse strategies to evade this powerful, IFN-mediated antiviral response, it is not well-defined if IAV manipulates the IFN receptor-mediated signaling pathway. Here, we uncovered that influenza viral hemagglutinin (HA) protein causes the degradation of type I IFN receptor subunit 1 (IFNAR1). HA promoted phosphorylation and polyubiquitination of IFNAR1, which facilitated the degradation of this receptor. The HA-mediated elimination of IFNAR1 notably decreased the cells' sensitivities to type I IFNs, as demonstrated by the diminished expression of IFN-induced antiviral genes. This discovery could help us understand how IAV regulates the host innate immune response to create an environment optimized for viral survival in host cells.

scholarly journals Influenza A virus antagonizes type I and type II interferon responses via SOCS1-dependent ubiquitination and degradation of JAK1

2020 ◽  
Author(s):  
Yinping Du ◽  
Fan Yang ◽  
Qiuxia Wang ◽  
Nuo Xu ◽  
Yizhang Xie ◽  
...  
Keyword(s):  
Influenza A Virus ◽  
Influenza A ◽  
Innate Immune ◽  
Cytokine Signaling ◽  
Type I ◽  
Type Ii ◽  
Innate Immune Responses ◽  
Suppressor Of Cytokine Signaling ◽  
Interferon Responses ◽  
Socs Protein

Abstract BACKGROUND Although influenza A virus (IAV) employs diverse strategies to evade IFN responses by inhibiting the synthesis of IFN, how IAV regulates signaling downstream of IFN is incompletely understood. METHODS In this study, we used Western blot-based protein analysis coupled with RT-qPCR, overexpression and RNA interference to investigate the regulation of JAK1 by IAV infection. RESULTS The results indicated that JAK1 was ubiquitinated and degraded, resulting in inhibition of type I and type II IFN responses, demonstrating that IAV antagonizes the IFN-activated JAK/STAT signaling pathway by inducing the degradation of JAK1. Furthermore. IAV infection upregulated the suppressor of cytokine signaling (SOCS) protein SOCS1, and SOCS1 mediated the ubiquitination and degradation of JAK1. CONCLUSION: Collectively, our findings suggest that IAV infection induced SOCS1 expression promotes JAK1 degradation, which in turn inhibits host innate immune responses.

scholarly journals Thapsigargin at Non-Cytotoxic Levels Induces a Potent Host Antiviral Response that Blocks Influenza A Virus Replication

Viruses ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 1093
Author(s):  
Leah V. Goulding ◽  
Jiayun Yang ◽  
Zhimin Jiang ◽  
Hongyu Zhang ◽  
Daniel Lea ◽  
...  
Keyword(s):  
Virus Infection ◽  
Influenza A Virus ◽  
Influenza A ◽  
Unmet Need ◽  
Virus Production ◽  
Antiviral Response ◽  
Interferon Response ◽  
Attractive Alternative ◽  
Type I ◽  
Host Antiviral Response

Influenza A virus is a major global pathogen of humans, and there is an unmet need for effective antivirals. Current antivirals against influenza A virus directly target the virus and are vulnerable to mutational resistance. Harnessing an effective host antiviral response is an attractive alternative. We show that brief exposure to low, non-toxic doses of thapsigargin (TG), an inhibitor of the sarcoplasmic/endoplasmic reticulum (ER) Ca2+ ATPase pump, promptly elicits an extended antiviral state that dramatically blocks influenza A virus production. Crucially, oral administration of TG protected mice against lethal virus infection and reduced virus titres in the lungs of treated mice. TG-induced ER stress unfolded protein response appears as a key driver responsible for activating a spectrum of host antiviral defences that include an enhanced type I/III interferon response. Our findings suggest that TG is potentially a viable host-centric antiviral for the treatment of influenza A virus infection without the inherent problem of drug resistance.

scholarly journals Properties of H7N7 influenza A virus strain SC35M lacking interferon antagonist NS1 in mice and chickens

2007 ◽  
Vol 88 (5) ◽  
pp. 1403-1409 ◽  
Author(s):  
Georg Kochs ◽  
Iris Koerner ◽  
Lena Thiel ◽  
Sonja Kothlow ◽  
Bernd Kaspers ◽  
...  
Keyword(s):  
Influenza A Virus ◽  
Virulence Factor ◽  
Influenza A ◽  
Severe Disease ◽  
A549 Cells ◽  
Type I ◽  
Upper Respiratory Tract ◽  
Structural Protein ◽  
Wild Type ◽  
Ns1 Gene

Non-structural protein NS1 of influenza A virus counteracts the host immune response by blocking the synthesis of type I interferon (IFN). As deletion of the complete NS1 gene has to date been reported only in the human H1N1 strain A/PR/8/34, it remained unclear whether NS1 is a non-essential virulence factor in other influenza A virus strains as well. In this report, the properties of NS1-deficient mutants derived from strain SC35M (H7N7) are described. A mutant of SC35M that completely lacks the NS1 gene was an excellent inducer of IFN in mammalian and avian cells in culture and, consequently, was able to multiply efficiently only in cell lines with defects in the type I IFN system. Virus mutants carrying C-terminally truncated versions of NS1 were less powerful inducers of IFN and were attenuated less strongly in human A549 cells. Although attenuated in wild-type mice, these mutants remained highly pathogenic for mice lacking the IFN-regulated antiviral factor Mx1. In contrast, the NS1-deficient SC35M mutant was completely non-pathogenic for wild-type mice, but remained pathogenic for mice lacking Mx1 and double-stranded RNA-activated protein kinase (PKR). Wild-type SC35M, but not the NS1-deficient mutant virus, was able to replicate in the upper respiratory tract of birds, but neither virus induced severe disease in adult chickens. Altogether, this study supports the view that NS1 represents a non-essential virulence factor of different influenza A viruses.

scholarly journals Inducible Guanylate-Binding Protein 7 Facilitates Influenza A Virus Replication by Suppressing Innate Immunity via NF-κB and JAK-STAT Signaling Pathways

2021 ◽  
Author(s):  
Mingkai Feng ◽  
Qiao Zhang ◽  
Wenjiao Wu ◽  
Lizhu Chen ◽  
Shuyin Gu ◽  
...  
Keyword(s):  
Immune Responses ◽  
Signaling Pathways ◽  
Influenza A ◽  
Binding Protein ◽  
A549 Cells ◽  
Innate Immune ◽  
Type I ◽  
Innate Immune Responses ◽  
Stat Signaling ◽  
Guanylate Binding Protein

Guanylate-binding protein 7 (GBP7) belongs to the GBP family, which plays key roles in mediating innate immune responses to intracellular pathogens. Thus far, GBP7 has been reported to be a critical cellular factor against bacterial infection. However, the relationship between GBP7 and influenza A virus (IAV) replication is unknown. Here, we showed that GBP7 expression was significantly up-regulated in the lungs of mice, human peripheral blood mononuclear cells (PBMCs), and A549 cells during IAV infection. Using the CRISPR-Cas9 system and overexpression approaches, it was found that GBP7 knockout inhibited IAV replication by enhancing the expression of IAV-induced type I interferon (IFN), type III IFN, and proinflammatory cytokines. Conversely, overexpression of GBP7 facilitated IAV replication by suppressing the expression of those factors. Furthermore, GBP7 knockout enhanced IAV-induced nuclear factor-κB (NF-κB) activation and phosphorylation of stat1 and stat2, overexpression of GBP7 had the opposite effect. Our data indicated that GBP7 suppresses innate immune responses to IAV infection via NF-κB and JAK-STAT signaling pathways. Taken together, upon IAV infection, the induced GBP7 facilitated IAV replication by suppressing innate immune responses to IAV infection, which suggested that GBP7 might serve as a potential therapeutic target for controlling IAV infection. IMPORTANCE So far, few studies have mentioned the distinct function of guanylate-binding protein 7 (GBP7) on virus infection. Here, we reported that GBP7 expression was significantly up-regulated in the lungs of mice, human PBMCs, and A549 cells during IAV infection. GBP7 facilitated IAV replication by suppressing the expression of type I interferon (IFN), type III IFN, and proinflammatory cytokines. Furthermore, it was indicated that GBP7 suppresses innate immune responses to IAV infection via NF-κB and JAK-STAT signaling pathways. Taken together, our results elucidate a critical role of GBP7 in host immune system during IAV infection.

scholarly journals Influenza A virus antagonizes type I and type II interferon responses via SOCS1-dependent ubiquitination and degradation of JAK1

2020 ◽  
Author(s):  
Yinping Du ◽  
Fan Yang ◽  
Qiuxia Wang ◽  
Nuo Xu ◽  
Yizhang Xie ◽  
...  
Keyword(s):  
Influenza A Virus ◽  
Influenza A ◽  
Innate Immune ◽  
Cytokine Signaling ◽  
Type I ◽  
Type Ii ◽  
Innate Immune Responses ◽  
Suppressor Of Cytokine Signaling ◽  
Interferon Responses ◽  
Socs Protein

Abstract BACKGROUND: Although influenza A virus (IAV) employs diverse strategies to evade IFN responses by inhibiting the synthesis of IFN, how IAV regulates signaling downstream of IFN is incompletely understood.METHODS: In this study, we used Western blot-based protein analysis coupled with RT-qPCR, overexpression and RNA interference to investigate the regulation of JAK1 by IAV infection.RESULTS: The results indicated that JAK1 was ubiquitinated and degraded, resulting in inhibition of type I and type II IFN responses, demonstrating that IAV antagonizes the IFN-activated JAK/STAT signaling pathway by inducing the degradation of JAK1. Furthermore. IAV infection upregulated the suppressor of cytokine signaling (SOCS) protein SOCS1, and SOCS1 mediated the ubiquitination and degradation of JAK1. CONCLUSION: Collectively, our findings suggest that IAV infection induces SOCS1 expression to promote JAK1 degradation, which in turn inhibits host innate immune responses.

scholarly journals Identification of an Interferon-Stimulated Long Noncoding RNA (LncRNA ISR) Involved in Regulation of Influenza A Virus Replication

2019 ◽  
Vol 20 (20) ◽  
pp. 5118 ◽  
Author(s):  
Qidong Pan ◽  
Zhonghui Zhao ◽  
Yuan Liao ◽  
Shih-Hsin Chiu ◽  
Song Wang ◽  
...  
Keyword(s):  
Viral Replication ◽  
Influenza A Virus ◽  
Noncoding Rna ◽  
Influenza A ◽  
Ectopic Expression ◽  
A549 Cells ◽  
Mouse Cell ◽  
Type I ◽  
Human Beings ◽  
Inhibitor Treatment

Long noncoding RNAs (lncRNAs) are involved in a diversity of biological processes. It is known that differential expression of thousands of lncRNAs occurs in host during influenza A virus (IAV) infection. However, only few of them have been well characterized. Here, we identified a lncRNA, named as interferon (IFN)-stimulated lncRNA (ISR), which can be significantly upregulated in response to IAV infection in a mouse model. A sequence alignment revealed that lncRNA ISR is present in mice and human beings, and indeed, we found that it was expressed in several human and mouse cell lines and tissues. Silencing lncRNA ISR in A549 cells resulted in a significant increase in IAV replication, whereas ectopic expression of lncRNA ISR reduced the viral replication. Interestingly, interferon-β (IFN-β) treatment was able to induce lncRNA ISR expression, and induction of lncRNA ISR by viral infection was nearly abolished in host deficient of IFNAR1, a type I IFN receptor. Furthermore, the level of IAV-induced lncRNA ISR expression was decreased either in retinoic acid-inducible gene I (RIG-I) knockout A549 cells and mice or by nuclear factor κ-light-chain-enhancer of activated B cells (NF-κB) inhibitor treatment. Together, these data elucidate that lncRNA ISR is regulated by RIG-I-dependent signaling that governs IFN-β production during IAV infection, and has an inhibitory capacity in viral replication.

scholarly journals Semi-perfusion cultures of suspension MDCK cells enable high cell concentrations and efficient influenza A virus production

Vaccine ◽  
2019 ◽  
Vol 37 (47) ◽  
pp. 7003-7010 ◽  
Author(s):  
Thomas Bissinger ◽  
Johannes Fritsch ◽  
Adrian Mihut ◽  
Yixiao Wu ◽  
Xuping Liu ◽  
...  
Keyword(s):  
Influenza A Virus ◽  
Influenza A ◽  
Mdck Cells ◽  
Virus Production ◽  
High Cell ◽  
Perfusion Cultures ◽  
Cell Concentrations
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