scholarly journals A natural variant in ANP32B impairs influenza virus replication in human cells

2021 ◽  
Vol 102 (9) ◽  
Author(s):  
Ecco Staller ◽  
Carol M. Sheppard ◽  
Laury Baillon ◽  
Rebecca Frise ◽  
Thomas P. Peacock ◽  
...  

Viruses require host factors to support their replication, and genetic variation in such factors can affect susceptibility to infectious disease. Influenza virus replication in human cells relies on ANP32 proteins, which are involved in assembly of replication-competent dimeric influenza virus polymerase (FluPol) complexes. Here, we investigate naturally occurring single nucleotide variants (SNV) in the human Anp32A and Anp32B genes. We note that variant rs182096718 in Anp32B is found at a higher frequency than other variants in either gene. This SNV results in a D130A substitution in ANP32B, which is less able to support FluPol activity than wild-type ANP32B and binds FluPol with lower affinity. Interestingly, ANP32B-D130A exerts a dominant negative effect over wild-type ANP32B and interferes with the functionally redundant paralogue ANP32A. FluPol activity and virus replication are attenuated in CRISPR-edited cells expressing wild-type ANP32A and mutant ANP32B-D130A. We propose a model in which the D130A mutation impairs FluPol dimer formation, thus resulting in compromised replication. We suggest that both homozygous and heterozygous carriers of rs182096718 may have some genetic protection against influenza viruses.

2020 ◽  
Author(s):  
Ecco Staller ◽  
Laury Baillon ◽  
Rebecca Frise ◽  
Thomas P. Peacock ◽  
Carol M. Sheppard ◽  
...  

ABSTRACTViruses require host factors to support their replication, and genetic variation in such factors can affect susceptibility to infectious disease. Influenza virus replication in human cells relies on ANP32 proteins, which are involved in assembly of replication-competent dimeric influenza virus polymerase (FluPol) complexes. Here, we investigate naturally occurring single nucleotide variants (SNV) in the human Anp32A and Anp32B genes. We note that variant rs182096718 in Anp32B is found at a higher frequency than other variants in either gene. This SNV results in a D130A substitution in ANP32B, which is less able to support FluPol activity than wildtype ANP32B and binds FluPol with lower affinity. Interestingly, ANP32B-D130A exerts a dominant negative effect over wildtype ANP32B and interferes with the functionally redundant paralogue ANP32A. FluPol activity and virus replication are attenuated in CRISPR-edited cells expressing wildtype ANP32A and mutant ANP32B-D130A. We propose a model in which the D130A mutation impairs FluPol dimer formation, thus resulting in compromised replication. We suggest that both homozygous and heterozygous carriers of rs182096718 may have some genetic protection against influenza viruses.


Author(s):  
Israa Elbashir ◽  
Heba Al Khatib ◽  
Hadi Yassine

Background: Influenza virus is a major cause of respiratory infections worldwide. Besides the common respiratory symptoms, namouras cases with gastrointestinal symptoms have been reported. Moreover, influenza virus has been detected in feces of up to 20.6 % of influenza-infected patients. Therefore, direct infection of intestinal cells with influenza virus is suspected; however, the mechanism of this infection has not been explored. AIM: To investigate influenza virus replication, cellular responses to infection, and virus evolution following serial infection in human Caucasian colon adenocarcinoma cells (Caco-2 cells). Method: Two influenza A subtypes (A/H3N2 and A/H1N1pdm 09) and one influenza B virus (B/Yamagata) were serially passaged in Caco-2. Quantitative PCR was used to study hormones and cytokines expression following infection. Deep sequencing analysis of viral genome was used to assess the virus evolution. Results: The replication capacity of the three viruses was maintained throughout 12 passages, with H3N2 virus being the fastest in adaptation. The expression of hormone and cytokines in Caco-2 cells was considerably different between the viruses and among the passages, however, a pattern of induction was observed at the late phase of infection. Deep sequencing analysis revealed a few amino acid substitutions in the HA protein of H3N2 and H1N1 viruses, mostly in the antigenic site. Moreover, virus evolution at the quasispecies level based on HA protein revealed that H3N2 and H1N1 harbored more diverse virus populations when compared to IBV, indicating their higher evolution within Caco-2 cells. Conclusion: The findings of this study indicate the possibility of influenza virus replication in intestinal cells. To further explain the gastrointestinal complications of influenza infections in-vivo experiments with different influenza viruses are needed.


2020 ◽  
Author(s):  
Chen Liang ◽  
Limei Zhu ◽  
Jun Chen

Abstract Background: Studies have shown that human interferon inducible transmembrane proteins (IFITM) family proteins have broad-spectrum antiviral capabilities. Preliminary studies in our laboratory have preliminarily proved that IFITMs have the effect of inhibiting influenza viruses. In order to further study its mechanism and role in the occurrence and development of influenza, relevant studies have been carried out.Methods: Fluorescence quantitative polymerase chain reaction (PCR) detection, yeast two-hybrid test and optical confocal microscopy were used to investigate the effect of hIFITM3 on influenza virus replication, the interaction with human abhydrolase domain containing 16A (hABHD16A) and the expression of inflammation-related factors.Results: In HEK293 cells, overexpression of hIFITM3 protein significantly inhibited the replication of influenza virus at 24h, 48h, and 72h; yeast two-hybrid experiment proved that IFITM3 interacts with ABHD16A; laser confocal microscopy observations showed that IFITM3 and ABHD16A co-localized in cell membrane area; the expression level of inflammation-related factors in cells overexpressing hIFITM3 or hABHD16A was detected by fluorescence quantitative PCR, and the results showed that the mRNA levels of interleukin (IL)-1β, IL-6, IL-10, tumor necrosis factor (TNF)-a and cyclooxygenase 2 (COX2) were significantly increased . But when IFITM3/ABHD16A was co-expressed, the mRNA expression levels of these cytokines were significantly reduced except for COX2. When influenza virus infected cells co-expressing IFITM3/ABHD16A, the expression level of inflammatory factors decreased compared with the control group, indicating that IFITM3 can play an important role in regulating inflammation balance.Conclusions: This study confirmed that hIFITM3 has an effect of inhibiting influenza virus replication. Furthermore, it was found that hIFITM3 interacts with hABHD16A, following which it can better inhibit the replication of influenza virus and the inflammatory response caused by the disease process.


2021 ◽  
Vol 102 (11) ◽  
Author(s):  
Nichole Orr-Burks ◽  
Jackelyn Murray ◽  
Kyle V. Todd ◽  
Abhijeet Bakre ◽  
Ralph A. Tripp

Influenza virus causes seasonal epidemics and sporadic pandemics resulting in morbidity, mortality, and economic losses worldwide. Understanding how to regulate influenza virus replication is important for developing vaccine and therapeutic strategies. Identifying microRNAs (miRs) that affect host genes used by influenza virus for replication can support an antiviral strategy. In this study, G-protein coupled receptor (GPCR) and ion channel (IC) host genes in human alveolar epithelial (A549) cells used by influenza virus for replication (Orr-Burks et al., 2021) were examined as miR target genes following A/CA/04/09- or B/Yamagata/16/1988 replication. Thirty-three miRs were predicted to target GPCR or IC genes and their miR mimics were evaluated for their ability to decrease influenza virus replication. Paired miR inhibitors were used as an ancillary measure to confirm or not the antiviral effects of a miR mimic. Fifteen miRs lowered influenza virus replication and four miRs were found to reduce replication irrespective of virus strain and type differences. These findings provide evidence for novel miR disease intervention strategies for influenza viruses.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Yvonne Boergeling ◽  
Linda Brunotte ◽  
Stephan Ludwig

Abstract Influenza viruses are small RNA viruses with a genome of about 13 kb. Because of this limited coding capacity, viral proteins have evolved to fulfil multiple functions in the infected cell. This implies that there must be mechanisms allowing to dynamically direct protein action to a distinct activity in a spatio-temporal manner. Furthermore, viruses exploit many cellular processes, which also have to be dynamically regulated during the viral replication cycle. Phosphorylation and dephosphorylation of proteins are fundamental for the control of many cellular responses. There is accumulating evidence that this mechanism represents a so far underestimated level of regulation in influenza virus replication. Here, we focus on the current knowledge of dynamics of phospho-modifications in influenza virus replication and show recent examples of findings underlining the crucial role of phosphorylation in viral transport processes as well as activation and counteraction of the innate immune response.


2020 ◽  
Vol 94 (10) ◽  
Author(s):  
Thomas Figueroa ◽  
Pierre Bessière ◽  
Amelia Coggon ◽  
Kim M. Bouwman ◽  
Roosmarijn van der Woude ◽  
...  

ABSTRACT Ducks usually show little or no clinical signs following highly pathogenic avian influenza virus infection. In order to analyze whether the microbiota could contribute to the control of influenza virus replication in ducks, we used a broad-spectrum oral antibiotic treatment to deplete the microbiota before infection with a highly pathogenic H5N9 avian influenza virus. Antibiotic-treated ducks and nontreated control ducks did not show any clinical signs following H5N9 virus infection. We did not detect any significant difference in virus titers neither in the respiratory tract nor in the brain nor spleen. However, we found that antibiotic-treated H5N9 virus-infected ducks had significantly increased intestinal virus excretion at days 3 and 5 postinfection. This was associated with a significantly decreased antiviral immune response in the intestine of antibiotic-treated ducks. Our findings highlight the importance of an intact microbiota for an efficient control of avian influenza virus replication in ducks. IMPORTANCE Ducks are frequently infected with avian influenza viruses belonging to multiple subtypes. They represent an important reservoir species of avian influenza viruses, which can occasionally be transmitted to other bird species or mammals, including humans. Ducks thus have a central role in the epidemiology of influenza virus infection. Importantly, ducks usually show little or no clinical signs even following infection with a highly pathogenic avian influenza virus. We provide evidence that the microbiota contributes to the control of influenza virus replication in ducks by modulating the antiviral immune response. Ducks are able to control influenza virus replication more efficiently when they have an intact intestinal microbiota. Therefore, maintaining a healthy microbiota by limiting perturbations to its composition should contribute to the prevention of avian influenza virus spread from the duck reservoir.


PLoS ONE ◽  
2021 ◽  
Vol 16 (10) ◽  
pp. e0259129
Author(s):  
Nichole Orr-Burks ◽  
Jackelyn Murray ◽  
Kyle V. Todd ◽  
Abhijeet Bakre ◽  
Ralph A. Tripp

Influenza viruses cause respiratory tract infections and substantial health concerns. Infection may result in mild to severe respiratory disease associated with morbidity and some mortality. Several anti-influenza drugs are available, but these agents target viral components and are susceptible to drug resistance. There is a need for new antiviral drug strategies that include repurposing of clinically approved drugs. Drugs that target cellular machinery necessary for influenza virus replication can provide a means for inhibiting influenza virus replication. We used RNA interference screening to identify key host cell genes required for influenza replication, and then FDA-approved drugs that could be repurposed for targeting host genes. We examined the effects of Clopidogrel and Triamterene to inhibit A/WSN/33 (EC50 5.84 uM and 31.48 uM, respectively), A/CA/04/09 (EC50 6.432 uM and 3.32 uM, respectively), and B/Yamagata/16/1988 (EC50 0.28 uM and 0.11 uM, respectively) replication. Clopidogrel and Triamterene provide a druggable approach to influenza treatment across multiple strains and subtypes.


2008 ◽  
Vol 82 (14) ◽  
pp. 6820-6828 ◽  
Author(s):  
Fanny LeBouder ◽  
Eric Morello ◽  
Guus F. Rimmelzwaan ◽  
Françoise Bosse ◽  
Christine Péchoux ◽  
...  

ABSTRACT For influenza viruses to become infectious, the proteolytic cleavage of hemagglutinin (HA) is essential. This usually is mediated by trypsin-like proteases in the respiratory tract. The binding of plasminogen to influenza virus A/WSN/33 leads to the cleavage of HA, a feature determining its pathogenicity and neurotropism in mice. Here, we demonstrate that plasminogen also promotes the replication of other influenza virus strains. The inhibition of the conversion of plasminogen into plasmin blocked influenza virus replication. Evidence is provided that the activation of plasminogen is mediated by the host cellular protein annexin II, which is incorporated into the virus particles. Indeed, the inhibition of plasminogen binding to annexin II by using a competitive inhibitor inhibits plasminogen activation into plasmin. Collectively, these results indicate that the annexin II-mediated activation of plasminogen supports the replication of influenza viruses, which may contribute to their pathogenicity.


Viruses ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 233 ◽  
Author(s):  
Emma Touizer ◽  
Christian Sieben ◽  
Ricardo Henriques ◽  
Mark Marsh ◽  
Romain F. Laine

With an estimated three to five million human cases annually and the potential to infect domestic and wild animal populations, influenza viruses are one of the greatest health and economic burdens to our society, and pose an ongoing threat of large-scale pandemics. Despite our knowledge of many important aspects of influenza virus biology, there is still much to learn about how influenza viruses replicate in infected cells, for instance, how they use entry receptors or exploit host cell trafficking pathways. These gaps in our knowledge are due, in part, to the difficulty of directly observing viruses in living cells. In recent years, advances in light microscopy, including super-resolution microscopy and single-molecule imaging, have enabled many viral replication steps to be visualised dynamically in living cells. In particular, the ability to track single virions and their components, in real time, now allows specific pathways to be interrogated, providing new insights to various aspects of the virus-host cell interaction. In this review, we discuss how state-of-the-art imaging technologies, notably quantitative live-cell and super-resolution microscopy, are providing new nanoscale and molecular insights into influenza virus replication and revealing new opportunities for developing antiviral strategies.


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