Influenza A Virus and Influenza B Virus Can Induce Apoptosis via Intrinsic or Extrinsic Pathways and Also via NF-κB in a Time and Dose Dependent Manner

Influenza viruses are able to cause annual epidemics and pandemics due to their mutation rates and reassortment capabilities leading to antigenic shifts and drifts. To identify host response to influenza A and B viruses on A549 and MDCK II cells at low and high MOIs, expressions of MxA and caspases 3, 8, and 9 and BAD, TNFα, and IκBαgenes were measured in the cells supernatants. H1N1 and H3N2 prefer to initially enhance the intrinsic pathway, determined by higher caspase 9 activity in MDCK II cells compared to caspase 8 activity and vice versa in A549 cells at different MOIs, while INF B prefers extrinsic pathway in A549 cells according to significant low or undetectable caspase 9 activity and high activity of caspase 8 but also can induce intrinsic pathway in MDCK II cells as determined by significant low or undetectable activity of caspase 8 and high caspase 9 activity at different MOIs; the considerable MxA expression was found in influenza A and B viruses infected A549 and MDCK II cells at low MOIs. In conclusion, influenza A and B viruses induced extrinsic and intrinsic apoptosis in parallel, and the induction was associated with viral infection in a dose dependent manner.

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Entry of influenza viruses into cells is inhibited by a highly specific protein kinase C inhibitor

Journal of General Virology ◽

10.1099/0022-1317-81-11-2697 ◽

2000 ◽

Vol 81 (11) ◽

pp. 2697-2705 ◽

Cited By ~ 60

Author(s):

Christiana N. Root ◽

Elizabeth G. Wills ◽

LaShonn L. McNair ◽

Gary R. Whittaker

Keyword(s):

Influenza Virus ◽

Protein Kinase C ◽

Protein Kinase ◽

Influenza Virus Infection ◽

Influenza Viruses ◽

Influenza B Virus ◽

Influenza B ◽

Dependent Manner ◽

Kinase C ◽

Dose Dependent

Following binding to cell surface sialic acid, entry of influenza viruses into cells is mediated by endocytosis. Productive entry of influenza virus requires the low-pH environment of the late endosome for fusion and release of the virus into the cytoplasm and transport of the virus genome into the nucleus. We investigated novel mechanisms to inhibit influenza virus infection using highly specific inhibitors of protein kinase C. We found that one inhibitor, bisindolylmaleimide I, prevented replication of influenza A virus in a dose-dependent manner when added at the time of infection, but had little specific effect when added 2 h after infection had commenced. Virus yields dropped by more than 3 log units in the presence of micromolar levels of bisindolylmaleimide I. Influenza B virus replication was also inhibited by bisindolylmaleimide at micromolar concentrations. We carried out experiments to determine the point in infection that was blocked by bisindolylmaleimide I, and determined that entry of viral ribonucleoproteins (vRNPs) into the nucleus was prevented. Upon drug washout vRNP nuclear entry resumed, showing that bisindolylmaleimide I is reversible. Bisindolylmaleimide I did not affect virus binding and was apparently not acting as a weak base, because its effects were independent of the pH of the external growth medium. These experiments show that bisindolylmaleimide I blocks replication of different types of influenza virus in a dose-dependent and reversible manner, and that virus entry into the cell is inhibited.

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Influenza B Virus Infection Is Enhanced Upon Heterotypic Co-infection With Influenza A Virus

Frontiers in Microbiology ◽

10.3389/fmicb.2021.631346 ◽

2021 ◽

Vol 12 ◽

Author(s):

Nicolas Malausse ◽

Sylvie van der Werf ◽

Nadia Naffakh ◽

Sandie Munier

Keyword(s):

Influenza A ◽

Reverse Genetics ◽

Viral Evolution ◽

A549 Cells ◽

Population Diversity ◽

Influenza Viruses ◽

Influenza B Virus ◽

Influenza B ◽

Genetic Population ◽

Fluorescent Reporter

Homotypic co-infections with influenza viruses are described to increase genetic population diversity, to drive viral evolution and to allow genetic complementation. Less is known about heterotypic co-infections between influenza A (IAV) and influenza B (IBV) viruses. Previous publications showed that IAV replication was suppressed upon co-infection with IBV. However, the effect of heterotypic co-infections on IBV replication was not investigated. To do so, we produced by reverse genetics a pair of replication-competent recombinant IAV (A/WSN/33) and IBV (B/Brisbane/60/2008) expressing a GFP and mCherry fluorescent reporter, respectively. A549 cells were infected simultaneously or 1 h apart at a high MOI with IAV-GFP or IBV-mCherry and the fluorescence was measured at 6 h post-infection by flow cytometry. Unexpectedly, we observed that IBV-mCherry infection was enhanced upon co-infection with IAV-GFP, and more strongly so when IAV was added 1 h prior to IBV. The same effect was observed with wild-type viruses and with various strains of IAV. Using UV-inactivated IAV or type-specific antiviral compounds, we showed that the enhancing effect of IAV infection on IBV infection was dependent on transcription/replication of the IAV genome. Our results, taken with available data in the literature, support the hypothesis that the presence of IAV proteins can enhance IBV genome expression and/or complement IBV defective particles.

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Clinical Investigations. Comparison of Directigen Flu A+B with Real Time PCR in the Diagnosis of Influenza / Сравнение Иммунохроматографического Метода (Directigen Flu A+B) И Теста RT-PCR При Инфекциях Гриппа

Folia Medica ◽

10.1515/folmed-2015-0027 ◽

2015 ◽

Vol 57 (2) ◽

pp. 104-110 ◽

Cited By ~ 4

Author(s):

Golubinka Bosevska ◽

Nikola Panovski ◽

Elizabeta Janceska ◽

Vladimir Mikik ◽

Irena Kondova Topuzovska ◽

...

Keyword(s):

Real Time ◽

Influenza A Virus ◽

Real Time Pcr ◽

Influenza A ◽

Age Groups ◽

Influenza Viruses ◽

Influenza B Virus ◽

Influenza B ◽

B Virus ◽

Nose And Throat

AbstractEarly diagnosis and treatment of patients with influenza is the reason why physicians need rapid high-sensitivity influenza diagnostic tests that require no complex lab equipment and can be performed and interpreted within 15 min. The Aim of this study was to compare the rapid Directigen Flu A+B test with real time PCR for detection of influenza viruses in the Republic of Macedonia. MATERIALS AND METHODS: One-hundred-eight respiratory samples (combined nose and throat swabs) were routinely collected for detection of influenza virus during influenza seasons. Forty-one patients were pediatric cases and 59 were adult. Their mean age was 23 years. The patients were allocated into 6 age groups: 0 - 4 yrs, 5 - 9 yrs, 10 - 14 yrs, 15 - 19 yrs, 20-64 yrs and > 65 yrs. Each sample was tested with Directigen Flu A+B and CDC real time PCR kit for detection and typisation/subtypisation of influenza according to the lab diagnostic protocol. RESULTS: Directigen Flu A+B identified influenza A virus in 20 (18.5%) samples and influenza B virus in two 2 (1.9%) samples. The high specificity (100%) and PPV of Directigen Flu A+B we found in our study shows that the positive results do not need to be confirmed. The overall sensitivity of Directigen Flu A+B is 35.1% for influenza A virus and 33.0% for influenza B virus. The sensitivity for influenza A is higher among children hospitalized (45.0%) and outpatients (40.0%) versus adults. CONCLUSION: Directigen Flu A+B has relatively low sensitivity for detection of influenza viruses in combined nose and throat swabs. Negative results must be confirmed.

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Haemagglutination-inhibition antibodies against influenza A and influenza B in maternal and neonatal sera

Journal of Hygiene ◽

10.1017/s0022172400053353 ◽

1978 ◽

Vol 80 (1) ◽

pp. 13-19 ◽

Cited By ~ 6

Author(s):

N. Masurel ◽

J. I. de Bruijne ◽

H. A. Beuningh ◽

H. J. A. Schouten

Keyword(s):

Influenza Virus ◽

Maternal Age ◽

Influenza A ◽

Haemagglutination Inhibition ◽

Influenza Viruses ◽

Influenza B Virus ◽

Influenza B ◽

B Virus ◽

Duration Of Pregnancy ◽

Pregnancy And Birth

SUMMARYHaemagglutination inhibition (HI) antibodies against the influenza viruses A/Hong Kong/8/68 (H3N2) and B/Nederland/77/66 were determined in 420 paired sera from mothers and newborns (umbilical cord sera), sampled in 1970–1.A higher concentration of antibodies against influenza A virus was found more frequently in neonatal than in maternal sera. By contrast, low titres against influenza B virus were more frequently observed in neonatal than in maternal sera. Maternal age, duration of pregnancy, and birth-weight did not affect the results of the tests.It is suggested that the titre of the newborn against an epidemic influenza virus can be predicted from that of the mother. Furthermore, the maternal titre may be an indication of the susceptibility of the newborn infant to influenza infections.

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Influenza A and B viruses in the population of Vojvodina, Serbia

Archives of Biological Sciences ◽

10.2298/abs1401043r ◽

2014 ◽

Vol 66 (1) ◽

pp. 43-50 ◽

Cited By ~ 2

Author(s):

J. Radovanov ◽

V. Milosevic ◽

I. Hrnjakovic ◽

V. Petrovic ◽

M. Ristic ◽

...

Keyword(s):

Influenza A ◽

Respiratory Infections ◽

Influenza Viruses ◽

Influenza B Virus ◽

Nasopharyngeal Swab ◽

Influenza B ◽

Influenza A Viruses ◽

B Virus ◽

Life Threatening ◽

Seasonal Epidemic

At present, two influenza A viruses, H1N1pdm09 and H3N2, along with influenza B virus co-circulate in the human population, causing endemic and seasonal epidemic acute febrile respiratory infections, sometimes with life-threatening complications. Detection of influenza viruses in nasopharyngeal swab samples was done by real-time RT-PCR. There were 60.2% (53/88) positive samples in 2010/11, 63.4% (52/82) in 2011/12, and 49.9% (184/369) in 2012/13. Among the positive patients, influenza A viruses were predominant during the first two seasons, while influenza B type was more active during 2012/13. Subtyping of influenza A positive samples revealed the presence of A (H1N1)pdm09 in 2010/11, A (H3N2) in 2011/12, while in 2012/13, both subtypes were detected. The highest seroprevalence against influenza A was in the age-group 30-64, and against influenza B in adults aged 30-64 and >65.

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Non-Uniform and Non-Random Binding of Nucleoprotein to Influenza A and B Viral RNA

Viruses ◽

10.3390/v10100522 ◽

2018 ◽

Vol 10 (10) ◽

pp. 522 ◽

Cited By ~ 10

Author(s):

Valerie Le Sage ◽

Adalena Nanni ◽

Amar Bhagwat ◽

Dan Snyder ◽

Vaughn Cooper ◽

...

Keyword(s):

Influenza A ◽

Gene Segment ◽

Influenza Viruses ◽

Viral Rna ◽

Influenza B Virus ◽

Viral Gene ◽

Influenza B ◽

Influenza A Viruses ◽

Binding Profile ◽

Random Manner

The genomes of influenza A and B viruses have eight, single-stranded RNA segments that exist in the form of a viral ribonucleoprotein complex in association with nucleoprotein (NP) and an RNA-dependent RNA polymerase complex. We previously used high-throughput RNA sequencing coupled with crosslinking immunoprecipitation (HITS-CLIP) to examine where NP binds to the viral RNA (vRNA) and demonstrated for two H1N1 strains that NP binds vRNA in a non-uniform, non-random manner. In this study, we expand on those initial observations and describe the NP-vRNA binding profile for a seasonal H3N2 and influenza B virus. We show that, similar to H1N1 strains, NP binds vRNA in a non-uniform and non-random manner. Each viral gene segment has a unique NP binding profile with areas that are enriched for NP association as well as free of NP-binding. Interestingly, NP-vRNA binding profiles have some conservation between influenza A viruses, H1N1 and H3N2, but no correlation was observed between influenza A and B viruses. Our study demonstrates the conserved nature of non-uniform NP binding within influenza viruses. Mapping of the NP-bound vRNA segments provides information on the flexible NP regions that may be involved in facilitating assembly.

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Detection of severe acute respiratory syndrome coronavirus 2 and influenza viruses based on CRISPR-Cas12a

Experimental Biology and Medicine ◽

10.1177/1535370220963793 ◽

2020 ◽

pp. 153537022096379

Author(s):

Oraphan Mayuramart ◽

Pattaraporn Nimsamer ◽

Somruthai Rattanaburi ◽

Naphat Chantaravisoot ◽

Kritsada Khongnomnan ◽

...

Keyword(s):

Influenza Virus ◽

Severe Acute Respiratory Syndrome ◽

Influenza A ◽

Limit Of Detection ◽

Cross Reactivity ◽

Influenza Viruses ◽

Influenza B Virus ◽

Influenza B ◽

Influenza Virus A ◽

B Virus

Due to the common symptoms of COVID-19, patients are similar to influenza-like illness. Therefore, the detection method would be crucial to discriminate between SARS-CoV-2 and influenza virus-infected patients. In this study, CRISPR-Cas12a-based detection was applied for detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), influenza A virus, and influenza B virus which would be a practical and attractive application for screening of patients with COVID-19 and influenza in areas with limited resources. The limit of detection for SARS-CoV-2, influenza A, and influenza B detection was 10, 103, and 103 copies/reaction, respectively. Moreover, the assays yielded no cross-reactivity against other respiratory viruses. The results revealed that the detection of influenza virus and SARS-CoV-2 by using RT-RPA and CRISPR-Cas12a technology reaches 96.23% sensitivity and 100% specificity for SARS-CoV-2 detection. The sensitivity for influenza virus A and B detections was 85.07% and 94.87%, respectively. In addition, the specificity for influenza virus A and B detections was approximately 96%. In conclusion, the RT-RPA with CRISPR-Cas12a assay was an effective method for the screening of influenza viruses and SARS-CoV-2 which could be applied to detect other infectious diseases in the future.

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Bacterial Sinusitis and Otitis Media following Influenza Virus Infection in Ferrets

Infection and Immunity ◽

10.1128/iai.74.5.2562-2567.2006 ◽

2006 ◽

Vol 74 (5) ◽

pp. 2562-2567 ◽

Cited By ~ 59

Author(s):

Ville T. Peltola ◽

Kelli L. Boyd ◽

Julie L. McAuley ◽

Jerold E. Rehg ◽

Jonathan A. McCullers

Keyword(s):

Influenza Virus ◽

Otitis Media ◽

Influenza A ◽

Bacterial Colonization ◽

Influenza Virus Infection ◽

Influenza Viruses ◽

Influenza B Virus ◽

Influenza B ◽

Complication Rates ◽

Pneumococcal Infections

ABSTRACT Streptococcus pneumoniae is the leading cause of otitis media, sinusitis, and pneumonia. Many of these infections result from antecedent influenza virus infections. In this study we sought to determine whether the frequency and character of secondary pneumococcal infections differed depending on the strain of influenza virus that preceded bacterial challenge. In young ferrets infected with influenza virus and then challenged with pneumococcus, influenza viruses of any subtype increased bacterial colonization of the nasopharynx. Nine out of 10 ferrets infected with H3N2 subtype influenza A viruses developed either sinusitis or otitis media, while only 1 out of 11 ferrets infected with either an H1N1 influenza A virus or an influenza B virus did so. These data may partially explain why bacterial complication rates are higher during seasons when H3N2 viruses predominate. This animal model will be useful for further study of the mechanisms that underlie viral-bacterial synergism.

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Impact of oseltamivir treatment on influenza A and B dynamics in human volunteers

10.1101/2020.11.13.20231357 ◽

2020 ◽

Author(s):

Kyla L. Hooker ◽

Vitaly V. Ganusov

Keyword(s):

Clinical Trials ◽

Influenza Virus ◽

Influenza A ◽

Influenza Viruses ◽

Influenza B Virus ◽

Influenza B ◽

Virus Shedding ◽

Viral Shedding ◽

Human Volunteers ◽

The Impact

AbstractInfluenza viruses infect millions of humans every year causing an estimated 400,000 deaths globally. Due to continuous virus evolution current vaccines provide only limited protection against the flu. Several antiviral drugs are available to treat influenza infection, and one of the most most commonly used drugs is oseltamivir (Tamiflu). While the mechanism of action of oseltamivir as a neuraminidase inhibitor is well understood, the impact of oseltamivir on influenza virus dynamics in humans has been controversial. Many clinical trials with oseltamivir have been done by pharmaceutical companies such as Roche but the results of these trials until recently have been reported as summary reports or papers. Typically, such reports included median virus shedding curves for placebo and drug-treated influenza virus infected volunteers often indicating high efficacy of the early treatment. However, median shedding curves may be not accurately representing drug impact in individual volunteers. Importantly, due to public pressure clinical trials data testing oseltamivir efficacy has been recently released in the form of redacted PDF documents. We digitized and re-analyzed experimental data on influenza virus shedding in human volunteers from three previously published trials: on influenza A (1 trial) or B viruses (2 trials). Given that not all volunteers exposed to influenza viruses actually start virus shedding we found that impact of oseltamivir on the virus shedding dynamics was dependent on i) selection of volunteers that were infected with the virus, and ii) the detection limit in the measurement assay; both of these details were not well articulated in the published studies. By assuming that any viral measurement is above the limit of detection we could match previously published data on median influenza A virus (flu A study) shedding but not on influenza B virus shedding (flu B study B) in human volunteers. Additional analyses confirmed that oseltamivir had an impact on the duration of shedding and overall shedding (defined as area under the curve) but this result was varied by the trial. Interestingly, treatment had no impact on the rates at which shedding increased or declined with time in individual volunteers. Additional analyses showed that oseltamivir impacted the kinetics of the start and end of viral shedding and in about 20-40% of volunteers treatment had no impact on viral shedding duration. Our results suggest an unusual impact of oseltamivir on influenza viruses shedding kinetics and caution about the use of published median data or data from a few individuals for inferences. Furthermore, we call for the need to publish raw data from critical clinical trials that can be then independently analyzed.

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Hemagglutination inhibition antibody titers as a correlate of protection against influenza disease in the 2018/2019 epidemic season in Poland

Acta Biochimica Polonica ◽

10.18388/abp.2020_5088 ◽

2020 ◽

Author(s):

Ewelina Hallmann-Szelińska ◽

Karol Szymański ◽

Katarzyna Łuniewska ◽

Katarzyna Kondratiuk ◽

Lidia Bernadeta Brydak

Keyword(s):

Hemagglutination Inhibition ◽

Influenza A ◽

Age Groups ◽

Influenza Viruses ◽

Clinical Samples ◽

Influenza B Virus ◽

Influenza B ◽

Epidemic Season ◽

Hemagglutination Inhibition Test ◽

Inhibition Antibody

The aim of this study was to determine the level of antibodies against hemagglutinin of influenza viruses in the sera of people in the seven age groups in the epidemic season 2018/2019 in Poland. The level of anti-hemagglutinin antibodies was determined by hemagglutination inhibition test (HAI). 1050 clinical samples from all over the country were tested. The level of antibodies against influenza viruses was highest in the 10–14 age group for A/Singapore/INFIMH-16-0019/2016 (H3N2) and B/Phuket/3073/2013 Yamagata lineage antigens. These results confirm the circulation of four antigenically different influenza virus strains, two subtypes of influenza A virus – A/Michigan/45/2015 (H1N1)pdm09 and A/Singapore/INFIMH-16-0019/2016 (H3N2) and two lineages of influenza B virus – B/Colorado/06/2017 – Victoria lineage and B/Phuket/3073/2013 Yamagata lineage.

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