scholarly journals Cell culture-based production and in vivo characterization of purely clonal defective interfering influenza virus particles

BMC Biology ◽  
2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Marc D. Hein ◽  
Prerna Arora ◽  
Pavel Marichal-Gallardo ◽  
Michael Winkler ◽  
Yvonne Genzel ◽  
...  
Keyword(s):  
Cell Culture ◽  
Influenza Virus ◽  
Influenza A ◽  
Mdck Cells ◽  
Animal Cell ◽  
Lethal Dose ◽  
High Morbidity ◽  
Stirred Tank Bioreactor ◽  
Working Volume ◽  
The Impact

Abstract Background Infections with influenza A virus (IAV) cause high morbidity and mortality in humans. Additional to vaccination, antiviral drugs are a treatment option. Besides FDA-approved drugs such as oseltamivir or zanamivir, virus-derived defective interfering (DI) particles (DIPs) are considered promising new agents. IAV DIPs typically contain a large internal deletion in one of their eight genomic viral RNA (vRNA) segments. Consequently, DIPs miss the genetic information necessary for replication and can usually only propagate by co-infection with infectious standard virus (STV), compensating for their defect. In such a co-infection scenario, DIPs interfere with and suppress STV replication, which constitutes their antiviral potential. Results In the present study, we generated a genetically engineered MDCK suspension cell line for production of a purely clonal DIP preparation that has a large deletion in its segment 1 (DI244) and is not contaminated with infectious STV as egg-derived material. First, the impact of the multiplicity of DIP (MODIP) per cell on DI244 yield was investigated in batch cultivations in shake flasks. Here, the highest interfering efficacy was observed for material produced at a MODIP of 1E−2 using an in vitro interference assay. Results of RT-PCR suggested that DI244 material produced was hardly contaminated with other defective particles. Next, the process was successfully transferred to a stirred tank bioreactor (500 mL working volume) with a yield of 6.0E+8 PFU/mL determined in genetically modified adherent MDCK cells. The produced material was purified and concentrated about 40-fold by membrane-based steric exclusion chromatography (SXC). The DI244 yield was 92.3% with a host cell DNA clearance of 97.1% (99.95% with nuclease digestion prior to SXC) and a total protein reduction of 97.2%. Finally, the DIP material was tested in animal experiments in D2(B6).A2G-Mx1r/r mice. Mice infected with a lethal dose of IAV and treated with DIP material showed a reduced body weight loss and all animals survived. Conclusion In summary, experiments not only demonstrated that purely clonal influenza virus DIP preparations can be obtained with high titers from animal cell cultures but confirmed the potential of cell culture-derived DIPs as an antiviral agent.

scholarly journals Comparison of Four Clinical Specimen Types for Detection of Influenza A and B Viruses by Optical Immunoassay (FLU OIA Test) and Cell Culture Methods

1999 ◽  
Vol 37 (12) ◽  
pp. 3971-3974 ◽  
Author(s):  
Kristi A. Covalciuc ◽  
Kenneth H. Webb ◽  
Curtis A. Carlson
Keyword(s):  
Cell Culture ◽  
Influenza Virus ◽  
Virus Infection ◽  
Influenza A ◽  
Influenza Virus Infection ◽  
Laboratory Diagnosis ◽  
Sample Type ◽  
Clinical Specimens ◽  
Viral Culture ◽  
The Impact

Although laboratory diagnosis of respiratory viruses has been widely studied, there is a relative insufficiency of literature examining the impact of specimen type on the laboratory diagnosis of influenza A and B. In a clinical study comparing the FLU OIA test with 14-day cell culture, clinical specimens from nasopharyngeal swabs, throat swabs, nasal aspirates, and sputum were obtained from patients experiencing influenza-like symptoms. A total of 404 clinical specimens were collected from 184 patients. Patients were defined as influenza positive if the viral culture of a specimen from any sample site was positive. Patients were defined as influenza negative if the viral cultures of specimens from all sample sites were negative. By this gold standard, culture and FLU OIA test results for each sample type were compared. For each of the four specimen types, the viral culture and FLU OIA test demonstrated equal abilities to detect the presence of influenza A or B virus or viral antigen. Sputum and nasal aspirate samples were the most predictive of influenza virus infection. Throat swabs were the least predictive of influenza virus infection, with both tests failing to detect influenza virus in nearly 50% of the throat samples studied.

Impact of influenza virus during pregnancy: from disease severity to vaccine efficacy

2020 ◽  
Vol 15 (7) ◽  
pp. 441-453
Author(s):  
Ana Vazquez-Pagan ◽  
Rebekah Honce ◽  
Stacey Schultz-Cherry
Keyword(s):  
Influenza Virus ◽  
Virus Infection ◽  
Immune Responses ◽  
Pregnant Women ◽  
Disease Severity ◽  
Influenza A ◽  
Antiviral Treatment ◽  
Influenza Virus Infection ◽  
Severe Influenza ◽  
The Impact

Pregnant women are among the individuals at the highest risk for severe influenza virus infection. Infection of the mother during pregnancy increases the probability of adverse fetal outcomes such as small for gestational age, preterm birth and fetal death. Animal models of syngeneic and allogeneic mating can recapitulate the increased disease severity observed in pregnant women and are used to define the mechanism(s) of that increased severity. This review focuses on influenza A virus pathogenesis, the unique immunological landscape during pregnancy, the impact of maternal influenza virus infection on the fetus and the immune responses at the maternal–fetal interface. Finally, we summarize the importance of immunization and antiviral treatment in this population and highlight issues that warrant further investigation.

scholarly journals In VitroSusceptibility of Canine Influenza A (H3N8) Virus to Nitazoxanide and Tizoxanide

2010 ◽  
Vol 2010 ◽  
pp. 1-5 ◽  
Author(s):  
Laura V. Ashton ◽  
Robert L. Callan ◽  
Sangeeta Rao ◽  
Gabriele A. Landolt
Keyword(s):  
Influenza Virus ◽  
Influenza A ◽  
The United States ◽  
Canine Influenza Virus ◽  
Valuable Adjunct ◽  
Canine Influenza ◽  
The Impact ◽  
H3n8 Virus

Infection of dogs with canine influenza virus (CIV) is considered widespread throughout the United States following the first isolation of CIV in 2004. While vaccination against influenza A infection is a common and important practice for disease control, antiviral therapy can serve as a valuable adjunct in controlling the impact of the disease. In this study, we examined the antiviral activity of nitazoxanide (NTZ) and tizoxanide (TIZ) against three CIV isolatesin vitro. NTZ and TIZ inhibited virus replication of all CIVs with 50% and 90% inhibitory concentrations ranging from 0.17 to 0.21 μMand from 0.60 to 0.76 μM, respectively. These results suggest that NTZ and TIZ are effective against CIV and may be useful for treatment of canine influenza in dogs but further investigation of thein vivoefficacy against CIV as well as the drug's potential for toxicity in dogs is needed.

scholarly journals Protective Efficacy of the Conserved NP, PB1, and M1 Proteins as Immunogens in DNA- and Vaccinia Virus-Based Universal Influenza A Virus Vaccines in Mice

2015 ◽  
Vol 22 (6) ◽  
pp. 618-630 ◽  
Author(s):  
Wenling Wang ◽  
Renqing Li ◽  
Yao Deng ◽  
Ning Lu ◽  
Hong Chen ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Virus Strain ◽  
Influenza A ◽  
Protective Efficacy ◽  
Lethal Dose ◽  
Influenza Vaccines ◽  
Strong Immune Response ◽  
Influenza Virus Strain ◽  
Vaccinia Viruses ◽  
Viral Components

ABSTRACTThe conventional hemagglutinin (HA)- and neuraminidase (NA)-based influenza vaccines need to be updated most years and are ineffective if the glycoprotein HA of the vaccine strains is a mismatch with that of the epidemic strain. Universal vaccines targeting conserved viral components might provide cross-protection and thus complement and improve conventional vaccines. In this study, we generated DNA plasmids and recombinant vaccinia viruses expressing the conserved proteins nucleoprotein (NP), polymerase basic 1 (PB1), and matrix 1 (M1) from influenza virus strain A/Beijing/30/95 (H3N2). BALB/c mice were immunized intramuscularly with a single vaccine based on NP, PB1, or M1 alone or a combination vaccine based on all three antigens and were then challenged with lethal doses of the heterologous influenza virus strain A/PR/8/34 (H1N1). Vaccines based on NP, PB1, and M1 provided complete or partial protection against challenge with 1.7 50% lethal dose (LD50) of PR8 in mice. Of the three antigens, NP-based vaccines induced protection against 5 LD50and 10 LD50and thus exhibited the greatest protective effect. Universal influenza vaccines based on the combination of NP, PB1, and M1 induced a strong immune response and thus might be an alternative approach to addressing future influenza virus pandemics.

scholarly journals International Laboratory Comparison of Influenza Microneutralization Assays for A(H1N1)pdm09, A(H3N2), and A(H5N1) Influenza Viruses by CONSISE

2015 ◽  
Vol 22 (8) ◽  
pp. 957-964 ◽  
Author(s):  
Karen L. Laurie ◽  
Othmar G. Engelhardt ◽  
John Wood ◽  
Alan Heath ◽  
Jacqueline M. Katz ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Incubation Time ◽  
Influenza A ◽  
Influenza Viruses ◽  
Enzyme Linked Immunosorbent Assay ◽  
Influenza A Viruses ◽  
H5n1 Influenza ◽  
The World ◽  
International Laboratory ◽  
The Impact

ABSTRACTThe microneutralization assay is commonly used to detect antibodies to influenza virus, and multiple protocols are used worldwide. These protocols differ in the incubation time of the assay as well as in the order of specific steps, and even within protocols there are often further adjustments in individual laboratories. The impact these protocol variations have on influenza serology data is unclear. Thus, a laboratory comparison of the 2-day enzyme-linked immunosorbent assay (ELISA) and 3-day hemagglutination (HA) microneutralization (MN) protocols, using A(H1N1)pdm09, A(H3N2), and A(H5N1) viruses, was performed by the CONSISE Laboratory Working Group. Individual laboratories performed both assay protocols, on multiple occasions, using different serum panels. Thirteen laboratories from around the world participated. Within each laboratory, serum sample titers for the different assay protocols were compared between assays to determine the sensitivity of each assay and were compared between replicates to assess the reproducibility of each protocol for each laboratory. There was good correlation of the results obtained using the two assay protocols in most laboratories, indicating that these assays may be interchangeable for detecting antibodies to the influenza A viruses included in this study. Importantly, participating laboratories have aligned their methodologies to the CONSISE consensus 2-day ELISA and 3-day HA MN assay protocols to enable better correlation of these assays in the future.

scholarly journals Deep Mutational Scan of the Highly Conserved Influenza A Virus M1 Matrix Protein Reveals Substantial Intrinsic Mutational Tolerance

2019 ◽  
Vol 93 (13) ◽  
Author(s):  
Nancy Hom ◽  
Lauren Gentles ◽  
Jesse D. Bloom ◽  
Kelly K. Lee
Keyword(s):  
Cell Culture ◽  
Influenza Virus ◽  
Amino Acid ◽  
Viral Replication ◽  
Influenza A Virus ◽  
Influenza A ◽  
Matrix Protein ◽  
Influenza Virus Infection ◽  
Sequence Diversity ◽  
Virus Protein

ABSTRACTInfluenza A virus matrix protein M1 is involved in multiple stages of the viral infectious cycle. Despite its functional importance, our present understanding of this essential viral protein is limited. The roles of a small subset of specific amino acids have been reported, but a more comprehensive understanding of the relationship between M1 sequence, structure, and virus fitness remains elusive. In this study, we used deep mutational scanning to measure the effect of every amino acid substitution in M1 on viral replication in cell culture. The map of amino acid mutational tolerance we have generated allows us to identify sites that are functionally constrained in cell culture as well as sites that are less constrained. Several sites that exhibit low tolerance to mutation have been found to be critical for M1 function and production of viable virions. Surprisingly, significant portions of the M1 sequence, especially in the C-terminal domain, whose structure is undetermined, were found to be highly tolerant of amino acid variation, despite having extremely low levels of sequence diversity among natural influenza virus strains. This unexpected discrepancy indicates that not all sites in M1 that exhibit high sequence conservation in nature are under strong constraint during selection for viral replication in cell culture.IMPORTANCEThe M1 matrix protein is critical for many stages of the influenza virus infection cycle. Currently, we have an incomplete understanding of this highly conserved protein’s function and structure. Key regions of M1, particularly in the C terminus of the protein, remain poorly characterized. In this study, we used deep mutational scanning to determine the extent of M1’s tolerance to mutation. Surprisingly, nearly two-thirds of the M1 sequence exhibits a high tolerance for substitutions, contrary to the extremely low sequence diversity observed across naturally occurring M1 isolates. Sites with low mutational tolerance were also identified, suggesting that they likely play critical functional roles and are under selective pressure. These results reveal the intrinsic mutational tolerance throughout M1 and shape future inquiries probing the functions of this essential influenza A virus protein.

scholarly journals Synthesis of DEAE-Soybean Starch Microspheres for Adhere Animal Cell Culture

2017 ◽  
Vol 9 (8) ◽  
pp. 91
Author(s):  
Lei Zhang ◽  
Mingsheng Li ◽  
Zhongren Ma ◽  
Yuping Feng
Keyword(s):  
Cell Culture ◽  
Mdck Cells ◽  
Animal Cell ◽  
Low Cost ◽  
Animal Cell Culture ◽  
Cross Linking ◽  
Animal Cells ◽  
Inoculation Density ◽  
Animal Cell Cultures ◽  
Adhere Cell

The present study outlines the synthesis of a new microcarrier for anchorage-dependent animal cell cultures. The new microcarriers were synthesized from the cross-linking soybean starch microspheres followed by modification with 2-diethylaminoethyl (DEAE). Furthermore, 5 g/100 mL of wet microspheres DEAE-soybean starch microspheres were applied in the adhere cell culture, with an inoculation density 2.0 × 105 cells/mL of BHK-21, Marc-145, and MDCK cells. The cells were shown to grow well in the DEAE-soybean starch microcarrier, with BHK-21 cells showing a higher cell density after 144 h (2.5 × 106 cells/mL) compared to cells grown on the commercial product Cytodex 1 (2.2 × 106 cells/mL). These starch microcarriers have a potential application in anchorage-dependent animal cells culture, due to its low cost and its simple process.

scholarly journals Neuraminidase Inhibitor-Rimantadine Combinations Exert Additive and Synergistic Anti-Influenza Virus Effects in MDCK Cells

2004 ◽  
Vol 48 (12) ◽  
pp. 4855-4863 ◽  
Author(s):  
Elena A. Govorkova ◽  
Hong-Bin Fang ◽  
Ming Tan ◽  
Robert G. Webster
Keyword(s):  
Influenza Virus ◽  
Influenza A ◽  
New Caledonia ◽  
Mdck Cells ◽  
Synergistic Effects ◽  
Drug Combinations ◽  
Virus Yield ◽  
Oseltamivir Carboxylate ◽  
Extracellular Virus ◽  
Drug Concentrations

ABSTRACT There is insufficient information about combination therapy with approved anti-influenza agents. We tested combinations that paired a neuraminidase (NA) inhibitor (zanamivir, oseltamivir carboxylate, or peramivir) with rimantadine against infection of MDCK cells with H1N1 and H3N2 subtypes of influenza A virus and characterized their mode of interaction. When reduction of extracellular virus was analyzed by individual regression models and three-dimensional representations of the data, all three combinations showed additive and synergistic effects with no cytotoxicity. Maximum synergy against A/New Caledonia/20/99 (H1N1) virus infection was observed with <2.5 μM rimantadine paired with low concentrations of NA inhibitors. All combinations reduced the extracellular yield of A/Panama/2007/99 (H3N2) influenza virus synergistically. However, our findings were different for the cell-associated virus yield. At some drug concentrations, the yield of cell-associated virus was inhibited antagonistically. Therefore, the method of analysis can be a crucial factor in evaluating the interactions of drugs with different mechanisms. We hypothesize that assays based on cell-associated virus yield may underestimate the efficacies of drug combinations that include an NA inhibitor. Taken together, our results suggest that regimens that combine NA inhibitors and rimantadine exert synergistic anti-influenza effects in vitro. These findings provide baseline information for therapeutic testing of the drug combinations in vivo.

scholarly journals Evaluation of the genotoxic and mutagenic potentials of a living nosode compounded with Influenza A virus

2021 ◽  
Vol 10 (36) ◽  
pp. 180-182
Author(s):  
Juliana Paiva ◽  
Camila Siqueira ◽  
Carla Holandino ◽  
Alvaro Leitao
Keyword(s):  
Influenza Virus ◽  
Side Effects ◽  
Influenza A Virus ◽  
Influenza A ◽  
Ames Test ◽  
Negative Control ◽  
Survival Fraction ◽  
Starting Point ◽  
Aseptic Conditions ◽  
The Impact

Background: The influenza virus has been responsible for contagious respiratory diseases with high mortality rates [1]. Some drugs have been used to treat human influenza. However, these drugs cause many common side effects and induce the appearance of resistant viral strains [2]. The impact caused by the influenza virus has motivated the development of new approaches for the prevention and control of influenza [3]. Therefore, a new homeopathic medicine was developed using, as a starting point, the infectious influenza virus [4]. This belongs to a group called living nosodes [5]. However, its mutagenic and genotoxic potentials, especially when used in low dilutions, has not yet been evaluated and it is important because this biotherapic is prepared from living microorganisms. Different methods can be used to detect mutagenic and genotoxicic effects. Aims: This study aims to evaluate the genotoxic and mutagenic potentials of influenza A living nosode at different homeopathic potencies. Methodology: 1 ml of purified viral suspension was diluted in 9 ml of sterile distilled water. This sample was submitted to 100 mechanical succussions (approximately 3 Hz), using Autic® Brazilian machine, originating the first dilution, named decimal (1x). 1 ml of this solution was diluted in 9 ml of solvent and was submitted to 100 sucussions, generating biotherapic 2x. This procedure was successively repeated, according to Brazilian Homeopathic Pharmacopoeia, to obtain the biotherapic 30x [6]. By the same technique, water vehicle was prepared until 30x potency to be used as control. All samples were prepared in sterile and under aseptic conditions, using laminar flow cabinet, class II, and were stored in the refrigerator (8ºC). The samples 1x, 6x, 12x, 18x, 24x and 30x and water 30x (vehicle control) were analysed by: the Inductest, which assesses the ability of physical or chemical agents to promote lysogenic induction as a reflection of damage in DNA molecules in lysogenic bacteria, and the Ames test, which uses indicator strains of Salmonella typhimurium, sensitive to substances that can induce different types of mutation. Results: The Inductest showed no decrease in the survival fraction of the bacteria used, and no increase in the formation of lysogenic induction, in any tested potency. The same profile was obtained after the Ames test, with similar results to negative control. Conclusion: We can conclude that this living nosode compounded with Influenza A virus is not able to induce DNA damage in prokaryotic cells. This result permits us to conclude that patients who use this medicine have no side effects related to mutagenesis and genotoxicity.

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

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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