scholarly journals Method for evaluating the neuraminidase activity of receptor-destroying enzyme (RDE) compounds using the influenza virus

2020 ◽  
Vol 65 (2) ◽  
pp. 113-118
Author(s):  
Artem Yu. Fedorov ◽  
Oleg P. Zhirnov
Keyword(s):  
Convenient Method ◽  
Influenza A ◽  
Influenza Infection ◽  
Hemagglutination Assay ◽  
Laboratory Equipment ◽  
Virus Attachment ◽  
Neuraminidase Activity ◽  
Acute Respiratory Diseases ◽  
Flu Virus ◽  
Inhibition Reaction

Introduction. The classic hemagglutination inhibition reaction (RTGA) is used to determine the level of antiviral antibodies in human and animal serum specimens. During the performance of RTGA the tested sera must be treated with a receptor-destroying enzyme (RDE) to remove serum glycans that degrade the accuracy of the RTGA results. To optimize the amounts of RDE compounds used, it is necessary to know their real neuraminidase activity. This article describes a simple and economical method for testing the neuraminidase activity of receptor-destroying compounds using standard reagents and laboratory equipment.Aims of investigation. Design of an improved simple and convenient method for evaluating the neuraminidase activity using the flu virus.Material and methods. Here, we propose a convenient method for evaluating the activity of neuraminidase by double-fold dilution procedure with human or animal erythrocytes followed by hemagglutination assay with influenza A virus.Results and discussion. The method is based on the ability of neuraminidase to hydrolyze sialic acid residues on the cell surface of erythrocytes, that deprives red blood cells to be agglutinated with the flu virus, since these sialic glycans provide virus attachment and hemagglutination.Conclusion. The designed method allows the accurate measurement of the receptor-destroying (neuraminidase) activity of RDE compounds and the comparison of the compounds with each other. This test is necessary to optimize the RTGA protocol when monitoring blood sera of animals and humans after influenza infection and/or Acute Respiratory diseases (ARD). The designed method can be included in the guidelines of regulations for the RTGA protocol, which is used in different laboratories to monitor the epidemic process of influenza and ARD infections.

scholarly journals Differential Expression of Serum Exosome microRNAs and Cytokines in Influenza A and B Patients Collected in the 2016 and 2017 Influenza Seasons

Pathogens ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 149
Author(s):  
Sreekumar Othumpangat ◽  
William G. Lindsley ◽  
Donald H. Beezhold ◽  
Michael L. Kashon ◽  
Carmen N. Burrell ◽  
...  
Keyword(s):  
Healthy Volunteers ◽  
Influenza A ◽  
Influenza Infection ◽  
Cell Types ◽  
Airway Epithelial Cells ◽  
Differentially Expressed ◽  
Influenza B ◽  
Airway Epithelial ◽  
Monocyte Chemoattractant Protein 1 ◽  
Novel Approach

MicroRNAs (miRNAs) have remarkable stability and are key regulators of mRNA transcripts for several essential proteins required for the survival of cells and replication of the virus. Exosomes are thought to play an essential role in intercellular communications by transporting proteins and miRNAs, making them ideal in the search for biomarkers. Evidence suggests that miRNAs are involved in the regulation of influenza virus replication in many cell types. During the 2016 and 2017 influenza season, we collected blood samples from 54 patients infected with influenza and from 30 healthy volunteers to identify the potential role of circulating serum miRNAs and cytokines in influenza infection. Data comparing the exosomal miRNAs in patients with influenza B to healthy volunteers showed 76 miRNAs that were differentially expressed (p < 0.05). In contrast, 26 miRNAs were differentially expressed between patients with influenza A (p < 0.05) and the controls. Of these miRNAs, 11 were commonly expressed in both the influenza A and B patients. Interferon (IFN)-inducing protein 10 (IP-10), which is involved in IFN synthesis during influenza infection, showed the highest level of expression in both influenza A and B patients. Influenza A patients showed increased expression of IFNα, GM-CSF, interleukin (IL)-13, IL-17A, IL-1β, IL-6 and TNFα, while influenza B induced increased levels of EGF, G-CSF, IL-1α, MIP-1α, and TNF-β. In addition, hsa-miR-326, hsa-miR-15b-5p, hsa-miR-885, hsa-miR-122-5p, hsa-miR-133a-3p, and hsa-miR-150-5p showed high correlations to IL-6, IL-15, IL-17A, IL-1β, and monocyte chemoattractant protein-1 (MCP-1) with both strains of influenza. Next-generation sequencing studies of H1N1-infected human lung small airway epithelial cells also showed similar pattern of expression of miR-375-5p, miR-143-3p, 199a-3p, and miR-199a-5p compared to influenza A patients. In summary, this study provides insights into the miRNA profiling in both influenza A and B virus in circulation and a novel approach to identify the early infections through a combination of cytokines and miRNA expression.

scholarly journals Effects of Basic Amino Acids and Their Derivatives on SARS-CoV-2 and Influenza-A Virus Infection

Viruses ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1301
Author(s):  
Ivonne Melano ◽  
Li-Lan Kuo ◽  
Yan-Chung Lo ◽  
Po-Wei Sung ◽  
Ni Tien ◽  
...  
Keyword(s):  
Amino Acids ◽  
Virus Infection ◽  
Influenza A Virus ◽  
Influenza A ◽  
Enveloped Viruses ◽  
Virus Attachment ◽  
Basic Amino Acids ◽  
Ester Derivative ◽  
Endosomal Acidification

Amino acids have been implicated with virus infection and replication. Here, we demonstrate the effects of two basic amino acids, arginine and lysine, and their ester derivatives on infection of two enveloped viruses, SARS-CoV-2, and influenza A virus. We found that lysine and its ester derivative can efficiently block infection of both viruses in vitro. Furthermore, the arginine ester derivative caused a significant boost in virus infection. Studies on their mechanism of action revealed that the compounds potentially disturb virus uncoating rather than virus attachment and endosomal acidification. Our findings suggest that lysine supplementation and the reduction of arginine-rich food intake can be considered as prophylactic and therapeutic regimens against these viruses while also providing a paradigm for the development of broad-spectrum antivirals.

Absence of SP-A modulates innate and adaptive defense responses to pulmonary influenza infection

2002 ◽  
Vol 282 (3) ◽  
pp. L563-L572 ◽  
Author(s):  
Ann Marie LeVine ◽  
Kevan Hartshorn ◽  
James Elliott ◽  
Jeffrey Whitsett ◽  
Thomas Korfhagen
Keyword(s):  
Lung Inflammation ◽  
Influenza A ◽  
Influenza Infection ◽  
Pulmonary Inflammation ◽  
Defense Responses ◽  
Interferon Γ ◽  
Viral Clearance ◽  
Myeloperoxidase Activity ◽  
Respiratory Pathogens ◽  
Innate Defense

Mice lacking surfactant protein SP-A [SP-A(−/−)] and wild type SP-A(+/+) mice were infected with influenza A virus (IAV) by intranasal instillation. Decreased clearance of IAV was observed in SP-A(−/−) mice and was associated with increased pulmonary inflammation. Treatment of SP-A(−/−) mice with exogenous SP-A enhanced viral clearance and decreased lung inflammation. Uptake of IAV by alveolar macrophages was similar in SP-A(−/−) and SP-A(+/+) mice. Myeloperoxidase activity was reduced in isolated bronchoalveolar lavage neutrophils from SP-A(−/−) mice. B lymphocytes and activated T lymphocytes were increased in the lung and spleen, whereas T helper (Th) 1 responses were increased [interferon-γ, interleukin (IL)-2, and IgG2a] and Th2 responses were decreased (IL-4, and IL-10, and IgG1) in the lungs of SP-A(−/−) mice 7 days after IAV infection. In the absence of SP-A, impaired viral clearance was associated with increased lung inflammation, decreased neutrophil myeloperoxidase activity, and increased Th1 responses. Because the airway is the usual portal of entry for IAV and other respiratory pathogens, SP-A is likely to play a role in innate defense and adaptive immune responses to IAV.

Amphotericin b effect on the sensitivity to influenza infection of WI-38 VA-13 cells with IFITM3 gene knockout

2021 ◽  
Vol 21 (3) ◽  
pp. 109-112
Author(s):  
Kira S. Koryabina ◽  
Mariya V. Sergeeva ◽  
Andrey B. Komissarov ◽  
Nataliya V. Eshchenko ◽  
Grigoriy A. Stepanov
Keyword(s):  
Amphotericin B ◽  
Influenza A Virus ◽  
Influenza A ◽  
Gene Knockout ◽  
Influenza Infection ◽  
Restriction Factors ◽  
Host Restriction ◽  
Host Restriction Factors ◽  
Infected Cells ◽  
The Difference

BACKGROUND: The application of CRISPR/Cas9 is one of the most rapidly developing areas in biotechnology. This method was used to obtain clones of а human origin cell line with knockout of one or more genes of the IFITM family, representing host restriction factors for influenza infection. Amphotericin B has previously been shown to promote influenza infection by blocking IFITM3 function. AIM: The aim of this study was to evaluate the effect of amphotericin B on the sensitivity of IFITM knockout cells to influenza A virus infection. MATERIALS AND METHODS: WI-38 VA-13 cells and mutant clones with IFITM3 knockout (F3 clone) or IFITM1, IFITM3 knockout (clone E12) were infected with influenza virus A/PR/8/34 (H1N1) in the presence or absence of amphotericin B. Forty-four hours after infection, the culture medium was taken to determine the infectious activity of the virus by titration in the MDCK cell culture, as well as the hemagglutinating activity of the virus. The infected cells were stained with fluorescently labeled antibodies against the viral NP protein, and the number of NP-positive cells was determined by flow cytometry. RESULTS: The addition of amphotericin B increased the hemagglutinating and infectious activity of the virus in WI-38 VA-13cells, while the difference was insignificant for clones with IFITM gene knockout. A similar dependency was obtained for the percent of infected cells. CONCLUSIONS: Mutant cells with a knockout of one or several genes of the IFITM family were equally susceptible to influenza infection regardless of the addition of amphotericin B, which confirms the crucial importance of a defect in the IFITM3 protein in increasing the permissiveness of cells to influenza A virus.

scholarly journals Novel influenza A antibodies reduce severity of secondary pneumococcal pneumonia after influenza infection in mice

Critical Care ◽  
2015 ◽  
Vol 19 (Suppl 1) ◽  
pp. P103
Author(s):  
KF Van der Sluijs ◽  
F Van Someren Greve ◽  
MD Jong ◽  
MJ Schultz ◽  
NP Juffermans
Keyword(s):  
Influenza A ◽  
Pneumococcal Pneumonia ◽  
Influenza Infection ◽  
Novel Influenza A

Sickness behavior in mice deficient in interleukin-6 during turpentine abscess and influenza pneumonitis

1997 ◽  
Vol 272 (2) ◽  
pp. R621-R630 ◽  
Author(s):  
W. Kozak ◽  
V. Poli ◽  
D. Soszynski ◽  
C. A. Conn ◽  
L. R. Leon ◽  
...  
Keyword(s):  
Interleukin 6 ◽  
Influenza A ◽  
Influenza Infection ◽  
Influenza Virus Infection ◽  
Sickness Behavior ◽  
Tissue Necrosis ◽  
Control Groups ◽  
Dark Cycle ◽  
Viral Origin ◽  
And Control

Interleukin-6 (IL-6), among other cytokines, is thought to be involved in the regulation of sickness behavior (e.g., anorexia, cachexia, fever, and lethargy) induced by infections bacterial and viral origin) and sterile tissue necrosis (burns and surgical traumas). Mice deficient in IL-6 (IL-6 KO) were generated by gene targeting. Homozygous IL-6 KO male and female mice and their appropriate controls were implanted with biotelemeters to monitor body temperature (Tb) and motor activity (Act). Normal circadian rhythms in Tb and Act as well as rates of food intake and weight gain did not differ significantly between sex-matched IL-6 KO and control groups at 30 degrees C in a 12:12-h light-dark cycle. Sterile tissue damage was induced in mice by subcutaneous injection of turpentine (0.1 ml, left hindlimb). Influenza pneumonitis was induced by intranasal inoculation of mouse-adapted influenza A virus (17.5 plaque-forming units). Lack of IL-6 completely prevented fever, anorexia, and cachexia because of turpentine abscess in both sexes. It did not prevent lethargy, although IL-6 KO mice recovered to normal Act significantly sooner than wild-type mice. Symptoms of sickness were only slightly modified during influenza virus infection in IL-6 KO mice. Attenuation of sickness behavior was more pronounced in IL-6 KO female than in male mice. We conclude that, although IL-6 is induced during both turpentine abscess and influenza infection, this cytokine appears to be more critical in induction of the symptoms of sickness behavior during sterile tissue abscess than during influenza infection.

scholarly journals Protein-bound sialic acid in saliva contributes directly to salivary anti-influenza virus activity

2021 ◽  
Author(s):  
Kaori Kobayashi ◽  
Chika Shono ◽  
Takuya Mori ◽  
Hidefumi Kitazawa ◽  
Noriyasu Ota ◽  
...  
Keyword(s):  
Sialic Acid ◽  
Influenza A ◽  
Significant Positive Correlation ◽  
Influenza Infection ◽  
Respiratory Viruses ◽  
Biological Factor ◽  
Virus Activity ◽  
Individual Variations ◽  
Antiviral Activities ◽  
Direct Regulator

ABSTRACTThe oral cavity is an entrance for respiratory viruses, such as influenza. Recently, saliva has been shown to exert both antimicrobial and antiviral activities. Thus, saliva may be a biological factor that contributes to the prevention of influenza infection. However, the actual salivary anti-influenza A virus (IAV) activity in individuals and its determinant factors are unknown. By assessing individual variations in salivary anti-IAV activity in 92 people using an established new high-throughput system in this study, we found that the anti-IAV activity varied widely between individuals and showed a significant positive correlation with protein-bound sialic acid (BSA) level (ρ=0.473; p < 0.001). Furthermore, the anti-IAV activity of saliva with enzymatically reduced BSA content was significantly lower. These results indicate that BSA is a direct regulator of salivary anti-IAV activity and is a determinant of individual differences. Additionally, after comparing the anti-IAV activity across the groups by age, anti-IAV activity in young people (aged 5–19 years) were lower than in adults aged 20–59 years and elderly people aged 60–79 years. Our study suggests that BSA levels in saliva may be important in preventing influenza infection.

scholarly journals Routine blood parameters are helpful for early identification of influenza infection in children

2020 ◽  
Author(s):  
Ronghe Zhu ◽  
Cuie Chen ◽  
Qiu Wang ◽  
Xixi Zhang ◽  
Chaosheng Lu ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Virus Infection ◽  
Influenza A Virus ◽  
Early Identification ◽  
Influenza A ◽  
Influenza Infection ◽  
Influenza Virus Infection ◽  
Cutoff Value ◽  
Routine Blood ◽  
Influenza A Virus Infection

Abstract Purpose Routine blood parameters, such as the lymphocyte (LYM) count, platelet (PLT) count, lymphocyte-to-monocyte ratio (LMR), neutrophil-to-lymphocyte ratio (NLR), LYM*PLT and mean platelet volume-to-platelet ratio (MPV/PLT), are widely used to predict the prognosis of infectious diseases. We aimed to explore the value of these parameters in the early identification of influenza virus infection in children.Methods We conducted a single-center, retrospective, observational study of fever with influenza-like symptoms in pediatric outpatients from different age groups and evaluated the predictive value of various routine blood parameters measured within 48 hours of the onset of fever for influenza virus infection.Results The LYM count, PLT count, LMR and LYM*PLT were lower, and the NLR and MPV/PLT were higher in children with an influenza infection (PCR-confirmed and symptomatic). The LYM count, LMR and LYM*PLT in the influenza infection group were lower in the 1- to 6-year-old subgroup, and the LMR and LYM*PLT in the influenza infection group were lower in the >6-year-old subgroup. In the 1- to 6-year-old subgroup, the cutoff value of the LMR for predicting influenza A virus infection was 3.75, the sensitivity was 81.87%, the specificity was 84.31%, and the area under the curve (AUC) was 0.886; the cutoff value of the LMR for predicting influenza B virus infection was 3.71, the sensitivity was 73.58%, the specificity was 84.31%, and the AUC was 0.843. In the >6-year-old subgroup, the cutoff value of the LMR for predicting influenza A virus infection was 3.05, the sensitivity was 89.27%, the specificity was 89.61%, and the AUC was 0.949; the cutoff value of the LMR for predicting influenza B virus infection was 2.88, the sensitivity was 83.19%, the specificity was 92.21%, and the AUC was 0.924.Conclusions Routine blood tests are simple, inexpensive and easy to perform, and they are useful for the early identification of influenza virus infection in children. The LMR had the strongest predictive value for influenza virus infection in children older than 1 year, particularly influenza A virus infection.

Evaluation of Influenza Patients Admitted in 2019–2020 Flu Season

2022 ◽  
Author(s):  
Bahar Öztelcan Gündüz ◽  
Erman Ataş ◽  
Bülent Ünay ◽  
Halit Halil
Keyword(s):  
Physical Examination ◽  
Chronic Diseases ◽  
Influenza A ◽  
Influenza Infection ◽  
Febrile Seizures ◽  
Influenza Viruses ◽  
Influenza B ◽  
Close Monitoring ◽  
Group 2 ◽  
Group 1

Abstract Objective Influenza viruses are among the most common respiratory pathogens for all age groups, and may cause seasonal outbreaks. The aim of our study was to describe the clinical characteristics of influenza cases in the 2019–2020 flu season and to study the risk factors for hospital admission and complications. Methods This was a retrospective study in 251 children (group 1: nonhospitalized; group 2: hospitalized) with influenza in the 2019–2020 flu season. Data on demographic features, influenza type, complaints, complications, and hospitalization length were collected and recorded. Results Influenza A was detected in 199 (79.3%) patients, and influenza B was detected in 52 (20.7%); 43.4% of patients were girls and 56.6% were boys. The mean age of the patients was 3.91 ± 3.3 years (16 days to 18 years). A total of 52 (20.7%) patients were hospitalized. The age of the patients in group 2 was lower than that in group 1 (3.1 vs. 4.2 years, p = 0.03). Group 2 patients were more likely to have creatine kinase (CK) elevation, febrile seizures, and physical examination abnormalities. Group 2 patients were also more likely to have influenza A. Patients with febrile seizures, chronic diseases, abnormal physical examination findings, developed complications, and additional drug use apart from oseltamivir in the treatment were also more likely to require hospitalization. Conclusion Infants and children with chronic diseases, history of febrile seizures, complications, and the use of drugs other than antiviral drugs should be carefully evaluated in case they need hospitalization. Increasing vaccination rates, initiation of antiviral treatment for selected patients, and close monitoring of patients in risk groups can decrease morbidity and mortality. Myalgias are a common complaint in patients with acute influenza infection. Previous studies suggest CK measurement be part of the work-up for the hospitalized patient with acute influenza infection.

scholarly journals Prior exposure to immunogenic peptides found in human influenza A viruses may influence the age distribution of cases with avian influenza H5N1 and H7N9 virus infections

2019 ◽  
Vol 147 ◽  
Author(s):  
N. Komadina ◽  
S. G. Sullivan ◽  
K. Kedzierska ◽  
S. M. Quiñones-Parra ◽  
K. Leder ◽  
...  
Keyword(s):  
Influenza A ◽  
H5n1 Virus ◽  
Seasonal Influenza ◽  
Influenza Infection ◽  
Age Distribution ◽  
Prior Exposure ◽  
H7n9 Virus ◽  
Age Related ◽  
Immunogenic Peptides ◽  
Older Populations

Abstract The epidemiology of H5N1 and H7N9 avian viruses of humans infected in China differs despite both viruses being avian reassortants that have inherited six internal genes from a common ancestor, H9N2. The median age of infected populations is substantially younger for H5N1 virus (26 years) compared with H7N9 virus (63 years). Population susceptibility to infection with seasonal influenza is understood to be influenced by cross-reactive CD8+ T cells directed towards immunogenic peptides derived from internal viral proteins which may provide some level of protection against further influenza infection. Prior exposure to seasonal influenza peptides may influence the age-related infection patterns observed for H5N1 and H7N9 viruses. A comparison of relatedness of immunogenic peptides between historical human strains and the two avian emerged viruses was undertaken for a possible explanation in the differences in age incidence observed. There appeared to be some relationship between past exposure to related peptides and the lower number of H5N1 virus cases in older populations, however the relationship between prior exposure and older populations among H7N9 virus patients was less clear.

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