scholarly journals Plasmacytoid dendritic cells and Toll-like receptor 7-dependent signalling promote efficient protection of mice against highly virulent influenza A virus

2012 ◽  
Vol 93 (3) ◽  
pp. 555-559 ◽  
Author(s):  
Michael M. Kaminski ◽  
Annette Ohnemus ◽  
Marius Cornitescu ◽  
Peter Staeheli
Keyword(s):  
Dendritic Cells ◽  
Influenza Virus ◽  
Virus Infection ◽  
Influenza A Virus ◽  
Virus Resistance ◽  
Influenza A ◽  
Influenza Virus Infection ◽  
Plasmacytoid Dendritic Cells ◽  
Toll Like Receptor

Types I and III interferons (IFNs) elicit protective antiviral immune responses during influenza virus infection. Although many cell types can synthesize IFN in response to virus infection, it remains unclear which IFN sources contribute to antiviral protection in vivo. We found that mice carrying functional alleles of the Mx1 influenza virus resistance gene partially lost resistance to infection with a highly pathogenic H7N7 influenza A virus strain if Toll-like receptor 7 (TLR7) signalling was compromised. This effect was achieved by deleting either the TLR7 gene or the gene encoding the TLR7 adaptor molecule MyD88. A similar decrease of influenza virus resistance was observed when animals were deprived of plasmacytoid dendritic cells (pDCs) at day 1 post-infection. Our results provide in vivo proof that pDCs contribute to the protection of the lung against influenza A virus infections, presumably via signals from TLR7.

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.

scholarly journals Protective effect of low-concentration chlorine dioxide gas against influenza A virus infection

2008 ◽  
Vol 89 (1) ◽  
pp. 60-67 ◽  
Author(s):  
Norio Ogata ◽  
Takashi Shibata
Keyword(s):  
Influenza Virus ◽  
Virus Infection ◽  
Influenza A Virus ◽  
Chlorine Dioxide ◽  
Influenza A ◽  
Influenza Virus Infection ◽  
Envelope Proteins ◽  
Viral Envelope ◽  
Exposure Level ◽  
Low Concentration

Influenza virus infection is one of the major causes of human morbidity and mortality. Between humans, this virus spreads mostly via aerosols excreted from the respiratory system. Current means of prevention of influenza virus infection are not entirely satisfactory because of their limited efficacy. Safe and effective preventive measures against pandemic influenza are greatly needed. We demonstrate that infection of mice induced by aerosols of influenza A virus was prevented by chlorine dioxide (ClO2) gas at an extremely low concentration (below the long-term permissible exposure level to humans, namely 0.1 p.p.m.). Mice in semi-closed cages were exposed to aerosols of influenza A virus (1 LD50) and ClO2 gas (0.03 p.p.m.) simultaneously for 15 min. Three days after exposure, pulmonary virus titre (TCID50) was 102.6±1.5 in five mice treated with ClO2, whilst it was 106.7±0.2 in five mice that had not been treated (P=0.003). Cumulative mortality after 16 days was 0/10 mice treated with ClO2 and 7/10 mice that had not been treated (P=0.002). In in vitro experiments, ClO2 denatured viral envelope proteins (haemagglutinin and neuraminidase) that are indispensable for infectivity of the virus, and abolished infectivity. Taken together, we conclude that ClO2 gas is effective at preventing aerosol-induced influenza virus infection in mice by denaturing viral envelope proteins at a concentration well below the permissible exposure level to humans. ClO2 gas could therefore be useful as a preventive means against influenza in places of human activity without necessitating evacuation.

scholarly journals Plasmacytoid Dendritic Cells Are Dispensable during Primary Influenza Virus Infection

2009 ◽  
Vol 182 (2) ◽  
pp. 871-879 ◽  
Author(s):  
Amaya I. Wolf ◽  
Darya Buehler ◽  
Scott E. Hensley ◽  
Lois L. Cavanagh ◽  
E. John Wherry ◽  
...  
Keyword(s):  
Dendritic Cells ◽  
Influenza Virus ◽  
Virus Infection ◽  
Influenza Virus Infection ◽  
Plasmacytoid Dendritic Cells

scholarly journals Δ12-Prostaglandin J2 Is a Potent Inhibitor of Influenza A Virus Replication

2000 ◽  
Vol 44 (1) ◽  
pp. 200-204 ◽  
Author(s):  
Francesca Pica ◽  
Anna Teresa Palamara ◽  
Antonio Rossi ◽  
Alessandra De Marco ◽  
Carla Amici ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Heat Shock ◽  
Influenza A Virus ◽  
Influenza A ◽  
Potent Inhibitor ◽  
Influenza Virus Infection ◽  
H1n1 Infection ◽  
Shock Proteins

ABSTRACT 9-Deoxy-Δ9,Δ12-13,14-dihydro-prostaglandin D2 (Δ12-PGJ2), a natural cyclopentenone metabolite of prostaglandin D2, is shown to possess therapeutic efficacy against influenza A virus A/PR8/34 (H1N1) infection in vitro and in vivo. The results indicate that the antiviral activity is associated with induction of cytoprotective heat shock proteins and suggest novel strategies for treatment of influenza virus infection.

scholarly journals Routine blood parameters can detect early influenza virus infection in children

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

Abstract Purpose We aimed to explore the value of 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, for predicting influenza virus infection in children. Methods We conducted a single-center, retrospective, observational study on fever with influenza-like symptom in pediatric outpatients in different age groups and evaluated the predictive value of various routine blood parameters within 48 hours of the onset of fever after influenza virus infection. Results The LYM count, PLT count, LMR and LYM*PLT were lower, and the NLR and MPV/PLT were higher in the infected children. The LYM count, LMR and LYM*PLT in the infected group were lower in the 1- to 6-year-old group, and the LMR and LYM*PLT in the infected group were lower in the > 6-year-old group. In the 1- to 6-year-old group, 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 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 group, 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 predicting influenza virus infection in children. The LMR had the strongest predictive value for influenza virus infection in children older than 1 year, especially influenza A virus infection.

scholarly journals Prevention of Murine Influenza a Virus Pneumonitis by Surfactant Nano-Emulsions

2000 ◽  
Vol 11 (1) ◽  
pp. 41-49 ◽  
Author(s):  
Brian W Donovan ◽  
Jon D Reuter ◽  
Zhengyi Cao ◽  
Andrzej Myc ◽  
Kent J Johnson ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Virus Infection ◽  
Influenza A ◽  
Therapeutic Potential ◽  
Clinical Signs ◽  
Influenza Virus Infection ◽  
Initial Study ◽  
Ionic Surfactant ◽  
Nano Emulsion

Non-ionic surfactant nano-emulsions have extensive anti-microbial activity and are biocompatible with skin and mucous membranes at effective concentrations. Two nano-emulsion formulations (8N8 and 20N10) made from soybean oil, tributyl phosphate and Triton X-100, were tested for their ability to prevent murine influenza virus pneumonia in vivo. In the initial study, CD-1 mice were administered various dilutions of the nano-emulsions intranasally, and safe dosages and concentrations were determined. Non-toxic concentrations of the nano-emulsions were then mixed with influenza virus and applied to the nares of mice. Animals receiving mixtures of two different emulsions (8N8 or 20N10) and a LD50 of virus survived the challenge without evidence of viral infection. To determine if the nano-emulsions could prevent influenza virus infection in vivo when used as a prophylactic treatment, the nano-emulsions (8N8 at 1.0% and 20N10 at 1.0% or 0.2%) were applied to mouse nares 90 min before exposure to 5×105 p.f.u./ml virus by nebulized aerosol. Animals pretreated with the nano-emulsions had significantly decreased clinical signs of infection. Only 26.0% (8N8 at 1.0%), 31.25% (20N10 at 1.0%) and 37.0% (20N10 at 0.2%) of animals pretreated with nano-emulsion died from pneumonitis, whereas >80.0% of mock pretreated animals succumbed to infection ( P<0.005). These findings suggest that non-ionic surfactant nano-emulsions have therapeutic potential for the prevention of influenza virus infection in vivo.

scholarly journals Role of Itk signalling in the interaction between influenza A virus and T-cells

2012 ◽  
Vol 93 (5) ◽  
pp. 987-997 ◽  
Author(s):  
Kewei Fan ◽  
Yinping Jia ◽  
Song Wang ◽  
Hua Li ◽  
Defeng Wu ◽  
...  
Keyword(s):  
T Cells ◽  
Influenza Virus ◽  
T Cell ◽  
Virus Infection ◽  
Influenza A Virus ◽  
T Cell Activation ◽  
Influenza A ◽  
Interleukin 2 ◽  
Significant Proportion ◽  
Influenza Virus Infection

Although the T-cell-mediated immune response to influenza virus has been studied extensively, little information is available on the direct interaction between influenza virus and T-cells that pertains to severe diseases in humans and animals. To address these issues, we utilized the BALB/c mouse model combined with primary T-cells infected with A/WSN/33 influenza virus to investigate whether influenza virus has an affinity for T-cells in vivo. We observed that small proportions of CD4+ T-cells and CD8+ T-cells in spleen and thymus expressed viral proteins in infected mice. A significant proportion of mouse primary T-cells displayed expression of α-2,6 sialic acid-linked influenza virus receptor and were infected directly by influenza A virus. These experiments reveal that there exists a population of T-cells that is susceptible to influenza A virus infection. Furthermore, we employed human Jurkat T-cells to investigate the virus–T-cell interaction, with particular emphasis on understanding whether Itk (interleukin-2-inducible T-cell kinase), a Tec family tyrosine kinase that regulates T-cell activation, is involved in virus infection of T-cells. Interestingly, influenza virus infection resulted in an increased recruitment of Itk to the plasma membrane and an increased level of phospholipase C-γ1 (PLC-γ1) phosphorylation, suggesting that Itk/PLC-γ1 signalling is activated by the virus infection. We demonstrated that depletion of Itk inhibited the replication of influenza A virus, whereas overexpression of Itk increased virus replication. These results indicate that Itk is required for efficient replication of influenza virus in infected T-cells.

scholarly journals Metabolomic Analysis of Influenza A Virus A/WSN/1933 (H1N1) Infected A549 Cells during First Cycle of Viral Replication

Viruses ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 1007 ◽  
Author(s):  
Xiaodong Tian ◽  
Kun Zhang ◽  
Jie Min ◽  
Can Chen ◽  
Ying Cao ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Virus Infection ◽  
Influenza A Virus ◽  
Influenza A ◽  
Cell Metabolism ◽  
A549 Cells ◽  
Influenza Virus Infection ◽  
Tca Cycle ◽  
Host Cells ◽  
Pathway Analyses

Influenza A virus (IAV) has developed strategies to utilize host metabolites which, after identification and isolation, can be used to discover the value of immunometabolism. During this study, to mimic the metabolic processes of influenza virus infection in human cells, we infect A549 cells with H1N1 (WSN) influenza virus and explore the metabolites with altered levels during the first cycle of influenza virus infection using ultra-high-pressure liquid chromatography–quadrupole time-of-flight mass spectrometer (UHPLC–Q-TOF MS) technology. We annotate the metabolites using MetaboAnalyst and the Kyoto Encyclopedia of Genes and Genomes pathway analyses, which reveal that IAV regulates the abundance of the metabolic products of host cells during early infection to provide the energy and metabolites required to efficiently complete its own life cycle. These metabolites are correlated with the tricarboxylic acid (TCA) cycle and mainly are involved in purine, lipid, and glutathione metabolisms. Concurrently, the metabolites interact with signal receptors in A549 cells to participate in cellular energy metabolism signaling pathways. Metabonomic analyses have revealed that, in the first cycle, the virus not only hijacks cell metabolism for its own replication, but also affects innate immunity, indicating a need for further study of the complex relationship between IAV and host cells.

scholarly journals Evaluation of Three Commercially Available Influenza A Type-Specific Blocking Enzyme-Linked Immunosorbent Assays for Seroepidemiological Studies of Influenza A Virus Infection in Pigs

2012 ◽  
Vol 19 (3) ◽  
pp. 334-337 ◽  
Author(s):  
Maying Tse ◽  
Mia Kim ◽  
Chung-Hei Chan ◽  
Po-Lai Ho ◽  
Siu-Kit Ma ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Virus Infection ◽  
Influenza A Virus ◽  
Sensitivity And Specificity ◽  
Influenza A ◽  
Influenza Virus Infection ◽  
Swine Influenza ◽  
Immunosorbent Assays ◽  
Cutoff Levels ◽  
Antibody Competition

ABSTRACTThe reverse zoonotic transmission of the pandemic H1N1 2009 influenza virus to swine necessitates enhanced surveillance of swine for influenza virus infection. Using a well-characterized panel of naturally infected swine sera, we evaluated and optimized the performances of three commercially available competitive enzyme-linked immunosorbent assays (ELISAs), namely, the IDEXX Influenza A Ab test, IDEXX AI MultiS-Screen Ab test, and IDVet ID Screen influenza A antibody competition ELISA, for detecting influenza A virus-reactive antibodies in swine. Receiver operating characteristic (ROC) analysis suggests that adjustment of the manufacturer-recommended cutoff values optimizes the sensitivity and specificity of these assays, making them applicable for seroepidemiology studies of swine influenza. Using such optimized cutoff levels, the sensitivity and specificity of the IDEXX Influenza A Ab test were 86% and 89%, respectively; those for the IDEXX AI MultiS-Screen Ab test were 91% and 87%, respectively; and those for the IDVet ID Screen influenza A test were 95% and 79%, respectively.

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