scholarly journals STUDIES ON INFLUENZA INFECTION IN FERRETS BY MEANS OF FLUORESCEIN-LABELLED ANTIBODY

1955 ◽  
Vol 101 (6) ◽  
pp. 677-686 ◽  
Author(s):  
Ch'ien Liu
Keyword(s):  
Influenza Virus ◽  
Epithelial Cells ◽  
Respiratory Tract ◽  
Influenza A Virus ◽  
Influenza A ◽  
Influenza Infection ◽  
Fluorescent Staining ◽  
Green Fluorescence ◽  
Viral Antigens ◽  
The Cross

Yellow-green fluorescence representing viral antigens was detected in both the nucleus and cytoplasm of epithelial cells of the respiratory tract in ferrets infected with influenza virus. This nuclear fluorescence was the chief manifestation of cross-fluorescent staining reactions among three strains of influenza A virus studied, PR8, Farrington, and Fm1. Absorption experiments with influenza viral V and soluble S antigens showed that S antigen was responsible for the presence of fluorescence in the nucleus and for the cross-staining reactions among these strains.

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 Influenza PB1-F2 Inhibits Avian MAVS Signaling

Viruses ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 409
Author(s):  
Yanna Xiao ◽  
Danyel Evseev ◽  
Chase A. Stevens ◽  
Adam Moghrabi ◽  
Domingo Miranzo-Navarro ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Influenza A Virus ◽  
Virus Strain ◽  
Species Interactions ◽  
Influenza A ◽  
Promoter Activity ◽  
Interferon Beta ◽  
Influenza Infection ◽  
Adaptor Protein ◽  
Human Cells

RIG-I plays an essential role in the duck innate immune response to influenza infection. RIG-I engages the critical adaptor protein mitochondrial antiviral signaling (MAVS) to activate the downstream signaling pathway. The influenza A virus non-structural protein PB1-F2 interacts with MAVS in human cells to inhibit interferon production. As duck and human MAVS share only 28% amino acid similarity, it is not known whether the influenza virus can similarly inhibit MAVS signaling in avian cells. Using confocal microscopy we show that MAVS and the constitutively active N-terminal end of duck RIG-I (2CARD) co-localize in DF-1 cells, and duck MAVS is pulled down with GST-2CARD. We establish that either GST-2CARD, or duck MAVS can initiate innate signaling in chicken cells and their co-transfection augments interferon-beta promoter activity. Demonstrating the limits of cross-species interactions, duck RIG-I 2CARD initiates MAVS signaling in chicken cells, but works poorly in human cells. The D122A mutation of human 2CARD abrogates signaling by affecting MAVS engagement, and the reciprocal A120D mutation in duck 2CARD improves signaling in human cells. We show mitochondrial localization of PB1-F2 from influenza A virus strain A/Puerto Rico/8/1934 (H1N1; PR8), and its co-localization and co-immunoprecipitation with duck MAVS. PB1-F2 inhibits interferon-beta promoter activity induced by overexpression of either duck RIG-I 2CARD, full-length duck RIG-I, or duck MAVS. Finally, we show that the effect of PB1-F2 on mitochondria abrogates TRIM25-mediated ubiquitination of RIG-I CARD in both human and avian cells, while an NS1 variant from the PR8 influenza virus strain does not.

scholarly journals RNA-Sequencing-Based Transcriptomic Analysis Reveals a Role for Annexin-A1 in Classical and Influenza A Virus-Induced Autophagy

Cells ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 1399 ◽  
Author(s):  
Jianzhou Cui ◽  
Dhakshayini Morgan ◽  
Dao Han Cheng ◽  
Sok Lin Foo ◽  
Gracemary L. R. Yap ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Influenza A Virus ◽  
Influenza A ◽  
Influenza Infection ◽  
Critical Role ◽  
Mtor Inhibitors ◽  
Influenza Viruses ◽  
Annexin A1 ◽  
Underlying Mechanisms

Influenza viruses have been shown to use autophagy for their survival. However, the proteins and mechanisms involved in the autophagic process triggered by the influenza virus are unclear. Annexin-A1 (ANXA1) is an immunomodulatory protein involved in the regulation of the immune response and Influenza A virus (IAV) replication. In this study, using clustered regularly interspaced short palindromic repeats (CRISPR)-Cas9 (CRISPR associated protein 9) deletion of ANXA1, combined with the next-generation sequencing, we systematically analyzed the critical role of ANXA1 in IAV infection as well as the detailed processes governing IAV infection, such as macroautophagy. A number of differentially expressed genes were uniquely expressed in influenza A virus-infected A549 parental cells and A549 ∆ANXA1 cells, which were enriched in the immune system and infection-related pathways. Gene ontology and the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway revealed the role of ANXA1 in autophagy. To validate this, the effect of mechanistic target of rapamycin (mTOR) inhibitors, starvation and influenza infection on autophagy was determined, and our results demonstrate that ANXA1 enhances autophagy induced by conventional autophagy inducers and influenza virus. These results will help us to understand the underlying mechanisms of IAV infection and provide a potential therapeutic target for restricting influenza viral replication and infection.

scholarly journals Influenza Virus A/Anhui/1/2013 (H7N9) Replicates Efficiently in the Upper and Lower Respiratory Tracts of Cynomolgus Macaques

mBio ◽  
2014 ◽  
Vol 5 (4) ◽  
Author(s):  
Emmie de Wit ◽  
Angela L. Rasmussen ◽  
Friederike Feldmann ◽  
Trenton Bushmaker ◽  
Cynthia Martellaro ◽  
...  
Keyword(s):  
Gene Expression ◽  
Influenza Virus ◽  
Respiratory Tract ◽  
Influenza A Virus ◽  
Influenza A ◽  
Clinical Aspects ◽  
Polymorphonuclear Cells ◽  
H7n9 Virus ◽  
Cynomolgus Macaques ◽  
H7n9 Infection

ABSTRACT In March 2013, three fatal human cases of infection with influenza A virus (H7N9) were reported in China. Since then, human cases have been accumulating. Given the public health importance of this virus, we performed a pathogenicity study of the H7N9 virus in the cynomolgus macaque model, focusing on clinical aspects of disease, radiographic, histological, and gene expression profile changes in the upper and lower respiratory tracts, and changes in systemic cytokine and chemokine profiles during infection. Cynomolgus macaques developed transient, mild to severe disease with radiographic evidence of pulmonary infiltration. Virus replicated in the upper as well as lower respiratory tract, with sustained replication in the upper respiratory tract until the end of the experiment at 6 days after inoculation. Virus shedding occurred mainly via the throat. Histopathological changes in the lungs were similar to those observed in humans, albeit less severe, with diffuse alveolar damage, infiltration of polymorphonuclear cells, formation of hyaline membranes, pneumocyte hyperplasia, and fibroproliferative changes. Analysis of gene expression profiles in lung lesions identified pathways involved in tissue damage during H7N9 infection as well as leads for development of therapeutics targeting host responses rather than virus replication. Overall, H7N9 infection was not as severe in cynomolgus macaques as in humans, supporting the possible role of underlying medical complications in disease severity as discussed for human H7N9 infection (H. N. Gao et al., N. Engl. J. Med. 368:2277–2285, 2013, doi:10.1056/NEJMoa1305584). IMPORTANCE Influenza A virus H7N9 emerged early in 2013, and human cases have continued to emerge since then. Although H7N9 virus-induced disease in humans is often very severe and even lethal, the majority of reported H7N9 cases occurred in older people and people with underlying medical conditions. To better understand the pathogenicity of this virus, healthy cynomolgus macaques were inoculated with influenza A virus H7N9. Cynomolgus macaques were used as a model because the receptor distribution for H7N9 virus in macaques was recently shown to be more similar to that in humans than that of other frequently used animal models. From comparison with previous studies, we conclude that the emerging H7N9 influenza virus was more pathogenic in cynomolgus macaques than seasonal influenza A viruses and most isolates of the pandemic H1N1 virus but less pathogenic than the 1918 Spanish influenza virus or highly pathogenic avian influenza (HPAI) H5N1 virus.

scholarly journals Features of immune response against influenza infection in animals vaccinated with recombinant cross-protective vaccine

2019 ◽  
Vol 9 (3-4) ◽  
pp. 485-494
Author(s):  
L. M. Tsybalova ◽  
L. A. Stepanova ◽  
A. V. Korotkov ◽  
M. A. Shuklina ◽  
M. V. Zaitseva ◽  
...  
Keyword(s):  
Immune Response ◽  
T Cells ◽  
Influenza Virus ◽  
Influenza A Virus ◽  
Cd4 T Cells ◽  
Influenza A ◽  
Influenza Infection ◽  
Sublethal Dose ◽  
Universal Vaccine ◽  
Toll Like Receptor 5

Generating cross-reactive vaccines aimed at targeting all human influenza A virus subtypes is among high priority tasks in contemporary vaccinology. Such vaccines will be primarily demanded during pre-pandemic period as well as used to prime some population cohorts prior to vaccination with standard vaccines containing area-relevant epidemic virus. Unlike routine approach universal vaccines do not induce a sterilizing immunity, but significantly ameliorate overt infection and probable complications. Our study was aimed at evaluating characteristics of immune response in experimental animals primed with a candidate universal vaccine challenged with sublethal influenza A virus infection. Mice were immunized intranasally with the recombinant protein FlgH2-2-4M2e containing conservative peptides derived from two influenza A virus proteins: M2 protein ectodomain and 76–130 amino acid sequence from the second hemagglutinin (HA2) subunit genetically linked to bacterial flagellin protein, which is a ligand for Toll-like receptor 5 (TLR5). Control mice received saline. Two weeks after immunization, mice from both groups were infected with a sublethal dose of A/Aichi/2/68 AN3N2 influenza virus strain. Level of immunoglobulins G and A in the blood sera and bronchoalveolar lavages (BAL) were determined two weeks after immunization and 1 month post infection. Percentage of lung CD4+ T and CD4+ Tem (CD44+CD62L–) cells secreting cytokines TNFα, IFNγ, IL-2 was determined. Immunized vs. control mice responded to sublethal infection with the influenza virus by insignificant weight loss and more pronounced production of vaccine peptide-specific (M2e and aa76–130 HA2) and pan-influenza A/Aichi/2/68 virus IgG and A in the blood sera and BAL. After challenge the number of CD4+ T cells secreting cytokines TNFα and/or IL-2 in immunized mice significantly exceeded counterpart T cells in unimmunized animals that was true for both CD4+T and CD4+ Tem cells. Memory CD4+ T cells were previously shown to play a key role in the prime-boost event and heterosubtypic immune response. Thus, we were able to demonstrate a priming effect for recombinant cross-protective vaccine used in our experiment.

scholarly journals Microbiome disturbance and resilience dynamics of the upper respiratory tract in response to influenza A virus infection in humans and ferrets

2018 ◽  
Author(s):  
Drishti Kaul ◽  
Raveen Rathnasinghe ◽  
Marcela Ferres ◽  
Gene S. Tan ◽  
Aldo Barrera ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Virus Infection ◽  
Respiratory Tract ◽  
Influenza A Virus ◽  
Influenza A ◽  
Cellular Damage ◽  
Upper Respiratory Tract ◽  
Upper Respiratory ◽  
Influenza A Virus Infection ◽  
Over Time

AbstractInfection with influenza can be aggravated by bacterial co-infections, which often results in disease exacerbation because of host responses and cellular damage. The native upper respiratory tract (URT) microbiome likely plays a role, yet the effects of influenza infection on the URT microbiome are largely unknown. We performed a longitudinal study to assess the temporal dynamics of the URT microbiomes of uninfected and influenza virus-infected humans and ferrets. Uninfected human patients and ferret URT microbiomes had stable “heathy ecostate” communities both within and between individuals. In contrast, infected patients and ferrets exhibited large changes in bacterial community composition over time and between individuals. The “unhealthy” ecostates of infected individuals progressed towards the “healthy ecostate” over time, coinciding with viral clearance and recovery. Blooms of Pseudomonas were a statistically associated constant in the disturbed microbiomes of infected individuals. The dynamic and resilient nature of the microbiome during influenza virus infection in multiple hosts provides a compelling rationale for the maintenance of the microbiome homeostasis as a potential therapeutic target to prevent IAV associated bacterial co-infections.One Sentence SummaryDynamics of the upper respiratory tract microbiome during influenza A virus infection

scholarly journals Hyperattenuated Recombinant Influenza A Virus Nonstructural-Protein-Encoding Vectors Induce Human Immunodeficiency Virus Type 1 Nef-Specific Systemic and Mucosal Immune Responses in Mice

2001 ◽  
Vol 75 (19) ◽  
pp. 8899-8908 ◽  
Author(s):  
Boris Ferko ◽  
Jana Stasakova ◽  
Sabine Sereinig ◽  
Julia Romanova ◽  
Dietmar Katinger ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Influenza Virus ◽  
Respiratory Tract ◽  
Influenza A Virus ◽  
Influenza A ◽  
Nonstructural Protein ◽  
T Cell Response ◽  
Immunodeficiency Virus ◽  
Hiv 1

ABSTRACT We have generated recombinant influenza A viruses belonging to the H1N1 and H3N2 virus subtypes containing an insertion of the 137 C-terminal amino acid residues of the human immunodeficiency virus type 1 (HIV-1) Nef protein into the influenza A virus nonstructural-protein (NS1) reading frame. These viral vectors were found to be genetically stable and capable of growing efficiently in embryonated chicken eggs and tissue culture cells but did not replicate in the murine respiratory tract. Despite the hyperattenuated phenotype of influenza/NS-Nef viruses, a Nef and influenza virus (nucleoprotein)-specific CD8+-T-cell response was detected in spleens and the lymph nodes draining the respiratory tract after a single intranasal immunization of mice. Compared to the primary response, a marked enhancement of the CD8+-T-cell response was detected in the systemic and mucosal compartments, including mouse urogenital tracts, if mice were primed with the H1N1 subtype vector and subsequently boosted with the H3N2 subtype vector. In addition, Nef-specific serum IgG was detected in mice which were immunized twice with the recombinant H1N1 and then boosted with the recombinant H3N2 subtype virus. These findings may contribute to the development of alternative immunization strategies utilizing hyperattenuated live recombinant influenza virus vectors to prevent or control infectious diseases, e.g., HIV-1 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.

The In Vivo Source of Type I and Type III IFNs is Pathogen Dependent

2021 ◽  
Author(s):  
Marvin J. Sandoval ◽  
Hsiang-Chi Tseng ◽  
Heidi P. Risman ◽  
Sergey Smirnov ◽  
Qing Li ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Virus Infection ◽  
Respiratory Tract ◽  
Influenza A ◽  
Influenza Infection ◽  
Type I ◽  
Protective Effects ◽  
Type Iii

Type I (-α, β) and type III (-λ) interferons (IFNs) are produced in response to virus infection and upregulate a largely overlapping set of IFN stimulated genes which mediate the protective effects of these antiviral cytokines. In vitro studies have demonstrated the redundancy of these two cytokine families which activate the same transcription factor, IFN stimulated gene factor 3 (ISGF3), via distinct ligands and receptors. However, in vivo, these IFN types do have distinct functions based on receptor distribution, but also ligand availability. Using a newly generated IFN-λ reporter mouse strain we have observed that both type I and type III IFNs are produced in response to respiratory tract infection by Newcastle disease virus (NDV) and influenza A virus (IAV). In the case of NDV these IFNs are synthesized by different cell types. Type I IFNs are produced primarily by alveolar macrophages, type III IFNs are made only by epithelial cells, and production of either is dependent on MAVS. While epithelial cells of the respiratory tract represent the primary target of IAV infection, we found that they did not significantly contribute to IFN-λ production, and IFN-λ protein levels were largely unaffected in the absence of MAVS. Instead we found that pDCs, a cell type known for robust IFN-α production via TLR/MyD88 signaling, were the major producers of IFN-λ during IAV infection, with pDC depletion during influenza infection resulting in significantly reduced levels of both IFN-α and IFN-λ. In addition, we were able to demonstrate that pDCs rely on type I IFN for optimal IFN-λ production. These studies therefore demonstrate that the in vivo producers of Type III IFNs in response to respiratory virus infection are pathogen dependent, a finding which may explain the varying levels of cytokine production induced by different viral pathogens.

scholarly journals Influenza A Virus Neuraminidase Enhances Meningococcal Adhesion to Epithelial Cells through Interaction with Sialic Acid-Containing Meningococcal Capsules

2009 ◽  
Vol 77 (9) ◽  
pp. 3588-3595 ◽  
Author(s):  
Marie-Anne Rameix-Welti ◽  
Maria Leticia Zarantonelli ◽  
Dario Giorgini ◽  
Corinne Ruckly ◽  
Monica Marasescu ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Sialic Acid ◽  
Epithelial Cells ◽  
Influenza A Virus ◽  
Influenza A ◽  
Bacterial Infections ◽  
Control Strategies ◽  
Direct Interaction ◽  
Virus Infections ◽  
Meningococcal Infections

ABSTRACT The underlying mechanisms of the epidemiological association between influenza virus infections and Neisseria meningitidis invasive infections are not fully understood. Here we report that adhesion of N. meningitidis to human Hec-1-B epithelial cells is enhanced by influenza A virus (IAV) infection. A potential role of the viral neuraminidase (NA) in facilitating meningococcal adhesion to influenza virus-infected epithelial cells was examined. Expression of a recombinant IAV NA in Hec-1-B human epithelial cells increased the adhesion of strains of N. meningitidis belonging to the sialic acid-containing capsular serogroups B, C, and W135 but not to the mannosamine phosphate-containing capsular serogroup A. Adhesion enhancement was not observed with an inactive NA mutant or in the presence of an NA inhibitor (zanamivir). Furthermore, purified IAV NA was shown to cleave sialic acid-containing capsular polysaccharides of N. meningitidis. On the whole, our findings suggest that a direct interaction between the NA of IAV and the capsule of N. meningitidis enhances bacterial adhesion to cultured epithelial cells, most likely through cleavage of capsular sialic acid-containing polysaccharides. A better understanding of the association between IAV and invasive meningococcal infections should help to set up improved control strategies against these seasonal dual viral-bacterial infections.

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