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  • Michaelis, Martin  (12)
  • Geiler, Janina  (12)
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  • 1
    Language: English
    In: Medical Microbiology and Immunology, 2011, Vol.200(1), pp.53-60
    Description: Influenza A virus infection of macrophages and virus-induced pro-inflammatory gene expression are regarded to contribute to severity of influenza A virus-caused diseases. Although some data are available on cytokine production by influenza A virus-infected macrophages, systematic comparisons of the virus types are currently considered to be of high relevance in humans (pandemic H1N1/2009, seasonal H1N1, seasonal H3N2, highly pathogenic avian influenza H5N1) on pro-inflammatory potential, and relevant underlying cellular signalling events are missing. Here, we show that the infection of human monocyte-derived macrophages with pandemic H1N1/2009 (A/HH/01/2009), seasonal H1N1/1999 (A/New Caledonia/20/99), seasonal H3N2/2004 (A/California/7/2004) or highly pathogenic H5N1/2004 (A/Thailand/1(Kan-1)/04) results in similar infection rates. However, the investigated H1N1 strains caused delayed and decreased apoptosis in comparison with H3N2/2004 or H5N1/2004. Moreover, human macrophage infection with H3N2/2004 or H5N1/2004 but not with H1N1 viruses was associated with pronounced pro-inflammatory cytokine production and activation of relevant mitogen-activated protein kinase pathways as indicated by phosphorylation of p38, JNK and ERK 1/2. These findings are in line with clinical observations indicating enhanced disease severity in H3N2- or H5N1-infected patients compared to individuals infected with pandemic H1N1/2009 or seasonal H1N1.
    Keywords: Influenza A ; MAPK ; Cytokines ; Seasonal influenza ; H5N1 ; Pandemic H1N1/2009
    ISSN: 0300-8584
    E-ISSN: 1432-1831
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  • 2
    Language: English
    In: PLoS ONE, 2011, Vol.6(5), p.e19705
    Description: Glycyrrhizin is known to exert antiviral and anti-inflammatory effects. Here, the effects of an approved parenteral glycyrrhizin preparation (Stronger Neo-Minophafen C) were investigated on highly pathogenic influenza A H5N1 virus replication, H5N1-induced apoptosis, and H5N1-induced pro-inflammatory responses in lung epithelial (A549) cells. Therapeutic glycyrrhizin concentrations substantially inhibited H5N1-induced expression of the pro-inflammatory molecules CXCL10, interleukin 6, CCL2, and CCL5 (effective glycyrrhizin concentrations 25 to 50 µg/ml) but interfered with H5N1 replication and H5N1-induced apoptosis to a lesser extent (effective glycyrrhizin concentrations 100 µg/ml or higher). Glycyrrhizin also diminished monocyte migration towards supernatants of H5N1-infected A549 cells. The mechanism by which glycyrrhizin interferes with H5N1 replication and H5N1-induced pro-inflammatory gene expression includes inhibition of H5N1-induced formation of reactive oxygen species and (in turn) reduced activation of NFκB, JNK, and p38, redox-sensitive signalling events known to be relevant for influenza A virus replication. Therefore, glycyrrhizin may complement the arsenal of potential drugs for the treatment of H5N1 disease.
    Keywords: Research Article ; Medicine ; Infectious Diseases ; Pharmacology
    E-ISSN: 1932-6203
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  • 3
    Language: English
    In: PLoS ONE, 2011, Vol.6(4), p.e18577
    Description: H5N1 influenza vaccines, including live intranasal, appear to be relatively less immunogenic compared to seasonal analogs. The main influenza virus surface glycoprotein hemagglutinin (HA) of highly pathogenic avian influenza viruses (HPAIV) was shown to be more susceptible to acidic pH treatment than that of human or low pathogenic avian influenza viruses. The acidification machinery of the human nasal passageway in response to different irritation factors starts to release protons acidifying the mucosal surface (down to pH of 5.2). We hypothesized that the sensitivity of H5 HA to the acidic environment might be the reason for the low infectivity and immunogenicity of intranasal H5N1 vaccines for mammals. ; We demonstrate that original human influenza viruses infect primary human nasal epithelial cells at acidic pH (down to 5.4), whereas H5N1 HPAIVs lose infectivity at pH≤5.6. The HA of A/Vietnam/1203/04 was modified by introducing the single substitution HA2 58K→I, decreasing the pH of the HA conformational change. The H5N1 reassortants containing the indicated mutation displayed an increased resistance to acidic pH and high temperature treatment compared to those lacking modification. The mutation ensured a higher viral uptake as shown by immunohistochemistry in the respiratory tract of mice and 25 times lower mouse infectious dose. Moreover, the reassortants keeping 58K→I mutation designed as a live attenuated vaccine candidate lacking an NS1 gene induced superior systemic and local antibody response after the intranasal immunization of mice. ; Our finding suggests that an efficient intranasal vaccination with a live attenuated H5N1 virus may require a certain level of pH and temperature stability of HA in order to achieve an optimal virus uptake by the nasal epithelial cells and induce a sufficient immune response. The pH of the activation of the H5 HA protein may play a substantial role in the infectivity of HPAIVs for mammals.
    Keywords: Research Article ; Biology ; Medicine ; Virology ; Immunology ; Infectious Diseases
    E-ISSN: 1932-6203
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  • 4
    Language: English
    In: The Journal of infectious diseases, 01 February 2010, Vol.201(3), pp.354-62
    Description: BACKGROUND. The nonstructural protein NS1 of influenza virus counteracts the interferon-mediated immune response of the host. By deleting the open reading frame of NS1, we have generated a novel type of influenza vaccine. We studied the safety and immunogenicity of an influenza strain lacking the NS1 gene (DeltaNS1-H1N1) in healthy volunteers. METHODS. Healthy seronegative adult volunteers were randomized to receive either a single intranasal dose of the DeltaNS1-H1N1 A/New Caledonia vaccine at 1 of 5 dose levels (6.4, 6.7, 7.0, 7.4, and 7.7 log(10) median tissue culture infective dose) (n = 36 recipients) or placebo (n = 12 recipients). RESULTS. Intranasal vaccination with the replication-deficient DeltaNS1-H1N1 vaccine was well tolerated. Rhinitis-like symptoms and headache were the most common adverse events identified during the 28-day observation period. Adverse events were similarly distributed between the treatment and placebo groups. Vaccine-specific local and serum antibodies were induced in a dose-dependent manner. In the highest dose group, vaccine-specific antibodies were detected in 10 of 12 volunteers. Importantly, the vaccine also induced neutralizing antibodies against heterologous drift variants. CONCLUSIONS. We show that vaccination with an influenza virus strain lacking the viral interferon antagonist NS1 induces statistically significant levels of strain-specific and cross-neutralizing antibodies despite the highly attenuated replication-deficient phenotype. Further studies are warranted to determine whether these results translate into protection from influenza virus infection. TRIAL REGISTRATION. ClinicalTrials.gov identifier: NCT00724997 .
    Keywords: Influenza A Virus, H1n1 Subtype -- Immunology ; Influenza Vaccines -- Immunology ; Influenza, Human -- Prevention & Control ; Vaccines, Attenuated -- Immunology ; Viral Nonstructural Proteins -- Genetics
    ISSN: 00221899
    E-ISSN: 1537-6613
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  • 5
    Language: English
    In: Medical Microbiology and Immunology, 2010, Vol.199(4), pp.291-297
    Description: Hypercytokinaemia is thought to contribute to highly pathogenic H5N1 influenza A virus disease. Glycyrrhizin is known to exert immunomodulatory and anti-inflammatory effects and therefore a candidate drug for the control of H5N1-induced pro-inflammatory gene expression. Here, the effects of an approved parenteral glycyrrhizin preparation were investigated on H5N1 virus replication, H5N1-induced pro-inflammatory responses, and H5N1-induced apoptosis in human monocyte-derived macrophages. Glycyrrhizin 100 μg/ml, a therapeutically achievable concentration, impaired H5N1-induced production of CXCL10, interleukin 6, and CCL5 and inhibited H5N1-induced apoptosis but did not interfere with H5N1 replication. Global inhibition of immune responses may result in the loss of control of virus replication by cytotoxic immune cells including natural killer cells and cytotoxic CD8 + T-lymphocytes. Notably, glycyrrhizin concentrations that inhibited H5N1-induced pro-inflammatory gene expression did not affect cytolytic activity of natural killer cells. Since H5N1-induced hypercytokinaemia is considered to play an important role within H5N1 pathogenesis, glycyrrhizin may complement the arsenal of potential drugs for the treatment of H5N1 disease.
    Keywords: Glycyrrhizin ; H5N1 ; Cytokines ; Monocyte-derived macrophages
    ISSN: 0300-8584
    E-ISSN: 1432-1831
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  • 6
    Language: English
    In: Medical Microbiology and Immunology, 2010, Vol.199(2), pp.93-101
    Description: Tumor resistance to lysis by resting natural killer (NK) cells may be overcome by priming of NK cells with cytokines or by binding of NK activating receptors to ligands expressed on target cells. In this study, major histocompatibility complex class I (MHC-I)-negative LNCaP and MHC-I-positive DU145 cells were infected with genetically modified influenza A virus lacking the non-structural gene 1 (∆NS1 IAV). The cells were used to investigate the influence of ∆NS1 IAV infection on NK cell lysis of tumor cells as well as to prime NK cells for lysis of LNCaP and DU145 cells. While LNCaP cells infected with ΔNS1 IAV showed enhanced lysis when compared with mock-infected cells (93% ± 1.47 vs. 52% ± 0.74), both mock-infected and ΔNS1 IAV-infected DU145 cells were resistant to NK cell lysis. Moreover, NK cells primed with ΔNS1 IAV-infected LNCaP/DU145 cells effectively lysed resistant DU145 and sensitive LNCaP cells to a greater extent than NK cells primed with mock-infected LNCaP/DU145 or non-primed NK cells. Also, NK cell priming with ΔNS1 IAV-infected tumor cells enhanced extracellular signal-regulated kinase phosphorylation and increased granule release in NK cells. The increased granule release was specifically mediated by NKp46, which eventually potentiated NK cells primed with ΔNS1 IAV-infected tumor cells to overcome the inhibitory effects posed by MHC-I expression on DU145 cells. These findings show that in addition to direct lytic activity of NK cells, ΔNS1 IAV may influence anti-tumoral responses by priming NK cells.
    Keywords: Cytotoxicity ; NK cell priming ; Major histocompatibility complex class I ; Degranulation ; Oncolytic influenza A virus
    ISSN: 0300-8584
    E-ISSN: 1432-1831
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  • 7
    Language: English
    In: Biochemical Pharmacology, 01 February 2010, Vol.79(3), pp.413-420
    Description: The antioxidant N-acetyl- -cysteine (NAC) had been shown to inhibit replication of seasonal human influenza A viruses. Here, the effects of NAC on virus replication, virus-induced pro-inflammatory responses and virus-induced apoptosis were investigated in H5N1-infected lung epithelial (A549) cells. NAC at concentrations ranging from 5 to 15 mM reduced H5N1-induced cytopathogenic effects (CPEs), virus-induced apoptosis and infectious viral yields 24 h post-infection. NAC also decreased the production of pro-inflammatory molecules (CXCL8, CXCL10, CCL5 and interleukin-6 (IL-6)) in H5N1-infected A549 cells and reduced monocyte migration towards supernatants of H5N1-infected A549 cells. The antiviral and anti-inflammatory mechanisms of NAC included inhibition of activation of oxidant sensitive pathways including transcription factor NF-κB and mitogen activated protein kinase p38. Pharmacological inhibitors of NF-κB (BAY 11-7085) or p38 (SB203580) exerted similar effects like those determined for NAC in H5N1-infected cells. The combination of BAY 11-7085 and SB203580 resulted in increased inhibitory effects on virus replication and production of pro-inflammatory molecules relative to either single treatment. NAC inhibits H5N1 replication and H5N1-induced production of pro-inflammatory molecules. Therefore, antioxidants like NAC represent a potential additional treatment option that could be considered in the case of an influenza A virus pandemic.
    Keywords: Ros ; NAC ; Cytokines ; H5n1 ; Apoptosis ; Pharmacy, Therapeutics, & Pharmacology ; Chemistry
    ISSN: 0006-2952
    E-ISSN: 1873-2968
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  • 8
    Language: English
    In: Biochemical and Biophysical Research Communications, 2006, Vol.339(1), pp.375-379
    Description: The measurement of natural killer (NK) cells toxicity against tumor or virus-infected cells especially in cases with small blood samples requires highly sensitive methods. Here, a coupled luminescent method (CLM) based on glyceraldehyde-3-phosphate dehydrogenase release from injured target cells was used to evaluate the cytotoxicity of interleukin-2 activated NK cells against neuroblastoma cell lines. In contrast to most other methods, CLM does not require the pretreatment of target cells with labeling substances which could be toxic or radioactive. The effective killing of tumor cells was achieved by low effector/target ratios ranging from 0.5:1 to 4:1. CLM provides highly sensitive, safe, and fast procedure for measurement of NK cell activity with small blood samples such as those obtained from pediatric patients.
    Keywords: Nk Cells ; Cytotoxicity ; Polio Virus Receptor ; Coupled Luminescent Method ; Neuroblastoma Cells ; Biology ; Chemistry ; Anatomy & Physiology
    ISSN: 0006-291X
    E-ISSN: 1090-2104
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  • 9
    Language: English
    In: Biochemical Pharmacology, 15 January 2010, Vol.79(2), pp.130-136
    Description: Artemisinin derivatives are well-tolerated anti-malaria drugs that also exert anti-cancer activity. Here, we investigated artemisinin and its derivatives dihydroartemisinin and artesunate in a panel of chemosensitive and chemoresistant human neuroblastoma cells as well as in primary neuroblastoma cultures. Only dihydroartemisinin and artesunate affected neuroblastoma cell viability with artesunate being more active. Artesunate-induced apoptosis and reactive oxygen species in neuroblastoma cells. Of 16 cell lines and two primary cultures, only UKF-NB-3 CDDP showed low sensitivity to artesunate. Characteristic gene expression signatures based on a previous analysis of artesunate resistance in the NCI60 cell line panel clearly separated UKF-NB-3 CDDP from the other cell lines. -Buthionine-S,R-sulfoximine, an inhibitor of GCL (glutamate–cysteine ligase), resensitised in part UKF-NB-3 CDDP cells to artesunate. This finding together with bioinformatic analysis of expression of genes involved in glutathione metabolism showed that this pathway is involved in artesunate resistance. These data indicate that neuroblastoma represents an artesunate-sensitive cancer entity and that artesunate is also effective in chemoresistant neuroblastoma cells.
    Keywords: Neuroblastoma ; Artesunate ; Artemisinin ; Chemoresistance ; Cancer ; Chemotherapy ; Pharmacy, Therapeutics, & Pharmacology ; Chemistry
    ISSN: 0006-2952
    E-ISSN: 1873-2968
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  • 10
    Language: English
    In: Biochemical Pharmacology, 13 November 2009, Vol.79(2), p.130
    Description: Artemisinin derivatives are well-tolerated anti-malaria drugs that also exert anti-cancer activity. Here, we investigated artemisinin and its derivatives dihydroartemisinin and artesunate in a panel of chemosensitive and chemoresistant human neuroblastoma cells as well as in primary neuroblastoma...
    Keywords: Neuroblastoma ; Artesunate ; Artemisinin ; Chemoresistance ; Cancer ; Chemotherapy ; Pharmacy, Therapeutics, & Pharmacology ; Chemistry
    ISSN: 0006-2952
    E-ISSN: 1873-2968
    Source: Hyper Article en Ligne (CCSd)
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