201
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Stanford MM, McFadden G, Karupiah G, Chaudhri G. Immunopathogenesis of poxvirus infections: forecasting the impending storm. Immunol Cell Biol 2007; 85:93-102. [PMID: 17228320 DOI: 10.1038/sj.icb.7100033] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Variola virus, the causative agent of smallpox, is a member of the poxvirus family and one of the most virulent human pathogens known. Although smallpox was eradicated almost 30 years ago, it is not understood why the mortality rates associated with the disease were high, why some patients recovered, and what constitutes an effective host response against infection. As variola virus infects only humans, our current understanding of poxvirus infections comes largely from historical clinical data from smallpox patients and from animal studies using closely related viruses such as ectromelia, myxoma and monkeypox. The outcome of an infection is determined by a complex interaction between the type of immune response mounted by the host and by evasion mechanisms that the virus has evolved to subvert it. Disease pathogenesis is also a function of both host and viral factors. Poxviruses are not only cytopathic, causing host tissue damage, but also encode an array of immunomodulatory molecules that affect the severity of disease. The ability of the host to control virus replication is therefore critical in limiting tissue damage. However, in addition to targeting virus, the immune response can inadvertently damage the host to such a degree that it causes illness and even death. There is growing evidence that many of the symptoms associated with serious poxvirus infections are a result of a 'cytokine storm' or sepsis and that this may be the underlying cause of pathology.
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202
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Zhu XQ, Zhang JY, Cheng JP. Mechanism and Driving Force of NO Transfer from S-Nitrosothiol to Cobalt(II) Porphyrin: A Detailed Thermodynamic and Kinetic Study. Inorg Chem 2006; 46:592-600. [PMID: 17279840 DOI: 10.1021/ic061427v] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The thermodynamics and kinetics of NO transfer from S-nitrosotriphenylmethanethiol (Ph(3)CSNO) to a series of alpha,beta,gamma,delta-tetraphenylporphinatocobalt(II) derivatives [T(G)PPCoII], generating the nitrosyl cobalt atom center adducts [T(G)PPCoIINO], in benzonitrile were investigated using titration calorimetry and stopped-flow UV-vis spectrophotometry, respectively. The estimation of the energy change for each elementary step in the possible NO transfer pathways suggests that the most likely route is a concerted process of the homolytic S-NO bond dissociation and the formation of the Co-NO bond. The kinetic investigation on the NO transfer shows that the second-order rate constants at room temperature cover the range from 0.76 x 10(4) to 4.58 x 10(4) M(-1) s(-1), and the reaction rate was mainly governed by activation enthalpy. Hammett-type linear free-energy analysis indicates that the NO moiety in Ph(3)CSNO is a Lewis acid and the T(G)PPCoII is a Lewis base; the main driving force for the NO transfer is electrostatic charge attraction rather than the spin-spin coupling interaction. The effective charge distribution on the cobalt atom in the cobalt porphyrin at the various stages, the reactant [T(G)PPCoII], the transition-state, and the product [T(G)PPCoIINO], was estimated to show that the cobalt atom carries relative effective positive charges of 2.000 in the reactant [T(G)PPCoII], 2.350 in the transition state, and 2.503 in the product [T(G)PPCoIINO], which indicates that the concerted NO transfer from Ph(3)CSNO to T(G)PPCoII with the release of the Ph(3)CS* radical was actually performed by the initial negative charge (-0.350) transfer from T(G)PPCoII to Ph(3)CSNO to form the transition state and was followed by homolytic S-NO bond dissociation of Ph(3)CSNO with a further negative charge (-0.153) transfer from T(G)PPCoII to the NO group to form the final product T(G)PPCoIINO. It is evident that these important thermodynamic and kinetic results would be helpful in understanding the nature of the interaction between RSNO and metal porphyrins in both chemical and biochemical systems.
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Affiliation(s)
- Xiao-Qing Zhu
- Department of Chemistry and the State Key Laboratory of Elemento-Organic Chemistry, Nankai University, Tianjin 300071, China.
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203
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Blanchette J, Pouliot P, Olivier M. Role of protein tyrosine phosphatases in the regulation of interferon-γ-induced macrophage nitric oxide generation: implication of ERK pathway and AP-1 activation. J Leukoc Biol 2006; 81:835-44. [PMID: 17170076 DOI: 10.1189/jlb.0505252] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
NO is a potent molecule involved in the cytotoxic events mediated by macrophages (MØ) against microorganisms. We reported previously that inhibition of MØ protein tyrosine phosphatases (PTPs) mediates a protective effect against Leishmania infection, which was NO-dependent. Herein, we show that the PTP inhibitors of the peroxovanadium (pV) class, bpV(phen) and bpV(pic), can similarly increase murine MØ IFN-gamma-induced NO generation. Using various second messenger (JAK2, MEK, Erk1/Erk2, and p38) antagonists, we found that the Erk1/Erk2 pathway was the principal pathway submitted to regulation by PTPs in the context of IFN-gamma-driven MØ activation and increase in NO production. We observed that bpV(phen) increases inducible NO synthase (iNOS) expression, resulting in enhanced NO production, whereas the bpV(pic) increase of NO production does not seem to result from a modulation of iNOS expression. Transcription factors STAT-1alpha and NF-kappaB, recognized for their importance in NO generation, were not affected by the pV treatment. However, AP-1 was strongly activated by bpV(phen) but not by bpV(pic). Collectively, our results suggest that increased IFN-gamma-induced NO production, observed after bpV(phen) treatment, involves the activation of the transcription factor AP-1 by Erk1/Erk2- and stress-activated protein kinase/JNK-dependent transduction mechanisms.
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Affiliation(s)
- Julie Blanchette
- Centre de Recherche en Infectiologie and Département de Biologie Médicale, Centre Hospitalier Universitaire de Québec, Pavillon CHUL, Université Laval, Ste-Foy, Québec, Canada
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204
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Granja AG, Sabina P, Salas ML, Fresno M, Revilla Y. Regulation of inducible nitric oxide synthase expression by viral A238L-mediated inhibition of p65/RelA acetylation and p300 transactivation. J Virol 2006; 80:10487-96. [PMID: 17041221 PMCID: PMC1641776 DOI: 10.1128/jvi.00862-06] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Uncontrolled generation of nitric oxide (NO) by inducible nitric-oxide synthase (iNOS) can cause damage to host cells and inflammation, two undesirable events for virus spreading. African swine fever virus (ASFV) infection regulates iNOS-induced gene expression through the synthesis of the A238L virus protein. We here explored the role of A238L, an NF-kappaB and NFAT inhibitor, in the regulation of iNOS transcription in macrophages. NO production and iNOS mRNA and protein levels as well as iNOS promoter activity after lipopolysaccharide (LPS)-gamma interferon (IFN-gamma) treatment were down-regulated both during ASFV infection and in Raw 264.7 cells stably expressing the viral protein. Overexpression of p300, but not of a histone acetyltransferase (HAT) defective mutant, reverted the A238L-mediated inhibition of both basal and LPS-IFN-gamma-induced iNOS promoter activity. Following stimulation with LPS-IFN-gamma, p65 and p300 interaction was abolished in Raw-A238L cells. Expression of A238L also inhibited p65/relA and p300 binding to the distal NF-kappaB sequence of the iNOS promoter together with p65 acetylation. Finally, A238L abrogated p300 transactivation mediated by a GAL4-p300 construction. These results provide evidence for an unique viral mechanism involved in transcriptional regulation of iNOS gene expression.
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Affiliation(s)
- Aitor G Granja
- Centro de Biología Molecular Severo Ochoa, Universidad Autónoma de Madrid, Madrid 28049, Spain
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205
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Jayasekera JP, Vinuesa CG, Karupiah G, King NJC. Enhanced antiviral antibody secretion and attenuated immunopathology during influenza virus infection in nitric oxide synthase-2-deficient mice. J Gen Virol 2006; 87:3361-3371. [PMID: 17030871 DOI: 10.1099/vir.0.82131-0] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
NOS2 gene-deficient (NOS2−/−) mice are less susceptible than wild-type (NOS2+/+) mice to infection with Influenza A virus. Virus titres in the lungs of influenza-infected NOS2−/− mice are significantly lower than those in NOS2+/+ mice, with enhanced viral clearance in NOS2−/− mice dependent on gamma interferon (IFN-γ). The current study was undertaken to ascertain the role of specific components of the immune response in promoting virus clearance in influenza-infected NOS2−/− mice. Levels of T cell- and natural killer cell-mediated cytotoxicity in the lungs of virus-infected mice were not significantly different between NOS2+/+ and NOS2−/− mice. However, virus-infected NOS2−/− mice produced higher levels of virus-specific IgG2a antibody. Furthermore, more viable B cells and plasmablasts, along with greater levels of IFN-γ, were found in NOS2−/− splenocyte cultures stimulated with B-cell mitogens. In addition to the early reduction in virus titres, clinical symptoms and proinflammatory cytokine production were attenuated in NOS2−/− mice. Thus, NOS2−/− B cells are capable of responding rapidly to influenza virus infection by proliferating and preferentially producing antibody of the IgG2a subtype. The relationship between viral load and the development of immunopathology is discussed.
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Affiliation(s)
- Jerome P Jayasekera
- Department of Pathology, Bosch Institute, School of Biomedical Sciences, Blackburn Building D06, University of Sydney, NSW 2006, Australia
| | - Carola G Vinuesa
- Division of Immunology and Genetics, John Curtin School of Medical Research (JCSMR), Australian National University, Canberra, ACT 2601, Australia
| | - Gunasegaran Karupiah
- Division of Immunology and Genetics, John Curtin School of Medical Research (JCSMR), Australian National University, Canberra, ACT 2601, Australia
| | - Nicholas J C King
- Department of Pathology, Bosch Institute, School of Biomedical Sciences, Blackburn Building D06, University of Sydney, NSW 2006, Australia
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206
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Puppo M, Bosco MC, Federico M, Pastorino S, Varesio L. Hypoxia inhibits Moloney murine leukemia virus expression in activated macrophages. J Leukoc Biol 2006; 81:528-38. [PMID: 17062606 DOI: 10.1189/jlb.0506361] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Hypoxia, a local decrease in oxygen tension, occurring in many pathological processes, modifies macrophage (Mphi) gene expression and function. Here, we provide the first evidence that hypoxia inhibits transgene expression driven by the Moloney murine leukemia virus-long terminal repeats (MoMLV-LTR) in IFN-gamma-activated Mphi. Hypoxia silenced the expression of several MoMLV-LTR-driven genes, including v-myc, enhanced green fluorescence protein, and env, and was effective in different mouse Mphi cell lines and on distinct MoMLV backbone-based viruses. Down-regulation of MoMLV mRNA occurred at the transcriptional level and was associated with decreased retrovirus production, as determined by titration experiments, suggesting that hypoxia may control MoMLV retroviral spread through the suppression of LTR activity. In contrast, genes driven by the CMV or the SV40 promoter were up-regulated or unchanged by hypoxia, indicating a selective inhibitory activity on the MoMLV promoter. It is interesting that hypoxia was ineffective in suppressing MoMLV-LTR-controlled gene expression in T or fibroblast cell lines, suggesting a Mphi lineage-selective action. Finally, we found that MoMLV-mediated gene expression in Mphi was also inhibited by picolinic acid, a tryptophan catabolite with hypoxia-like activity and Mphi-activating properties, suggesting a pathophysiological role of this molecule in viral resistance and its possible use as an antiviral agent.
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Affiliation(s)
- Maura Puppo
- Laboratory of Molecular Biology, Istituto Giannina Gaslini, Padiglione 2, L go Gerolamo Gaslini 5, 16147 Genova Quarto, Italy
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207
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Wu GJ, Tsai GJ. Chitooligosaccharides in combination with interferon-gamma increase nitric oxide production via nuclear factor-kappaB activation in murine RAW264.7 macrophages. Food Chem Toxicol 2006; 45:250-8. [PMID: 17107743 DOI: 10.1016/j.fct.2006.07.025] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2006] [Revised: 07/21/2006] [Accepted: 07/25/2006] [Indexed: 11/26/2022]
Abstract
A low-molecular weight chitosan (LMWC) with a molecular mass of 20 kDa and a chitooligosaccharide mixture (oligomixture) which is composed of sugars with a degree of polymerization (DP) of 1-6 were isolated from the chitosan hydrolysate. The effects of the chitosan hydrolysate, LMWC and oligomixture on the production of nitric oxide (NO) in RAW 264.7 macrophages were evaluated, and their effects on NF-kappaB activation and the gene expression of inducible NO synthase (iNOS) were further investigated. None of the tested 3 samples of hydrolysate, LMWC and oligomixture alone affected the NO production in RAW 264.7 macrophages. However, treatment of macrophages with a combination of hydrolysate/oligomixture and interferon-gamma (IFN-gamma) significantly induced NO production in a dose-dependent manner, whereas a combination of LMWC and IFN-gamma inhibited NO production. These effects on NO synthesis were evidenced via regulating the iNOS gene expression. Both hydrolysate and oligomixture promoted the migration of NF-kappaB into the nucleus and enhanced its DNA binding activity. MG132, a specific inhibitor of NF-kappaB, eliminated the NO synthesis in IFN-gamma plus hydrolysate/oligomixture-induced RAW264.7 macrophages. The treatment of RAW264.7 macrophages with anti-CD14, anti-TLR4, and anti-CR3 antibodies significantly blocked NO production induced by IFN-gamma plus hydrolysate/oligomixture. These results demonstrated that the oligomixture, which is the main functional component in the chitosan hydrolysate, in combination with IFN-gamma, synergistically induced NF-kappaB activation and NO production through binding with the receptors of CD14, TLR4 and CR3 in RAW264.7 macrophages.
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Affiliation(s)
- Guan James Wu
- Department of Food Science, National Taiwan Ocean University, 2 Pei-Ning Road, Keelung 202, Taiwan
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208
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Abstract
Interferons (IFNs) elicit multifaceted effects in host innate defence. Accumulating evidence revealed that not only the first identified Jak-Stat pathway but also other newly found signalling pathways are required for the induction of versatile responses by IFNs. In particular, type I IFNs are inducible by viral infection through the recognition of pathogen-associated molecules by pattern recognition receptors, and the induction of multiple IFN-stimulated genes through the activation of type I IFN signalling confers antiviral and immunomodulatory activities. Any step in this process is often targeted by viruses for their immuno-evasion. The regulatory function of constitutive IFN-alpha/beta signalling has been recognized in terms of its boosting effect on cellular responsiveness in host defence systems. Further comprehensive understanding of IFN signalling may offer a better direction to unravelling the complex signalling networks in the host defence system, and may contribute to their more effective therapeutic applications.
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Affiliation(s)
- Akinori Takaoka
- Department of Immunology, Graduate School of Medicine and Faculty of Medicine, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033, Japan.
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209
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Hammerbeck DM, Burleson GR, Schuller CJ, Vasilakos JP, Tomai M, Egging E, Cochran FR, Woulfe S, Miller RL. Administration of a dual toll-like receptor 7 and toll-like receptor 8 agonist protects against influenza in rats. Antiviral Res 2006; 73:1-11. [PMID: 16959331 DOI: 10.1016/j.antiviral.2006.07.011] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2006] [Revised: 07/14/2006] [Accepted: 07/25/2006] [Indexed: 01/08/2023]
Abstract
Toll-like receptors (TLR) detect conserved molecular patterns expressed by pathogens. Detection of the "molecular signature" for RNA viruses including influenza has been attributed to TLR3, TLR7, and TLR8. In the present study, compound 3M-011 was shown to be a synthetic human TLR7/8 agonist and cytokine inducer. 3M-011 was investigated as a stand-alone immune response modifier in a rat model of human influenza. Intranasal (IN) administration of 3M-011 significantly inhibited H3N2 influenza viral replication in the nasal cavity when administered from 72 h before IN viral inoculation to 6h after inoculation. Viral inhibition correlated with the ability of the TLR7/8 agonist to stimulate type I interferon (IFN) and other cytokines such as tumor necrosis factor-alpha, interleukin-12, and IFN-gamma from rat peripheral blood mononuclear cells. Prophylactic administration of TLR7/8 agonist also suppressed influenza viral titers in the lung, which corresponded with local IFN production. The activity of the TLR7/8 agonist resulted in greater inhibition of viral titers compared to rat recombinant IFN-alpha administered in a comparable dosing regimen. These studies indicate that TLR7/8 agonists may have prophylactic and therapeutic benefits in the treatment of respiratory viral infections, such as influenza, when administered prior to or shortly after viral inoculation.
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Affiliation(s)
- David M Hammerbeck
- Department of Pharmacology, 3M Pharmaceuticals, 3M Center, Building 270-3A-10, St. Paul, MN 55144, USA
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210
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Chaudhri G, Panchanathan V, Bluethmann H, Karupiah G. Obligatory requirement for antibody in recovery from a primary poxvirus infection. J Virol 2006; 80:6339-44. [PMID: 16775322 PMCID: PMC1488964 DOI: 10.1128/jvi.00116-06] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
To understand the correlates of protective immunity against primary variola virus infection in humans, we have used the well-characterized mousepox model. This is an excellent surrogate small-animal model for smallpox in which the disease is caused by infection with the closely related orthopoxvirus, ectromelia virus. Similarities between the two infections include virus replication and transmission, aspects of pathology, and development of pock lesions. Previous studies using ectromelia virus have established critical roles for cytokines and effector functions of CD8 T cells in the control of acute stages of poxvirus infection. Here, we have used mice deficient in B cells to demonstrate that B-cell function is also obligatory for complete virus clearance and recovery of the host. In the absence of B cells, virus persists and the host succumbs to infection, despite the generation of CD8 T-cell responses. Intriguingly, transfer of naive B cells or ectromelia virus-immune serum to B-cell-deficient mice with established infection allowed these animals to clear virus and fully recover. In contrast, transfer of ectromelia virus-immune CD8 T cells was ineffective. Our data show that mice deficient in CD8 T-cell function die early in infection, whereas those deficient in B cells or antibody production die much later, indicating that B-cell function becomes critical after the effector phase of the CD8 T-cell response to infection subsides. Strikingly, our results show that antibody prevents virus from seeding the skin and forming pock lesions, which are important for virus transmission between hosts.
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Affiliation(s)
- Geeta Chaudhri
- Infection and Immunology Group, Division of Immunology and Genetics, The John Curtin School of Medical Research, Australian National University, Mills Road, Acton, ACT 0200, Australia
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211
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Son CG, Shin JW, Cho JH, Cho CK, Yun CH, Chung W, Han SH. Macrophage activation and nitric oxide production by water soluble components of Hericium erinaceum. Int Immunopharmacol 2006; 6:1363-9. [PMID: 16782550 DOI: 10.1016/j.intimp.2006.03.005] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2005] [Revised: 11/14/2005] [Accepted: 03/08/2006] [Indexed: 10/24/2022]
Abstract
Hericium erinaceum is a medicinal and edible mushroom with anti-microbial and anti-cancer activities. To evaluate the immunoregulatory functions of H. erinaceum, we prepared water extract from H. erinaceum (WEHE) and investigated its ability to activate macrophages and to induce nitric oxide (NO) production in macrophages. Rat peritoneal macrophages stimulated with 1 to 100 mug/ml of WEHE for 24, 48, or 72 h produced NO in a time- and dose-dependent manner. Reverse transcription-polymerase chain reaction demonstrated that WEHE augmented the steady-state level of inducible NO synthase (iNOS) mRNA in both the peritoneal macrophages and a murine macrophage cell-line, RAW 264.7. Electrophoretic mobility shift assay showed that WEHE increased DNA binding activity of the transcription factor NF-kappaB, which is responsible for iNOS gene expression. Furthermore, its trans-acting activity was confirmative as determined by in vitro transfection assay using a reporter gene construct, p(NF-kappaB)(3)-CAT, whose expression is solely regulated by the activity of NF-kappaB. Concomitantly with the activation of NF-kappaB, WEHE markedly decreased intracellular IkappaBalpha level as demonstrated by Western blot assay. These results suggested that WEHE induces iNOS gene expression followed by NO production in macrophages via enhancing the activation of transcription factor, NF-kappaB.
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Affiliation(s)
- Chang Gue Son
- East-West Cancer Center, Dunsan Oriental Hospital of Daejon University, Daejon 301-724, Republic of Korea
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212
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Zhang Y, Zhu H, Huang C, Cui X, Gao Y, Huang Y, Gong W, Zhao Y, Guo S. Astragaloside IV exerts antiviral effects against coxsackievirus B3 by upregulating interferon-gamma. J Cardiovasc Pharmacol 2006; 47:190-5. [PMID: 16495755 DOI: 10.1097/01.fjc.0000199683.43448.64] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Coxsackievirus B3 (CVB3) is a major pathogen for viral myocarditis and dilated cardiomyopathy in children and young adults. The aim of this study was to determine the antiviral effects of astragaloside IV against CVB3, and the underlying mechanism. First, we evaluated antiviral effects of astragaloside IV in vitro by measuring the virus titers of CVB3 in primarily cultured myocardial cells infected with CVB3, and in vivo by assessing the morbidity, mortality, heart-to-body weight ratio (HW/BW), and virus titers in BALB/c mice infected with CVB3. Then, we performed serum pharmacological experiments by testing the effect of sera from SD rats treated with astragaloside IV on proliferation of CVB3 in primarily cultured myocardial cells. Finally, we determined the effect of astragaloside IV on IFN-gamma mRNA expression in the hearts of infected BALB/c mice. We observed that astragaloside IV decreased virus titers of CVB3 in primarily cultured myocardial cells. Morbidity, mortality, HW/BW, and virus titers all decreased, and necrosis and mononuclear cell infiltration were alleviated in CVB3-infected mice treated with astragaloside IV, compared with those infected mice without the treatment. In addition, proliferation of CVB3 was inhibited by the sera of rats treated with astragaloside IV. Moreover, we observed that IFN-gamma mRNA expression was increased in mice treated with astragaloside IV. Therefore, we conclude that astragaloside IV exerts antiviral effects against CVB3 by upregulating expression of IFN-gamma mRNA.
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MESH Headings
- Animals
- Animals, Newborn
- Antiviral Agents/chemistry
- Antiviral Agents/pharmacology
- Cell Line, Tumor
- Cells, Cultured
- Coxsackievirus Infections/drug therapy
- Coxsackievirus Infections/mortality
- Coxsackievirus Infections/pathology
- Coxsackievirus Infections/virology
- Enterovirus B, Human/physiology
- Injections, Intraperitoneal
- Interferon-gamma/biosynthesis
- Male
- Mice
- Mice, Inbred BALB C
- Molecular Structure
- Myocarditis/drug therapy
- Myocarditis/metabolism
- Myocarditis/pathology
- Myocarditis/virology
- Myocytes, Cardiac/drug effects
- Myocytes, Cardiac/metabolism
- Myocytes, Cardiac/pathology
- RNA, Messenger/metabolism
- Saponins/chemistry
- Saponins/pharmacology
- Triterpenes/chemistry
- Triterpenes/pharmacology
- Up-Regulation
- Virus Replication/drug effects
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Affiliation(s)
- Yuanyuan Zhang
- Shanghai Institute of Materia Medica, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
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213
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Bratslavska O, Platace D, Miklasevics E, Fuchs D, Martinsons A. Influence of neopterin and 7,8-dihydroneopterin on the replication of Coxsackie type B5 and influenza A viruses. Med Microbiol Immunol 2006; 196:23-9. [PMID: 16868770 DOI: 10.1007/s00430-006-0025-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2006] [Indexed: 10/24/2022]
Abstract
Pteridine derivatives neopterin and 7,8-dihydroneopterin are produced by human macrophages and dendritic cells upon stimulation with interferon-gamma (IFN-gamma) and therefore become detectable in increased amounts in humans during cell-mediated (Th1-type) immune response. Compounds produced upon influence of cytokine IFN-gamma often exert antiproliferative and antiviral activity. The aim of this study was to investigate the effect of neopterin and 7,8-dihydroneopterin on the replication of Coxsackie type B5 and influenza A viruses. The changes in the replication of these viruses were evaluated by the degree of cytopathic effect and their ability to form plaques in Coxsackie B5-infected human larynx carcinoma epithelial (Hep-2) cells and in influenza A-infected canine kidney epithelial cells (MDCK). Potential toxicity of neopterin and 7,8-dihydroneopterin was estimated by the incorporation of (3)H-thymidine and (3)H-uridine into Hep-2 and MDCK cells. Whereas 30 nmol/l neopterin delayed the development of the cytopathic effect of Coxsackie B5 virus in Hep-2 cells (P < 0.01), 7,8-dihydroneopterin did not have any essential influence at any of the concentrations tested between 10 nmol/l and 1,000 micromol/l. However, 100-1,500 micromol/l 7,8-dihydroneopterin significantly suppressed the propagation of influenza A virus. Neopterin and 7,8-dihydroneopterin were practically nontoxic for Hep-2 and MDCK cells even at high microM concentration. Results suggest that the increased production of neopterin derivatives by activated macrophages and dendritic cells may represent part of the antiviral armature induced by IFN-gamma. The mechanisms of the inhibitory effects of neopterin and 7,8-dihydroneopterin on virus replication apparently are different.
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Affiliation(s)
- Olga Bratslavska
- August Kirchenstein Institute of Microbiology and Virology, University of Latvia, Rātsupītes iela 1, 1067 Riga, Latvia
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214
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Zhu XQ, Zhang JY, Mei LR, Cheng JP. Mechanism of NO transfer from NO-donors (SNAP and G-MNBS) to ferrous tetraphenylporphyrin in CH3OH. Org Lett 2006; 8:3065-7. [PMID: 16805553 DOI: 10.1021/ol061021m] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
[reaction: see text] The mechanism of NO transfer from NO-donors (SNAP and G-MNBS) to ferrous tetraphenylporphyrin (TPPFe(II)) in CH(3)OH is discovered for the first time by using a laser flash technique. The results show that the NO transfer is completed by NO(+) transfer followed by electron transfer rather than direct NO transfer in one step.
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Affiliation(s)
- Xiao-Qing Zhu
- Department of Chemistry, the State Key Laboratory of Elemento-Organic Chemistry, Nankai University, Tianjin, China.
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215
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Xu W, Zheng S, Dweik RA, Erzurum SC. Role of epithelial nitric oxide in airway viral infection. Free Radic Biol Med 2006; 41:19-28. [PMID: 16781449 PMCID: PMC7127628 DOI: 10.1016/j.freeradbiomed.2006.01.037] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/29/2005] [Revised: 01/20/2006] [Accepted: 01/23/2006] [Indexed: 12/13/2022]
Abstract
The airway mucosal epithelium is the first site of virus contact with the host, and the main site of infection and inflammation. Nitric oxide (NO) produced by the airway epithelium is vital to antiviral inflammatory and immune defense in the lung. Multiple mechanisms function coordinately to support high-level basal NO synthesis in healthy airway epithelium and further induction of NO synthesis in the infected airway of normal hosts. Hosts deficient in NO synthesis, such as those patients with cystic fibrosis, have impaired antiviral defense and may benefit from therapies to augment NO levels in the airways.
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Key Words
- balf, bronchoalveolar lavage fluid
- cf, cystic fibrosis
- cgmp, guanosine 3′,5′-cyclic monophosphate
- cmv, cytomegalovirus
- dsrna, double-stranded rna
- epo, eosinophil peroxidase
- gas, γ-activated site
- gsh, reduced glutathione
- hiv, human immunodeficiency virus
- hocl, hypochlorous acid
- hpivs, human parainfluenza viruses
- hrsv, human respiratory syncytial virus
- h2o2, hydrogen peroxide
- irf, interferon regulatory factor
- lpo, lactoperoidase
- mpo, myeloperoxidase
- no3−, nitrate
- no, nitric oxide
- nos, nitric oxide synthases
- no2−, nitrite
- onoo−, peroxynitrite
- pkr, dsrna-activated protein kinase
- poly(ic), polyinosinic-polycytidylic acid
- ros, reactive oxygen species
- o2−, superoxide
- gsno, s-nitrosoglutathione
- ssrna, single-stranded rna
- stat, signal transducer and activator of transcription
- antiviral host defense
- nitric oxide
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Affiliation(s)
- Weiling Xu
- Department of Pathobiology, Lerner Research Institute, Cleveland Clinic Foundation, 9500 Euclid Ave., NC 20, Cleveland, OH 44195, USA.
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216
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Abstract
Human immunodeficiency virus-1 (HIV-1)-infected and immune-activated macrophages and microglia secrete neurotoxins. Two of these neurotoxins are the pro-inflammatory cytokines tumour necrosis factor-alpha (TNF-alpha) and interleukin-1beta (IL-1beta), which are thought to play a major role in inducing neuronal death. Both TNF-alpha and IL-1beta increase the permeability of the blood-brain barrier, through which subsequently HIV-infected monocytes can enter the brain. They both induce over-stimulation of the NMDA-receptor via several pathways, resulting in a lethal neuronal increase in Ca(2+) levels. Additionally, TNF-alpha co-operates with several other proinflammatory mediators to enhance their toxic effects. Although most research has focused on the neurotoxic effects of TNF-alpha and IL-1beta in HAD, there is also evidence that these cytokines can be neuroprotective. In this paper the effect of TNF-alpha and IL-1beta on neuronal life and death in HAD is discussed.
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Affiliation(s)
- N A C H Brabers
- Department of Virology, University Medical Center Utrecht, Heidelberglaan 100, 3584 CX Utrecht, the Netherlands
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217
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Bonaparte KL, Hudson CA, Wu C, Massa PT. Inverse regulation of inducible nitric oxide synthase (iNOS) and arginase I by the protein tyrosine phosphatase SHP-1 in CNS glia. Glia 2006; 53:827-35. [PMID: 16565987 DOI: 10.1002/glia.20344] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
We have previously shown that the SH2 domain-containing protein tyrosine phosphatase SHP-1 plays a critical role in controlling virus infection in CNS glia in vivo and in vitro. The present study addressed whether increased virus replication in SHP-1-deficient glia in vitro may be a result of altered expression of inducible nitric oxide synthase (iNOS/NOS2). First, we observed a profound reduction in iNOS protein expression and production of nitric oxide (NO) in response to the viral mimic double-stranded RNA (dsRNA), despite the induction of high levels of iNOS mRNA, in SHP-1-deficient motheaten mouse compared to wild type littermate mouse glia. Because both iNOS expression and NO production are suppressed by multiple pathways involving arginase I activity, it was important that we observed abnormally high constitutive expression of arginase I in cultured glia of SHP-1-deficient compared to wild type mice. Further, both constitutive and IL-4/IL-10-induced expression of arginase I correlated with elevated STAT6 nuclear binding activity, decreased NO production, and increased virus replication in motheaten compared to wild type astrocytes. These findings provide the first evidence of an inverse relationship between NO and arginase I activity regulated by SHP-1 in CNS glia that is relevant to modulation of innate anti-viral responses. Thus, we propose that SHP-1 is a critical regulator of innate immunity to virus infections in CNS cells.
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Affiliation(s)
- Kathryn L Bonaparte
- Department of Neurology, Upstate Medical University, State University of New York, Syracuse, New York 13210, USA
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218
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Khatri M, Sharma JM. Infectious bursal disease virus infection induces macrophage activation via p38 MAPK and NF-κB pathways. Virus Res 2006; 118:70-7. [PMID: 16388870 DOI: 10.1016/j.virusres.2005.11.015] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2005] [Revised: 11/17/2005] [Accepted: 11/21/2005] [Indexed: 10/25/2022]
Abstract
In the present study, we show that infection with infectious bursal disease virus (IBDV) causes activation of macrophages, the key cells involved in inflammatory and immune-regulatory functions. Exposure of cultured spleen macrophages (SM) from SPF chickens to IBDV resulted in the production of nitric oxide (NO). In addition, there was upregulation of mRNA expression of inducible nitric oxide synthase (iNOS), IL-8 and cyclooxygenase-2 (COX-2). The signal transduction pathways involved in macrophage activation were examined. The role of mitogen-activated protein kinases (MAPKs) and nuclear factor-kappaB (NF-kappaB) was tested by using specific pharmacological inhibitors. Addition of p38 MAPK inhibitor, SB-203580 and NF-kappaB inhibitor Bay 11-7082, suppressed IBDV-induced NO production and mRNA expression of iNOS, IL-8 and COX-2. The results suggest that IBDV uses cellular signal transduction machinery, in particular the p38 MAPK and NF-kappaB pathways, to elicit macrophage activation. The increased production of NO, IL-8 and COX-2 by macrophages may contribute to bursa inflammatory responses commonly seen during the acute IBDV infection.
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Affiliation(s)
- Mahesh Khatri
- Department of Veterinary and Biomedical Sciences, College of Veterinary Medicine, University of Minnesota, 1971 Commonwealth Avenue, St. Paul, 55108, USA
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219
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Pedras-Vasconcelos JA, Goucher D, Puig M, Tonelli LH, Wang V, Ito S, Verthelyi D. CpG oligodeoxynucleotides protect newborn mice from a lethal challenge with the neurotropic Tacaribe arenavirus. THE JOURNAL OF IMMUNOLOGY 2006; 176:4940-9. [PMID: 16585590 DOI: 10.4049/jimmunol.176.8.4940] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The innate immune system is key to limiting the early spread of most pathogens and directing the development of Ag-specific immunity. Recently, a number of synthetic molecules that activate the innate immune system by stimulating TLRs have been identified. Among them, synthetic oligodeoxynucleotides (ODNs) containing unmethylated CpG motifs (CpG ODNs) were shown to activate TLR9-bearing B cells, macrophages, and dendritic cells to induce a strong proinflammatory milieu and a type 1-biased immune response that protects mice from a variety of parasitic, bacterial, and viral infections. Although the protective effect of CpG ODN in adult mice was well established, its effectiveness in neonates, which have lower numbers of dendritic, B, and T cells and tend to favor Th2 responses, was unclear. This study uses the New World arenavirus Tacaribe, a neurotropic pathogen that is lethal in newborn mice, to explore the effectiveness of TLR-mediated innate immune responses. Neonatal BALB/c mice treated with CpG ODN at the time of infection had reduced viral load (p < 0.01) and increased survival (52%, p < 0.001 i.p.; 36%, p < 0.05 intranasally). Protection was achieved in mice treated no later than 3 days postchallenge and appears to be mediated by an increase in Ag-specific Abs (IgG and IgM) and to require inducible NO synthase expression and NO production. To our knowledge, this is the first study assessing the mechanisms by which CpG ODN can protect mice from a neurotropic viral infection.
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Affiliation(s)
- João A Pedras-Vasconcelos
- Division of Therapeutic Proteins, Office of Biotechnology Products, Center for Drug Evaluation and Research, Federal Drug Administration, Bethesda, MD 20892, USA
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220
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Simon M, Falk KI, Lundkvist A, Mirazimi A. Exogenous nitric oxide inhibits Crimean Congo hemorrhagic fever virus. Virus Res 2006; 120:184-90. [PMID: 16632039 DOI: 10.1016/j.virusres.2006.03.005] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2006] [Revised: 03/07/2006] [Accepted: 03/13/2006] [Indexed: 11/17/2022]
Abstract
Crimean Congo hemorrhagic fever virus (CCHFV) is a geographically widespread pathogen that causes severe hemorrhagic fever with high mortality. Even though one of the main objectives focuses on the progress of antiviral agents, the research on CCHFV is strongly hampered due to its BSL-4 classification. Nitric oxide (NO), a mediator with broad biological effects, has been shown to possess inhibitory properties against various pathogens. The molecule constitutes a component of the innate immunity and serves to assist in the early immunological events where it contributes to clearance of microorganisms. In this study, we investigated the inhibitory properties of exogenous NO on CCHFV. We found that NO had a significant antiviral activity against CCHFV replication. By using the NO-donor S-nitroso-N-acetylpenicillamine (SNAP) we were able to show up to 99% reduction in virion progeny yield. In contrast, 3-morpholinosydnonimine hydrochloride (SIN-1), a peroxynitrite donor, had no significant antiviral activity against CCHFV. Furthermore the expression of viral proteins; the nucleocapsid protein and the glycoprotein, were clearly reduced with increasing concentrations of SNAP. We have also shown that the amount of total vRNA in SNAP-treated cells was reduced by about 50% compared to the controls.
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Affiliation(s)
- M Simon
- Swedish Institute for Infectious Disease Control, SE-171 82 Solna, Sweden
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221
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Abaitua F, Rodríguez JR, Garzón A, Rodríguez D, Esteban M. Improving recombinant MVA immune responses: Potentiation of the immune responses to HIV-1 with MVA and DNA vectors expressing Env and the cytokines IL-12 and IFN-gamma. Virus Res 2006; 116:11-20. [PMID: 16214252 DOI: 10.1016/j.virusres.2005.08.008] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2005] [Revised: 07/22/2005] [Accepted: 08/22/2005] [Indexed: 11/23/2022]
Abstract
Recombinants based on vaccinia virus vectors, especially on the highly attenuated modified vaccinia virus Ankara (MVA) strain, are now being tested in clinical trials for safety and immunogenicity, using prime/boost heterologous regimes of vaccination. Due to the limited replication capacity of MVA, it is necessary to develop procedures that can enhance the specific cellular immune responses to the recombinant antigen delivered by the MVA vector. In this investigation, we have characterized the systemic immune responses in BALB/c mice using interferon-gamma (IFN-gamma) or interleukin-12 (IL-12) in an adjuvant-like manner elicited by MVA recombinants or naked DNA vectors expressing one of those cytokines in combination with the human immunodeficiency virus type 1 (HIV-1) envelope (Env) as antigen. In infected mice, virus gene expression in splenocytes and levels of cytokines IFN-gamma and IL-12 in serum were maximal by 6h post-infection (hpi) with MVA recombinants expressing IFN-gamma (MVAIFN-gamma) or IL-12 (MVAIL-12). In the infected animals, co-expression of HIV-1 env (MVAENV) and either IFN-gamma or IL-12 from MVA recombinants produced a two and three-fold increase of anti-env CD8+ T cell response, respectively. When priming was carried out with DNA vectors expressing HIV-1 env and either IFN-gamma or IL-12, the magnitude of the specific anti-env CD8+ T cell stimulation after MVAENV booster was further enhanced. Our findings revealed that IFN-gamma or IL-12 can be used to potentiate the cellular immune response to HIV-1 env, when delivered either from a single MVA recombinant or from a DNA vector. The increment of the CD8+ T cell response was higher in a DNA/MVA prime/boost protocol. Thus, the immune response of MVA vectors can be improved with the co-delivery of the cytokines IFN-gamma or IL-12.
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MESH Headings
- AIDS Vaccines/administration & dosage
- AIDS Vaccines/genetics
- AIDS Vaccines/immunology
- Adjuvants, Immunologic/genetics
- Animals
- CD8-Positive T-Lymphocytes/immunology
- Cytokines/biosynthesis
- DNA, Viral
- Female
- Gene Products, env/genetics
- Gene Products, env/immunology
- Genetic Vectors/genetics
- Genetic Vectors/immunology
- HIV-1/immunology
- Immunization, Secondary
- Interferon-gamma/genetics
- Interferon-gamma/immunology
- Interleukin-12/genetics
- Interleukin-12/immunology
- Mice
- Mice, Inbred BALB C
- Models, Animal
- Vaccines, DNA/administration & dosage
- Vaccines, DNA/genetics
- Vaccines, DNA/immunology
- Vaccines, Synthetic/genetics
- Vaccines, Synthetic/immunology
- Vaccinia virus/genetics
- Vaccinia virus/immunology
- Viral Vaccines/administration & dosage
- Viral Vaccines/genetics
- Viral Vaccines/immunology
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Affiliation(s)
- Fernando Abaitua
- Department of Molecular and Cellular Biology, Centro Nacional de Biotecnología, CSIC, Campus Ciudad Universitaria Cantoblanco, 28049 Madrid, Spain
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222
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Ricciardolo FLM, Di Stefano A, Sabatini F, Folkerts G. Reactive nitrogen species in the respiratory tract. Eur J Pharmacol 2006; 533:240-52. [PMID: 16464450 DOI: 10.1016/j.ejphar.2005.12.057] [Citation(s) in RCA: 173] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/13/2005] [Indexed: 11/23/2022]
Abstract
Endogenous Nitric Oxide (NO) plays a key role in the physiological regulation of airway functions. In response to various stimuli activated inflammatory cells (e.g., eosinophils and neutrophils) generate oxidants ("oxidative stress") which in conjunction with exaggerated enzymatic release of NO and augmented NO metabolites produce the formation of strong oxidizing reactive nitrogen species, such as peroxynitrite, in various airway diseases including asthma, chronic obstructive pulmonary diseases (COPD), cystic fibrosis and acute respiratory distress syndrome (ARDS). Reactive nitrogen species provoke amplification of inflammatory processes in the airways and lung parenchyma causing DNA damage, inhibition of mitochondrial respiration, protein dysfunction and cell damage ("nitrosative stress"). These effects alter respiratory homeostasis (such as bronchomotor tone and pulmonary surfactant activity) and the long-term persistence of "nitrosative stress" may contribute to the progressive deterioration of pulmonary functions leading to respiratory failure. Recent studies showing that protein nitration can be dynamic and reversible ("denitration mechanisms") open new horizons in the treatment of chronic respiratory diseases affected by the deleterious actions of "nitrosative stress".
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223
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Lenschow DJ, Giannakopoulos NV, Gunn LJ, Johnston C, O'Guin AK, Schmidt RE, Levine B, Virgin HW. Identification of interferon-stimulated gene 15 as an antiviral molecule during Sindbis virus infection in vivo. J Virol 2006; 79:13974-83. [PMID: 16254333 PMCID: PMC1280211 DOI: 10.1128/jvi.79.22.13974-13983.2005] [Citation(s) in RCA: 214] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The innate immune response, and in particular the alpha/beta interferon (IFN-alpha/beta) system, plays a critical role in the control of viral infections. Interferons alpha and beta exert their antiviral effects through the induction of hundreds of interferon-induced (or -stimulated) genes (ISGs). While several of these ISGs have characterized antiviral functions, their actions alone do not explain all of the effects mediated by IFN-alpha/beta. To identify additional IFN-induced antiviral molecules, we utilized a recombinant chimeric Sindbis virus to express selected ISGs in IFN-alpha/beta receptor (IFN-alpha/betaR)(-/-) mice and looked for attenuation of Sindbis virus infection. Using this approach, we identified a ubiquitin homolog, interferon-stimulated gene 15 (ISG15), as having antiviral activity. ISG15 expression protected against Sindbis virus-induced lethality and decreased Sindbis virus replication in multiple organs without inhibiting the spread of virus throughout the host. We establish that, much like ubiquitin, ISG15 requires its C-terminal LRLRGG motif to form intracellular conjugates. Finally, we demonstrate that ISG15's LRLRGG motif is also required for its antiviral activity. We conclude that ISG15 can be directly antiviral.
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Affiliation(s)
- Deborah J Lenschow
- Department of Pathology, Washington University School of Medicine, St. Louis, Missouri 63110, USA
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224
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Dobbs ME, Strasser JE, Chu CF, Chalk C, Milligan GN. Clearance of herpes simplex virus type 2 by CD8+ T cells requires gamma interferon and either perforin- or Fas-mediated cytolytic mechanisms. J Virol 2006; 79:14546-54. [PMID: 16282454 PMCID: PMC1287581 DOI: 10.1128/jvi.79.23.14546-14554.2005] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The T-cell-mediated resolution of herpes simplex virus type 2 (HSV-2) genital infections is not fully understood. In these studies, the mechanisms by which CD8+ T cells clear virus from the genital epithelium were examined. Ovalbumin (OVA)-specific CD8+ T cells from OT-I transgenic mice cleared a thymidine kinase-deficient, ovalbumin-expressing HSV-2 virus (HSV-2 tk- OVA) from the genital epithelium of recipient mice, and clearance was abrogated by in vivo neutralization of gamma interferon (IFN-gamma). Further, CD8+ OT-I T cells deficient in IFN-gamma were unable to clear HSV-2 tk- OVA from the vaginal epithelium. The requirement for cytolytic mechanisms in HSV-2 tk- OVA clearance was tested in radiation chimeras by adoptive transfer of wild-type or perforin-deficient OT-I T cells to irradiated Fas-defective or wild-type recipients. Although a dramatic decrease in viral load was observed early after challenge with HSV-2 tk- OVA, full resolution of the infection was not achieved in recipients lacking both perforin- and Fas-mediated cytolytic pathways. These results suggest that IFN-gamma was responsible for an early rapid decrease in HSV-2 virus titer. However, either perforin- or Fas-mediated cytolytic mechanisms were required to achieve complete clearance of HSV-2 from the genital epithelium.
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Affiliation(s)
- Melanie E Dobbs
- Department of Pathology, University of Texas Medical Branch, Galveston, TX 77555, USA
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225
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Abstract
Ectromelia virus (ECTV) is an orthopoxvirus whose natural host is the mouse; it is related closely to Variola virus, the causative agent of smallpox, and Monkeypox virus, the cause of an emerging zoonosis. The recent sequencing of its genome, along with an effective animal model, makes ECTV an attractive model for the study of poxvirus pathogenesis, antiviral and vaccine testing and viral immune and inflammatory responses. This review discusses the pathogenesis of mousepox, modulation of the immune response by the virus and the cytokine and cellular components of the skin and systemic immune system that are critical to recovery from infection.
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Affiliation(s)
- David J Esteban
- University of Victoria, Department of Biochemistry and Microbiology, PO Box 3055 STN CSC, Victoria BC, Canada V8W 3P6
| | - R Mark L Buller
- St Louis University Health Sciences Center, Department of Molecular Microbiology and Immunology, 1402 S. Grand Blvd, St Louis, MO 63104, USA
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226
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Keadle TL, Morris JL, Stuart PM. The effects of aminoguanidine on primary and recurrent ocular herpes simplex virus infection. Nitric Oxide 2005; 13:247-53. [PMID: 16125422 DOI: 10.1016/j.niox.2005.07.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2005] [Revised: 07/14/2005] [Accepted: 07/14/2005] [Indexed: 11/28/2022]
Abstract
In primary ocular herpes simplex virus (HSV) infection, nitric oxide may function to control viral replication and herpetic stromal keratitis (HSK) lesions. Recurrent HSK, manifested as corneal opacity and neovascularization, is the potentially blinding sequel to primary infection. Here, we assess the effects of nitric oxide synthase inhibition on a mouse model of recurrent HSK. In preliminary primary infection experiments, NIH inbred mice treated with aminoguanidine, an inhibitor of inducible nitric oxide synthase (iNOS), experienced no changes in post-infection tear, brain, or ganglia virus titers, but encephalitis-related mortality was elevated. After UV-B stimulated viral reactivation, iNOS inhibition did not affect virus shedding or clinical disease. In contrast to primary HSK, there was no exacerbation of mortality in recurrent disease. Our findings indicate that nitric oxide can be neuroprotective without antiviral effects in primary HSK, and does not play a significant role in the pathogenesis of recurrent HSK. Compared with data from other mouse strains, this work suggests that there may be a genetic component to the importance of NO in controlling ocular HSV infection.
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Affiliation(s)
- Tammie L Keadle
- Washington University School of Medicine, Department of Ophthalmology Visual Sciences, 660 S. Euclid, Box 8096, St. Louis, MO 63110, USA.
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227
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Terajima M, Leporati AM. Role of Indoleamine 2,3-Dioxygenase in Antiviral Activity of Interferon-γ Against Vaccinia Virus. Viral Immunol 2005; 18:722-9. [PMID: 16359238 DOI: 10.1089/vim.2005.18.722] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Interferon-gamma (IFN-gamma) has antiviral activity against poxviruses as well as many other viruses, bacteria and a parasite, Toxoplasma gondii. Inducible nitric oxide synthase (NOS2) has been shown to mediate the antiviral activity of IFN-gamma in both in vivo and in vitro experiments. In macrophages, inhibition of replication of poxviruses by IFN-gamma is NOS2-dependent. In this report we tested nonmacrophage cell lines and found that indoleamine 2,3-dioxygenase (IDO) also mediated the antiviral activity of IFN-gamma against vaccinia virus. L-tryptophan, an inhibitor of IDO, completely blocked the antiviral activity of IFN-gamma against vaccinia virus in 143B cells, an human osteosarcoma cell line, whereas N(G)-methyl-L-arginine, a NOS2 inhibitor, did not. IDO may account for the NOS2-independent antiviral mechanism induced by IFN-gamma. IFN-gamma may use different antiviral mechanisms in different cell types.
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Affiliation(s)
- Masanori Terajima
- Center for Infectious Disease and Vaccine Research, University of Massachusetts Medical School, Worcester, Massachusetts 01655, USA.
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228
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Liu YH, Carretero OA, Cingolani OH, Liao TD, Sun Y, Xu J, Li LY, Pagano PJ, Yang JJ, Yang XP. Role of inducible nitric oxide synthase in cardiac function and remodeling in mice with heart failure due to myocardial infarction. Am J Physiol Heart Circ Physiol 2005; 289:H2616-23. [PMID: 16055518 DOI: 10.1152/ajpheart.00546.2005] [Citation(s) in RCA: 92] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Using inducible nitric oxide (NO) synthase (iNOS) knockout mice (iNOS−/−), we tested the hypotheses that 1) lack of iNOS attenuates cardiac remodeling and dysfunction and improves cardiac reserve postmyocardial infarction (MI), an effect that is partially mediated by reduction of oxidative stress due to reduced interaction between NO and reactive oxygen species (ROS); and 2) the cardioprotection afforded by iNOS deletion is eliminated by Nω-nitro-l-arginine methyl ester (l-NAME) due to inhibition of endothelial NOS (eNOS) and neuronal NOS (nNOS). MI was induced by ligating the left anterior descending coronary artery. Male iNOS−/− mice and wild-type controls (WT, C57BL/6J) were divided into sham MI, MI+vehicle, and MI+l-NAME (100 mg·kg−1·day−1 in drinking water for 8 wk). Cardiac function was evaluated by echocardiography. Left ventricular (LV) maximum rate of rise of ventricular pressure divided by pressure at the moment such maximum occurs (dP/d t/instant pressure) in response to isoproterenol (100 ng·kg−1·min−1 iv) was measured with a Millar catheter. Collagen deposition, myocyte cross-sectional area, and expression of nitrotyrosine and 4-hydroxy-2-nonenal (4-HNE), markers for ROS, were determined by histopathological and immunohistochemical staining. We found that the MI-induced increase in LV chamber dimension and the decrease in ejection fraction, an index of systolic function, were less severe in iNOS−/− compared with WT mice. l-NAME worsened LV remodeling and dysfunction further, and these detrimental effects were also attenuated in iNOS−/− mice, associated with better preservation of cardiac function. Lack of iNOS also reduced nitrotyrosine and 4-HNE expression after MI, indicating reduced oxidative stress. We conclude that iNOS does not seem to be a pathological mediator of heart failure; however, the lack of iNOS improves cardiac reserve post-MI, particularly when constitutive NOS isoforms are blocked. Decreased oxidative stress and other adaptive mechanisms independent of NOS may be partially responsible for such an effect, which needs to be studied further.
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Affiliation(s)
- Yun-He Liu
- Hypertension and Vascular Research Div., Henry Ford Hospital, 2799 W. Grand Blvd., Detroit, MI 48202-2689, USA
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229
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Jarasch N, Martin U, Kamphausen E, Zell R, Wutzler P, Henke A. Interferon-gamma-induced activation of nitric oxide-mediated antiviral activity of macrophages caused by a recombinant coxsackievirus B3. Viral Immunol 2005; 18:355-64. [PMID: 16035947 DOI: 10.1089/vim.2005.18.355] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Cardiovascular disease is one of the major causes of human death and has been linked to many different risks including viral infections. Coxsackievirus B3 (CVB3) is one of the most important pathogens responsible for virus-induced myocarditis. Cytokines are normally involved in the control of CVB3 replication and pathogenesis. Among them, interferon-gamma (IFN-gamma) in particular is highly protective against CVB3. A novel strategy to circumvent virus-caused heart disease is based on the development of cytokine-expressing recombinant virus vectors. Using in vitro co-culture experiments, the release of IFN-gamma by the recombinant virus variant CVB3/IFN-gamma activates the expression of the inducible nitric oxide synthase (iNOS) in CVB3 non-susceptible murine macrophages and the release of nitric oxide (NO), which reduce coxsackieviral replication directly. In addition, the expression of IFN-gamma by CVB3/IFN-gamma contributes to protect mice from lethal infections by iNOS induction in murine peritoneal macrophages, viral load reduction, and pancreatic tissue protection.
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Affiliation(s)
- Nadine Jarasch
- Institute of Virology and Antiviral Therapy, Medical Center, Friedrich Schiller University, Hans-Knöll-Str. 2, D-07745 Jena, Germany
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230
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Moran JM, Moxley MA, Buller RML, Corbett JA. Encephalomyocarditis virus induces PKR-independent mitogen-activated protein kinase activation in macrophages. J Virol 2005; 79:10226-36. [PMID: 16051816 PMCID: PMC1182679 DOI: 10.1128/jvi.79.16.10226-10236.2005] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
In this study, we provide evidence that the double-stranded RNA-dependent protein kinase (PKR) is not required for virus-induced expression of inducible nitric oxide synthase (iNOS) or the activation of specific signaling pathways in macrophages. The infection of RAW264.7 cells with encephalomyocarditis virus (EMCV) induces iNOS expression and nitric oxide production, which are unaffected by a dominant-negative mutant of PKR. EMCV infection also activates the mitogen-activated protein kinase, cyclic AMP response element binding protein, and nuclear factor kappaB (NF-kappaB) signaling cascades at 15 to 30 min postinfection in PKR+/+ and PKR-/- macrophages. Activation of these signaling cascades does not temporally correlate with PKR activity or the accumulation of EMCV RNA, suggesting that an interaction between a structural component of the virion and the cell surface may activate macrophages. Consistent with this hypothesis, empty EMCV capsids induced comparable levels of iNOS expression, nitrite production, and activation of these signaling cascades to those induced by intact virions. These findings support the hypothesis that virion-host cell interactions are primary mediators of the PKR-independent activation of signaling pathways that participate in the macrophage antiviral response of inflammatory gene expression.
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Affiliation(s)
- Jason M Moran
- Edward A. Doisy Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, 1402 South Grand Boulevard, Saint Louis, MO 63104, USA
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231
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Panchanathan V, Chaudhri G, Karupiah G. Interferon function is not required for recovery from a secondary poxvirus infection. Proc Natl Acad Sci U S A 2005; 102:12921-6. [PMID: 16123129 PMCID: PMC1200282 DOI: 10.1073/pnas.0505180102] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
IFN function is critical for recovery from most primary viral infections, including poxvirus infection. In contrast, very little is known about the requirement for IFN function in mediating recovery from a secondary virus infection. We have used ectromelia virus (ECTV), an orthopoxvirus very closely related to variola virus, to investigate the importance of IFN function in recovery from a secondary infection. Variola virus, the causative agent of smallpox in humans, and ECTV, which causes mousepox in mice, both encode receptor homologs that are thought to interfere with host IFN function. Using a prime-challenge regime, in which avirulent ECTV is used to prime mice deficient in type I/II IFN function or IFN regulatory factor 1 (IRF-1) and then challenging the mice with a virulent strain, we show that IFN function is redundant for virus clearance during a secondary ECTV infection. A neutralizing Ab response is generated in a secondary infection, even in the absence of IFN function, although when present, IFN strongly influences the neutralizing titer and subtype of IgG that is produced. Importantly, the depletion of CD8+ T lymphocytes during a secondary challenge in IFN-deficient mice does not affect their capacity to clear ECTV, indicating that Ab is critical for the control of a secondary infection.
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Affiliation(s)
- Vijay Panchanathan
- Infection and Immunity Group, Division of Immunology and Genetics, John Curtin School of Medical Research, Australian National University, Canberra ACT 2601, Australia
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232
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Hokari A, Zeniya M, Esumi H, Ishikawa T, Kurasima Y, Toda G. Role of nitric oxide (NO) in interferon-alpha therapy for hepatitis C. J Infect 2005; 51:47-53. [PMID: 15979491 DOI: 10.1016/j.jinf.2004.08.025] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/28/2004] [Indexed: 12/23/2022]
Abstract
BACKGROUND AND AIM The role of nitric oxide in infectious disease is gaining increased attention because antiviral effects of nitric oxide. In addition, there is evidence that nitric oxide synthase-2 expression was noted in chronic hepatitis C found within mononuclear cells. METHODS We studied serum levels of nitrite and nitrate before and during interferon alpha therapy in 66 patients with chronic hepatitis C. RESULTS There was no significant difference of their levels between the healthy control subjects and the patients before the treatment with interferon (55.9+/-21.8 microM vs. 60.9+/-30.0 microM). Their levels were determined at 2 weeks after the initiation of treatment with interferon and compared with those before the treatment in the patients with chronic hepatitis C. In the total patients treated, there was no significant difference between their levels before and at 2 weeks after the treatment (60.9+/-30.0 microM vs. 65.5+/-30.0 microM, P=0.14). However, when the levels were compared between sustained responders, in whom hepatitis C virus was eradicated, and non-responders, in whom the virus was not eradicated, the former had significantly higher levels of nitrite and nitrate than the latter at 2 weeks after the initiation of treatment (83.7+/-40.9 microM vs. 57.6+/-19.5 microM, P<0.01). The multivariate logistic regression analysis showed that the rise of nitrite and nitrate was an independent predictive factor for efficacy of interferon treatment. CONCLUSIONS Nitric oxide may be an important factor for antiviral therapy by interferon treatment for chronic hepatitis C, which suggests an additional therapeutic pathway for further study.
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Affiliation(s)
- Atsushi Hokari
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, Jikei University School of Medicine, 3-25-8 Nishishimbashi, Minato, Tokyo 105-0003, Japan.
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233
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Neves-Souza PCF, Azeredo EL, Zagne SMO, Valls-de-Souza R, Reis SRNI, Cerqueira DIS, Nogueira RMR, Kubelka CF. Inducible nitric oxide synthase (iNOS) expression in monocytes during acute Dengue Fever in patients and during in vitro infection. BMC Infect Dis 2005; 5:64. [PMID: 16109165 PMCID: PMC1208887 DOI: 10.1186/1471-2334-5-64] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2004] [Accepted: 08/18/2005] [Indexed: 11/10/2022] Open
Abstract
UNLABELLED Mononuclear phagocytes are considered to be main targets for Dengue Virus (DENV) replication. These cells are activated after infection, producing proinflammatory mediators, including tumour-necrosis factor-alpha, which has also been detected in vivo. Nitric oxide (NO), usually produced by activated mononuclear phagocytes, has antimicrobial and antiviral activities. METHODS The expression of DENV antigens and inducible nitric oxide synthase (iNOS) in human blood isolated monocytes were analysed by flow cytometry using cells either from patients with acute Dengue Fever or after DENV-1 in vitro infection. DENV-1 susceptibility to iNOS inhibition and NO production was investigated using NG-methyl L-Arginine (NGMLA) as an iNOS inhibitor, which was added to DENV-1 infected human monocytes, and sodium nitroprussiate (SNP), a NO donor, added to infected C6/36 mosquito cell clone. Viral antigens after treatments were detected by flow cytometry analysis. RESULTS INOS expression in activated monocytes was observed in 10 out of 21 patients with Dengue Fever and was absent in cells from ten healthy individuals. DENV antigens detected in 25 out of 35 patients, were observed early during in vitro infection (3 days), significantly diminished with time, indicating that virus replicated, however monocytes controlled the infection. On the other hand, the iNOS expression was detected at increasing frequency in in vitro infected monocytes from three to six days, exhibiting an inverse relationship to DENV antigen expression. We demonstrated that the detection of the DENV-1 antigen was enhanced during monocyte treatment with NGMLA. In the mosquito cell line C6/36, virus detection was significantly reduced in the presence of SNP, when compared to that of untreated cells. CONCLUSION This study is the first to reveal the activation of DENV infected monocytes based on induction of iNOS both in vivo and in vitro, as well as the susceptibility of DENV-1 to a NO production.
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Affiliation(s)
- Patrícia CF Neves-Souza
- Departmento de Virologia, Instituto Oswaldo Cruz Fundação Oswaldo Cruz, Av. Brasil, 4365, CEP 21040-360 Rio de Janeiro, RJ, Brazil
| | - Elzinandes L Azeredo
- Departmento de Virologia, Instituto Oswaldo Cruz Fundação Oswaldo Cruz, Av. Brasil, 4365, CEP 21040-360 Rio de Janeiro, RJ, Brazil
| | - Sonia MO Zagne
- Departamento de Clínica Médica, Hospital Antonio Pedro, Universidade Federal Fluminense, Niterói, RJ, Brazil
| | - Rogério Valls-de-Souza
- Instituto de Pesquisas Evandro Chagas, Fundação Oswaldo Cruz, Av. Brasil, 4365, CEP 21040-360 Rio de Janeiro, RJ, Brazil
| | - Sonia RNI Reis
- Departmento de Virologia, Instituto Oswaldo Cruz Fundação Oswaldo Cruz, Av. Brasil, 4365, CEP 21040-360 Rio de Janeiro, RJ, Brazil
| | - Denise IS Cerqueira
- Departmento de Virologia, Instituto Oswaldo Cruz Fundação Oswaldo Cruz, Av. Brasil, 4365, CEP 21040-360 Rio de Janeiro, RJ, Brazil
| | - Rita MR Nogueira
- Departmento de Virologia, Instituto Oswaldo Cruz Fundação Oswaldo Cruz, Av. Brasil, 4365, CEP 21040-360 Rio de Janeiro, RJ, Brazil
| | - Claire F Kubelka
- Departmento de Virologia, Instituto Oswaldo Cruz Fundação Oswaldo Cruz, Av. Brasil, 4365, CEP 21040-360 Rio de Janeiro, RJ, Brazil
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234
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Ellermann-Eriksen S. Macrophages and cytokines in the early defence against herpes simplex virus. Virol J 2005; 2:59. [PMID: 16076403 PMCID: PMC1215526 DOI: 10.1186/1743-422x-2-59] [Citation(s) in RCA: 91] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2005] [Accepted: 08/03/2005] [Indexed: 11/12/2022] Open
Abstract
Herpes simplex virus (HSV) type 1 and 2 are old viruses, with a history of evolution shared with humans. Thus, it is generally well-adapted viruses, infecting many of us without doing much harm, and with the capacity to hide in our neurons for life. In rare situations, however, the primary infection becomes generalized or involves the brain. Normally, the primary HSV infection is asymptomatic, and a crucial element in the early restriction of virus replication and thus avoidance of symptoms from the infection is the concerted action of different arms of the innate immune response. An early and light struggle inhibiting some HSV replication will spare the host from the real war against huge amounts of virus later in infection. As far as such a war will jeopardize the life of the host, it will be in both interests, including the virus, to settle the conflict amicably. Some important weapons of the unspecific defence and the early strikes and beginning battle during the first days of a HSV infection are discussed in this review. Generally, macrophages are orchestrating a multitude of anti-herpetic actions during the first hours of the attack. In a first wave of responses, cytokines, primarily type I interferons (IFN) and tumour necrosis factor are produced and exert a direct antiviral effect and activate the macrophages themselves. In the next wave, interleukin (IL)-12 together with the above and other cytokines induce production of IFN-gamma in mainly NK cells. Many positive feed-back mechanisms and synergistic interactions intensify these systems and give rise to heavy antiviral weapons such as reactive oxygen species and nitric oxide. This results in the generation of an alliance against the viral enemy. However, these heavy weapons have to be controlled to avoid too much harm to the host. By IL-4 and others, these reactions are hampered, but they are still allowed in foci of HSV replication, thus focusing the activity to only relevant sites. So, no hero does it alone. Rather, an alliance of cytokines, macrophages and other cells seems to play a central role. Implications of this for future treatment modalities are shortly considered.
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Affiliation(s)
- Svend Ellermann-Eriksen
- Department of Clinical Microbiology, Aarhus University Hospital, Skejby Sygehus, Brendstrupgaardsvej 100, DK-8200 Aarhus N., Denmark.
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235
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Cameron CM, Barrett JW, Liu L, Lucas AR, McFadden G. Myxoma virus M141R expresses a viral CD200 (vOX-2) that is responsible for down-regulation of macrophage and T-cell activation in vivo. J Virol 2005; 79:6052-67. [PMID: 15857991 PMCID: PMC1091733 DOI: 10.1128/jvi.79.10.6052-6067.2005] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
M141R is a myxoma virus gene that encodes a cell surface protein with significant amino acid similarity to the family of cellular CD200 (OX-2) proteins implicated in the regulation of myeloid lineage cell activation. The creation of an M141R deletion mutant myxoma virus strain (vMyx141KO) and its subsequent infection of European rabbits demonstrated that M141R is required for the full development of a lethal infection in vivo but is not required for efficient virus replication in susceptible cell lines in vitro. Minor secondary sites of infection were detected in the majority of rabbits infected with the M141R deletion mutant, demonstrating that the M141R protein is not required for the dissemination of virus within the host. When compared to wild-type myxoma virus-infected rabbits, vMyx141KO-infected rabbits showed higher activation levels of both monocytes/macrophages and lymphocytes in situ through assessments of inducible nitric oxide synthase-positive and CD25(+) infiltrating cells in infected and lymphoid tissues. Purified peripheral blood mononuclear cells from vMyx141KO-infected rabbits demonstrated an increased ability to express gamma interferon upon activation by phorbol myristate acetate plus ionomycin compared to cells purified from wild-type myxoma virus-infected rabbits. We concluded that the M141R protein is a bona fide CD200-like immunomodulator protein which is required for the full pathogenesis of myxoma virus in the European rabbit and that its loss from the virus results in increased activation levels of macrophages in infected lesions and draining lymph nodes as well as an increased activation level of circulating T lymphocytes during infection. We propose a model whereby M141R transmits inhibitory signals to tissue macrophages, and possibly resident CD200R(+) dendritic cells, that reduce their ability to antigenically prime lymphocytes and possibly provides anergic signals to T cells directly.
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Affiliation(s)
- Cheryl M Cameron
- Robarts Research Institute, Siebens-Drake Building, Room 116.1, 1400 Western Road, London, Ontario, Canada.
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236
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Cameron CM, Barrett JW, Mann M, Lucas A, McFadden G. Myxoma virus M128L is expressed as a cell surface CD47-like virulence factor that contributes to the downregulation of macrophage activation in vivo. Virology 2005; 337:55-67. [PMID: 15914220 DOI: 10.1016/j.virol.2005.03.037] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2005] [Revised: 02/25/2005] [Accepted: 03/25/2005] [Indexed: 11/15/2022]
Abstract
The M128L myxoma virus gene expresses a five-membrane spanning cell surface protein with significant amino acid homology to the cellular CD47 proteins. CD47, also called integrin-associated protein (IAP), is associated with the modulation of leukocyte adhesion, motility, activation, and phagocytosis. Creation of an M128L-deletion mutant myxoma virus strain and subsequent infection of the European rabbit demonstrated that M128L is necessary for the production of a lethal infection in susceptible rabbits, while it is fully dispensable for virus replication in vitro. Secondary sites of infection developed on the majority of rabbits infected with the M128L-deletion mutant (vMyx128KO), demonstrating that the M128L protein is nonessential for the dissemination of virus within the host. Although the size and severity of the primary lesions on vMyx128KO-infected rabbits were comparable to rabbits infected with the wild-type virus at the early stages of disease progression, by day 7 the reduced virulence of the vMyx128KO virus was clearly evident and all of the animals recovered from infection by the M128L-knockout virus. Histological analysis of the tissues of vMyx128KO-infected rabbits revealed greater activation of monocyte/macrophage cells in infected and/or lymphoid tissues when compared to those of wild-type myxoma-infected rabbits. We conclude that the M128L protein is a novel CD47-like immunomodulatory gene of myxoma virus required for full pathogenesis of the virus in the European rabbit and that its loss from the virus results in increased activation of monocyte/macrophage cells during infection.
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Affiliation(s)
- C M Cameron
- BioTherapeutics Research Group, Robarts Research Institute, London, ON, Canada
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237
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Kadowaki S, Chikumi H, Yamamoto H, Yoneda K, Yamasaki A, Sato K, Shimizu E. Down-regulation of inducible nitric oxide synthase by lysophosphatidic acid in human respiratory epithelial cells. Mol Cell Biochem 2005; 262:51-9. [PMID: 15532709 DOI: 10.1023/b:mcbi.0000038215.89821.7f] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Viral infection generally results in the activation of inducible nitric oxide synthase (iNOS or NOS2) in respiratory epithelial cells by inflammatory cytokines. Activated NOS2 catalyzes synthesis of nitric oxide (NO), which in excess can cause cellular injury. On the other hand, lysophosphatidic acid (LPA), a lipid mediator released from epithelial cells, platelets, and fibroblasts in injured tissue, functions in repair of cell injury. However, details of the mechanism for repair by LPA remain unknown. We demonstrated one effect of LPA favoring repair, specifically inhibition by LPA of cytokine-induced NOS2 protein and mRNA expression by human respiratory epithelial cells in vitro. NO production by LPA-treated, cytokine-stimulated cells was also reduced. These decreases were prevented by Rho kinase inhibition with Y-27632. Thus, down-regulation by LPA of cytokine-induced increases in NOS2 activity is likely to involve a Rho-dependent signaling pathway. Harmful biologic effects of NO in viral respiratory infection might be modified by therapeutic manipulations involving LPA or Rho.
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Affiliation(s)
- Saori Kadowaki
- Division of Internal Medicine and Molecular Therapeutics, Department of Multidisciplinary Internal Medicine, Faculty of Medicine, Tottori University, Yonago Tottori, Japan
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238
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Abstract
IL-12, IL-23 and IFN-γ form a loop and have been thought to play a crucial role against infectious viruses, which are the prototype of “intracellular” pathogens. In the last 10 years, the generation of knock-out (KO) mice for genes that control IL-12/IL-23-dependent IFN-γ-dependent mediated immunity (STAT1, IFN-γR1, IFNγR2, IL-12p40 and IL-12Rβ1) and the identification of patients with spontaneous germline mutations in these genes has led to a re-examination of the role of these cytokines in anti-viral immunity. We here review viral infections in mice and humans with genetic defects in the IL-12/IL-23-IFN-γ axis. A comparison of the phenotypes observed in KO mice and deficient patients suggests that the human IL-12/IL-23-IFN-γ axis plays a redundant role in immunity to most viruses, whereas its mouse counterparts play a more important role against several viruses.
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Affiliation(s)
- Francesco Novelli
- Laboratory of Human Genetics of Infectious Diseases, Necker Medical School, René Descartes University of Paris, INSERM U550, 156 Rue de Vaugirard, 75015 Paris, France.
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239
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Bai H, Buller RML, Chen N, Green M, Nuara AA. Biosynthesis of the IFN-γ binding protein of ectromelia virus, the causative agent of mousepox. Virology 2005; 334:41-50. [PMID: 15749121 DOI: 10.1016/j.virol.2005.01.015] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2004] [Revised: 11/24/2004] [Accepted: 01/11/2005] [Indexed: 11/29/2022]
Abstract
Ectromelia virus (ECTV), the causative agent of mousepox, expresses an extracellular interferon-gamma binding protein (IFN-gammaBP) with homology to the ligand binding domains of the IFN-gamma high affinity receptor (IFN-gammaR1). Unlike the cellular receptor, the IFN-gammaBP binds IFN-gamma from several species. The IFN-gammaBP is synthesized early after infection, accumulating in the extracellular milieu as dimers composed of two protein species with Mr of 34.6 or 33.0 kDa. Homodimers are covalently linked by an interchain disulphide bond at position 216. The IFN-gammaBP has complex N-linked oligosaccharides at positions 41 and 149 as determined by site-directed mutagenesis and glycosidase treatment. Glycosylation at position 41 is required for secretion from mammalian cells and may play a role in the activity of the IFN-gammaBP. Glycosylation at position 149 is not required for secretion, and the lack of glycosylation at this site does not diminish ligand binding as measured by surface plasmon resonance (SPR) and ELISA.
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Affiliation(s)
- Hongdong Bai
- Department of Molecular Microbiology and Immunology, Saint Louis University Health Sciences Center, 1402 South Grand Boulevard, St. Louis, MO 63104, USA
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240
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Huang YCT, Li Z, Brighton LE, Carson JL, Becker S, Soukup JM. 3-nitrotyrosine attenuates respiratory syncytial virus infection in human bronchial epithelial cell line. Am J Physiol Lung Cell Mol Physiol 2005; 288:L988-96. [PMID: 15653711 DOI: 10.1152/ajplung.00378.2004] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
3-nitrotyrosine (NO2Tyr), an L-tyrosine derivative during nitrative stress, can substitute the COOH-terminal tyrosine of alpha-tubulin, posttranslationally altering microtubular functions. Because infection of the cells by respiratory syncytial virus (RSV) may require intact microtubules, we tested the hypothesis that NO2Tyr would inhibit RSV infection and intracellular signaling via nitrotyrosination of alpha-tubulin. A human bronchial epithelial cell line (BEAS-2B) was incubated with RSV with or without NO2Tyr. The release of chemokines and viral particles and activation of interferon regulatory factor-3 (IRF-3) were measured. Incubation with NO2Tyr increased nitrotyrosinated alpha-tubulin, and NO2Tyr colocalized with microtubules. RSV-infected cells released viral particles, RANTES, and IL-8 in a time- and dose-dependent manner, and intracellular RSV proteins coprecipitated with alpha-tubulin. NO2Tyr attenuated the RSV-induced release of RANTES, IL-8, and viral particles by 50-90% and decreased alpha-tubulin-associated RSV proteins. 3-chlorotyrosine, another L-tyrosine derivative, had no effects. NO2Tyr also inhibited the RSV-induced shift of the unphosphorylated form I of IRF-3 to the phosphorylated form II. Pre-exposure of the cells to NO(2) (0.15 ppm, 4 h), which produced diffuse protein tyrosine nitration, did not affect RSV-induced release of RANTES, IL-8, or viral particles. NO2Tyr did not affect the potential of viral spreading to the neighboring cells since the RSV titers were not decreased when the uninfected cells were cocultured with the preinfected cells in NO2Tyr-containing medium. These results indicate that NO2Tyr, by replacing the COOH-terminal tyrosine of alpha-tubulin, attenuated RSV infection, and the inhibition appeared to occur at the early stages of RSV infection.
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Affiliation(s)
- Yuh-Chin T Huang
- National Health and Environmental Effects Research Laboratory, Office of Research and Development, Environmental Protection Agency, Research Triangle Park, NC, USA.
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241
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Zaki MH, Akuta T, Akaike T. Nitric Oxide-Induced Nitrative Stress Involved in Microbial Pathogenesis. J Pharmacol Sci 2005; 98:117-29. [PMID: 15937405 DOI: 10.1254/jphs.crj05004x] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
Abstract
The pathogenic mechanism of infections is a complicated but important scientific theme that is now attracting great attention because of its association with host-derived as well as microbial factors. Recent advances in free radical research revealed that reactive oxygen and nitrogen oxide species such as superoxide (O(2)(-)) and nitric oxide (NO) play a leading role in the pathogenesis of infections caused by viral pathogens including influenza virus and other RNA viruses. Although NO and O(2)(-) have antimicrobial activity against bacteria, fungi, and parasites, in some viral infections they have an opposite effect. This exacerbation caused by NO and O(2)(-) is mediated by reactive nitrogen oxides, for example, peroxynitrite (ONOO(-)), generated by reaction of NO with O(2)(-). These nitrogen oxides have strong oxidation and nitration potential and can modify biological molecules, thereby creating oxidative and nitrative stress that contributes to pathogenic processes during viral infection. Nitrative stress-mediated 8-nitroguanosine formation during influenza or Sendai virus infection has been the focus of enormous interest because it involves unique biochemical and pharmacological properties such as redox activity and mutagenic potential. In this review, we discuss the nature and impact of nitrative stress in viral infection, with emphasis on nitrative stress-mediated viral pathogenesis, which we have recently been investigating.
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Affiliation(s)
- Mohammad Hasan Zaki
- Department of Microbiology, Graduate School of Medical Sciences, Kumamoto University, Japan
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242
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Murphey ED, Herndon DN, Sherwood ER. Gamma interferon does not enhance clearance of Pseudomonas aeruginosa but does amplify a proinflammatory response in a murine model of postseptic immunosuppression. Infect Immun 2004; 72:6892-901. [PMID: 15557610 PMCID: PMC529160 DOI: 10.1128/iai.72.12.6892-6901.2004] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Patients that have suffered a major injury may sustain a period of immunocompromise and altered Th1/Th2 cytokine balance that can predispose them to opportunistic infections. Pseudomonas aeruginosa is frequently a causative organism for nosocomial infections in critically ill patients and is associated with high mortality. We previously mimicked this clinical scenario by challenging mice with P. aeruginosa 5 days after a cecal ligation and puncture (CLP) procedure. Mice that were subjected to CLP had reduced ability to clear bacteria, significantly lower gamma interferon (IFN-gamma) concentrations in plasma, and significantly elevated levels of interleukin 10 (IL-10) in plasma in response to the Pseudomonas challenge compared to uninjured control mice. We investigated the significance of the alteration in IFN-gamma by administering recombinant IFN-gamma to post-CLP mice at the time of Pseudomonas challenge and by challenging IFN-gamma knockout (IFN-gamma KO) mice with Pseudomonas. Administration of IFN-gamma to post-CLP mice attenuated IL-10 secretion and enhanced IL-12 secretion but did not improve bacterial clearance or survival after Pseudomonas challenge. Furthermore, IFN-gamma KO mice had significantly higher plasma IL-10 concentrations but did not exhibit impaired bacterial clearance or increased mortality following Pseudomonas challenge. These data indicate that systemic administration of IFN-gamma effectively reverses alterations in immune function that are commonly associated with immunosuppression in critically injured mice but does not improve bacterial clearance or survival following Pseudomonas challenge. Further, endogenous IFN-gamma does not appear to contribute significantly to early clearance of Pseudomonas bacteremia, nor does it affect the mortality rate after a lethal Pseudomonas challenge.
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Affiliation(s)
- E D Murphey
- Department of Anesthesiology, University of Texas Medical Branch, 301 University Boulevard, Galveston, TX 77555-0591, USA.
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243
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Liu G, Zhai Q, Schaffner D, Popova T, Hayford A, Bailey C, Alibek K. Bacillus alcalophilus peptidoglycan induces IFN-alpha-mediated inhibition of vaccinia virus replication. ACTA ACUST UNITED AC 2004; 42:197-204. [PMID: 15364104 DOI: 10.1016/j.femsim.2004.05.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2003] [Revised: 04/16/2004] [Accepted: 05/10/2004] [Indexed: 01/12/2023]
Abstract
Bacterial products such as cell walls (CW) and peptidoglycan (PGN) are known to activate macrophages and NK cells during microbial infections. In this report, we demonstrated that whole CW and PGN of four Gram-positive bacteria are capable of enhancing the anti-poxviral activity of murine macrophage RAW 264.7 cells. Among the major Bacillus alcalophilus CW components, PGN contributes the most to antiviral activity and induces remarkably higher levels of IFN-alpha. Anti-IFN-alpha/beta antibody, but not anti-IFN-gamma, anti-IFN-gamma receptor, or anti-IL-12, reversed the PGN-induced inhibition of vaccinia virus replication and reduced nitric oxide (NO) production. Our data thus suggest that PGN induce antiviral activity through IFN-alpha and to a lesser extent, through NO production.
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Affiliation(s)
- Ge Liu
- Advanced Biosystems, Inc., George Mason University, 10900 University Blvd., MSN 1A8 Manassas, VA 20110, USA.
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Bhatt JM, Everard ML. Do environmental pollutants influence the onset of respiratory syncytial virus epidemics or disease severity? Paediatr Respir Rev 2004; 5:333-8. [PMID: 15531259 DOI: 10.1016/j.prrv.2004.07.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The trigger for annual epidemics of respiratory syncytial virus (RSV) infections and the factors contributing to the disappearance of RSV infections in late winter remain obscure. Similarly, there is no adequate explanation for the higher morbidity and admission rates in industrialised as compared with rural areas. It has been suggested that a variety of environmental factors such as temperature, daylight and humidity may influence the onset and waning of the epidemics. However, the few studies assessing these variables fail to support such a link. In many tropical countries the annual epidemic occurs in the summer or autumn, arguing against temperature having a direct influence. A number of studies have suggested that indoor pollutants, including cigarette smoke, are associated with an increased likelihood of being admitted to hospital with severe lower respiratory tract disease. One study exploring the potential role of outdoor pollutants on the pattern of RSV related illness in infancy was unable to identify a clear link between a variety of pollutants and the timing of the epidemic. Nitric oxide levels were higher in winter than during the summer and much higher winter peaks of NO were observe in industrialised areas as compared with urban and rural areas. Whether this or other environmental pollutants contribute to the higher incidence of severe disease in industrialised areas is unclear. Further work is required to explore the possible influence of NO and other environmental pollutants on both the timing and severity of epidemics.
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Affiliation(s)
- Jayesh M Bhatt
- Pediatric Respiratory Unit, Sheffield Children's Hospital, Western Bank, Sheffield S10 2TH, UK
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245
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Jiang G, Yu R, Zhou M. Modulatory effects of ammonia-N on the immune system of Penaeus japonicus to virulence of white spot syndrome virus. AQUACULTURE (AMSTERDAM, NETHERLANDS) 2004; 241:61-75. [PMID: 32287452 PMCID: PMC7112129 DOI: 10.1016/j.aquaculture.2004.08.020] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2004] [Revised: 08/07/2004] [Accepted: 08/16/2004] [Indexed: 05/28/2023]
Abstract
To study response to white spot syndrome virus (WSSV) under ammonia stress, Penaeus japonicus were exposed to 5 mg l-1 ammonia-N and challenged orally with WSSV (NW). Controls consisted of an ammonia-N-exposed control group (N), a WSSV-challenged positive control group (W), and an untreated control group (control). Immune parameters measured were total haemocyte count (THC), haemocyte phagocytosis, plasma protein content and haemolymph enzymatic activities for prophenoloxidase (proPO), alkaline phosphatase (ALP), and nitric oxide synthase (NOS). THC and plasma protein had downward trends with time in all treatment groups (NW, N, and W) in contrast to the untreated control group (control). The percentage phagocytosis, NOS activity, and ALP and proPO activity of W and NW decreased initially then increased from 6 to 78 h (except for NOS and ALP, from 6 to 54 h) before declining thereafter until the end of the experiment. Compared with untreated controls (control), there was a downward trend for all measured parameters in the treatment groups (N, NW, and W), but the degree was W>NW>N. WSSV was detected at 78 h postchallenge in both W and NW. In conclusion, 5 mg l-1 ammonia-N reduced the immunocompetence of P. japonicus and may have decreased the virulence of WSSV.
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Affiliation(s)
- Guojian Jiang
- Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, The Chinese Academy of Sciences, Qingdao 266071, China
- Graduate School, The Chinese Academy of Sciences, Beijing 100039, China
| | - Rencheng Yu
- Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, The Chinese Academy of Sciences, Qingdao 266071, China
| | - Mingjiang Zhou
- Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, The Chinese Academy of Sciences, Qingdao 266071, China
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246
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Liu G, Zhai Q, Schaffner D, Bradburne C, Wu A, Hayford A, Popov S, Grene E, Bailey C, Alibek K. IL-15 induces IFN-beta and iNOS gene expression, and antiviral activity of murine macrophage RAW 264.7 cells. Immunol Lett 2004; 91:171-8. [PMID: 15019287 DOI: 10.1016/j.imlet.2003.11.015] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2003] [Revised: 11/20/2003] [Accepted: 11/27/2003] [Indexed: 01/12/2023]
Abstract
The effects of interleukine-15 (IL-15) on macrophage activation and antiviral activity have been investigated in this study. We have provided evidence that IL-15 stimulates murine macrophage RAW 264.7 cells to release nitric oxide (NO) and inhibit vaccinia virus (VV) replication in bystander human 293 cells in a dose-dependent manner. The IL-15-induced antiviral activity was partially mediated by NO, as blocking NO production by NO synthase (iNOS) inhibitor NG-monomethyl-L-arginine acetate (L-NMA) partially restored the virus replication. Interferon-gamma (IFN-gamma) was not detectable by ELISA in the cell supernatant of IL-15-activated macrophages or in the co-cultures of macrophages and infected bystander cells. Neutralizing anti-IFN-gamma, anti-IFN-gamma receptor R2, anti-TNF-alpha, or anti-IL-12 antibodies had no effect on NO production or antiviral activity. In contrast, neutralizing anti-IFN-alpha/beta antibody completely restored the VV replication and reduced the NO level to one third of that in the control. Elevated mRNA levels of IFN-beta and iNOS genes were detected in IL-15-activated RAW 264.7 cells by RT-PCR. Our data suggest that IL-15 is capable of inducing IFN-beta, which could participate in NO-mediated antiviral effect.
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Affiliation(s)
- Ge Liu
- Advanced Biosystems Inc., George Mason University, 10900 University Boulevard, MSN 1A8, Manassas, VA 20110, USA.
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247
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Balercia G, Moretti S, Vignini A, Magagnini M, Mantero F, Boscaro M, Ricciardo-Lamonica G, Mazzanti L. Role of nitric oxide concentrations on human sperm motility. ACTA ACUST UNITED AC 2004; 25:245-9. [PMID: 14760010 DOI: 10.1002/j.1939-4640.2004.tb02784.x] [Citation(s) in RCA: 91] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Nitric oxide (NO) is a free radical generated from the oxidation of L-arginine to L-citrulline by 3 isoforms of reduced nicotinamide adenine dinucleotide phosphate (NADPH)-dependent NO synthases. Several data suggest a relevant role in sperm cell pathophysiology, but any conclusive data on its role in spermatozoa motility are still lacking. In the present study, we have correlated NO concentration in semen and kinetic features of sperm cells from normozoospermic fertile donors and infertile patients affected by idiopathic asthenozoospermia. Normozoospermic fertile men exhibited NO concentrations that were significantly lower than those of asthenozoospermic infertile men. A significant linear negative correlation was evident between NO concentration and percentage of total sperm motility. A further significant linear negative correlation was found between NO concentration and spermatozoa kinetic characteristics determined by a computerized analysis (curvilinear and straight progressive velocity). These data suggest that the overproduction of this free radical and the consequent excessive exposure to oxidative conditions have a potential pathogenetic implication in the reduction of sperm motility. The positive role played by NO in spermatozoa capacitation leads us to speculate that such paradoxical involvement in both pathologic and physiologic processes depends on the alternative redox state and relative level of NO.
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Affiliation(s)
- Giancarlo Balercia
- Endocrinology Division, Department of Internal Medicine, University of Ancona, Ancona, Italy.
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248
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Nakamichi K, Inoue S, Takasaki T, Morimoto K, Kurane I. Rabies virus stimulates nitric oxide production and CXC chemokine ligand 10 expression in macrophages through activation of extracellular signal-regulated kinases 1 and 2. J Virol 2004; 78:9376-88. [PMID: 15308732 PMCID: PMC506932 DOI: 10.1128/jvi.78.17.9376-9388.2004] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Macrophages represent an essential part of innate immunity, and the viral infection of macrophages results in the release of multiple proinflammatory mediators, such as nitric oxide (NO), cytokines, and chemokines. This study was undertaken to define the molecular mechanism of macrophage activation in response to rabies virus (RV) infection. In RAW264 murine macrophage cells, a well-characterized macrophage model, RV replication was strictly restricted, whereas cell proliferation was significantly enhanced upon RV inoculation. Transcriptional analyses for the expression of inducible forms of NO synthase (iNOS), cytokines, and chemokines revealed that RV virions potentiate the gene expression of iNOS and CXC chemokine ligand 10 (CXCL10), a major chemoattractant of T helper cell type 1. However, RV stimulation had little or no effect on the expression profiles of proinflammatory cytokines and other types of chemokines. In macrophages stimulated with UV-inactivated RV virions, as well as infectious viruses, the phosphorylation of extracellular signal-regulated kinase (ERK) 1 and 2, members of the mitogen-activated protein kinase family, was significantly induced. Specific inhibitors of MAPK/ERK kinase reduced the RV-induced production of NO and CXCL10. Furthermore, the RV-induced activation of the ERK1/2 pathway was severely impaired by the neutralization of the endosomal and lysosomal pH environment with lysosomotropic agents, indicating that endocytosis is a key step leading to the activation of ERK1/2 signaling. Taken together, these results suggest that the ERK1/2-mediated signaling pathway plays a cardinal role in the selective activation of macrophages in response to RV virions, thereby regulating cellular functions during virus infection.
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Affiliation(s)
- Kazuo Nakamichi
- Department of Virology I, National Institute of Infectious Diseases, Toyama, Shinjuku, Tokyo, Japan
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249
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Pham TNQ, Brown BL, Dobson PRM, Richardson VJ. Protein kinase C-eta (PKC-eta) is required for the development of inducible nitric oxide synthase (iNOS) positive phenotype in human monocytic cells. Nitric Oxide 2004; 9:123-34. [PMID: 14732335 DOI: 10.1016/j.niox.2003.09.006] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Several murine and human monocytic cell lines and monocyte-derived macrophages (MDM) from healthy volunteers were studied to compare their production of nitric oxide (NO) and induction of iNOS following endotoxin treatment. Although the human cells were sensitive to endotoxin and responded well by producing TNF-alpha and matrix metalloproteases (MMP), there was no induction of iNOS expression or NO production by any of these cells. Murine cells, however, produced large amounts of NO and expressed iNOS following similar endotoxin stimulation. We investigated the expression of PKC isotypes in all human and murine cell lines as well as in MDM, and found that the human cells lacked PKC-eta while the murine counterparts lacked PKC-beta1. Subsequently, human cells that were transfected with PKC-eta were found to make large quantities of NO following endotoxin exposure, an observation not seen in untransfected cells. We propose that PKC-eta is essential for the development of the iNOS positive phenotype in human monocytic cells, and may be responsible for the development of a number of inflammatory related conditions. As such it may be a suitable target for therapeutic intervention.
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Affiliation(s)
- Tram N Q Pham
- Basic Medical Sciences, Faculty of Medicine, Memorial University, St. John's NL, Canada A1B 3V6
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250
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Gamba G, Cavalieri H, Courreges MC, Massouh EJ, Benencia F. Early inhibition of nitric oxide production increases HSV-1 intranasal infection. J Med Virol 2004; 73:313-22. [PMID: 15122810 DOI: 10.1002/jmv.20093] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Here, we studied the role of nitric oxide (NO) production during the first steps of the respiratory infection of BALB/c mice with herpes simplex virus type 1 (HSV-1), strain F. Nitric oxide synthase II (NOS-II) mRNA and protein were detected by reverse transcription (RT)-PCR and dot blot, respectively in samples of lungs and turbinates early post-infection (p.i.). Immunohistochemical analysis revealed pulmonar macrophages and PMN expressing NOS-II in the lungs of infected animals. Animals intranasally treated with aminoguanidine (AG), a NOS inhibitor, during the first steps of infection, showed a dose-dependent increase in pneumonitis compared to controls. Viral titres in turbinates, lungs, and brains were higher in AG treated mice. Finally, histopathology studies revealed a stronger inflammation in eyes, and lungs of these animals. Taken together, these results suggest a role of NO in controlling primary HSV intranasal infection.
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Affiliation(s)
- Gisela Gamba
- Laboratory of Immunochemistry, Department of Biological Chemistry, Faculty of Sciences, University of Buenos Aires, Ciudad Universitaria, Buenos Aires, Argentina
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