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Influenza Virus Infection (influenza + virus_infection)
Selected AbstractsType,I interferon-dependent and -independent expression of tripartite motif proteins in immune cellsEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 3 2008Ricardo Rajsbaum Abstract The tripartite motif (TRIM) proteins are important in a variety of cellular functions additional to anti-viral activity. We systematically analysed mRNA expression of representative TRIM molecules in mouse macrophages, myeloid and plasmacytoid dendritic cells, and a selection of CD4+ T cell subsets. We defined four clusters of TRIM genes based on their selective expression in these cells. The first group of TRIM genes was preferentially expressed in CD4+ T cells and contained the COS-FN3 motif previously shown to be involved in protein interactions. Additional TRIM genes were identified that showed up-regulation in macrophages and dendritic cells upon influenza virus infection in a type,I IFN-dependent manner, suggesting that they have anti-viral activity. In support of this notion, a subset of these TRIM molecules mapped to mouse chromosome,7, syntenic to human chromosome,11, where TRIM family members such as TRIM5, shown to have anti-viral activity, are localized. A distinct group of TRIM was constitutively expressed in plasmacytoid dendritic cells independently of viral infection or signalling through the type,I IFN receptor. Our findings on expression and regulation of TRIM genes in cells of the immune system that have different effector functions in innate and adaptive immune responses, may provide leads for determining functions of this diverse family of molecules. [source] Bone marrow-derived cells expand memory CD8+ T,cells in response to viral infections of the lung and skinEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 2 2006Gabrielle Abstract While naive CD8+ T,cells have been shown to require bone marrow-derived dendritic cells (DC) to initiate immunity, such a requirement for memory CD8+ T,cells has had limited assessment. By generating bone marrow chimeras that express the appropriate antigen-presenting molecules on either radiation-sensitive bone marrow-derived or radiation-resistant non-bone marrow-derived compartments, we showed that both primary and secondary immune responses to influenza virus infection of the lung were initiated in the draining LN. This required cells of bone marrow origin, most likely DC, for optimal expansion within the secondary lymphoid compartment. This was similarly the case with HSV-1 infection of the skin. As Langerhans cells are radioresistant, unlike other DC populations, these studies also demonstrate that the radiosensitive DC responsible for secondary expansion of HSV-specific memory are not Langerhans cells. [source] A miniaturized assay for influenza neuraminidase-inhibiting antibodies utilizing reverse genetics-derived antigensINFLUENZA AND OTHER RESPIRATORY VIRUSES, Issue 5 2009Matthew R. Sandbulte Background, Antibodies to neuraminidase (NA) contribute to protection during influenza virus infection, but NA inhibition (NI) titers are not routinely analyzed in vaccine trials. One reason is the cumbersome nature of the conventional thiobarbituric acid (TBA) NI assay, which uses chemical methods to quantify free sialic acid following incubation of NA with substrate in the presence of serum. In addition, the assay is complicated by the need to use virus of a hemagglutinin (HA) subtype novel to the host to detect NA-specific antibodies only. Objectives, Our primary objectives were to miniaturize the colorimetric NI assay to a format suitable for quantitative analysis of large numbers of samples, and validate the specificity and sensitivity of the miniaturized format with ferret and human sera. An additional aim was to use reverse genetics to construct HA-mismatched viral reagents bearing NA of recent influenza A vaccine strains and H6 HA. Results, Analysis of ferret antisera by the miniaturized assay demonstrated sensitivity and specificity comparable with the conventional assay. Similar increases in the NI titers in sera from vaccinated human volunteers were measured in miniaturized and conventional assays. Inactivated and live-attenuated vaccines increased NI titers against a given subtype at approximately the same rate. Conclusions, The reagents and miniaturized format of the TBA method described here provide a platform for practical serological monitoring of functional antibodies against NA. [source] Protection against influenza virus infection by intranasal vaccine with surf clam microparticles (SMP) as an adjuvantJOURNAL OF MEDICAL VIROLOGY, Issue 7 2006Takeshi Ichinohe Abstract A safe and effective adjuvant is necessary to enhance mucosal immune responses for the development of an inactivated intranasal influenza vaccine. The present study demonstrated the effectiveness of surf clam microparticles (SMP) derived from natural surf clams as an adjuvant for an intranasal influenza vaccine. The adjuvant effect of SMP was examined when co-administered intranasally with inactivated A/PR8 (H1N1) influenza virus hemagglutinin vaccine in BALB/c mice. Administration of the vaccine with SMP induced a high anti-PR8 haemagglutinin (HA)-specific immunoglobulin A (IgA) response in the nasal wash and immunoglobulin G (IgG) response in the serum, resulting in protection against both nasal-restricted infection and lethal lung infection by A/PR8 virus. In addition, administration of SMP with A/Yamagata (H1N1), A/Beijing (H1N1), or A/Guizhou (H3N2) vaccine conferred complete protection against A/PR8 virus challenge in the nasal infection model, suggesting that SMP adjuvanted vaccine can confer cross-protection against variant influenza viruses. The use of SMP is suggested as a new safe and effective mucosal adjuvant for nasal vaccination against influenza virus infection. J. Med. Virol. 78:954,963, 2006. © 2006 Wiley-Liss, Inc. [source] A comparison of epidemiologic and immunologic features of bronchiolitis caused by influenza virus and respiratory syncytial virusJOURNAL OF MEDICAL VIROLOGY, Issue 2 2005Roberto P. Garofalo Abstract We studied epidemiologic and immunologic factors in infants with bronchiolitis caused by influenza virus. The proportion of these infants who were male and who had an immediate family member with a history of asthma was similar to that of a control group of infants with respiratory syncytial virus (RSV) bronchiolitis. In subjects with influenza virus infection, concentrations of the beta chemokine macrophage inflammatory protein-1alpha (MIP-1,), but not other beta chemokines, in nasopharyngeal secretions (NPS) were greater among infants with more severe, hypoxic bronchiolitis than in subjects with mild, nonhypoxic bronchiolitis, or upper respiratory tract infection alone. Quantities of MIP-1, were also correlated with lower values of oxygen saturation. These findings point out epidemiologic and immunologic similarities between bronchiolitis caused by influenza and RSV, and suggest that host factors are more important than the nature of the infecting virus in the development of severe forms of bronchiolitis caused by influenza and RSV. J. Med. Virol. 75:282,289, 2005. © 2004 Wiley-Liss, Inc. [source] Oral administration of lactobacilli from human intestinal tract protects mice against influenza virus infectionLETTERS IN APPLIED MICROBIOLOGY, Issue 1 2010M. Kawase Abstract Aims:, Our study was conducted to evaluate the potent protective effects of oral administration of probiotic Lactobacillus strains against influenza virus (Flu) infection in a mouse model. Method and Results:, Lyophilized Lactobacillus rhamnosus GG (LGG) and Lactobacillus gasseri TMC0356 (TMC0356) were orally administered to BALB/c mice for 19 days. The test mice were intranasally infected with Flu A/PR/8/34 (H1N1) on day 14, and any changes in clinical symptoms were monitored. After 6 days of infection, the mice were killed and pulmonary virus titres were determined. The clinical symptom scores of mice administered oral LGG and TMC0356 were significantly ameliorated, compared to those of the control mice (P < 0·01). The pulmonary virus titres of the mice fed LGG and TMC0356 were also significantly decreased compared to those of control mice (P < 0·05). Conclusions:, These results indicate that oral administration of lactobacilli, such as LGG and TMC0356, might protect a host animal against Flu infection. Significance and Impact of the Study:, These results demonstrate that oral administration of selected lactobacilli might protect host animals from Flu infection by interactions with gut immunity. [source] Effects of Clinacanthus siamensis leaf extract on influenza virus infectionMICROBIOLOGY AND IMMUNOLOGY, Issue 2 2009Mali Wirotesangthong ABSTRACT Ethanolic extracts of 20 medicinal plants were screened for influenza virus NA inhibition and in vitro antiviral activities using MDCK cells in an MTT assay. The vaccine proteins of influenza virus A/New Caledonia/20/99 (H1N1), mouse-adapted influenza virus A/Guizhou/54/89 (A/G)(H3N2) and mouse-adapted influenza virus B/Ibaraki/2/85 (B/I) were used in the NA inhibition assay, and mouse-adapted influenza viruses A/PR/8/34 (H1N1), A/G and B/I were used in the in vitro antiviral assay. The results of the in vitro antiviral assay indicated that the A/G virus was the most susceptible and an extract of the leaf of CS possessed the highest in vitro anti-A/G virus activity (41.98%). Therefore, the A/G virus and the CS extract were selected for studying in vivo anti-influenza virus activity. BALB/c mice were treated with CS extract (100 mg/kg per day, 5 times) orally from 4 hr before to 4 days after infection. CS extract elicited significant production of anti-influenza virus IgG1 antibody in BAW and increased mouse weight compared to oseltamivir (0.1 mg/kg per day) on day 19 or water on days 17,19 of infection. Moreover, CS extract produced a higher anti-influenza virus IgA antibody level in BAW compared to oseltamivir, and a tendency towards an increase in anti-influenza virus IgA compared to water was shown. The results suggest that CS extract has a protective effect against influenza virus infection. [source] Serum regulated upon activation, normal T cell expressed and presumably secreted concentrations and eosinophils in respiratory syncytial virus infectionPEDIATRICS INTERNATIONAL, Issue 3 2006YUKIHIKO KAWASAKI Abstract Background: The aim of this study was to characterize respiratory syncytial virus (RSV) infection. To do this, the authors evaluated eosinophil counts and chemokines including regulated upon activation, normal T cell expressed and presumably secreted (RANTES) in children with RSV, adenoviral, and influenza virus infections. Methods: The authors enrolled 80 patients who had been diagnosed with acute viral respiratory infection caused by RSV, adenoviral, or influenza viruses. In total, 35 patients (Group A) had RSV infection, 18 (Group B) had adenoviral infection, and 27 (Group C) had influenza virus infection. The authors evaluated clinical manifestations, white blood cell and eosinophil counts, and serum chemokines including RANTES concentrations in the acute and recovery phases in each group. Results: In recovery phase, eosinophil counts were higher in Group A than Groups B and C. In Group A, eosinophil counts were higher in recovery phase than in the acute phase. In Group A, serum RANTES concentration was significantly higher in the recovery phase than in the acute phase (132 ± 76 pg/mL vs 52 ± 25 pg/mL, P < 0.05). Conclusion: The findings suggest that high values of RANTES in children with RSV infection may be associated with the presence of eosinophils and be an important mediator of inflammatory response. [source] Hypothetical pathophysiology of acute encephalopathy and encephalitis related to influenza virus infection and hypothermia therapyPEDIATRICS INTERNATIONAL, Issue 2 2000Shumpei Yokota AbstractBackground: To establish a treatment strategy for acute encephalopathy and encephalitis associated with influenza virus infection, the pathophysiology of the disease was investigated through manifestations and laboratory findings of patients. Patients and Methods: A child with central nervous system (CNS) complications during the course of influenza virus infection was analyzed in view of immunologic abnormalities. In addition, four children with acute encephalopathy and encephalitis were enrolled in the hypothermia treatment for the purpose of stabilizing the cytokine storm in the CNS. Results: The CNS symptoms preceded the systemic progression to the failure of multiple organs (MOF) and disseminated intravascular coagulopathy (DIC). The mild hypothermia suppressed the brain edema on computed tomography (CT) scanning and protected the brain from the subsequent irreversible neural cell damage. Conclusion: The replicated viruses at the nasopharyngeal epithelium may disrupt the olfactory mucosa and gain access to the brain via the olfactory nerve system. The direct virus,glial cell interaction or viral stimulation of the glial cells induces the production and accumulation of the pro-inflammatory cytokines, especially tumor necrosis factor (TNF)-,, in the CNS. The cytokine storm results in neural cell damage as well as the apoptosis of astrocytes, due to the TNF-,,induced mitochondrial respiratory failure. The disruption of the blood,brain barrier progresses to the systemic cytokine storm, resulting in DIC and MOF. Mild hypothermia appears promising in stabilizing the immune activation and the brain edema to protect the brain from ongoing functional, apoptotic neural and glial damage and the systemic expansion of the cytokine storm. [source] Analysis of gene expression in human bronchial epithelial cells upon influenza virus infection and regulation by p38 mitogen-activated protein kinase and c-Jun-N-terminal kinaseRESPIROLOGY, Issue 2 2008Shinichi HAYASHI Background and objective: Airway epithelial cells, which are the initial site of influenza virus (IV) infection, participate in the inflammatory process through the expression of various genes. In this process, mitogen-activated protein kinase (MAPK) may be associated with the expression of many genes, but its precise role remains unknown. Methods: A comprehensive analysis was performed of gene expression in human bronchial epithelial cells upon IV infection, using an Affymetrix gene chip containing 12 000 genes. Regulation of gene expression by MAPK was also analysed. Results: A total of 5998 genes were detected. Upon IV infection, 165 genes were upregulated and 49 of these were interferon-stimulated genes. The functions of 129 genes, including 14 apoptosis-related genes and 6 antiviral genes, were well characterized; however, those of 36 genes were unknown. The expression of 29 genes was inhibited either by SB 203580, a specific inhibitor of p38 MAPK, or by CEP-11004, a specific inhibitor of the c-Jun-N-terminal kinase (JNK) cascade, and the percentage inhibition by SB 203580 correlated with that by CEP-11004, suggesting that p38 and JNK participate in a common downstream pathway involved in the regulation of gene expression. p38 MAPK- or JNK-dependent genes were functionally classified into diverse categories. Conclusions: Although further studies are needed to obtain a more complete understanding of gene expression and the role of MAPK in gene expression, the present results are important in understanding the molecular mechanisms involved in the response of bronchial epithelial cells to IV infection. [source] Comparison of cytokine responses in nasopharyngeal aspirates from children with viral lower respiratory tract infectionsACTA PAEDIATRICA, Issue 4 2009Jung Hye Byeon Abstract Aim: To determine whether nasopharyngeal aspirates (NPAs) cytokine response is different according to the causative viruses in children with lower respiratory tract infections (LRTI). Methods: NPAs from 277 children with LRTI caused by respiratory virus were evaluated. Based on the proven viral agents, LRTI patients were divided into four groups. Levels of IL-4, IL-5 and IFN-, were determined by ELISA. Results: Patients with influenza virus infection demonstrated significantly lower IL-4 and IL-5 levels than those with other three groups. Patients with respiratory syncytial virus (RSV) infection showed an increase in production of IL-4 and IL-5, and a decrease in the IFN-, level when compared to patients with influenza virus infection. Interestingly, a similar Th2 response was seen in patients with parainfluenza virus or adenovirus infection. Conclusion: These results demonstrate that respiratory viruses can induce different local cytokine responses. However, Th2 biased responses are not unique for RSV but seem to be predominant in respiratory viruses of young children. [source] Selective expansion of CD16highCCR2, subpopulation of circulating monocytes with preferential production of haem oxygenase (HO)-1 in response to acute inflammationCLINICAL & EXPERIMENTAL IMMUNOLOGY, Issue 3 2005K. Mizuno Summary Monocytes are composed of two distinct subpopulations in the peripheral blood as determined by their surface antigen expressions, profiles of cytokine production and functional roles played in vivo. We attempted to delineate the unique functional roles played by a minor CD16highCCR2, subpopulation of circulating monocytes. They produced significant levels of interleukin (IL)-6 and tumour necrosis factor (TNF)-,, but very low levels of IL-10 upon in vitro stimulation. Characteristic profiles of cytokine production were confirmed by stimulating purified subpopulations of monocytes after cell sorting. It was noteworthy that freshly isolated CD16highCCR2, monocyte subpopulations produced significant levels of haem oxygenase (HO)-1, whereas the major CD16lowCCR2+ subpopulation produced little. These results were contrary to the generally accepted notion that the CD16highCCR2, monocyte subpopulation plays a predominantly proinflammatory role in vivo. The CD16highCCR2, subpopulation increased in Kawasaki disease and influenza virus infection. In accord with this, HO-1 mRNA expression by mononuclear cells was significantly increased in these illnesses. These results indicate that CD16highCCR2, subpopulations are of a distinct lineage from CD16lowCCR2+ monocytes. More importantly, they may represent a monocyte subpopulation with a unique functional role to regulate inflammation by producing HO-1 in steady state in vivo. [source] | |||||||||||||||||||||||||