Sample records for giant viruses infecting

  1. Influenza A(H1N1)pdm09 virus infection in giant pandas, China.

    PubMed

    Li, Desheng; Zhu, Ling; Cui, Hengmin; Ling, Shanshan; Fan, Shengtao; Yu, Zhijun; Zhou, Yuancheng; Wang, Tiecheng; Qian, Jun; Xia, Xianzhu; Xu, Zhiwen; Gao, Yuwei; Wang, Chengdong

    2014-03-01

    We confirmed infection with influenza A(H1N1)pdm09 in giant pandas in China during 2009 by using virus isolation and serologic analysis methods. This finding extends the host range of influenza viruses and indicates a need for increased surveillance for and control of influenza viruses among giant pandas. PMID:24565026

  2. "Marseilleviridae", a new family of giant viruses infecting amoebae.

    PubMed

    Colson, Philippe; Pagnier, Isabelle; Yoosuf, Niyaz; Fournous, Ghislain; La Scola, Bernard; Raoult, Didier

    2013-04-01

    The family "Marseilleviridae" is a new proposed taxon for giant viruses that infect amoebae. Its first member, Acanthamoeba polyphaga marseillevirus (APMaV), was isolated in 2007 by culturing on amoebae a water sample collected from a cooling tower in Paris, France. APMaV has an icosahedral shape with a diameter of ?250 nm. Its genome is a double-stranded circular DNA that is 368,454 base pairs (bp) in length. The genome has a GC content of 44.7 % and is predicted to encode 457 proteins. Phylogenetic reconstructions showed that APMaV belongs to a new viral family among nucleocytoplasmic large DNA viruses, a group of viruses that also includes Acanthamoeba polyphaga mimivirus (APMV) and the other members of the family Mimiviridae as well as the members of the families Poxviridae, Phycodnaviridae, Iridoviridae, Ascoviridae, and Asfarviridae. In 2011, Acanthamoeba castellanii lausannevirus (ACLaV), another close relative of APMaV, was isolated from river water in France. The ACLaV genome is 346,754 bp in size and encodes 450 genes, among which 320 have an APMaV protein as the closest homolog. Two other giant viruses closely related to APMaV and ACLaV have been recovered in our laboratory from a freshwater sample and a human stool sample using an amoebal co-culture method. The only currently identified hosts for "marseilleviruses" are Acanthamoeba spp. The prevalence of these viruses in the environment and in animals and humans remains to be determined. PMID:23188494

  3. Epidermal multinucleated giant cells are not always a histopathologic clue to a herpes virus infection: multinucleated epithelial giant cells in the epidermis of lesional skin biopsies from patients with acantholytic dermatoses can histologically mimic a herpes virus infection

    PubMed Central

    Cohen, Philip R.; Paravar, Taraneh; Lee, Robert A.

    2014-01-01

    Background: Multinucleated giant cells in the epidermis can either be epithelial or histiocytic. Epithelial multinucleated giant cells are most often associated with herpes virus infections. Purpose: To review the histologic differential diagnosis of conditions with epithelial and histiocytic multinucleated giant cells—since multinucleated giant cells in the epidermis are not always pathognomonic of a cutaneous herpes virus infection—and to summarize dermatoses in which herpes virus infection has been observed to coexist. Methods: Two individuals with acantholytic dermatoses whose initial lesional skin biopsies showed multinucleated epithelial giant cells suggestive of a herpes virus infection are reported. Using the PubMed database, an extensive literature search was performed on multinucleated giant cell (and epidermis, epithelial, and histiocytic) and herpes virus infection. Relevant papers were reviewed to discover the skin conditions with either multinucleated giant cells in the epidermis or coincident cutaneous herpes virus infection. Results: Initial skin biopsies from patients with either pemphigus vulgaris or transient acantholytic dermatosis mimicked herpes virus infection; however, laboratory studies and repeat biopsies established the correct diagnosis of their acantholytic dermatosis. Hence, epidermal multinucleated giant cells are not always a histopathologic clue to a herpes virus infection. Indeed, epithelial multinucleated giant cells in the epidermis can be observed not only in the presence of infection (herpes virus), but also acantholytic dermatoses and tumors (trichoepithelioma and pleomorphic basal cell carcinoma). Histiocytic multinucleated giant cells in the epidermis can be observed in patients with either giant cell lichenoid dermatitis or lichen nitidus of the palms. Conclusions: Epithelial and histiocytic multinucleated giant cell can occur in the epidermis. Keratinocyte-derived multinucleated giant cells are most commonly associated with herpes virus infection; yet, they can also be observed in patients with skin tumors or acantholytic dermatoses. Cutaneous herpes simplex virus infection can coexist in association with other conditions such as acantholytic dermatoses, benign skin tumors, bullous disorders, hematologic malignancies, inflammatory dermatoses, and physical therapies. However, when a herpes virus infection is suspected based upon the discovery of epithelial multinucleated giant cells in the epidermis, but either the clinic presentation or lack of response to viral therapy or absence of confirmatory laboratory studies does not support the diagnosis of a viral infection, the possibility of a primary acantholytic dermatosis should be considered and additional lesional skin biopsies performed. Also, because hematoxylin and eosin staining is not the golden standard for confirmation of autoimmune bullous dermatoses, skin biopsies for direct immunofluorescence should be performed when a primary bullous dermatosis is suspected since the histopathology observed on hematoxylin and eosin stained sections can be misleading. PMID:25396080

  4. Plant genomes enclose footprints of past infections by giant virus relatives.

    PubMed

    Maumus, Florian; Epert, Aline; Nogué, Fabien; Blanc, Guillaume

    2014-01-01

    Nucleocytoplasmic large DNA viruses (NCLDVs) are eukaryotic viruses with large genomes (100 kb-2.5 Mb), which include giant Mimivirus, Megavirus and Pandoravirus. NCLDVs are known to infect animals, protists and phytoplankton but were never described as pathogens of land plants. Here, we show that the bryophyte Physcomitrella patens and the lycophyte Selaginella moellendorffii have open reading frames (ORFs) with high phylogenetic affinities to NCLDV homologues. The P. patens genes are clustered in DNA stretches (up to 13 kb) containing up to 16 NCLDV-like ORFs. Molecular evolution analysis suggests that the NCLDV-like regions were acquired by horizontal gene transfer from distinct but closely related viruses that possibly define a new family of NCLDVs. Transcriptomics and DNA methylation data indicate that the NCLDV-like regions are transcriptionally inactive and are highly cytosine methylated through a mechanism not relying on small RNAs. Altogether, our data show that members of NCLDV have infected land plants. PMID:24969138

  5. Characterisation of three novel giant viruses reveals huge diversity among viruses infecting Prymnesiales (Haptophyta).

    PubMed

    Johannessen, Torill Vik; Bratbak, Gunnar; Larsen, Aud; Ogata, Hiroyuki; Egge, Elianne S; Edvardsen, Bente; Eikrem, Wenche; Sandaa, Ruth-Anne

    2015-02-01

    We have isolated three novel lytic dsDNA-viruses from Raunefjorden (Norway) that are putative members of the Mimiviridae family, namely Haptolina ericina virus RF02 (HeV RF02), Prymnesium kappa virus RF01 (PkV RF01), and Prymnesium kappa virus RF02 (PkV RF02). Each of the novel haptophyte viruses challenges the common conceptions of algal viruses with respect to host range, phylogenetic affiliation and size. PkV RF01 has a capsid of ~310 nm and is the largest algal virus particle ever reported while PkV RF01 and HeV RF02 were able to infect different species, even belonging to different genera. Moreover, PkV RF01 and HeV RF02 infected the same hosts, but phylogenetic analysis placed them in different groups. Our results reveal large variation among viruses infecting closely related microalgae, and challenge the common conception that algal viruses have narrow host range, and phylogeny reflecting their host affiliation. PMID:25546253

  6. Giant virus in the sea

    PubMed Central

    Claverie, Jean-Michel

    2013-01-01

    The viral nature of the first “giant virus,” Mimivirus, was realized in 2003, 10 y after its initial isolation from the water of a cooling tower in Bradford, UK. Soon after its genome was sequenced, the mining of the Global Ocean Sampling environmental sequence database revealed that the closest relatives of Mimivirus, only known to infect Acanthamoeba, were to be found in the sea. These predicted marine Mimivirus relatives remained elusive until 2010, with the first genomic characterization of a virus infecting a heterotrophic unicellular eukaryote, the microflagellate grazer Cafeteria roenbergensis. The genome analysis of a virus (PgV) infecting the common unicellular algae Phaeocystis globosa now shows that it is a bona fide member of the Mimivirus family (i.e., the Megaviridae), extending the realm of these giant viruses to abundant blooming phytoplankton species. Despite its smaller genome size (460 kb encoding 434 proteins), PgV exhibits the most intriguing feature of the previously characterized Megaviridae: an associated virophage. However, the 19-kb virophage genome, devoid of a capsid gene, is packaged in the PgV particle and propagated as a “viral plasmid,” the first ever described. The PgV genome also exhibits the duplication of “core genes,” normally present as single copies and a putative new type of mobile element. In a DNA polymerase phylogeny including representatives of the three cellular domains, PgV and the other Megaviridae cluster into their own clade deeply branching between domains Archaea and Eukarya domains, thus exhibiting the topology of a fourth domain in the Tree of Life. PMID:24563700

  7. Hypoxia induces permeability and giant cell responses of Andes virus-infected pulmonary endothelial cells by activating the mTOR-S6K signaling pathway.

    PubMed

    Gavrilovskaya, Irina N; Gorbunova, Elena E; Mackow, Erich R

    2013-12-01

    Andes virus (ANDV) is a South American hantavirus that causes a highly lethal hantavirus pulmonary syndrome (HPS) characterized by hypoxia, thrombocytopenia, and vascular leakage leading to acute pulmonary edema. ANDV infects human pulmonary microvascular and lymphatic endothelial cells (MECs and LECs, respectively) and nonlytically enhances the permeability of interendothelial cell adherence junctions in response to vascular endothelial growth factor (VEGF). Recent findings also indicate that ANDV causes the formation of giant endothelial cells. Here, we demonstrate that hypoxic conditions alone enhance permeability and giant cell responses of ANDV-infected MECs and LECs through activation of the mTOR signaling pathway. In contrast to infection of cells with nonpathogenic Tula virus (TULV), we observed that exposure of ANDV-infected MECs and LECs to hypoxic conditions resulted in a 3- to 6-fold increase in monolayer permeability and the formation of giant cells 3× to 5× normal size. ANDV infection in combination with hypoxic conditions resulted in the enhancement of hypoxia-inducible factor 1? (HIF1?)-directed VEGF A, angiopoietin 4, and EGLN3 transcriptional responses. Constitutive mTOR signaling induces the formation of giant cells via phosphorylation of S6K, and mTOR regulates hypoxia and VEGF A-induced cellular responses. We found that S6K was hyperphosphorylated in ANDV-infected, hypoxia-treated MECs and LECs and that rapamycin treatment for 1 h inhibited mTOR signaling responses and blocked permeability and giant cell formation in ANDV-infected monolayers. These findings indicate that ANDV infection and hypoxic conditions enhance mTOR signaling responses, resulting in enhanced endothelial cell permeability and suggest a role for rapamycin in therapeutically stabilizing the endothelium of microvascular and lymphatic vessels during ANDV infection. PMID:24067973

  8. Provirophages and transpovirons as the diverse mobilome of giant viruses

    PubMed Central

    Desnues, Christelle; La Scola, Bernard; Yutin, Natalya; Fournous, Ghislain; Robert, Catherine; Azza, Saïd; Jardot, Priscilla; Monteil, Sonia; Campocasso, Angélique; Koonin, Eugene V.; Raoult, Didier

    2012-01-01

    A distinct class of infectious agents, the virophages that infect giant viruses of the Mimiviridae family, has been recently described. Here we report the simultaneous discovery of a giant virus of Acanthamoeba polyphaga (Lentille virus) that contains an integrated genome of a virophage (Sputnik 2), and a member of a previously unknown class of mobile genetic elements, the transpovirons. The transpovirons are linear DNA elements of ?7 kb that encompass six to eight protein-coding genes, two of which are homologous to virophage genes. Fluorescence in situ hybridization showed that the free form of the transpoviron replicates within the giant virus factory and accumulates in high copy numbers inside giant virus particles, Sputnik 2 particles, and amoeba cytoplasm. Analysis of deep-sequencing data showed that the virophage and the transpoviron can integrate in nearly any place in the chromosome of the giant virus host and that, although less frequently, the transpoviron can also be linked to the virophage chromosome. In addition, integrated fragments of transpoviron DNA were detected in several giant virus and Sputnik genomes. Analysis of 19 Mimivirus strains revealed three distinct transpovirons associated with three subgroups of Mimiviruses. The virophage, the transpoviron, and the previously identified self-splicing introns and inteins constitute the complex, interconnected mobilome of the giant viruses and are likely to substantially contribute to interviral gene transfer. PMID:23071316

  9. Origin of giant viruses from smaller DNA viruses not from a fourth domain of cellular life.

    PubMed

    Yutin, Natalya; Wolf, Yuri I; Koonin, Eugene V

    2014-10-01

    The numerous and diverse eukaryotic viruses with large double-stranded DNA genomes that at least partially reproduce in the cytoplasm of infected cells apparently evolved from a single virus ancestor. This major group of viruses is known as Nucleocytoplasmic Large DNA Viruses (NCLDV) or the proposed order Megavirales. Among the "Megavirales", there are three groups of giant viruses with genomes exceeding 500kb, namely Mimiviruses, Pithoviruses, and Pandoraviruses that hold the current record of viral genome size, about 2.5Mb. Phylogenetic analysis of conserved, ancestral NLCDV genes clearly shows that these three groups of giant viruses have three distinct origins within the "Megavirales". The Mimiviruses constitute a distinct family that is distantly related to Phycodnaviridae, Pandoraviruses originate from a common ancestor with Coccolithoviruses within the Phycodnaviridae family, and Pithoviruses are related to Iridoviridae and Marseilleviridae. Maximum likelihood reconstruction of gene gain and loss events during the evolution of the "Megavirales" indicates that each group of giant viruses evolved from viruses with substantially smaller and simpler gene repertoires. Initial phylogenetic analysis of universal genes, such as translation system components, encoded by some giant viruses, in particular Mimiviruses, has led to the hypothesis that giant viruses descend from a fourth, probably extinct domain of cellular life. The results of our comprehensive phylogenomic analysis of giant viruses refute the fourth domain hypothesis and instead indicate that the universal genes have been independently acquired by different giant viruses from their eukaryotic hosts. PMID:25042053

  10. Hepatitis B virus infection.

    PubMed

    Trépo, Christian; Chan, Henry L Y; Lok, Anna

    2014-12-01

    Hepatitis B virus infection is a major public health problem worldwide; roughly 30% of the world's population show serological evidence of current or past infection. Hepatitis B virus is a partly double-stranded DNA virus with several serological markers: HBsAg and anti-HBs, HBeAg and anti-HBe, and anti-HBc IgM and IgG. It is transmitted through contact with infected blood and semen. A safe and effective vaccine has been available since 1981, and, although variable, the implementation of universal vaccination in infants has resulted in a sharp decline in prevalence. Hepatitis B virus is not cytopathic; both liver damage and viral control--and therefore clinical outcome--depend on the complex interplay between virus replication and host immune response. Overall, as much as 40% of men and 15% of women with perinatally acquired hepatitis B virus infection will die of liver cirrhosis or hepatocellular carcinoma. In addition to decreasing hepatic inflammation, long-term antiviral treatment can reverse cirrhosis and reduce hepatocellular carcinoma. Development of new therapies that can improve HBsAg clearance and virological cure is warranted. PMID:24954675

  11. Hepatitis E Virus Infection

    PubMed Central

    Dalton, Harry R.; Abravanel, Florence; Izopet, Jacques

    2014-01-01

    SUMMARY Hepatitis E virus (HEV) infection is a worldwide disease. An improved understanding of the natural history of HEV infection has been achieved within the last decade. Several reservoirs and transmission modes have been identified. Hepatitis E is an underdiagnosed disease, in part due to the use of serological assays with low sensitivity. However, diagnostic tools, including nucleic acid-based tests, have been improved. The epidemiology and clinical features of hepatitis E differ between developing and developed countries. HEV infection is usually an acute self-limiting disease, but in developed countries it causes chronic infection with rapidly progressive cirrhosis in organ transplant recipients, patients with hematological malignancy requiring chemotherapy, and individuals with HIV. HEV also causes extrahepatic manifestations, including a number of neurological syndromes and renal injury. Acute infection usually requires no treatment, but chronic infection should be treated by reducing immunosuppression in transplant patients and/or the use of antiviral therapy. In this comprehensive review, we summarize the current knowledge about the virus itself, as well as the epidemiology, diagnostics, natural history, and management of HEV infection in developing and developed countries. PMID:24396139

  12. Proteomic analysis of differentially expressed protein in hemocytes of wild giant freshwater prawn Macrobrachium rosenbergii infected with infectious hypodermal and hematopoietic necrosis virus (IHHNV)

    PubMed Central

    Alinejad, T.; Bin, Kwong Q.; Vejayan, J.; Othman, R.Y.; Bhassu, S.

    2015-01-01

    Epizootic diseases cause huge mortality and economical loses at post larvae stages in freshwater prawn aquaculture industry. These prawns seem less susceptible to viral diseases except for infectious hypodermal and hematopoietic necrosis virus (IHHNV). During viral infection in prawns, hemocytes are the primary organ that shows immunological response within the early stages of infection. We applied proteomic approaches to understand differential expression of the proteins in hemocytes during the viral disease outbreak. To aid the goal, we collected Macrobrachium rosenbergii broodstocks from the local grow out hatchery which reported the first incidence of IHHNV viral outbreak during larvae stage. Primarily, application of the OIE primer targeting 389 bp fragments of IHHNV virus was used in identification of the infected and non-infected samples of the prawn breeding line. Analysis of two-dimensional gel electrophoresis showed specific down-regulation of Arginine kinase and Sarcoplasmic calcium-binding protein and up/down-regulation of Prophenoloxidase1 and hemocyanin isoforms. These proteins were validated using semi quantitative RT-PCR and gene transcripts at mRNA level. These identified proteins can be used as biomarkers, providing a powerful approach to better understanding of the immunity pathway of viral disease with applications in analytic and observational epidemiology diagnosis. Proteomic profiling allows deep insight into the pathogenesis of IHHNV molecular regulation and mechanism of hemocyte in freshwater prawns. PMID:26106581

  13. Proteomic analysis of differentially expressed protein in hemocytes of wild giant freshwater prawn Macrobrachium rosenbergii infected with infectious hypodermal and hematopoietic necrosis virus (IHHNV).

    PubMed

    Alinejad, T; Bin, Kwong Q; Vejayan, J; Othman, R Y; Bhassu, S

    2015-09-01

    Epizootic diseases cause huge mortality and economical loses at post larvae stages in freshwater prawn aquaculture industry. These prawns seem less susceptible to viral diseases except for infectious hypodermal and hematopoietic necrosis virus (IHHNV). During viral infection in prawns, hemocytes are the primary organ that shows immunological response within the early stages of infection. We applied proteomic approaches to understand differential expression of the proteins in hemocytes during the viral disease outbreak. To aid the goal, we collected Macrobrachium rosenbergii broodstocks from the local grow out hatchery which reported the first incidence of IHHNV viral outbreak during larvae stage. Primarily, application of the OIE primer targeting 389 bp fragments of IHHNV virus was used in identification of the infected and non-infected samples of the prawn breeding line. Analysis of two-dimensional gel electrophoresis showed specific down-regulation of Arginine kinase and Sarcoplasmic calcium-binding protein and up/down-regulation of Prophenoloxidase1 and hemocyanin isoforms. These proteins were validated using semi quantitative RT-PCR and gene transcripts at mRNA level. These identified proteins can be used as biomarkers, providing a powerful approach to better understanding of the immunity pathway of viral disease with applications in analytic and observational epidemiology diagnosis. Proteomic profiling allows deep insight into the pathogenesis of IHHNV molecular regulation and mechanism of hemocyte in freshwater prawns. PMID:26106581

  14. Serosurvey of selected viruses in captive giant pandas (Ailuropoda melanoleuca) in China.

    PubMed

    Qin, Qin; Li, Desheng; Zhang, Hemin; Hou, Rong; Zhang, Zhihe; Zhang, Chenglin; Zhang, Jinguo; Wei, Fuwen

    2010-05-19

    Serum samples from 92 giant pandas in three captive facilities were tested for antibodies against five viruses of carnivores. Antibody titers against canine distemper virus (CDV) in two facilities in which giant pandas were vaccinated were variable. The canine adenovirus (CAV-1) and canine parvovirus (CPV) titers in vaccinated group were both positive, but titers were not high and varied among individual except one vaccinated panda had extremely high CAV-1 titer, indicating infection with the field virus following vaccination. Our results suggest that the vaccines used for these giant pandas do not elicit consistent antibody titers. Antibody titers against CDV, CPV and CAV-1 in unvaccinated giant pandas were highly variable, especially CPV titer. Almost half of sera were CPV antibody positive, and CPV titers were high enough to suggest infection with the virus. Canine coronavirus (CCV) and canine parainfluenza virus (CPIV) titers were not detected in all serum samples. The results of this study emphasize the need for research on infectious diseases of giant pandas and development of suitable vaccines for the species. PMID:19913371

  15. GB virus-C infection in patients infected with the human immunodeficiency virus

    Microsoft Academic Search

    Hans L Tillmann; Michael P Manns

    2001-01-01

    Hepatitis virus infections are frequent in patients suffering from HIV infection due to similar transmission routes of these viruses. In addition, hepatitis virus infections lead to impaired survival in HIV positive patients. The recently discovered flavivirus GB virus C (alias Hepatitis G Virus) was initially believed to be another hepatitis virus. While there is still some minor discussion whether GB

  16. Human Papilloma Virus Infections

    PubMed Central

    Wright, V. Cecil

    1989-01-01

    Genital warts are believed to be caused by human papilloma viruses and to be sexually transmitted. The viruses are classified by DNA types, which appear to cause different types of disease. The choice of treatment, and usually its success rate, vary according to the type of disease and its location. PMID:21248973

  17. Membrane Assembly during the Infection Cycle of the Giant Mimivirus

    PubMed Central

    Mutsafi, Yael; Shimoni, Eyal; Shimon, Amir; Minsky, Abraham

    2013-01-01

    Although extensively studied, the structure, cellular origin and assembly mechanism of internal membranes during viral infection remain unclear. By combining diverse imaging techniques, including the novel Scanning-Transmission Electron Microscopy tomography, we elucidate the structural stages of membrane biogenesis during the assembly of the giant DNA virus Mimivirus. We show that this elaborate multistage process occurs at a well-defined zone localized at the periphery of large viral factories that are generated in the host cytoplasm. Membrane biogenesis is initiated by fusion of multiple vesicles, ?70 nm in diameter, that apparently derive from the host ER network and enable continuous supply of lipid components to the membrane-assembly zone. The resulting multivesicular bodies subsequently rupture to form large open single-layered membrane sheets from which viral membranes are generated. Membrane generation is accompanied by the assembly of icosahedral viral capsids in a process involving the hypothetical major capsid protein L425 that acts as a scaffolding protein. The assembly model proposed here reveals how multiple Mimivirus progeny can be continuously and efficiently generated and underscores the similarity between the infection cycles of Mimivirus and Vaccinia virus. Moreover, the membrane biogenesis process indicated by our findings provides new insights into the pathways that might mediate assembly of internal viral membranes in general. PMID:23737745

  18. Chikungunya Virus Infection

    Microsoft Academic Search

    Fabrice Simon; Emilie Javelle; Manuela Oliver; Isabelle Leparc-Goffart; Catherine Marimoutou

    2011-01-01

    Chikungunya virus (CHIKV) is an alphavirus transmitted by mosquitoes, mostly Aedes aegypti and Aedes albopictus. After half a century of focal outbreaks of acute febrile polyarthralgia in Africa and Asia, the disease unexpectedly spread\\u000a in the past decade with large outbreaks in Africa and around the Indian Ocean and rare autochthonous transmission in temperate\\u000a areas. This emergence brought new insights

  19. 62 FR 36546 - Applied Research in Emerging Infections Hepatitis C Virus Infection

    Federal Register 2010, 2011, 2012, 2013, 2014

    1997-07-08

    ...Applied Research in Emerging Infections Hepatitis C Virus Infection Introduction The Centers...infections--epidemiologic studies of hepatitis C virus (HCV) infection. CDC is committed...announcement specifically addresses the area of hepatitis C virus infection (HCV). In the...

  20. Immunotherapy for chronic hepatitis B virus infections

    Microsoft Academic Search

    Xian-Jie Yu; Gui-Qiang Wang

    2007-01-01

    The immune system functions to control and clear virus infections. Viral persistence has been closely associated with dysfunctional specific immunity, especially cellular immunity. Current antiviral therapies have been disappointing. Immunotherapies with strategies to boost or restore the virus-specific immune response of patients with chronic hepatitis B virus infection have been proposed for curing persistent i n f e c t

  1. Chikungunya Virus Infections.

    PubMed

    Simon, Fabrice; Javelle, Emilie; Gasque, Philippe

    2015-07-01

    To the Editor: Weaver and Lecuit's review (March 26 issue)(1) on chikungunya fever mentions that the disease may alter the quality of life for up to 6 years.(2) On the basis of our clinical experience, two types of persistent post-chikungunya fever rheumatic disorders can be distinguished.(2) Approximately 95% of patients who still have pain beyond 3 months after acute infection have varied musculoskeletal features but not polyarthritis and have substantial improvement with prolonged administration of nonsteroidal antiinflammatory drugs (strictly limiting the use of glucocorticoids), analgesics, and local treatment, including physiotherapy.(3) In contrast, the conditions of the other 5% of patients . . . PMID:26132957

  2. Chikungunya Virus Infections.

    PubMed

    2015-07-01

    To the Editor: Weaver and Lecuit's review (March 26 issue)(1) on chikungunya fever mentions that the disease may alter the quality of life for up to 6 years.(2) On the basis of our clinical experience, two types of persistent post-chikungunya fever rheumatic disorders can be distinguished.(2) Approximately 95% of patients who still have pain beyond 3 months after acute infection have varied musculoskeletal features but not polyarthritis and have substantial improvement with prolonged administration of nonsteroidal antiinflammatory drugs (strictly limiting the use of glucocorticoids), analgesics, and local treatment, including physiotherapy.(3) In contrast, the conditions of the other 5% of patients . . . PMID:26132956

  3. Chikungunya Virus Infections.

    PubMed

    Cabié, André; Ledrans, Martine; Abel, Sylvie

    2015-07-01

    To the Editor: Weaver and Lecuit's review (March 26 issue)(1) on chikungunya fever mentions that the disease may alter the quality of life for up to 6 years.(2) On the basis of our clinical experience, two types of persistent post-chikungunya fever rheumatic disorders can be distinguished.(2) Approximately 95% of patients who still have pain beyond 3 months after acute infection have varied musculoskeletal features but not polyarthritis and have substantial improvement with prolonged administration of nonsteroidal antiinflammatory drugs (strictly limiting the use of glucocorticoids), analgesics, and local treatment, including physiotherapy.(3) In contrast, the conditions of the other 5% of patients . . . PMID:26132958

  4. Vaginal infections in human immunodeficiency virus–infected women

    Microsoft Academic Search

    Andrew Helfgott; Nancy Eriksen; C. Michael Bundrick; Ronald Lorimor; Barbara Van Eckhout

    2000-01-01

    Objective: This study was undertaken to compare the frequencies of vaginal infections among human immunodeficiency virus–infected women with those among human immunodeficiency virus–seronegative women. Study Design: Human immunodeficiency virus–seropositive women attending a comprehensive care center for human immunodeficiency virus disease at the outpatient department of an inner-city hospital in Houston underwent rigorous gynecologic evaluation for sexually transmitted diseases, including evidence

  5. Infectivity of rabies virus-exposed macrophages.

    PubMed

    Nazé, Florence; Suin, Vanessa; Lamoral, Sophie; Francart, Aurélie; Brochier, Bernard; Roels, Stefan; Mast, Jan; Kalai, Michael; Van Gucht, Steven

    2013-02-01

    Rabies virus distributes widely in infected mice, including lymphoid tissues and spleen macrophages. The infection characteristics in murine macrophages and the infectivity of virus-exposed macrophages were examined upon inoculation in mice. In vitro, Mf4/4 spleen macrophages supported mild virus production (10(4)-fold less than neuroblastoma), with formation of typical virions. Bone marrow-derived macrophages (BMM) were most efficient to capture virus, but new virus production was not detected. Virus-induced cell death was significantly stronger in BMM, which might have eliminated BMM with productive infection. Still, viral RNA remained detectable in the remaining BMM for at least 4 weeks. Injection of in vitro-infected Mf4/4 in the nose or brain proved efficient to propagate infection in mice, even when cells were pre-incubated with neutralizing antibodies. Surprisingly, injection of ex-vivo-infected BMM in the brain also led to lethal infection in 8 out of 12 mice. Injection of infected Mf4/4 in the muscle mostly favoured a protective antibody response. Despite that macrophages are less fit to support virus production, they can still act as a source of infectious virus upon transfer in mice. This may be relevant for screening donor organs/cells, for which RT-PCR should be preferred over the traditional antigen or virus isolation assays. PMID:23159243

  6. CELLULAR PATHOLOGY OF A GRANULOSIS VIRUS INFECTION

    EPA Science Inventory

    Nuclear and cytoplasmic ultrastructural changes were examined in Spodoptera frugiperda (SF) larval fat body cells infected with granulosis virus (GV). Soon after infection necleocapsidlike structures were observed within the nucleus associated with nuclear pores. The earliest cel...

  7. Immunology of hepatitis B virus and hepatitis C virus infection

    Microsoft Academic Search

    Michelina Nascimbeni; Barbara Rehermann

    2005-01-01

    More than 500 million people worldwide are persistently infected with the hepatitis B virus (HBV) and\\/or hepatitis C virus (HCV) and are at risk of developing chronic liver disease, cirrhosis and hepatocellular carcinoma. Despite many common features in the pathogenesis of HBV- and HCV-related liver disease, these viruses markedly differ in their virological properties and in their immune escape and

  8. Immunopathogenesis of hepatitis C virus infection

    Microsoft Academic Search

    Anthony J Freeman; George Marinos; Rosemary A Ffrench; Andrew R Lloyd

    2001-01-01

    Hepatitis C virus, a recently identified member of the family Flaviviridae, is an important cause of chronic viral hepatitis and cirrhosis. There are similarities in the nature of the immune response to this pathogen with immunity in other flavivirus and hepatotropic virus infections, such as hepatitis B. However, the high rate of viral persistence after primary hepatitis C infection, and

  9. Influenza A Virus Infections in Land

    E-print Network

    Clayton, Dale H.

    Influenza A Virus Infections in Land Birds, People's Republic of China A. Townsend Peterson, Sarah­PCR testing of 939 Asian land birds of 153 species. Influenza A infection was found, particularly among influenza virus ecology has long regarded water- birds as a primary reservoir. Although the benchmark study

  10. Divergent Roles of Autophagy in Virus Infection

    PubMed Central

    Chiramel, Abhilash I.; Brady, Nathan R.; Bartenschlager, Ralf

    2013-01-01

    Viruses have played an important role in human evolution and have evolved diverse strategies to co-exist with their hosts. As obligate intracellular pathogens, viruses exploit and manipulate different host cell processes, including cellular trafficking, metabolism and immunity-related functions, for their own survival. In this article, we review evidence for how autophagy, a highly conserved cellular degradative pathway, serves either as an antiviral defense mechanism or, alternatively, as a pro-viral process during virus infection. Furthermore, we highlight recent reports concerning the role of selective autophagy in virus infection and how viruses manipulate autophagy to evade lysosomal capture and degradation. PMID:24709646

  11. Systems analysis of West Nile virus infection.

    PubMed

    Suthar, Mehul S; Pulendran, Bali

    2014-06-01

    Emerging and re-emerging mosquito-borne viruses continue to pose a significant threat to human health throughout the world. Over the past decade, West Nile virus (WNV), Dengue virus (DENV), and Chikungunya virus (CHIKV), have caused annual epidemics of virus-induced encephalitis, hemorrhagic fever\\shock syndromes, and arthritis, respectively. Currently, no specific antiviral therapies or vaccines exist for use in humans to combat or prevent these viral infections. Thus, there is a pressing need to define the virus-host interactions that govern immunity and infection outcome. Recent technological breakthroughs in 'omics' resources and high-throughput based assays are beginning to accelerate antiviral drug discovery and improve on current strategies for vaccine design. In this review, we highlight studies with WNV and discuss how traditional and systems biological approaches are being used to rapidly identify novel host targets for therapeutic intervention and develop a deeper conceptual understanding of the host response to virus infection. PMID:24851811

  12. Systems analysis of West Nile virus infection

    PubMed Central

    Suthar, Mehul S.; Pulendran, Bali

    2014-01-01

    Emerging and re-emerging mosquito-borne viruses continue to pose a significant threat to human health throughout the world. Over the past decade, West Nile virus (WNV), Dengue virus (DENV), and Chikungunya virus (CHIKV), have caused annual epidemics of virus-induced encephalitis, hemorrhagic fever\\shock syndromes, and arthritis, respectively. Currently, no specific antiviral therapies or vaccines exist for use in humans to combat or prevent these viral infections. Thus, there is a pressing need to define the virus-host interactions that govern immunity and infection outcome. Recent technological breakthroughs in ‘omics’ resources and high-throughput based assays are beginning to accelerate antiviral drug discovery and improve on current strategies for vaccine design. In this review, we highlight studies with WNV and discuss how traditional and systems based approaches are being used to rapidly identify novel host targets for therapeutic intervention and develop a deeper conceptual understanding of the host response to virus infection. PMID:24851811

  13. Characterization of Chinese giant salamander iridovirus tissue tropism and inflammatory response after infection.

    PubMed

    Jiang, Nan; Fan, Yuding; Zhou, Yong; Liu, Wenzhi; Ma, Jie; Meng, Yan; Xie, Congxin; Zeng, Lingbing

    2015-06-01

    The Chinese giant salamander iridovirus (GSIV), belonging to the genus Ranavirus in the family Iridoviridae, causes severe hemorrhagic lesions and nearly 100% mortality in naturally infected Chinese giant salamanders Andrias davidiamus. However, the replication and distribution of the virus has not been well characterized in vivo. Using in situ hybridization, the expression of the GSIV major capsid protein (MCP) was detected in the cytoplasm of cells of the spleen, kidney, liver and gut tissues. MCP expression in the spleen and kidney appeared to fluctuate significantly during the acute phase of infection. Using an immunofluorescence assay, GSIV antigens were abundant in the spleen and kidney tissues but appeared to be at relatively low levels in the liver and gut. Additionally, there were significant changes in the expression of the pro-inflammatory cytokines macrophage migration inhibitory factor (MIF), tumor necrosis factor ? (TNF-?) and interleukin-1? (IL-1?) in different tissues in response to infection with GSIV. The expression of MIF, TNF-? and IL-1? had significantly increased in the spleen at 3 d post-infection; this correlated with a decrease in virus replication in the spleen. These results suggest that the spleen and kidney are the major target tissues of GSIV, and the increased expression of MIF, TNF?? and IL-1? may contribute to a reduction of virus replication in the spleen. PMID:26036830

  14. Ebola Virus Infection: What Should Be Known?

    PubMed Central

    Wiwanitkit, Viroj

    2014-01-01

    Ebola virus infection is the present global consideration. This deadly virus can result in a deadly acute febrile hemorrhagic illness. The patient can have several clinical manifestations. As a new emerging infection, the knowledge on this infection is extremely limited. The interesting issues to be discussed include a) the atypical clinical presentation, b) new diagnostic tool, c) new treatment, and d) disease prevention. Those topics will be discussed in this special review. PMID:25535601

  15. Thirty-thousand-year-old distant relative of giant icosahedral DNA viruses with a pandoravirus morphology

    PubMed Central

    Legendre, Matthieu; Bartoli, Julia; Shmakova, Lyubov; Jeudy, Sandra; Labadie, Karine; Adrait, Annie; Lescot, Magali; Poirot, Olivier; Bertaux, Lionel; Bruley, Christophe; Couté, Yohann; Rivkina, Elizaveta; Abergel, Chantal; Claverie, Jean-Michel

    2014-01-01

    The largest known DNA viruses infect Acanthamoeba and belong to two markedly different families. The Megaviridae exhibit pseudo-icosahedral virions up to 0.7 ?m in diameter and adenine–thymine (AT)-rich genomes of up to 1.25 Mb encoding a thousand proteins. Like their Mimivirus prototype discovered 10 y ago, they entirely replicate within cytoplasmic virion factories. In contrast, the recently discovered Pandoraviruses exhibit larger amphora-shaped virions 1 ?m in length and guanine–cytosine-rich genomes up to 2.8 Mb long encoding up to 2,500 proteins. Their replication involves the host nucleus. Whereas the Megaviridae share some general features with the previously described icosahedral large DNA viruses, the Pandoraviruses appear unrelated to them. Here we report the discovery of a third type of giant virus combining an even larger pandoravirus-like particle 1.5 ?m in length with a surprisingly smaller 600 kb AT-rich genome, a gene content more similar to Iridoviruses and Marseillevirus, and a fully cytoplasmic replication reminiscent of the Megaviridae. This suggests that pandoravirus-like particles may be associated with a variety of virus families more diverse than previously envisioned. This giant virus, named Pithovirus sibericum, was isolated from a >30,000-y-old radiocarbon-dated sample when we initiated a survey of the virome of Siberian permafrost. The revival of such an ancestral amoeba-infecting virus used as a safe indicator of the possible presence of pathogenic DNA viruses, suggests that the thawing of permafrost either from global warming or industrial exploitation of circumpolar regions might not be exempt from future threats to human or animal health. PMID:24591590

  16. Thirty-thousand-year-old distant relative of giant icosahedral DNA viruses with a pandoravirus morphology.

    PubMed

    Legendre, Matthieu; Bartoli, Julia; Shmakova, Lyubov; Jeudy, Sandra; Labadie, Karine; Adrait, Annie; Lescot, Magali; Poirot, Olivier; Bertaux, Lionel; Bruley, Christophe; Couté, Yohann; Rivkina, Elizaveta; Abergel, Chantal; Claverie, Jean-Michel

    2014-03-18

    The largest known DNA viruses infect Acanthamoeba and belong to two markedly different families. The Megaviridae exhibit pseudo-icosahedral virions up to 0.7 ?m in diameter and adenine-thymine (AT)-rich genomes of up to 1.25 Mb encoding a thousand proteins. Like their Mimivirus prototype discovered 10 y ago, they entirely replicate within cytoplasmic virion factories. In contrast, the recently discovered Pandoraviruses exhibit larger amphora-shaped virions 1 ?m in length and guanine-cytosine-rich genomes up to 2.8 Mb long encoding up to 2,500 proteins. Their replication involves the host nucleus. Whereas the Megaviridae share some general features with the previously described icosahedral large DNA viruses, the Pandoraviruses appear unrelated to them. Here we report the discovery of a third type of giant virus combining an even larger pandoravirus-like particle 1.5 ?m in length with a surprisingly smaller 600 kb AT-rich genome, a gene content more similar to Iridoviruses and Marseillevirus, and a fully cytoplasmic replication reminiscent of the Megaviridae. This suggests that pandoravirus-like particles may be associated with a variety of virus families more diverse than previously envisioned. This giant virus, named Pithovirus sibericum, was isolated from a >30,000-y-old radiocarbon-dated sample when we initiated a survey of the virome of Siberian permafrost. The revival of such an ancestral amoeba-infecting virus used as a safe indicator of the possible presence of pathogenic DNA viruses, suggests that the thawing of permafrost either from global warming or industrial exploitation of circumpolar regions might not be exempt from future threats to human or animal health. PMID:24591590

  17. RNA Viruses Infecting Pest Insects

    Technology Transfer Automated Retrieval System (TEKTRAN)

    RNA viruses are viruses whose genetic material is ribonucleic acid (RNA). RNA viruses may be double or single-stranded based on the type of RNA they contain. Single-stranded RNA viruses can be further grouped into negative sense or positive-sense viruses according to the polarity of their RNA. Fur...

  18. Virus-Induced Aggregates in Infected Cells

    PubMed Central

    Moshe, Adi; Gorovits, Rena

    2012-01-01

    During infection, many viruses induce cellular remodeling, resulting in the formation of insoluble aggregates/inclusions, usually containing viral structural proteins. Identification of aggregates has become a useful diagnostic tool for certain viral infections. There is wide variety of viral aggregates, which differ by their location, size, content and putative function. The role of aggregation in the context of a specific virus is often poorly understood, especially in the case of plant viruses. The aggregates are utilized by viruses to house a large complex of proteins of both viral and host origin to promote virus replication, translation, intra- and intercellular transportation. Aggregated structures may protect viral functional complexes from the cellular degradation machinery. Alternatively, the activation of host defense mechanisms may involve sequestration of virus components in aggregates, followed by their neutralization as toxic for the host cell. The diversity of virus-induced aggregates in mammalian and plant cells is the subject of this review. PMID:23202461

  19. Heat shock response to vaccinia virus infection.

    PubMed Central

    Sedger, L; Ruby, J

    1994-01-01

    We have investigated the induction of heat shock proteins (HSPs) in mice infected with vaccinia virus. Vaccinia virus replicates to high levels in the ovaries of infected mice and causes a significant inhibition of host cell DNA, RNA, and protein synthesis. Many HSPs are constitutively expressed in murine ovarian tissue at low levels, consistent with their obligatory role in normal physiological events. In contrast with these events, HSP expression was augmented in virus-infected mouse ovaries 6 days postinfection. In particular, there was a dramatic increase in the expression of a protein identified as the inducible 72-kDa HSP. Analysis of cellular mRNA confirmed this protein to be the major mouse inducible HSP70 and demonstrated its presence within virus-infected cells. Hence, we have demonstrated the expression of stress proteins during poxvirus infection in vivo. Images PMID:8207845

  20. Dengue Virus Infection Perturbs Lipid Homeostasis in Infected Mosquito Cells

    SciTech Connect

    Perera, Rushika M.; Riley, Catherine; Isaac, Georgis; Hopf- Jannasch, Amber; Moore, Ronald J.; Weitz, Karl K.; Pasa-Tolic, Ljiljana; Metz, Thomas O.; Adamec, Jiri; Kuhn, Richard J.

    2012-03-22

    Dengue virus causes {approx}50-100 million infections per year and thus is considered one of the most aggressive arthropod-borne human pathogen worldwide. During its replication, dengue virus induces dramatic alterations in the intracellular membranes of infected cells. This phenomenon is observed both in human and vector-derived cells. Using high-resolution mass spectrometry of mosquito cells, we show that this membrane remodeling is directly linked to a unique lipid repertoire induced by dengue virus infection. Specifically, 15% of the metabolites detected were significantly different between DENV infected and uninfected cells while 85% of the metabolites detected were significantly different in isolated replication complex membranes. Furthermore, we demonstrate that intracellular lipid redistribution induced by the inhibition of fatty acid synthase, the rate-limiting enzyme in lipid biosynthesis, is sufficient for cell survival but is inhibitory to dengue virus replication. Lipids that have the capacity to destabilize and change the curvature of membranes as well as lipids that change the permeability of membranes are enriched in dengue virus infected cells. Several sphingolipids and other bioactive signaling molecules that are involved in controlling membrane fusion, fission, and trafficking as well as molecules that influence cytoskeletal reorganization are also up regulated during dengue infection. These observations shed light on the emerging role of lipids in shaping the membrane and protein environments during viral infections and suggest membrane-organizing principles that may influence virus-induced intracellular membrane architecture.

  1. Dendritic cells during Epstein Barr virus infection

    PubMed Central

    Christian, Münz

    2014-01-01

    Epstein Barr virus (EBV) causes persistent infection in more than 90% of the human adult population and is associated with 2% of all tumors in humans. This ?-herpes virus infects primarily human B and epithelial cells, but it has been reported to be sensed by dendritic cells (DCs) during primary infection. These activated DCs are thought to contribute to innate restriction of EBV infection and initiate EBV-specific adaptive immune responses via cross-priming. The respective evidence and their potential importance for EBV-specific vaccine development will be discussed in this review. PMID:24999343

  2. Human immunodeficiency virus infection and pneumothorax.

    PubMed

    Terzi, Eirini; Zarogoulidis, Konstantinos; Kougioumtzi, Ioanna; Dryllis, Georgios; Kioumis, Ioannis; Pitsiou, Georgia; Machairiotis, Nikolaos; Katsikogiannis, Nikolaos; Tsiouda, Theodora; Madesis, Athanasios; Karaiskos, Theodoros; Zarogoulidis, Paul

    2014-10-01

    Pneumothorax is a serious and relatively frequent complication of human immunodeficiency virus (HIV) infection that may associate with increased morbidity and mortality and may prove difficult to manage, especially in patients with acquired immunodeficiency syndrome (AIDS). PMID:25337392

  3. DIESEL EXHAUST ENHANCES INFLUENZA VIRUS INFECTIONS IN RESPIRATORY EPITHELIAL CELLS

    EPA Science Inventory

    Several factors, such as age and nutritional status can affect the susceptibility to influenza infections. Moreover, exposure to air pollutants, such as diesel exhaust (DE), has been shown to affect respiratory virus infections in rodent models. Influenza virus primarily infects ...

  4. Brain pathology induced by infection with the human immunodeficiency virus (HIV)

    Microsoft Academic Search

    H. Budka; G. Costanzi; S. Cristina; A. Lechi; C. Parravicini; R. Trabattoni; L. Vago

    1987-01-01

    Neuropathological examination of brain tissue of 100 patients with infection by the human immunodeficiency virus (HIV), including 98 with clinically manifest acquired immune deficiency syndrome (AIDS), revealed distinct multifocal-disseminated and diffuse brain tissue lesions, which can be regarded as HIV-induced brain lessions: multifocal giant cell encephalitis (MGCE; 4) and progressive diffuse leukoencephalopathy (PDL; 25). These lesions were found in 38

  5. Screening of parasitic and IHHNV infections in wild giant freshwater prawn Macrobrachium rosenbergii from Rejang River at Kuching, Sarawak.

    PubMed

    Kua, Beng Chu; Choong, F C; Hazreen Nita, M K; Muhd Faizul H, A H; Bhassu, S; Imelda, R R; Mohammed, M

    2011-04-01

    A preliminary survey of parasitic and infectious hypodermal and haematopoietic necrosis virus (IHHNV) infections in giant freshwater prawn from the Damak Sea of Rejang River, Kuching, Sarawak was conducted. Symptoms of black spots/patches on the rostrum, carapace, pleopods or telson were observed in most of the 107 samples collected. Parasitic examination revealed sessiline peritrichs such as (Zoothamnium sp.), nematode larvae, gregarine stage and cocoon of leech with prevalences of 1.2%, 1.2%, 5% and 17% respectively. Under histopathological examination, changes like accumulation of hemocytes around hepatopancreatic tubules due to vibriosis, basophilic intranuclear inclusions in the epithelium and E-cell of hepatopancreatic tubules as a result of HPV were seen through the section. No positive infection of IHHNV was detected in 78 samples. As such, the wild giant freshwater prawns in Damak Sea of Rejang River in Kuching are IHHNV-free though infections of parvo-like virus and bacteria were seen in histopathology. PMID:21602773

  6. Molecular biology of hepatitis B virus infection.

    PubMed

    Seeger, Christoph; Mason, William S

    2015-05-01

    Human hepatitis B virus (HBV) is the prototype of a family of small DNA viruses that productively infect hepatocytes, the major cell of the liver, and replicate by reverse transcription of a terminally redundant viral RNA, the pregenome. Upon infection, the circular, partially double-stranded virion DNA is converted in the nucleus to a covalently closed circular DNA (cccDNA) that assembles into a minichromosome, the template for viral mRNA synthesis. Infection of hepatocytes is non-cytopathic. Infection of the liver may be either transient (<6 months) or chronic and lifelong, depending on the ability of the host immune response to clear the infection. Chronic infections can cause immune-mediated liver damage progressing to cirrhosis and hepatocellular carcinoma (HCC). The mechanisms of carcinogenesis are unclear. Antiviral therapies with nucleoside analog inhibitors of viral DNA synthesis delay sequelae, but cannot cure HBV infections due to the persistence of cccDNA in hepatocytes. PMID:25759099

  7. Giant virus in the sea: Extending the realm of Megaviridae to Viridiplantae.

    PubMed

    Claverie, Jean-Michel

    2013-11-01

    The viral nature of the first "giant virus," Mimivirus, was realized in 2003, 10 y after its initial isolation from the water of a cooling tower in Bradford, UK. Soon after its genome was sequenced, the mining of the Global Ocean Sampling environmental sequence database revealed that the closest relatives of Mimivirus, only known to infect Acanthamoeba, were to be found in the sea. These predicted marine Mimivirus relatives remained elusive until 2010, with the first genomic characterization of a virus infecting a heterotrophic unicellular eukaryote, the microflagellate grazer Cafeteria roenbergensis. The genome analysis of a virus (PgV) infecting the common unicellular algae Phaeocystis globosa now shows that it is a bona fide member of the Mimivirus family (i.e., the Megaviridae), extending the realm of these giant viruses to abundant blooming phytoplankton species. Despite its smaller genome size (460 kb encoding 434 proteins), PgV exhibits the most intriguing feature of the previously characterized Megaviridae: an associated virophage. However, the 19-kb virophage genome, devoid of a capsid gene, is packaged in the PgV particle and propagated as a "viral plasmid," the first ever described. The PgV genome also exhibits the duplication of "core genes," normally present as single copies and a putative new type of mobile element. In a DNA polymerase phylogeny including representatives of the three cellular domains, PgV and the other Megaviridae cluster into their own clade deeply branching between domains Archaea and Eukarya domains, thus exhibiting the topology of a fourth domain in the Tree of Life. PMID:24563700

  8. Immune system and hepatitis B virus infection

    Microsoft Academic Search

    Chee-Kin Hui; George K. K. Lau

    2005-01-01

    The immune system plays an important role in determining the outcome of hepatitis B virus (HBV) infection. This is because recovery from of acute HBV infection is associated with a clear division in the profile of adaptive immune response. Multispecific antiviral CD4 and CD8 responses with a type 1 cytokine production can be observed in patients who recover from acute

  9. Pathogenic Simian Immunodeficiency Virus Infection Is Associated

    E-print Network

    Wang, David

    -level tax- onomy of enteric bacteria was detected. Thus, enteric viral infections may contribute to AIDS enPathogenic Simian Immunodeficiency Virus Infection Is Associated with Expansion of the Enteric candidate etiologies for AIDS enteropathy, we used next-generation sequencing to define the enteric virome

  10. Respiratory syncytial virus infection in cattle

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bovine respiratory syncytial virus (bRSV) is a cause of respiratory disease in cattle world-wide. It has an integral role in enzootic pneumonia in young dairy calves and summer pneumonia in nursing beef calves. Furthermore, bRSV infection can predispose calves to secondary bacterial infection by org...

  11. Experimental Schmallenberg virus infection of pigs.

    PubMed

    Poskin, Antoine; Van Campe, Willem; Mostin, Laurent; Cay, Brigitte; De Regge, Nick

    2014-06-01

    Schmallenberg virus (SBV) is a newly emerged virus responsible for an acute non-specific syndrome in adult cattle including high fever, decrease in milk production and severe diarrhea. It also causes reproductive problems in cattle, sheep and goat including abortions, stillbirths and malformations. The role of pigs in the epidemiology of SBV has not yet been evaluated while this could be interesting seen their suggested role in the epidemiology of the closely related Akabane virus. To address this issue, four 12 week old seronegative piglets were subcutaneously infected with 1 ml of SBV infectious serum (FLI) and kept into contact with four non-infected piglets to examine direct virus transmission. Throughout the experiment blood, swabs and feces samples were collected and upon euthanasia at 28 dpi different organs (cerebrum, cerebellum, brain stem, lung, liver, iliac lymph nodes, kidney and spleen) were sampled. No clinical impact was observed and all collected samples tested negative for SBV in rRT-PCR. Despite the absence of viremia and virus transmission, low and short lasting amounts of neutralizing antibodies were found in 2 out of 4 infected piglets. The limited impact of SBV infection in pigs was further supported by the absence of neutralizing anti-SBV antibodies in field collected sera from indoor housed domestic pigs (n=106). In conclusion, SBV infection of pigs can induce seroconversion but is ineffective in terms of virus replication and transmission indicating that pigs have no obvious role in the SBV epidemiology. PMID:24679959

  12. Experimental infection of camels with bluetongue virus.

    PubMed

    Batten, C A; Harif, B; Henstock, M R; Ghizlane, S; Edwards, L; Loutfi, C; Oura, C A L; El Harrak, M

    2011-06-01

    Three camels aged 4-5 years were experimentally infected with Bluetongue virus serotype 1 (BTV-1) and were observed for 75 days. No clinical signs of disease were observed throughout the experiment, however all three animals seroconverted and developed BTV-1 specific neutralising antibodies after challenge. All three camels developed a viraemia from 7 days post infection albeit at a lower level than that usually observed in experimental infections of sheep and cattle. Virus was isolated from the blood of all three animals suggesting that camels may act as a reservoir for BTV and play an important role in its transmission. PMID:20701938

  13. Inhibition of enveloped viruses infectivity by curcumin.

    PubMed

    Chen, Tzu-Yen; Chen, Da-Yuan; Wen, Hsiao-Wei; Ou, Jun-Lin; Chiou, Shyan-Song; Chen, Jo-Mei; Wong, Min-Liang; Hsu, Wei-Li

    2013-01-01

    Curcumin, a natural compound and ingredient in curry, has antiinflammatory, antioxidant, and anticarcinogenic properties. Previously, we reported that curcumin abrogated influenza virus infectivity by inhibiting hemagglutination (HA) activity. This study demonstrates a novel mechanism by which curcumin inhibits the infectivity of enveloped viruses. In all analyzed enveloped viruses, including the influenza virus, curcumin inhibited plaque formation. In contrast, the nonenveloped enterovirus 71 remained unaffected by curcumin treatment. We evaluated the effects of curcumin on the membrane structure using fluorescent dye (sulforhodamine B; SRB)-containing liposomes that mimic the viral envelope. Curcumin treatment induced the leakage of SRB from these liposomes and the addition of the influenza virus reduced the leakage, indicating that curcumin disrupts the integrity of the membranes of viral envelopes and of liposomes. When testing liposomes of various diameters, we detected higher levels of SRB leakage from the smaller-sized liposomes than from the larger liposomes. Interestingly, the curcumin concentration required to reduce plaque formation was lower for the influenza virus (approximately 100 nm in diameter) than for the pseudorabies virus (approximately 180 nm) and the vaccinia virus (roughly 335 × 200 × 200 nm). These data provide insights on the molecular antiviral mechanisms of curcumin and its potential use as an antiviral agent for enveloped viruses. PMID:23658730

  14. Human Immunodeficiency Virus Type 1 Infection of Neural Xenografts

    NASA Astrophysics Data System (ADS)

    Cvetkovich, Therese A.; Lazar, Eliot; Blumberg, Benjamin M.; Saito, Yoshihiro; Eskin, Thomas A.; Reichman, Richard; Baram, David A.; del Cerro, Coca; Gendelman, Howard E.; del Cerro, Manuel; Epstein, Leon G.

    1992-06-01

    Human immunodeficiency virus type 1 (HIV-1) infection is highly specific for its human host. To study HIV-1 infection of the human nervous system, we have established a small animal model in which second-trimester (11 to 17.5 weeks) human fetal brain or neural retina is transplanted to the anterior chamber of the eye of immunosuppressed adult rats. The human xenografts vascularized, formed a blood-brain barrier, and differentiated, forming neurons and glia. The xenografts were infected with cell-free HIV-1 or with HIV-1-infected human monocytes. Analysis by polymerase chain reaction revealed HIV-1 sequences in DNA from xenograft tissue exposed to HIV-1 virions, and in situ hybridization demonstrated HIV-1 mRNA localized in macrophages and multinucleated giant cells. Pathological damage was observed only in neural xenografts containing HIV-1-infected human monocytes, supporting the hypothesis that these cells mediate neurotoxicity. This small animal model allows the study of direct and indirect effects of HIV-1 infection on developing human fetal neural tissues, and it should prove useful in evaluating antiviral therapies, which must ultimately target HIV-1 infection of the brain.

  15. Plant growth regulators and virus infection: A critical review

    Microsoft Academic Search

    R. S. S. Fraser; R. J. Whenham

    1982-01-01

    Virus infection can severely inhibit plant growth and distort development. This article reviews changes in plant growth regulator metabolism caused by infection. In general, virus infection decreases auxin and gibberellin concentrations and increases abscisic acid concentration. Ethylene production is stimulated in necrotic or chlorotic reactions to infection, but not where the virus spreads systemically without necrosis. While these broad trends

  16. Laboratory diagnosis of intrauterine and perinatal virus infections

    Microsoft Academic Search

    Jennifer M. Best

    1996-01-01

    Background: Intrauterine infection with rubella, cytomegalovirus (CMV), varicella zoster virus (VZV), parvovirus B19 and human immunodeficiency virus type 1 (HIV-1) may occur following maternal infection. Diagnosis of congenital infection in the neonate is dependant on the appropriate laboratory techniques being used. Prenatal diagnosis of intrauterine infection may also be indicated. Herpes simplex virus (HSV), HIV-1, VZV, enteroviruses, hepatitis B (HBV)

  17. Infection of phytoplankton by aerosolized marine viruses.

    PubMed

    Sharoni, Shlomit; Trainic, Miri; Schatz, Daniella; Lehahn, Yoav; Flores, Michel J; Bidle, Kay D; Ben-Dor, Shifra; Rudich, Yinon; Koren, Ilan; Vardi, Assaf

    2015-05-26

    Marine viruses constitute a major ecological and evolutionary driving force in the marine ecosystems. However, their dispersal mechanisms remain underexplored. Here we follow the dynamics of Emiliania huxleyi viruses (EhV) that infect the ubiquitous, bloom-forming phytoplankton E. huxleyi and show that EhV are emitted to the atmosphere as primary marine aerosols. Using a laboratory-based setup, we showed that the dynamic of EhV aerial emission is strongly coupled to the host-virus dynamic in the culture media. In addition, we recovered EhV DNA from atmospheric samples collected over an E. huxleyi bloom in the North Atlantic, providing evidence for aerosolization of marine viruses in their natural environment. Decay rate analysis in the laboratory revealed that aerosolized viruses can remain infective under meteorological conditions prevailing during E. huxleyi blooms in the ocean, allowing potential dispersal and infectivity over hundreds of kilometers. Based on the combined laboratory and in situ findings, we propose that atmospheric transport of EhV is an effective transmission mechanism for spreading viral infection over large areas in the ocean. This transmission mechanism may also have an important ecological impact on the large-scale host-virus "arms race" during bloom succession and consequently the turnover of carbon in the ocean. PMID:25964340

  18. Infection of phytoplankton by aerosolized marine viruses

    PubMed Central

    Sharoni, Shlomit; Trainic, Miri; Schatz, Daniella; Lehahn, Yoav; Flores, Michel J.; Bidle, Kay D.; Ben-Dor, Shifra; Rudich, Yinon; Vardi, Assaf

    2015-01-01

    Marine viruses constitute a major ecological and evolutionary driving force in the marine ecosystems. However, their dispersal mechanisms remain underexplored. Here we follow the dynamics of Emiliania huxleyi viruses (EhV) that infect the ubiquitous, bloom-forming phytoplankton E. huxleyi and show that EhV are emitted to the atmosphere as primary marine aerosols. Using a laboratory-based setup, we showed that the dynamic of EhV aerial emission is strongly coupled to the host–virus dynamic in the culture media. In addition, we recovered EhV DNA from atmospheric samples collected over an E. huxleyi bloom in the North Atlantic, providing evidence for aerosolization of marine viruses in their natural environment. Decay rate analysis in the laboratory revealed that aerosolized viruses can remain infective under meteorological conditions prevailing during E. huxleyi blooms in the ocean, allowing potential dispersal and infectivity over hundreds of kilometers. Based on the combined laboratory and in situ findings, we propose that atmospheric transport of EhV is an effective transmission mechanism for spreading viral infection over large areas in the ocean. This transmission mechanism may also have an important ecological impact on the large-scale host–virus “arms race” during bloom succession and consequently the turnover of carbon in the ocean. PMID:25964340

  19. Hantaan virus infection of human endothelial cells.

    PubMed

    Pensiero, M N; Sharefkin, J B; Dieffenbach, C W; Hay, J

    1992-10-01

    The primary pathophysiologic finding of the viral disease known as Korean hemorrhagic fever, the etiological agent of which is Hantaan virus (HTV), is vascular instability. To investigate whether HTV was able to infect cells derived from human vascular tissue and alter their behavior, we infected in vitro primary adult human endothelial cells from saphenous veins (HSVEC). We were able to detect the presence of viral antigens in infected cells both by immunofluorescence and by Western blot (immunoblot) analysis as early as day 1 postinfection. HSVEC infected with HTV produce infectious virus during the first 3 days of infection but, at later times (days 4 to 8), show decreasing yields of virus. This contrasts with the HTV growth pattern observed for the permissive simian CV-7 cell line, which generates infectious virus up to day 12 after infection. Further investigation showed that the late decrease in viral production in HSVEC is the result of the induction of beta interferon and can be reversed by the addition of anti-beta interferon serum to the culture medium. At no time during the course of infection of HSVEC with HTV was any obvious cytopathic effect observed. When tests for changes in mRNA levels of other cytokines and endothelial cell gene products following HTV infection of HSVEC were done by reverse transcription and polymerase chain reaction methods, no significant changes were observed in the levels of interleukin 1, interleukin 6, or von Willebrand factor mRNA. We hypothesize that, while HTV can replicate in human vascular endothelial cells, the mechanism of microvascular damage seen with Korean hemorrhagic fever is not likely to be a direct effect of virus replication but may conceivably be the consequence of an immune-mediated endothelial injury triggered by viral infection. PMID:1356160

  20. Multiple virus infections in the honey bee and genome divergence of honey bee viruses

    Microsoft Academic Search

    Yanping Chen; Yan Zhao; John Hammond; Hei-ti Hsu; Jay Evans; Mark Feldlaufer

    2004-01-01

    Using uniplex RT-PCR we screened honey bee colonies for the presence of several bee viruses, including black queen cell virus (BQCV), deformed wing virus (DWV), Kashmir bee virus (KBV), and sacbrood virus (SBV), and described the detection of mixed virus infections in bees from these colonies. We report for the first time that individual bees can harbor four viruses simultaneously.

  1. SFTS virus infection in nonhuman primates.

    PubMed

    Jin, Cong; Jiang, Hong; Liang, Mifang; Han, Ying; Gu, Wen; Zhang, Fushun; Zhu, Hua; Wu, Wei; Chen, Ting; Li, Chuan; Zhang, Weilun; Zhang, Quanfu; Qu, Jing; Wei, Qiang; Qin, Chuan; Li, Dexin

    2015-03-15

    SFTS virus (SFTSV) is a highly pathogenic bunyavirus that causes severe fever with thrombocytopenia syndrome (SFTS), an emerging infectious disease in China. Laboratory mice have been reported to be susceptible to SFTSV infection, but the infection in nonhuman primates has not been investigated. This study is the first to report that, in rhesus macaques, SFTSV does not cause severe symptoms or death but causes fever, thrombocytopenia, leukocytopenia, and increased levels of transaminases and myocardial enzymes in blood. Viremia, virus-specific immunoglobulin M and immunoglobulin G antibodies, and neutralizing antibodies were identified in all infected macaques. Levels of the cytokines interferon ?, eotaxin, tumor necrosis factor ?, and macrophage inflammatory protein 1? were significantly elevated in the blood. Minor pathological lesions were observed in the liver and kidney during the late stages of infection. Overall, SFTSV infection in rhesus macaques resembled mild SFTS in humans. PMID:25326554

  2. Adaptive response in hepatitis B virus infection.

    PubMed

    Loggi, E; Gamal, N; Bihl, F; Bernardi, M; Andreone, P

    2014-05-01

    Hepatitis B virus (HBV) is a major cause of acute and chronic liver inflammation worldwide. The immune response against the virus represents a key factor in determining infection outcome, in terms of both viral clearance and the perpetuation of liver damage. Significant advances have recently been achieved regarding the functions of antiviral CD8+ T cells, leading to a better understanding of their abnormalities during chronic infection as well as the pathways to be manipulated to reverse the immune impairment of chronic infection. In this review, we aimed to analyse the patterns of adaptive immunity that develop during acute infection and the profiles in chronic infection. In addition to CD8+ T cells, which are the best-described subset to date, we reviewed and commented on the direct and indirect roles of CD4+ T cells and B cells. PMID:24674098

  3. Human Immunology of Measles Virus Infection

    Microsoft Academic Search

    D. Naniche

    Measles is a highly contagious disease, which was responsible for high infant mortality before the advent of an effective\\u000a vaccine in 1963. In immuno-competent individuals, measles virus (MV) infection triggers an effective immune response that\\u000a starts with innate responses and then leads to successful adaptive immunity, including cell-mediated immunity and humoral\\u000a immunity. The virus is cleared and lifelong protection is

  4. Herpes simplex virus infection during pregnancy.

    PubMed

    Stephenson-Famy, Alyssa; Gardella, Carolyn

    2014-12-01

    Genital herpes in pregnancy continues to cause significant maternal morbidity, with an increasing number of infections being due to oral-labial transmission of herpes simplex virus (HSV)-1. Near delivery, primary infections with HSV-1 or HSV-2 carry the highest risk of neonatal herpes infection, which is a rare but potentially devastating disease for otherwise healthy newborns. Prevention efforts have been limited by lack of an effective intervention for preventing primary infections and the unclear role of routine serologic testing. PMID:25454993

  5. Epidemiology of genital herpes simplex virus infection.

    PubMed

    Guinan, M E; Wolinsky, S M; Reichman, R C

    1985-01-01

    This paper offers a comprehensive review of the literature on the epidemiology of genital herpes simplex virus infection. Topics covered include its microbiology, immunology, incidence, prevalence, pathogenesis and clinical course, diagnosis, treatment, transmission, prevention, and effect on pregnancy outcome. The prevalence of genital herpes is estimated at 20 million persons in the US, about 25% of whom are symptomatic. Determination of the actual incidence and prevalence of genital herpes requires the availability of methods able to distinguish precisely between type 1 and type 2 antibody. Indirect evidence suggests an increasing incidence of the disease over the past 15 years. Asymptomatic infected persons may shed virus in the absence of lesions and thus transmit genital herpes to their sexual partners. Of particular concern is vertical transmission of virus from the maternal genital tract to newborns. In the majority of documented cases of neonatal herpes, the mothers were asymptomatic at the time of delivery. Because of the severe morbidity and mortality associated with neonatal herpes infection, studies are urgently needed to identify risk factors for vertical transmission and to design and test appropriate preventive intervention strategies. At present, treatment of genital herpes is limited to palliative therapy. No known antiviral agent either prevents or eliminates viral latency, although vaccines are under development for primary prevention. The role of contraceptive practice in the prevention of genital herpes infection is unclear. Although theoretically plausible, the efficacy of barrier methods in decreasing the risk of acquiring or transmitting infection has not yet been demonstrated. Virus may be present in areas not covered by condoms. Use of a spermicidal cream or jelly with a diaphragm may reduce the risk of virus infection and transmissions, but, again, this method cannot protect from virus transmission to or from the external genitalia. PMID:2996917

  6. Influenza virus infection in a compromised immune system 

    E-print Network

    Campbell, Gillian Mhairi

    2012-06-30

    Severe influenza virus infection, including human infection with highly pathogenic H5N1 viruses is characterised by massive pulmonary inflammation, immunopathology and excessive cytokine production, a process in ...

  7. Persistence in herpes simplex virus infections.

    PubMed Central

    Longson, M.

    1978-01-01

    Diseases of man caused by the virus of herpes simplex fall into two broad categories. The primary disease occurs only once in any individual's life and is caused by transmission of virus from an already infected human. Thereafter, the individual may be subject to recurrent herpetic disease, the manifestations of which are different from the primary disease. Recurrent disease varies in severity from trivial, to incapacitating and frankly lethal (as in diseases resulting from the virus's neurotropic and oncogenic properties). The source of the virus in recurrent herpetic disease has never been conclusively resolved, but is almost certainly endogenous to the patient. Theories, case reports and experiments exist to show that endogenous virus may, in periods of clinical quiescence, be latent (or persistent) at the site of the recurrent lesions itself, or more remotely in nerve tissues related to the site of recurrence. Images Fig. 1 PMID:214773

  8. Immune responses and Lassa virus infection.

    PubMed

    Russier, Marion; Pannetier, Delphine; Baize, Sylvain

    2012-11-01

    Lassa fever is a hemorrhagic fever endemic to West Africa and caused by Lassa virus, an Old World arenavirus. It may be fatal, but most patients recover from acute disease and some experience asymptomatic infection. The immune mechanisms associated with these different outcomes have not yet been fully elucidated, but considerable progress has recently been made, through the use of in vitro human models and nonhuman primates, the only relevant animal model that mimics the pathophysiology and immune responses induced in patients. We discuss here the roles of the various components of the innate and adaptive immune systems in Lassa virus infection and in the control of viral replication and pathogenesis. PMID:23202504

  9. Epstein-Barr virus infection mechanisms

    PubMed Central

    Chesnokova, Liudmila S.; Hutt-Fletcher, Lindsey M.

    2014-01-01

    Epstein-Barr virus (EBV) infection occurs by distinct mechanisms across different cell types. EBV infection of B cells in vitro minimally requires 5 viral glycoproteins and 2 cellular proteins. By contrast, infection of epithelial cells requires a minimum of 3 viral glycoproteins, which are capable of interacting with one or more of 3 different cellular proteins. The full complement of proteins involved in entry into all cell types capable of being infected in vivo is unknown. This review discusses the events that occur when the virus is delivered into the cytoplasm of a cell, the players known to be involved in these events, and the ways in which these players are thought to function. PMID:25322867

  10. Chronic Hepatitis B Virus Infection and Pregnancy

    PubMed Central

    Kumar, Manoj; Singh, Tarandeep; Sinha, Swati

    2012-01-01

    Planning of pregnancy and management of chronic hepatitis B virus during pregnancy includes recognition of maternal virological status, assessment of liver disease severity and minimization of risk for mother to infant transmission of infection. Decisions regarding the use of antivirals during pregnancy need to be individualized. Monitoring for infection and immunization in newborns is also important. For mothers on antiviral therapy, breastfeeding is not recommended. PMID:25755458

  11. Cytological effect of virus infection in five crop species

    Microsoft Academic Search

    Atika Naz; G. KABIR; M. M. UD-DEEN

    2008-01-01

    Meiotic abnormalities and pollen sterility due to virus infection in Capsicum annuum L., Carica papaya L., Lablab purpureus L., Lycopersicon esculentum L., and Solanum melongena L. were studied. Comparison in with unaffected plants showed that virus infected plants, asynapsis, multivalents and lower chiasma frequencies were present. Frequencies of chromosomal irregularities and pollen sterility were high in virus infected plants. Different

  12. Infection of cells by Sindbis virus at low temperature

    Microsoft Academic Search

    Gongbo Wang; Raquel Hernandez; Keith Weninger; Dennis T.. Brown

    2007-01-01

    Sindbis virus, which belongs to the family Togaviridae genus Alphavirus infects a variety of vertebrate and invertebrate cells. The initial steps of Sindbis virus infection involve attachment, penetration and uncoating. Two different pathways of infection have been proposed for Alphaviruses. One proposed mechanism involves receptor mediated virion endocytosis followed by membrane fusion triggered by endosome acidification. This virus–host membrane fusion

  13. Pseudorabies virus infection in Oklahoma hunting dogs.

    PubMed

    Cramer, Sarah D; Campbell, Gregory A; Njaa, Bradley L; Morgan, Sandra E; Smith, Stephen K; McLin, William R; Brodersen, Bruce W; Wise, Annabel G; Scherba, Gail; Langohr, Ingeborg M; Maes, Roger K

    2011-09-01

    Pseudorabies is caused by Suid herpesvirus 1, a member of the Alphaherpesvirinae subfamily. Although pigs are the natural host of Pseudorabies virus (PRV), the virus has a broad host range and may cause fatal encephalitis in many species. The United States obtained PRV-free status in 2004 after the virus was eradicated from domestic swineherds, but the virus is still present in feral swine populations. The current report describes PRV infection in 3 dogs that were used to hunt feral swine. The dogs developed clinical signs including facial pruritus with facial abrasions, dyspnea, vomiting, diarrhea, ataxia, muscle stiffness, and death. Two were euthanized, and 1 died within approximately 48 hr after onset of clinical signs. The salient histologic changes consisted of neutrophilic trigeminal ganglioneuritis with neuronophagia and equivocal intranuclear inclusion bodies. Pseudorabies virus was isolated from fresh tissues from 2 of the dogs, and immunohistochemistry detected the virus in the third dog. Virus sequencing and phylogeny, based upon available GenBank sequences, revealed that the virus was likely a field strain that was closely related to a cluster of PRV strains previously identified in Illinois. Though eradicated from domestic swine in the United States, PRV is present in populations of feral swine, and should therefore continue to be considered a possible cause of disease in dogs and other domestic animals with compatible clinical history and signs. Continued surveillance is necessary to prevent reintroduction of PRV into domestic swine. PMID:21908347

  14. Cellular scent of influenza virus infection.

    PubMed

    Aksenov, Alexander A; Sandrock, Christian E; Zhao, Weixiang; Sankaran, Shankar; Schivo, Michael; Harper, Richart; Cardona, Carol J; Xing, Zheng; Davis, Cristina E

    2014-05-01

    Volatile organic compounds (VOCs) emanating from humans have the potential to revolutionize non-invasive diagnostics. Yet, little is known about how these compounds are generated by complex biological systems, and even less is known about how these compounds are reflective of a particular physiological state. In this proof-of-concept study, we examined VOCs produced directly at the cellular level from B lymphoblastoid cells upon infection with three live influenza virus subtypes: H9N2 (avian), H6N2 (avian), and H1N1 (human). Using a single cell line helped to alleviate some of the complexity and variability when studying VOC production by an entire organism, and it allowed us to discern marked differences in VOC production upon infection of the cells. The patterns of VOCs produced in response to infection were unique for each virus subtype, while several other non-specific VOCs were produced after infections with all three strains. Also, there was a specific time course of VOC release post infection. Among emitted VOCs, production of esters and other oxygenated compounds was particularly notable, and these may be attributed to increased oxidative stress resulting from infection. Elucidating VOC signatures that result from the host cells response to infection may yield an avenue for non-invasive diagnostics and therapy of influenza and other viral infections. PMID:24719290

  15. Cellular Scent of Influenza Virus Infection

    PubMed Central

    Aksenov, Alexander A.; Sandrock, Christian E.; Zhao, Weixiang; Sankaran, Shankar; Schivo, Michael; Harper, Richart; Cardona, Carol J.; Xing, Zheng; Davis, Cristina E.

    2014-01-01

    Volatile organic compounds (VOCs) emanating from humans have the potential to revolutionize non-invasive diagnostics. Yet, little is known about how these compounds are generated by complex biological systems, and even less is known about how these compounds are reflective of a particular physiological state. In this proof-of-concept study, we examined VOCs produced directly at the cellular level from B lymphoblastoid cells upon infection with three live influenza virus subtypes: H9N2 (avian), H6N2 (avian), and H1N1 (human). Using a single cell line helped to alleviate some of the complexity and variability when studying VOC production by an entire organism, and it allowed us to discern marked differences in VOC production upon infection of the cells. The patterns of VOCs produced in response to infection were unique for each virus subtype, while several other non-specific VOCs were produced after infections with all three strains. Also, there was a specific time course of VOC release post infection. Among emitted VOCs, production of esters and other oxygenated compounds was particularly notable, and these may be attributed to increased oxidative stress resulting from infection. Elucidating VOC signatures that result from the host cells response to infection may yield an avenue for non-invasive diagnostics and therapy of influenza and other viral infections. PMID:24719290

  16. 63 FR 8204 - Applied Research in Emerging Infections; Hepatitis C Virus InfectionSexual Transmission

    Federal Register 2010, 2011, 2012, 2013, 2014

    1998-02-18

    ...Applied Research in Emerging Infections; Hepatitis C Virus Infection--Sexual Transmission...epidemiologic studies of sexual transmission of hepatitis C virus (HCV) infection. CDC is committed...announcement specifically addresses the area of hepatitis c virus (HCV) infection. In the...

  17. Ocular problem in Ebola virus infection: A short review.

    PubMed

    Wiwanitkit, Somsri; Wiwanitkit, Viroj

    2015-01-01

    In 2014, the outbreak of Ebola virus infection occured in Africa and became the global concern. The infection is an acute febrile illness and the patient can have several clinical manifestations including the hemorrhage. The ocular manifestation of Ebola infection is interesting. In this brief review, the authors summarize on the ocular manifestation in Ebola virus infection. PMID:26155084

  18. Ocular problem in Ebola virus infection: A short review

    PubMed Central

    Wiwanitkit, Somsri; Wiwanitkit, Viroj

    2015-01-01

    In 2014, the outbreak of Ebola virus infection occured in Africa and became the global concern. The infection is an acute febrile illness and the patient can have several clinical manifestations including the hemorrhage. The ocular manifestation of Ebola infection is interesting. In this brief review, the authors summarize on the ocular manifestation in Ebola virus infection.

  19. Zebrafish: Modeling for Herpes Simplex Virus Infections

    PubMed Central

    Antoine, Thessicar Evadney; Jones, Kevin S.; Dale, Rodney M.; Shukla, Deepak

    2014-01-01

    Abstract For many years, zebrafish have been the prototypical model for studies in developmental biology. In recent years, zebrafish has emerged as a powerful model system to study infectious diseases, including viral infections. Experiments conducted with herpes simplex virus type-1 in adult zebrafish or in embryo models are encouraging as they establish proof of concept with viral-host tropism and possible screening of antiviral compounds. In addition, the presence of human homologs of viral entry receptors in zebrafish such as 3-O sulfated heparan sulfate, nectins, and tumor necrosis factor receptor superfamily member 14-like receptor bring strong rationale for virologists to test their in vivo significance in viral entry in a zebrafish model and compare the structure–function basis of virus zebrafish receptor interaction for viral entry. On the other end, a zebrafish model is already being used for studying inflammation and angiogenesis, with or without genetic manipulations, and therefore can be exploited to study viral infection-associated pathologies. The major advantage with zebrafish is low cost, easy breeding and maintenance, rapid lifecycle, and a transparent nature, which allows visualizing dissemination of fluorescently labeled virus infection in real time either at a localized region or the whole body. Further, the availability of multiple transgenic lines that express fluorescently tagged immune cells for in vivo imaging of virus infected animals is extremely attractive. In addition, a fully developed immune system and potential for receptor-specific knockouts further advocate the use of zebrafish as a new tool to study viral infections. In this review, we focus on expanding the potential of zebrafish model system in understanding human infectious diseases and future benefits. PMID:24266790

  20. DNA-Dependent RNA Polymerase Detects Hidden Giant Viruses in Published Databanks

    PubMed Central

    Sharma, Vikas; Colson, Philippe; Giorgi, Roch; Pontarotti, Pierre; Raoult, Didier

    2014-01-01

    Environmental metagenomic studies show that there is a “dark matter,” composed of sequences not linked to any known organism, as determined mainly using ribosomal DNA (rDNA) sequences, which therefore ignore giant viruses. DNA-dependent RNA polymerase (RNAP) genes are universal in microbes and conserved in giant viruses and may replace rDNA for identifying microbes. We found while reconstructing RNAP subunit 2 (RNAP2) phylogeny that a giant virus sequenced together with the genome of a large eukaryote, Hydra magnipapillata, has been overlooked. To explore the dark matter, we used viral RNAP2 and reconstructed putative ancestral RNAP2, which were significantly superior in detecting distant clades than current sequences, and we revealed two additional unknown mimiviruses, misclassified as an euryarchaeote and an oomycete plant pathogen, and detected unknown putative viral clades. We suggest using RNAP systematically to decipher the black matter and identify giant viruses. PMID:24929085

  1. Penicillium marneffei infection in patients infected with human immunodeficiency virus.

    PubMed

    Supparatpinyo, K; Chiewchanvit, S; Hirunsri, P; Uthammachai, C; Nelson, K E; Sirisanthana, T

    1992-04-01

    From June 1990 to August 1991, 21 patients infected with the human immunodeficiency virus (HIV) presented with systemic mycosis caused by Penicillium marneffei. Between August 1987 and August 1991, only five patients were observed who had P. marneffei infection but not HIV infection. The clinical presentation included fever, cough, and generalized papular skin lesions. For 11 of these 21 patients, the presumptive diagnosis of P. marneffei infection could be made by microscopic examination of Wright's-stained bone marrow aspirate and/or touch smears of skin specimens obtained by biopsy several days before the results of culture were available. Initial clinical response to treatment with either parenteral amphotericin B or oral itraconazole was favorable in most patients. Epidemiological and clinical evidence suggest that this systemic mycosis is caused by an important opportunistic pathogen and that it should be included in the differential diagnosis of AIDS, at least for countries in areas of endemicity, i.e., Southeast Asia and China. PMID:1315586

  2. Sexual transmission of hepatitis C virus infection

    PubMed Central

    Rooney, G.; Gilson, R. J.

    1998-01-01

    BACKGROUND: Hepatitis C virus (HCV) is the cause of almost all cases of parenterally transmitted non-A, non-B viral hepatitis (NANBH). HCV is an RNA virus, unrelated to the hepatitis viruses, A, B, D, or E; it was first identified in 1989. Although most infections become chronic, and it may lead to chronic liver disease, most patients with HCV infection are asymptomatic. The predominant modes of transmission are by blood, blood products, or other parenteral exposure, particularly injecting drug use. More contentious is the role of sexual transmission, although evidence for this was provided by studies of NANBH. OBJECTIVE: This review considers the evidence for sexual transmission, and the types of studies used to estimate the rate of transmission and the factors that may influence it. METHOD: A Medline search using the keywords hepatitis C, sex, transmission, and prevalence in MeSH and free text. References in papers were searched, and some unpublished data identified. References were further selected to illustrate different methodologies. FINDINGS: Evidence for sexual transmission is provided by several types of study including prevalence studies in groups at risk of other STDs, investigation of cases identified from surveillance reports, and cross sectional and longitudinal partner studies. Many studies are limited by their small size, the sensitivity and specificity of early assays, lack of controls, or the difficulty of excluding other routes of transmission. One prospective cohort study reported an incidence of 12 per 1000 person years in the sexual partners of HCV infected patients. 1-3% of partners of HCV infected patients are found to be infected in cross sectional studies. Co-infection with HIV, duration of the relationship, or chronic liver disease may be independent cofactors increasing the risk of transmission. A meta-analysis of selected studies may be informative, and further larger prospective studies are required. There is a small but definite risk of sexual transmission of hepatitis C. ??? PMID:10195047

  3. Regulating the adaptive immune response to respiratory virus infection

    Microsoft Academic Search

    Thomas J. Braciale; Jie Sun; Taeg S. Kim

    2012-01-01

    Recent years have seen several advances in our understanding of immunity to virus infection of the lower respiratory tract, including to influenza virus infection. Here, we review the cellular targets of viruses and the features of the host immune response that are unique to the lungs. We describe the interplay between innate and adaptive immune cells in the induction, expression

  4. Vaccinia virus infections in martial arts gym, Maryland, USA, 2008.

    PubMed

    Hughes, Christine M; Blythe, David; Li, Yu; Reddy, Ramani; Jordan, Carol; Edwards, Cindy; Adams, Celia; Conners, Holly; Rasa, Catherine; Wilby, Sue; Russell, Jamaal; Russo, Kelly S; Somsel, Patricia; Wiedbrauk, Danny L; Dougherty, Cindy; Allen, Christopher; Frace, Mike; Emerson, Ginny; Olson, Victoria A; Smith, Scott K; Braden, Zachary; Abel, Jason; Davidson, Whitni; Reynolds, Mary; Damon, Inger K

    2011-04-01

    Vaccinia virus is an orthopoxvirus used in the live vaccine against smallpox. Vaccinia virus infections can be transmissible and can cause severe complications in those with weakened immune systems. We report on a cluster of 4 cases of vaccinia virus infection in Maryland, USA, likely acquired at a martial arts gym. PMID:21470473

  5. Vaccinia Virus Infections in Martial Arts Gym, Maryland, USA, 2008

    PubMed Central

    Blythe, David; Li, Yu; Reddy, Ramani; Jordan, Carol; Edwards, Cindy; Adams, Celia; Conners, Holly; Rasa, Catherine; Wilby, Sue; Russell, Jamaal; Russo, Kelly S.; Somsel, Patricia; Wiedbrauk, Danny L.; Dougherty, Cindy; Allen, Christopher; Frace, Mike; Emerson, Ginny; Olson, Victoria A.; Smith, Scott K.; Braden, Zachary; Abel, Jason; Davidson, Whitni; Reynolds, Mary; Damon, Inger K.

    2011-01-01

    Vaccinia virus is an orthopoxvirus used in the live vaccine against smallpox. Vaccinia virus infections can be transmissible and can cause severe complications in those with weakened immune systems. We report on a cluster of 4 cases of vaccinia virus infection in Maryland, USA, likely acquired at a martial arts gym. PMID:21470473

  6. Experimental Infection of Prairie Dogs with Monkeypox Virus

    Microsoft Academic Search

    Shu-Yuan Xiao; Elena Sbrana; Douglas M. Watts; Marina Siirin; Travassos da Rosa; Robert B. Tesh

    2005-01-01

    Studies of experimental infection of prairie dogs (Cynomys ludovicianus) with monkeypox virus are described. After intraperitoneal infection, all of the animals died within 11 days. Virus was cultured from their blood and oropharynx several days before death; at necropsy, most of the organs tested contained monkeypox virus. Marked hepatic and splenic necrosis were observed, along with mild inflammatory changes in

  7. Ebola virus (EboV) infection causes fatal

    E-print Network

    Chandran, Kartik

    Ebola virus (EboV) infection causes fatal haemorrhagic fever with mortality rates exceeding 75 Carette, J. E. et al. Ebola virus entry requires the cholesterol transporter Niemann­Pick C1. Nature 24 is essential for Ebola virus infection. Nature 24 Aug 2011 (doi:10.1038/nature10380) ANTIVIRALS Achilles heel

  8. ANALYSIS OF HEPATITIS C VIRUS INFECTION MODELS WITH HEPATOCYTE HOMEOSTASIS

    E-print Network

    Reluga, Tim

    ANALYSIS OF HEPATITIS C VIRUS INFECTION MODELS WITH HEPATOCYTE HOMEOSTASIS TIMOTHY C. RELUGA ALAMOS NATIONAL LABORATORY LOS ALAMOS, NM 87545 Abstract. Recently, we developed a model for hepatitis C infections with hepatotropic viruses, such as hepatitis B virus. Key words. HCV, viral dynamics, bifurcation

  9. A single vertebrate DNA virus protein disarms invertebrate immunity to RNA virus infection

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Virus-host interactions drive a remarkable diversity of immune responses and countermeasures. While investigating virus-invertebrate host interactions we found that two RNA viruses with broad host ranges, vesicular stomatitis virus (VSV) and Sindbis virus (SINV), were unable to infect certain Lepido...

  10. [Human immunodeficiency virus infection and viral hepatitis].

    PubMed

    Soriano, Vicente; Martin-Carbonero, Luz; Vispo, Eugenia; Labarga, Pablo; Barreiro, Pablo

    2011-11-01

    Hepatic complications currently represent one of the leading reasons for medical consultations, hospitalisation, and death in the HIV-infected population. This is due to a large extent to viral hepatitis, given its disproportionate frequency in this population. Chronic hepatitis B affects 5-10% of the HIV-infected population. Vaccination has reduced the incidence of liver disease related to hepatitis-B virus (HBV), and the availability of tenofovir has dramatically improved the prognosis of HIV/HBV carriers. Delta hepatitis affects around 15% of HIV-infected individuals in Europe harbouring positive HBsAg. It has the worst prognosis, given its accelerated course to cirrhosis and the absence of successful therapy. Lastly, chronic hepatitis C is the major cause of liver disease in the HIV population. Although classically linked to persons infected parenterally (i.e., intravenous drug users), outbreaks of acute hepatitis C among homosexual men have been reported over the last decade. Treatment with pegylated interferon plus ribavirin provides a cure in less than 40% of patients. However, the introduction of new direct acting antivirals against hepatitis- C virus (HCV) (telaprevir, boceprevir) has revolutionised the field, as HAART did in 1996 in the HIV field, improving the prognosis of co-infected patients. However, interactions between these drugs and antiretroviral agents and the risk of selective resistance pose huge threats in this population. PMID:21978797

  11. Host Species Barriers to Influenza Virus Infections

    NSDL National Science Digital Library

    Thijs Kuiken (Erasmus Medical Center; Department of Virology)

    2006-04-21

    Access to the article is free, however registration and sign-in are required: Most emerging infectious diseases in humans originate from animal reservoirs; to contain and eradicate these diseases we need to understand how and why some pathogens become capable of crossing host species barriers. Influenza virus illustrates the interaction of factors that limit the transmission and subsequent establishment of an infection in a novel host species. Influenza species barriers can be categorized into virus-host interactions occurring within individuals and host-host interactions, either within or between species, that affect transmission between individuals. Viral evolution can help surmount species barriers, principally by affecting virus-host interactions; however, evolving the capability for sustained transmission in a new host species represents a major adaptive challenge because the number of mutations required is often large.

  12. Hypocomplementemia and Human Immunodeficiency Virus Infection

    Microsoft Academic Search

    Robert Y. Lin; Olga Wildfeuer; Monica M. Franklin; Kenneth Candido

    1988-01-01

    The levels of C4 and C3 were measured and related to other immunological and clinical parameters in 44 patients with the human immunodeficiency virus (HIV) infection. Circulating immune complexes (C1q-C?C) as measured by an enzyme-linked immunosorbent assay employing monoclonal antibody with specificity for bound C1q, and serum immunoglobulin G (IgG) concentrations were assessed simultaneously. Clinical parameters assessed included: (1) the

  13. West Nile Virus: Biology, Transmission, and Human Infection

    PubMed Central

    Colpitts, Tonya M.; Conway, Michael J.; Montgomery, Ruth R.

    2012-01-01

    Summary: West Nile Virus was introduced into the Western Hemisphere during the late summer of 1999 and has been causing significant and sometimes severe human diseases since that time. This article briefly touches upon the biology of the virus and provides a comprehensive review regarding recent discoveries about virus transmission, virus acquisition, and human infection and disease. PMID:23034323

  14. Vaginal and rectal infection of cats with feline immunodeficiency virus

    Microsoft Academic Search

    Sarah A. Bishop; Christopher R. Stokes; Timothy J. Gruffydd-Jones; Christine V. Whiting; David A. Harbour

    1996-01-01

    The objective of this study was to examine the potential of vaginal and rectal mucosal routes for feline immunodeficiency virus (FIV) uptake and infection, as a model of mucosal HIV infection, and to determine the fate of virus at these mucosal sites following transmission of infection. SPF cats were exposed to FIV isolates (PET, GL-8, T637), administered as either cell-associated

  15. KINETIC PROFILE OF INFLUENZA VIRUS INFECTION IN THREE RAT STRAINS

    EPA Science Inventory

    Abstract Influenza infection is a respiratory disease of viral origin that can cause major epidemics in man. The influenza virus infects and damages epithelial cells of the respiratory tract and causes pneumonia. Lung lesions of mice infected with influenza virus resembl...

  16. Chronic hepatitis B virus infection.

    PubMed

    McMahon, Brian J

    2014-01-01

    All providers, regardless of specialty, should perform screening for HBV on high-risk persons, especially those born in endemic countries. The primary care physician can perform the initial evaluation and follow-up of patients with chronic HBV by following the algorithm in this article and consulting with specialists when appropriate. Chronically infected patients should be followed on a regular basis, preferably every 6 months, with liver function tests, and when appropriate, HBV DNA levels. Those who meet the criteria for high risk for HCC should undergo liver ultrasound every 6 months. Powerful antiviral medications are available that can suppress but not cure HBV and result in resolution of liver inflammation and fibrosis, even cirrhosis, as well as decrease the risk of developing HCC. They should be used in those patients who meet the criteria outlined in the practice guidelines of the major liver societies. PMID:24266913

  17. Human immunodeficiency virus infection in Haiti.

    PubMed Central

    Pierre, J. A.; Fournier, A. M.

    1999-01-01

    This article reviews human immunodeficiency virus (HIV) infection in Haiti. The evolution of the epidemic in Haiti, its spread from urban to rural areas, its varied clinical manifestations, and the attitudes of Haitian people toward HIV infection provide important lessons on understanding and managing this infection in a developing country. The heterosexual spread of HIV, particularly among the poor, is well-documented as is the role of other sexually transmitted diseases along with tuberculosis. Coinfection of HIV and tuberculosis have led researchers to study the effects of six-month supervised intermittent tuberculosis therapy both in controlling tuberculosis and slowing the progression of HIV. Various surveys and discussion groups about acquired immunodeficiency virus knowledge and beliefs demonstrate a large deficit in HIV education despite campaigns to educate the population. The great impact of HIV disease on morbidity and mortality in Haiti indicates that a great deal of work still needs to be accomplished and demonstrates the frustration in fighting the infection in countries with inadequate resources and infrastructure. Advances in HIV vaccine research seem to be the most promising option for developing countries such as Haiti. PMID:10203919

  18. Seroepidemiology of Hantaan virus infection in Taiwan.

    PubMed

    Kao, C L; Chen, C J; Yen, T S; Lien, J C; Yang, C S

    1996-12-01

    In order to investigate the infection rate of Hantaan virus in Taiwan, a total of 6,536 human serum samples were collected from residents, selected by stratified random sampling, from 19 townships covering four different ethnic groups: Aborigines, Fukien Taiwanese, Hakka Taiwanese, and Mainland Chinese. Serum samples were screened for Hantaan virus antibodies by indirect immunofluorescence. The prototype Hantaan virus (76/118)-infected Vero E6 cells were used as the viral antigen for the antibody detection. Among 6,536 human serum samples, 403 (6.2%) samples had Hantaan virus antibodies. The seropositive rates for males and females were 6.1% and 6.2%, respectively. A higher seropositive rate was found among Aborigines on the Orchid Islets (11.5%) and Fukien Taiwanese on the Penghu Islets (11.6%), while the lowest rate was observed among Hakka Taiwanese in the south of Taiwan (2.5%). In comparing with different ethnic groups, the highest prevalence was found among Fukien Taiwanese (8.1%) and the lowest among Mainland Chinese (4.9%). Among the different geographical areas, the highest positive rate was found in western Taiwan (7.1%) and the lowest in southern Taiwan (5.4%). Hantaan virus antibodies were also detected in 22 of 548 (4.0%) rat serum samples. The highest seropositive rate was found in rat sera collected from the Orchid Islets (21.4%). None of the rat sera collected from Hsinchu, Miaoli, Changhua, Nantu, Yunlin, Chiayi, Tainan, and Penghu Counties were positive. Hantaan virus antibodies were found in rats: Rattus rattus (20%), Bandicota indica (9.0%), Rattus norvegicus (8.3%), Bandicota nemorivaga (6.3%), Rattus losea (4.2%), and Apodemus agrarius (1.6%). Hantaan virus antibodies were not detected in rat sera collected from species of Rattus coxinga, Rattus culturatus, Mus musculus, Mus caroli, Suncus murinus, and Apodemus semotus. The results show that the Hantaan or Hantaan-related virus exists and is distributed widely in both human and rats in Taiwan. PMID:8950687

  19. Hepatitis C virus infection and autoimmune diseases

    PubMed Central

    Paroli, Marino; Iannucci, Gino; Accapezzato, Daniele

    2012-01-01

    Hepatitis C virus (HCV) infection is associated with a number of extrahepatic disorders. The most studied conditions associated with HCV are type II mixed cryoglobulinemia and B cell lymphoma. However, many reports suggest that HCV might also be associated with a number of autoimmune disorders, both organ-specific and not organ-specific. Although concomitant treatment of HCV infection is a confounding factor when ascertaining the actual role of HCV in inducing autoimmune disease, a considerable amount of experimental data indicates that HCV is able to subvert the immune system and consequently induce autoimmunity. In the present review, we report a series of observations which associate chronic HCV infection with the onset of autoimmune disorders. PMID:23118549

  20. Bovine viral diarrhea virus (BVDV) infections in pigs.

    PubMed

    Tao, Jie; Liao, Jinhu; Wang, Yin; Zhang, Xinjun; Wang, Jianye; Zhu, Guoqiang

    2013-08-30

    Cattle are the natural hosts of bovine viral diarrhea virus (BVDV), which causes mucosal disease, respiratory and gastrointestinal tract infections, and reproductive problems in cattle. However, BVDV can also infect goats, sheep, deer, and pigs. The prevalence of BVDV infection in pig herds has substantially increased in the last several years, causing increased economic losses to the global pig breeding industry. This article is a summary of BVDV infections in pigs, including a historical overview, clinical signs, pathology, source of infection, genetic characteristics, impacts of porcine BVDV infection for diagnosis of classical swine fever virus (CSFV), differentiation of infection with CSFV and BVDV, and future prospects of porcine BVDV infection. PMID:23587625

  1. [Skin symptoms associated with human immunodeficiency virus infection].

    PubMed

    Tamási, Béla; Marschalkó, Márta; Kárpáti, Sarolta

    2015-01-01

    The recently observed accelerated increase of human immunodeficiency virus infection in Hungary poses a major public concern for the healthcare system. Given the effective only but not the curative therapy, prevention should be emphasized. Current statistics estimate that about 50% of the infected persons are not aware of their human immunodeficiency virus-positivity. Thus, early diagnosis of the infection by serological screening and timely recognition of the disease-associated symptoms are crucial. The authors' intention is to facilitate early infection detection with this review on human immunodeficiency virus-associated skin symptoms, and highlight the significance of human immunodeficiency virus care in the everyday medical practice. PMID:25544049

  2. Autophagic flux without a block differentiates varicella-zoster virus infection from herpes simplex virus infection

    PubMed Central

    Buckingham, Erin M.; Carpenter, John E.; Jackson, Wallen; Zerboni, Leigh; Arvin, Ann M.; Grose, Charles

    2015-01-01

    Autophagy is a process by which misfolded and damaged proteins are sequestered into autophagosomes, before degradation in and recycling from lysosomes. We have extensively studied the role of autophagy in varicella-zoster virus (VZV) infection, and have observed that vesicular cells are filled with >100 autophagosomes that are easily detectable after immunolabeling for the LC3 protein. To confirm our hypothesis that increased autophagosome formation was not secondary to a block, we examined all conditions of VZV infection as well as carrying out two assessments of autophagic flux. We first investigated autophagy in human skin xenografts in the severe combined immunodeficiency (SCID) mouse model of VZV pathogenesis, and observed that autophagosomes were abundant in infected human skin tissues. We next investigated autophagy following infection with sonically prepared cell-free virus in cultured cells. Under these conditions, autophagy was detected in a majority of infected cells, but was much less than that seen after an infected-cell inoculum. In other words, inoculation with lower-titered cell-free virus did not reflect the level of stress to the VZV-infected cell that was seen after inoculation of human skin in the SCID mouse model or monolayers with higher-titered infected cells. Finally, we investigated VZV-induced autophagic flux by two different methods (radiolabeling proteins and a dual-colored LC3 plasmid); both showed no evidence of a block in autophagy. Overall, therefore, autophagy within a VZV-infected cell was remarkably different from autophagy within an HSV-infected cell, whose genome contains two modifiers of autophagy, ICP34.5 and US11, not present in VZV. PMID:25535384

  3. Autophagic flux without a block differentiates varicella-zoster virus infection from herpes simplex virus infection.

    PubMed

    Buckingham, Erin M; Carpenter, John E; Jackson, Wallen; Zerboni, Leigh; Arvin, Ann M; Grose, Charles

    2015-01-01

    Autophagy is a process by which misfolded and damaged proteins are sequestered into autophagosomes, before degradation in and recycling from lysosomes. We have extensively studied the role of autophagy in varicella-zoster virus (VZV) infection, and have observed that vesicular cells are filled with >100 autophagosomes that are easily detectable after immunolabeling for the LC3 protein. To confirm our hypothesis that increased autophagosome formation was not secondary to a block, we examined all conditions of VZV infection as well as carrying out two assessments of autophagic flux. We first investigated autophagy in human skin xenografts in the severe combined immunodeficiency (SCID) mouse model of VZV pathogenesis, and observed that autophagosomes were abundant in infected human skin tissues. We next investigated autophagy following infection with sonically prepared cell-free virus in cultured cells. Under these conditions, autophagy was detected in a majority of infected cells, but was much less than that seen after an infected-cell inoculum. In other words, inoculation with lower-titered cell-free virus did not reflect the level of stress to the VZV-infected cell that was seen after inoculation of human skin in the SCID mouse model or monolayers with higher-titered infected cells. Finally, we investigated VZV-induced autophagic flux by two different methods (radiolabeling proteins and a dual-colored LC3 plasmid); both showed no evidence of a block in autophagy. Overall, therefore, autophagy within a VZV-infected cell was remarkably different from autophagy within an HSV-infected cell, whose genome contains two modifiers of autophagy, ICP34.5 and US11, not present in VZV. PMID:25535384

  4. Purified Influenza Virus Nucleoprotein Protects Mice from Lethal Infection

    Microsoft Academic Search

    DAVID C. WRAITH; ANGELA E. VESSEY; BRIGITTE A. ASKONAS

    1987-01-01

    SUMMARY Local administration of nucleoprotein purified from X31 (H3N2) influenza A virus primed for A virus cross-reactive cytotoxic T cells and resulted in substantial protection (75 ~) of mice from a lethal challenge with the heterologous mouse-adapted A\\/PR\\/8\\/34 (H1N1) virus. By following the course of a lethal virus challenge we found that nucleoprotein priming did not prevent virus infection but

  5. Spatiotemporal Analysis of Hepatitis C Virus Infection

    PubMed Central

    Shulla, Ana; Randall, Glenn

    2015-01-01

    Hepatitis C virus (HCV) entry, translation, replication, and assembly occur with defined kinetics in distinct subcellular compartments. It is unclear how HCV spatially and temporally regulates these events within the host cell to coordinate its infection. We have developed a single molecule RNA detection assay that facilitates the simultaneous visualization of HCV (+) and (?) RNA strands at the single cell level using high-resolution confocal microscopy. We detect (+) strand RNAs as early as 2 hours post-infection and (?) strand RNAs as early as 4 hours post-infection. Single cell levels of (+) and (?) RNA vary considerably with an average (+):(?) RNA ratio of 10 and a range from 1–35. We next developed microscopic assays to identify HCV (+) and (?) RNAs associated with actively translating ribosomes, replication, virion assembly and intracellular virions. (+) RNAs display a defined temporal kinetics, with the majority of (+) RNAs associated with actively translating ribosomes at early times of infection, followed by a shift to replication and then virion assembly. (?) RNAs have a strong colocalization with NS5A, but not NS3, at early time points that correlate with replication compartment formation. At later times, only ~30% of the replication complexes appear to be active at a given time, as defined by (?) strand colocalization with either (+) RNA, NS3, or NS5A. While both (+) and (?) RNAs colocalize with the viral proteins NS3 and NS5A, only the plus strand preferentially colocalizes with the viral envelope E2 protein. These results suggest a defined spatiotemporal regulation of HCV infection with highly varied replication efficiencies at the single cell level. This approach can be applicable to all plus strand RNA viruses and enables unprecedented sensitivity for studying early events in the viral life cycle. PMID:25822891

  6. Assessment of virus infection in cultured cells using metabolic monitoring.

    PubMed

    Singhvi, R; Markusen, J F; Ky, B; Horvath, B J; Aunins, J G

    1996-01-01

    A rapid, in-process assessment of virus replication is disired to quickly investigate the effects of process parameters on virus infection, and to monitor consistency of process in routine manufacturing of viral vaccines. Live virus potency assays are generally based on plaque formation, cytopathic effect, or antigen production (TCID(50)) and can take days to weeks to complete. Interestingly, when infected with viruses, cultured cells undergo changes in cellular metabolism that can be easily measured. These phenomena appear to be common as they has been observed in a variety of virus-host systems, e.g., in insect cells infected with baculovirus, Vero cells infected with Rotavirus, MRC-5 cells infected with Hepatitis A virus, and MRC-5 cells infected with the Varicella Zoster Virus (VZV). In this article, changes in glycolytic metabolism of MRC-5 cells as a result of CVZ infection are described. Both glucose consumption and lactate production in VZV infected MRC-5 cells are significantly elevated in comparison to uninfected cells. Based on this result, a rapid, in-process assay to follow VZV infection has been developed. The relative increase in lactate production in infected cells (?) increases as the infection progresses and then plateaus as the infection peaks. This plateau correlates with time of peak virus titer and could be used as a harvest triggering parameter in a virus production process.X(u) = cell density of uninfected cellsX(i) = cell density of infected cellsX(T) = total cell densityL(i) = cumulative lactate production in infected culturesL(u) = cumulative lactate production in uninfected culturesq(Li) = specific lactate production of infected cellsq(Lu) = specific lactate production of uninfected cellsk(1), K(2) = constants. PMID:22358917

  7. ROLE OF MONOCYTES IN RESPIRATORY SYNCTIAL VIRUS (RSV) INFECTION.

    EPA Science Inventory

    ROLE OF MONOCYTES IN RESPIRATORY SYNCYTIAL VIRUS (RSV) INFECTION. Joleen M. Soukup and Susanne Becker, National Health and Environmental Effects Research Laboratory, US EPA, Research Traingle Park, NC USA. RSV infection in airway epithelial cells (EC) results i...

  8. T-lymphocyte senescence and hepatitis C virus infection

    E-print Network

    Hoare, Matthew

    2010-07-06

    Hepatitis C virus (HCV) infection is a leading cause of cirrhosis and hepatocellular carcinoma. The degree of fibrosis progression and treatment-related outcomes are critically dependent on the age of the infected individual. Progressive ageing...

  9. Transfer of neuropathogenic simian immunodeficiency virus with naturally infected microglia.

    PubMed Central

    Watry, D.; Lane, T. E.; Streb, M.; Fox, H. S.

    1995-01-01

    The central nervous system (CNS) is a target for human immunodeficiency virus infection, and, in individuals with acquired immune deficiency syndrome, this can lead to a devastating dementia. Only certain viral variants appear capable of invading the CNS and infecting microglia and brain macrophages. To determine whether the virus entering the brain may be particularly pathogenic to the CNS, we isolated microglia from the brains of simian immunodeficiency virus-infected rhesus monkeys. Serial transfer of these cells into naive animals indicated that productive simian immunodeficiency virus infection could indeed be transferred. Furthermore, CNS infection occurred within a relatively short time span and was associated with viral gene expression in the brain and pathology characteristic of human immunodeficiency virus encephalitis. While demonstrating that neuropathogenic variants partition into the CNS, our approach will allow the dissection of functional neuropathogenic elements present in these viruses. Images Figure 2 Figure 4 Figure 5 Figure 6 Figure 7 PMID:7717458

  10. [Application possibility of the macrolides for the RS virus infections].

    PubMed

    Yokota, Shin-ichi; Tsutsumi, Hiroyuki; Himi, Tetsuo

    2014-06-01

    Human respiratory syncytial virus (RSV) is a major causative agent of respiratory infections. Common cold syndrome caused by RS virus, which is prevalent in winter, occasionally develops into bronchitis, bronchiolitis and pneumonia. In particular, severe RS virus infections in infants with underlying cardiopulmonary diseases and with low-birth weight baby have been a problem. Furthermore, repetitive RS virus infections occur for the entire lifetime, and the relationship between RS virus infections and exacerbation of COPD and bronchial asthma is also indicated mainly in elderly individuals. Various immunomodulatory effects other than antimicrobial activity of macrolides, including clarithromycin, have been reported, and their clinical usefulness is shown mainly in respiratory diseases. This review describes the findings of action of macrolides on RS virus infections. PMID:25163248

  11. Schmallenberg virus experimental infection of sheep.

    PubMed

    Wernike, Kerstin; Hoffmann, Bernd; Bréard, Emmanuel; Bøtner, Anette; Ponsart, Claire; Zientara, Stéphan; Lohse, Louise; Pozzi, Nathalie; Viarouge, Cyril; Sarradin, Pierre; Leroux-Barc, Céline; Riou, Mickael; Laloy, Eve; Breithaupt, Angele; Beer, Martin

    2013-10-25

    Since late 2011, a novel orthobunyavirus, named Schmallenberg virus (SBV), has been implicated in many cases of severely malformed bovine and ovine offspring in Europe. In adult cattle, SBV is known to cause a mild transient disease; clinical signs include short febrile episodes, decreased milk production and diarrhoea for a few days. However, the knowledge about clinical signs and pathogenesis in adult sheep is limited. In the present study, adult sheep of European domestic breeds were inoculated with SBV either as cell culture grown virus or as virus with no history of passage in cell cultures. Various experimental set-ups were used. Sampling included blood collection at different time points during the experimental period and selected organ material at autopsy. Data from this study showed, that the RNAemic period in sheep was as short as reported for cattle; viral genome was detectable for about 3-5 days by real-time RT-PCR. In total, 13 out of 30 inoculated sheep became RNAemic, with the highest viral load in animals inoculated with virus from low cell culture passaged or the animal passaged material. Contact animals remained negative throughout the study. One RNAemic sheep showed diarrhoea for several days, but fever was not recorded in any of the animals. Antibodies were first detectable 10-14 days post inoculation. Viral RNA was detectable in spleen and lymph nodes up to day 44 post inoculation. In conclusion, as described for cattle, SBV-infection in adult sheep predominantly results in subclinical infection, transient RNAemia and a specific antibody response. Maintenance of viral RNA in the lymphoreticular system is observed for an extended period. PMID:23972950

  12. Infection cycles of large DNA viruses: emerging themes and underlying questions.

    PubMed

    Mutsafi, Yael; Fridmann-Sirkis, Yael; Milrot, Elad; Hevroni, Liron; Minsky, Abraham

    2014-10-01

    The discovery of giant DNA viruses and the recent realization that such viruses are diverse and abundant blurred the distinction between viruses and cells. These findings elicited lively debates on the nature and origin of viruses as well as on their potential roles in the evolution of cells. The following essay is, however, concerned with new insights into fundamental structural and physical aspects of viral replication that were derived from studies conducted on large DNA viruses. Specifically, the entirely cytoplasmic replication cycles of Mimivirus and Vaccinia are discussed in light of the highly limited trafficking of large macromolecules in the crowded cytoplasm of cells. The extensive spatiotemporal order revealed by cytoplasmic viral factories is described and contended to play an important role in promoting the efficiency of these 'nuclear-like' organelles. Generation of single-layered internal membrane sheets in Mimivirus and Vaccinia, which proceeds through a novel membrane biogenesis mechanism that enables continuous supply of lipids, is highlighted as an intriguing case study of self-assembly. Mimivirus genome encapsidation was shown to occur through a portal different from the 'stargate' portal that is used for genome release. Such a 'division of labor' is proposed to enhance the efficacy of translocation processes of very large viral genomes. Finally, open questions concerning the infection cycles of giant viruses to which future studies are likely to provide novel and exciting answers are discussed. PMID:24996494

  13. Dynamics of perinatal bovine leukemia virus infection

    PubMed Central

    2014-01-01

    Background Bovine leukemia virus (BLV) is highly endemic in many countries, including Argentina. As prevention of the spread from infected animals is of primary importance in breaking the cycle of BLV transmission, it is important to know the pathophysiology of BLV infection in young animals, as they are the main source of animal movement. In this work, we determined the proviral load and antibody titers of infected newborn calves from birth to first parturition (36 months). Results All calves under study were born to infected dams with high proviral load (PVL) in blood and high antibody titers and detectable provirus in the colostrum. The PVL for five out of seven calves was low at birth. All animals reached PVLs of more than 1% infected peripheral blood mononuclear cells (PBMCs), three at 3 months, one at 6 months, and one at 12 months. High PVLs persisted until the end of the study, and, in two animals, exceeded one BLV copy per cell. Two other calves maintained a high PVL from birth until the end of the study. Antibody titers were 32 or higher in the first sample from six out of seven calves. These decayed at 3–6 months to 16 or lower, and then increased again after this point. Conclusions Calves infected during the first week of life could play an active role in early propagation of BLV to susceptible animals, since their PVL raised up during the first 12 months and persist as high for years. Early elimination could help to prevent transmission to young susceptible animals and to their own offspring. To our knowledge, this is the first study of the kinetics of BLV proviral load and antibody titers in newborn infected calves. PMID:24708791

  14. Suppression of human immunodeficiency virus replication by ascorbate in chronically and acutely infected cells.

    PubMed Central

    Harakeh, S; Jariwalla, R J; Pauling, L

    1990-01-01

    We have studied the action of ascorbate (vitamin C) on human immunodeficiency virus type 1 (HIV-1), the etiological agent clinically associated with AIDS. We report the suppression of virus production and cell fusion in HIV-infected T-lymphocytic cell lines grown in the presence of nontoxic concentrations of ascorbate. In chronically infected cells expressing HIV at peak levels, ascorbate reduced the levels of extracellular reverse transcriptase (RT) activity (by greater than 99%) and of p24 antigen (by 90%) in the culture supernatant. Under similar conditions, no detectable inhibitory effects on cell viability, host metabolic activity, and protein synthesis were observed. In freshly infected CD4+ cells, ascorbate inhibited the formation of giant-cell syncytia (by approximately 93%). Exposure of cell-free virus to ascorbate at 37 degrees C for 1 day had no effect on its RT activity or syncytium-forming ability. Prolonged exposure of virus (37 degrees C for 4 days) in the presence of ascorbate (100-150 micrograms/ml) resulted in the drop by a factor of 3-14 in RT activity as compared to a reduction by a factor of 25-172 in extracellular RT released from chronically infected cells. These results indicate that ascorbate mediates an anti-HIV effect by diminishing viral protein production in infected cells and RT stability in extracellular virions. Images PMID:1698293

  15. ENHANCED AND PROLONGED PULMONARY INFLUENZA VIRUS INFECTION FOLLOWING PHOSGENE INHALATION

    EPA Science Inventory

    Animal infectivity models have been important in the demonstration of enhanced susceptibility to viral and bacterial infection as a result of low level toxicant exposure. his study demonstrated an enhanced and prolonged viral infection using an influenza virus infectivity model i...

  16. Enhanced and prolonged pulmonary influenza virus infection following phosgene inhalation

    Microsoft Academic Search

    Jeffrey P. Ehrlich; Gary R. Burleson

    1991-01-01

    Animal infectivity models have been important in the demonstration of enhanced susceptibility to viral and bacterial infection as a result of low?level toxicant exposure. This study demonstrated an enhanced and prolonged viral infection using an influenza virus infectivity model in the rat following exposure to the toxicant gas phosgene. Fischer?344 rats exposed to either air or a sublethal concentration of

  17. Update on hepatitis B virus infection

    PubMed Central

    You, Chan Ran; Lee, Sung Won; Jang, Jeong Won; Yoon, Seung Kew

    2014-01-01

    Chronic infection with hepatitis B virus (HBV) leads to the development of hepatocellular carcinoma and/or chronic liver failure. Despite extensive research, the immunopathogenesis is not completely understood. Viral persistence and clinical outcomes following HBV infection depend on viral factors and host factors; including genetic factors that determine a host’s immune mechanisms. The primary goal of chronic hepatitis B (CHB) treatment is to eradicate HBV or to at least maintain suppression of HBV replication. Despite recent advances in anti-viral agents for chronic HBV infection, complete eradication of the virus has been difficult to achieve. Agents for the treatment of CHB are divided mainly into two groups: immunomodulating agents and antiviral nucleos(t)ide analogues (NAs). Although NAs are safe, effective and easily administered orally, their long-term use poses the risk of drug resistance. Currently, international evidence-based guidelines have been developed to support physicians in managing CHB patients. However, treatment of patients with drug resistance is still challenging, as only a few classes of anti-HBV drugs are available and cross-resistance between drugs can occur. In addition, as the currently available genotypic test for detection of drug resistance still has limitations in identifying the different substitutions present in the same viral genome, the development of a new virologic test to overcome this limitation is necessary. Among the predictive factors associated with response to pegylated interferon (PEG-IFN) therapy, hepatitis B surface antigen quantification is considered to be a surrogate marker for monitoring response to PEG-IFN. Current practice guidelines stress the importance of profound and durable HBV viral suppression in the treatment of CHB patients. To this end, it is essential to choose a potent antiviral drug with a low risk of resistance for initial treatment of CHB to achieve sustained virological response. This review highlights recent advances in the understanding of the immunopathogenesis of HBV and currently available and developing treatment strategies against HBV infection. PMID:25309066

  18. Rabies virus infects mouse and human lymphocytes and induces apoptosis.

    PubMed Central

    Thoulouze, M I; Lafage, M; Montano-Hirose, J A; Lafon, M

    1997-01-01

    Attenuated and highly neurovirulent rabies virus strains have distinct cellular tropisms. Highly neurovirulent strains such as the challenge virus standard (CVS) are highly neurotropic, whereas the attenuated strain ERA also infects nonneuronal cells. We report that both rabies virus strains infect activated murine lymphocytes and the human lymphoblastoid Jurkat T-cell line in vitro. The lymphocytes are more permissive to the attenuated ERA rabies virus strain than to the CVS strain in both cases. We also report that in contrast to that of the CVS strain, ERA viral replication induces apoptosis of infected Jurkat T cells, and cell death is concomitant with viral glycoprotein expression, suggesting that this protein has a role in the induction of apoptosis. Our data indicate that (i) rabies virus infects lymphocytes, (ii) lymphocyte infection with the attenuated rabies virus strain causes apoptosis, and (iii) apoptosis does not hinder rabies virus production. In contrast to CVS, ERA rabies virus and other attenuated rabies virus vaccines stimulate a strong immune response and are efficient live vaccines. The paradoxical finding that a rabies virus triggers a strong immune response despite the fact that it infects lymphocytes and induces apoptosis is discussed in terms of the function of apoptosis in the immune response. PMID:9311815

  19. Simultaneous multiplex PCR detection of seven cucurbit-infecting viruses.

    PubMed

    Kwon, Ji Yeon; Hong, Jin Sung; Kim, Min Jea; Choi, Sun Hee; Min, Byeong Eun; Song, Eun Gyeong; Kim, Hyun Hee; Ryu, Ki Hyun

    2014-09-01

    Two multiplex polymerase chain reaction (PCR) systems using dual priming oligonucleotide (DPO) primers were developed for the simultaneous detection of seven cucurbit-infecting viruses. One system allows for the detection of papaya ringspot virus, watermelon mosaic virus, and zucchini yellow mosaic virus, whereas the other permits the detection of cucumber green mottle mosaic virus, cucumber fruit mottle mosaic virus, kyuri green mottle mosaic virus, and zucchini green mottle mosaic virus. Viral species-specific DPO primers developed in this study detected as little as 10 fg/?l of viral RNA under monoplex conditions and 10 pg/?l of viral RNA under multiplex conditions. Multiplex PCR using the DPO primer sets was capable of amplifying viral genes at annealing temperatures ranging from 53 °C to 63 °C. Whereas the use of conventional primers gave rise to non-specific bands, the DPO primers detected target viral genes in the absence of non-specific amplification. When these DPO multiplex primer sets were applied to virus-infected cucurbit samples obtained in the field, multiple infection as well as single infection was accurately identified. This novel approach could also detect multiple viruses in infected seeds. The reliability of multiplex PCR systems using DPO primers for plant virus detection is discussed. PMID:24937806

  20. Treatment of fatal disseminated vaccinia virus infection in immunosuppressed mice.

    PubMed

    Worthington, M; Conliffe, M

    1977-08-01

    Studies were performed to compare the therapeutic effectiveness of three antiviral drugs (ARA-A, ARA-C and IDU) on the course of fatal disseminated vaccinia virus infection in immunosuppressed mice. Treatment with ARA-A begun as late as 7 days after virus infection was significantly effective in preventing death; no antiviral effect of the other two drugs was demonstrated. PMID:302323

  1. Mayaro Virus Infection, Amazon Basin Region, Peru, 2010–2013

    PubMed Central

    Siles, Crystyan; Guevara, Carolina; Vilcarromero, Stalin; Jhonston, Erik J.; Ramal, Cesar; Aguilar, Patricia V.; Ampuero, Julia S.

    2013-01-01

    During 2010–2013, we recruited 16 persons with confirmed Mayaro virus infection in the Peruvian Amazon to prospectively follow clinical symptoms and serologic response over a 12-month period. Mayaro virus infection caused long-term arthralgia in more than half, similar to reports of other arthritogenic alphaviruses. PMID:24210165

  2. Comparative pathology of select agent influenza A virus infections

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Influenza A virus infections may spread rapidly in human populations and cause acute respiratory disease with variable mortality. Two of these influenza viruses have been designated as select agents because of the high case fatality rate: 1918 H1N1 virus and highly pathogenic avian influenza (HPAI) ...

  3. Highly Pathogenic Avian Influenza Virus Infection in Feral Raccoons, Japan

    PubMed Central

    Maeda, Ken; Murakami, Shin; Kiso, Maki; Iwatsuki-Horimoto, Kiyoko; Sashika, Mariko; Ito, Toshihiro; Suzuki, Kazuo; Yokoyama, Mayumi; Kawaoka, Yoshihiro

    2011-01-01

    Although raccoons (Procyon lotor) are susceptible to influenza viruses, highly pathogenic avian influenza virus (H5N1) infection in these animals has not been reported. We performed a serosurvey of apparently healthy feral raccoons in Japan and found specific antibodies to subtype H5N1 viruses. Feral raccoons may pose a risk to farms and public health. PMID:21470469

  4. A framework for modelling trojans and computer virus infection

    E-print Network

    Cairns, Paul

    A framework for modelling trojans and computer virus infection Harold Thimbleby1 , Stuart Anderson2 world, including the possibility of Trojan Horse programs and computer viruses, as simply a finite realisation of a Turing Machine. We consider the actions of Trojan Horses and viruses in real computer systems

  5. Control of immunopathology during chikungunya virus infection.

    PubMed

    Petitdemange, Caroline; Wauquier, Nadia; Vieillard, Vincent

    2015-04-01

    After several decades of epidemiologic silence, chikungunya virus (CHIKV) has recently re-emerged, causing explosive outbreaks and reaching the 5 continents. Transmitted through the bite of Aedes species mosquitoes, CHIKV is responsible for an acute febrile illness accompanied by several characteristic symptoms, including cutaneous rash, myalgia, and arthralgia, with the latter sometimes persisting for months or years. Although CHIKV has previously been known as a relatively benign disease, more recent epidemic events have brought waves of increased morbidity and fatality, leading it to become a serious public health problem. The host's immune response plays a crucial role in controlling the infection, but it might also contribute to the promotion of viral spread and immunopathology. This review focuses on the immune responses to CHIKV in human subjects with an emphasis on early antiviral immune responses. We assess recent developments in the understanding of their possible Janus-faced effects in the control of viral infection and pathogenesis. Although preventive vaccination and specific therapies are yet to be developed, exploring this interesting model of virus-host interactions might have a strong effect on the design of novel therapeutic options to minimize immunopathology without impairing beneficial host defenses. PMID:25843597

  6. Honey Bee Infecting Lake Sinai Viruses

    PubMed Central

    Daughenbaugh, Katie F.; Martin, Madison; Brutscher, Laura M.; Cavigli, Ian; Garcia, Emma; Lavin, Matt; Flenniken, Michelle L.

    2015-01-01

    Honey bees are critical pollinators of important agricultural crops. Recently, high annual losses of honey bee colonies have prompted further investigation of honey bee infecting viruses. To better characterize the recently discovered and very prevalent Lake Sinai virus (LSV) group, we sequenced currently circulating LSVs, performed phylogenetic analysis, and obtained images of LSV2. Sequence analysis resulted in extension of the LSV1 and LSV2 genomes, the first detection of LSV4 in the US, and the discovery of LSV6 and LSV7. We detected LSV1 and LSV2 in the Varroa destructor mite, and determined that a large proportion of LSV2 is found in the honey bee gut, suggesting that vector-mediated, food-associated, and/or fecal-oral routes may be important for LSV dissemination. Pathogen-specific quantitative PCR data, obtained from samples collected during a small-scale monitoring project, revealed that LSV2, LSV1, Black queen cell virus (BQCV), and Nosema ceranae were more abundant in weak colonies than strong colonies within this sample cohort. Together, these results enhance our current understanding of LSVs and illustrate the importance of future studies aimed at investigating the role of LSVs and other pathogens on honey bee health at both the individual and colony levels. PMID:26110586

  7. Honey Bee Infecting Lake Sinai Viruses.

    PubMed

    Daughenbaugh, Katie F; Martin, Madison; Brutscher, Laura M; Cavigli, Ian; Garcia, Emma; Lavin, Matt; Flenniken, Michelle L

    2015-01-01

    Honey bees are critical pollinators of important agricultural crops. Recently, high annual losses of honey bee colonies have prompted further investigation of honey bee infecting viruses. To better characterize the recently discovered and very prevalent Lake Sinai virus (LSV) group, we sequenced currently circulating LSVs, performed phylogenetic analysis, and obtained images of LSV2. Sequence analysis resulted in extension of the LSV1 and LSV2 genomes, the first detection of LSV4 in the US, and the discovery of LSV6 and LSV7. We detected LSV1 and LSV2 in the Varroa destructor mite, and determined that a large proportion of LSV2 is found in the honey bee gut, suggesting that vector-mediated, food-associated, and/or fecal-oral routes may be important for LSV dissemination. Pathogen-specific quantitative PCR data, obtained from samples collected during a small-scale monitoring project, revealed that LSV2, LSV1, Black queen cell virus (BQCV), and Nosema ceranae were more abundant in weak colonies than strong colonies within this sample cohort. Together, these results enhance our current understanding of LSVs and illustrate the importance of future studies aimed at investigating the role of LSVs and other pathogens on honey bee health at both the individual and colony levels. PMID:26110586

  8. Paramecium bursaria Chlorella Virus 1 Proteome Reveals Novel Architectural and Regulatory Features of a Giant Virus

    PubMed Central

    Cerny, Ronald L.; Bauman, Andrew T.; Roach, Jared C.; Lane, Leslie C.; Agarkova, Irina V.; Wulser, Kurt; Yanai-Balser, Giane M.; Gurnon, James R.; Vitek, Jason C.; Kronschnabel, Bernard J.; Jeanniard, Adrien; Blanc, Guillaume; Upton, Chris; Duncan, Garry A.; McClung, O. William; Ma, Fangrui

    2012-01-01

    The 331-kbp chlorovirus Paramecium bursaria chlorella virus 1 (PBCV-1) genome was resequenced and annotated to correct errors in the original 15-year-old sequence; 40 codons was considered the minimum protein size of an open reading frame. PBCV-1 has 416 predicted protein-encoding sequences and 11 tRNAs. A proteome analysis was also conducted on highly purified PBCV-1 virions using two mass spectrometry-based protocols. The mass spectrometry-derived data were compared to PBCV-1 and its host Chlorella variabilis NC64A predicted proteomes. Combined, these analyses revealed 148 unique virus-encoded proteins associated with the virion (about 35% of the coding capacity of the virus) and 1 host protein. Some of these proteins appear to be structural/architectural, whereas others have enzymatic, chromatin modification, and signal transduction functions. Most (106) of the proteins have no known function or homologs in the existing gene databases except as orthologs with proteins of other chloroviruses, phycodnaviruses, and nuclear-cytoplasmic large DNA viruses. The genes encoding these proteins are dispersed throughout the virus genome, and most are transcribed late or early-late in the infection cycle, which is consistent with virion morphogenesis. PMID:22696644

  9. Immunomodulatory Activity of Red Ginseng against Influenza A Virus Infection

    PubMed Central

    Lee, Jong Seok; Hwang, Hye Suk; Ko, Eun-Ju; Lee, Yu-Na; Kwon, Young-Man; Kim, Min-Chul; Kang, Sang-Moo

    2014-01-01

    Ginseng herbal medicine has been known to have beneficial effects on improving human health. We investigated whether red ginseng extract (RGE) has preventive effects on influenza A virus infection in vivo and in vitro. RGE was found to improve survival of human lung epithelial cells upon influenza virus infection. Also, RGE treatment reduced the expression of pro-inflammatory genes (IL-6, IL-8) probably in part through interference with the formation of reactive oxygen species by influenza A virus infection. Long-term oral administration of mice with RGE showed multiple immunomodulatory effects such as stimulating antiviral cytokine IFN-? production after influenza A virus infection. In addition, RGE administration in mice inhibited the infiltration of inflammatory cells into the bronchial lumens. Therefore, RGE might have the potential beneficial effects on preventing influenza A virus infections via its multiple immunomodulatory functions. PMID:24473234

  10. Experimental infection of prairie dogs with monkeypox virus.

    PubMed

    Xiao, Shu-Yuan; Sbrana, Elena; Watts, Douglas M; Siirin, Marina; da Rosa, Amelia P A Travassos; Tesh, Robert B

    2005-04-01

    Studies of experimental infection of prairie dogs (Cynomys ludovicianus) with monkeypox virus are described. After intraperitoneal infection, all of the animals died within 11 days. Virus was cultured from their blood and oropharynx several days before death; at necropsy, most of the organs tested contained monkeypox virus. Marked hepatic and splenic necrosis were observed, along with mild inflammatory changes in the lungs. After intranasal (IN) infection, the primary pathologic changes were in the lungs and pleural cavity. Some of the IN infected animals (40%) survived, and monkeypox virus could be cultured from their nasal discharge and oropharynx for <22 days. Ulcerative lesions also developed on the lips, tongue, and buccal mucosa of the surviving animals. Our findings support an earlier report, which suggested that infected prairie dogs can transmit monkeypox virus by respiratory and mucocutaneous contact with susceptible animals and persons. PMID:15829191

  11. Regulatory Role of CD1d in Neurotropic Virus Infection

    Microsoft Academic Search

    Ikuo Tsunoda; Tomoko Tanaka; Robert S. Fujinami

    2008-01-01

    The GDVII strain of Theiler's murine encephalomyelitis virus (TMEV) causes an acute fatal polioencepha- lomyelitis in mice. Infection of susceptible mice with the DA strain of TMEV results in an acute polioencepha- lomyelitis followed by chronic immune-mediated demyelination with virus persistence in the central nervous system (CNS); DA virus infection is used as an animal model for multiple sclerosis. CD1d-restricted

  12. Inhibition of hepatitis C virus infection by polyoxometalates.

    PubMed

    Qi, Yue; Xiang, Yu; Wang, Juan; Qi, Yanfei; Li, Juan; Niu, Junqi; Zhong, Jin

    2013-11-01

    Hepatitis C virus (HCV) infects about 2% of the world population. The standard treatment of chronic HCV infection is still discontented because of the low sustained virological response rate. The development of new HCV antivirals is a healthcare imperative. We explored the potentials of polyoxometalates to inhibit HCV infection using newly developed HCVcc cell culture system. We found one polyoxometalate compound (named POM-12) can inhibit HCV infection at the nanomolar range while displayed little cytotoxicity. We showed that POM-12 inhibited pseudotyped HCV infection but had no effect on HCV RNA replication. Furthermore, we showed that POM-12 was virucidal and can disrupt HCV particles. Finally we demonstrated that POM-12 had no effect on the vesicular stomatitis virus infection while had weak inhibitory activity against the influenza virus infection. In conclusion, we identified a potent anti-HCV compound which may provide an attractive drug candidate to cure HCV infection. PMID:24025401

  13. Epidemiological and clinical evaluation of children with respiratory virus infections

    PubMed Central

    Shatizadeh, Somayeh; Yavarian, Jila; Rezaie, Farhad; Mahmoodi, Mahmood; Naseri, Maryam; Mokhtari Azad, Talat

    2014-01-01

    Background: Respiratory viruses are the leading cause of respiratory tract infections among children and are responsible for causing morbidity and mortality worldwide. This study was performed to detect viruses in children with respiratory infections and describe their epidemiology and clinical characteristics. Methods: In this descriptive cross sectional study, throat swabs and wash specimens from 202 children younger than six years of age with diagnosis of a respiratory tract infection from a total of 897 specimens were evaluated using multiplex PCR method. Results: Respiratory viruses were detected in 92 children: respiratory synsytial virus, 16.8%; influenza virus, 5.4%; parainfluenza virus, 8.4%; adenovirus, 14.4% and human metapneumo virus 0.49% with male predominance and higher distribution in children younger than 1 year of age with preference in the cold months of year. The clinical presentations of all detected viruses were almost similar. Conclusion: In the present study, nine different respiratory viruses were detected. RSV causes the great majority of respiratory virus infections in children. There was no significant difference in epidemiologic patterns of these viruses in comparison to other studies. PMID:25664303

  14. New virus dynamics in the presence of multiple infection.

    PubMed

    Asatryan, Ani; Wodarz, Dominik; Komarova, Natalia L

    2015-07-21

    While most aspects of virus dynamics are well understood in standard models, the phenomenon of multiple infection (or coinfection) can change the properties of the dynamics, and this has so far not been fully explored. An important parameter in determining the properties of the model is the virus output from multiply infected cells compared to that from singly infected cells. If the amount of virus produced by infected cells during their life-span is independent of the infection multiplicity, then multiple infection does not change the dynamics. If, however, multiply infected cells produce more virus during their life-span than singly infected cells, then the properties of the dynamics can change fundamentally. This paper presents a detailed mathematical analysis of this scenario. We demonstrate that under some realistic conditions, the equilibrium structure of the solutions acquires novel properties. In particular, infection can persist even for values of the basic reproductive number, R0, smaller than unity. In this regime, we observe the phenomenon of bistability, when two stable equilibria are present simultaneously, and the outcome is determined by the initial conditions. The two possible solutions are the virus-free equilibrium, which is exactly the same as the one observed in the absence of multiple infection, and a novel infection equilibrium. In the presence of this outcome, it is clear that the meaning of the parameter R0 changes, as it no longer simply indicates the possibility of successful infection. This adds to our understanding and interpretation of R0 in virus dynamics models, and also provides further insights about conditions that can lead to virus extinction rather than persistence. It turns out that conditions for bistability depend (in a fully specified way) on the model structure, particularly on the way the infection term is formulated. We provide a general condition that informs us whether or not bistability occurs, and define what needs to be measured when examining the dynamics of multiple infection in specific biological systems. PMID:25908207

  15. Hepatitis B virus infection and intrahepatic cholangiocarcinoma.

    PubMed

    Zhou, Hua-Bang; Hu, Jing-Yi; Hu, He-Ping

    2014-05-21

    Intrahepatic cholangiocarcinoma (ICC) is a devastating malignant tumor arising from the peripheral intrahepatic bile duct epithelium. The incidence and mortality of ICC is markedly increasing over the past two decades worldwide, though the cause for this rise in incidence is unclear, thus intensifying the search for alternative etiological agents and pathogenetic mechanisms. Hepatolithiasis, primary sclerosing cholangitis, parasitic infection (Opisthorchis viverrini or Clonorchis sinensis), fibropolycystic liver disease, and chemical carcinogen exposure are thought to be the risk factors for ICC. Nevertheless, the majority of ICC patients do not have any of these risk factors, and none of the established risk factors can explain the recent increasing trend of ICC. Therefore, identifying other risk factors may lead to the prevention and early detection of ICC. Chronic hepatitis B virus (HBV) infection is the predominant cause of hepatocellular carcinoma in HBV-endemic areas. This review discusses the evidence implicating chronic HBV infection as a likely etiology of ICC and the pathogenetic mechanisms that might be involved. PMID:24914333

  16. Hepatitis C virus infection and glomerular disease.

    PubMed

    Fabrizi, F; Donato, F; Messa, P

    2014-06-01

    The association between hepatitis C virus (HCV) infection and chronic kidney disease (CKD) is well established and remains an area of intense research. HCV infection is associated with a large spectrum of histo-pathological lesions in both native and transplanted kidneys. The frequency of kidney damage in HCV-infected patients appears low even if is not fully detailed. The most frequent HCV-associated renal lesion is type I membrano-proliferative glomerulonephritis, usually in the context of type II mixed cryoglobulinemia. Various approaches have been tried for the treatment of HCV-related glomerulonephritis, including immunosuppressive therapy (corticosteroids and cytotoxic agents), plasma exchange and antiviral agents. Antiviral treatment of HCV-associated glomerulonephritis has shown encouraging results. Immunosuppressive therapy is particularly recommended for cryoglobulinemic kidney disease. Two distinct approaches should be considered for the treatment of HCV-associated cryoglobulinemic glomerulonephritis according to the level of proteinuria and kidney failure. Some evidence on rituximab therapy for HCV-related cryoglobulinemic glomerulonephritis exists but several questions related to its use need to be addressed. PMID:24988205

  17. Inhibition of cowpox virus and monkeypox virus infection by mitoxantrone

    PubMed Central

    Altmann, Sharon E.; Smith, Alvin L.; Dyall, Julie; Johnson, Reed F.; Dodd, Lori E.; Jahrling, Peter B.; Paragas, Jason; Blaney, Joseph E.

    2012-01-01

    Summary Mitoxantrone, an FDA-approved therapeutic for the treatment of cancer and multiple sclerosis, was previously reported to exhibit antiviral activity against vaccinia virus. To determine whether this activity extends to other orthopoxviruses, mitoxantrone was tested against cowpox and monkeypox. Mitoxantrone demonstrated an EC50 of 0.25 ?M against cowpox and 0.8 ?M against monkeypox. Intraperitoneal treatment of cowpox virus-challenged C57Bl/6 mice with 0.5 mg/kg mitoxantrone resulted in 25% survival and a significant increase in survival time. In an effort to improve its efficacy, mitoxantrone was tested for synergistic activity with cidofovir. In vitro tests demonstrated significant synergy between the two drugs against cowpox; however, no synergistic effect on animal survival or median time-to-death was seen in intranasally-infected BALB/c mice. Significantly fewer animals survived when treated with a combination of 0.5 mg/kg mitoxantrone and 100 mg/kg cidofovir than with 100 mg/kg cidofovir alone. This is, to our knowledge, the first report of limited anti-orthopoxvirus activity by mitoxantrone in an animal model. PMID:22182595

  18. Choclo Virus Infection in the Syrian Golden Hamster

    PubMed Central

    Eyzaguirre, Eduardo J.; Milazzo, Mary Louise; Koster, Frederick T.; Fulhorst, Charles F.

    2009-01-01

    Andes virus and Choclo virus are agents of hantavirus pulmonary syndrome. Andes virus in hamsters almost always causes a disease that is pathologically indistinguishable from fatal hantavirus pulmonary syndrome. The purpose of this study was to assess the pathogenicity of Choclo virus in hamsters. None of 18 hamsters infected with Choclo virus exhibited any symptom of disease. No evidence of inflammation or edema was found in the lungs of the 10 animals killed on days 7, 9, 11, 13, and 16 post-inoculation or in the lungs of the 8 animals killed on day 28 post-inoculation; however, hantavirus antigen was present in large numbers of endothelial cells in the microvasculature of the lungs of the animals killed on days 7, 9, 11, and 13 post-inoculation. These results suggest that infection in the microvasculature of lung tissue alone does not result in the life-threatening pulmonary edema in hamsters infected with Andes virus. PMID:18385367

  19. Unfolded protein response in hepatitis C virus infection

    PubMed Central

    Chan, Shiu-Wan

    2014-01-01

    Hepatitis C virus (HCV) is a single-stranded, positive-sense RNA virus of clinical importance. The virus establishes a chronic infection and can progress from chronic hepatitis, steatosis to fibrosis, cirrhosis, and hepatocellular carcinoma (HCC). The mechanisms of viral persistence and pathogenesis are poorly understood. Recently the unfolded protein response (UPR), a cellular homeostatic response to endoplasmic reticulum (ER) stress, has emerged to be a major contributing factor in many human diseases. It is also evident that viruses interact with the host UPR in many different ways and the outcome could be pro-viral, anti-viral or pathogenic, depending on the particular type of infection. Here we present evidence for the elicitation of chronic ER stress in HCV infection. We analyze the UPR signaling pathways involved in HCV infection, the various levels of UPR regulation by different viral proteins and finally, we propose several mechanisms by which the virus provokes the UPR. PMID:24904547

  20. Early Dengue Virus Infection in Human Skin: A Cycle of Inflammation and Infectivity.

    PubMed

    Ivory, Matthew O; Birchall, James C; Piguet, Vincent

    2015-07-01

    Early events during dengue virus (DENV) infection remain poorly understood. In this issue, Schaeffer and colleagues employ ex vivo human skin cells to investigate viral infection. They show that skin-resident immune cells are infected by DENV and that their infectability is increased in the inflammatory skin conditions (especially those in which IL-4 is released) that accompany the mosquito bites transmitting the virus. PMID:26066889

  1. A Novel Single Virus Infection System Reveals That Influenza Virus Preferentially Infects Cells in G1 Phase

    PubMed Central

    Ueda, Ryuta; Sugiura, Tadao; Kume, Shinichiro; Ichikawa, Akihiko; Larsen, Steven; Miyoshi, Hideaki; Hiramatsu, Hiroaki; Nagatsuka, Yasuko; Arai, Fumihito; Suzuki, Yasuo; Hirabayashi, Yoshio; Fukuda, Toshio; Honda, Ayae

    2013-01-01

    Background Influenza virus attaches to sialic acid residues on the surface of host cells via the hemagglutinin (HA), a glycoprotein expressed on the viral envelope, and enters into the cytoplasm by receptor-mediated endocytosis. The viral genome is released and transported in to the nucleus, where transcription and replication take place. However, cellular factors affecting the influenza virus infection such as the cell cycle remain uncharacterized. Methods/Results To resolve the influence of cell cycle on influenza virus infection, we performed a single-virus infection analysis using optical tweezers. Using this newly developed single-virus infection system, the fluorescence-labeled influenza virus was trapped on a microchip using a laser (1064 nm) at 0.6 W, transported, and released onto individual H292 human lung epithelial cells. Interestingly, the influenza virus attached selectively to cells in the G1-phase. To clarify the molecular differences between cells in G1- and S/G2/M-phase, we performed several physical and chemical assays. Results indicated that: 1) the membranes of cells in G1-phase contained greater amounts of sialic acids (glycoproteins) than the membranes of cells in S/G2/M-phase; 2) the membrane stiffness of cells in S/G2/M-phase is more rigid than those in G1-phase by measurement using optical tweezers; and 3) S/G2/M-phase cells contained higher content of Gb3, Gb4 and GlcCer than G1-phase cells by an assay for lipid composition. Conclusions A novel single-virus infection system was developed to characterize the difference in influenza virus susceptibility between G1- and S/G2/M-phase cells. Differences in virus binding specificity were associated with alterations in the lipid composition, sialic acid content, and membrane stiffness. This single-virus infection system will be useful for studying the infection mechanisms of other viruses. PMID:23874406

  2. Characterization of shrimp Drosha in virus infection.

    PubMed

    Huang, Tianzhi; Xu, Dandan; Zhang, Xiaobo

    2012-09-01

    RNA interference (RNAi) mediated by microRNA (miRNA) is an evolutionarily conserved mechanism of posttranscriptional gene regulation in all eukaryotes, involving in natural antiviral immunity. The RNAase III Drosha is a key component for miRNA maturation. To date, however, the roles of Drosha in virus infection remain to be addressed. In this study, the Drosha was characterized in Marsupenaeus japonicus shrimp. The sequence analysis revealed that the shrimp Drosha gene encoded a 1081-amino-acid peptide, which comprised two tandem ribonuclease III C terminal domains and a double-stranded RNA binding motif. The shrimp Drosha was homologous with those of other animal species. The quantitative RT-PCR analysis revealed that the Drosha gene was highly expressed in lymphoid organ and was significantly up-regulated in response to WSSV challenge, suggesting that the Drosha was involved in the antiviral immunity of shrimp. The results showed that the knock down of Drosha gene led to the defect of miRNA maturation, and subsequent higher virus loads in shrimp. Our study presented that Drosha played important roles in the antiviral defense of shrimp. PMID:22796424

  3. Initiation and maintenance of persistent infection by respiratory syncytial virus.

    PubMed Central

    P'ringle, C R; Shirodaria, P V; Cash, P; Chiswell, D J; Malloy, P

    1978-01-01

    Propagation of cells infected with temperature-sensitive (ts) mutants of respiratory syncytial (RS) virus at nonpermissive temperature (39 degrees C) resulted in cytolytic, abortive, or persistent infection, depending on the mutant used to initiate infection. Five mutants from complementation group B produced cytolytic or abortive infections, whereas a single mutant (ts1) from group D and a noncomplbmenting mutant produced persistent infections. The persistently infected culture initiated by mutant ts1 (RS ts1/BS-C-1) has been maintained in serial culture for greater than 100 transfers, and infectious-center assays and immunofluorescent staining indicated that all cells harbored the RS virus genome. RS ts1/BS-C-1 cultures were resistant to superinfection by homologous and some heterologous viruses, and interferon-like activity against some heterologous viruses was present in the culture medium. Small amounts (0.002 to 0.2 PFU/cell) of infectious virus were present in the culture fluid, but autointerfering defective particles were not detected. This released virus formed small plaques and produced persistent infection of BS-C-1 cells at 37 degrees C. The RS ts1/BS-C-1 cells contained abundant RS virus antigen internally, but little at the surface, although the cells showed enhanced agglutinability by concanavalin A. Nucleocapsids and the 41,000-molecular-weight nucleoprotein were present in extracts of both nucleated and enucleated cells. No infectious RS virus was obtained by transfection of DNA from RS tsl/BS-C-1 cells to susceptible BS-C-1 or feline embryo cells under conditions allowing efficient transfection of a foamy virus proviral DNA. It was concluded that persistent infection was maintained in part by a non-ts variant of RS virus partially defective in maturation. The karyotype of the RS ts1/BS-C-1 culture differed from that of unifected cells. Images PMID:702647

  4. The Epidemiology of Herpes Simplex Virus Infections in Adolescents

    Microsoft Academic Search

    Susan L Rosenthal

    1999-01-01

    SUMMARY Herpes simplex virus type 1 and type 2 (HSV-1 and -2) infections are common among adolescents. HSV-1 can cause either oral or genital infections, whereas HSV-2 causes predominantly genital herpes. Therefore, HSV-2 seroprevalence can be used as a marker of genital herpes. As in adults, genital infections in adolescents are often unrecognized; consequently the magnitude of the problem of

  5. Estimating progression to cirrhosis in chronic hepatitis C virus infection

    Microsoft Academic Search

    Anthony J. Freeman; Gregory J. Dore; Matthew G. Law; Max Thorpe; Jan Von Overbeck; Andrew R. Lloyd; George Marinos; John M. Kaldor

    2001-01-01

    To gain a clearer understanding of the rate of progression to cirrhosis and its determinants in chronic hepatitis C virus (HCV) infection, a systematic review of published epidemiologic studies that incorporated assessment for cirrhosis has been undertaken. Inclusion criteria were more than 20 cases of chronic HCV infection, and information on either age of subjects or duration of infection. Of

  6. Human Immunodeficiency Virus Infection Prevention: Strategies for Clinicians

    Microsoft Academic Search

    Tanya Schreibman; Gerald Friedland

    2003-01-01

    The complexity of the epidemic of human immunodeficiency virus (HIV) infection has made the creation of effective prevention programs an evolving and challenging task. Prevention of new HIV infections is an issue of increasing importance as the prevalence of HIV infection continues to increase. The integration of prevention and clinical care is recognized as a key element of future prevention

  7. Hepatitis C Virus Neuroinvasion: Identification of Infected Cells

    Microsoft Academic Search

    Jeffrey Wilkinson; Marek Radkowski; Tomasz Laskus

    2009-01-01

    Hepatitis C virus (HCV) infection often is associated with cognitive dysfunction and depression. HCV sequences and replicative forms were detected in autopsy brain tissue and cerebrospinal fluid from infected patients, suggesting direct neuroinvasion. However, the phenotype of cells harboring HCV in brain remains unclear. We studied autopsy brain tissue from 12 HCV-infected patients, 6 of whom were coinfected with human

  8. Effects of influenza A virus infection on migrating mallard ducks

    PubMed Central

    Latorre-Margalef, Neus; Gunnarsson, Gunnar; Munster, Vincent J.; Fouchier, Ron A.M.; Osterhaus, Albert D.M.E.; Elmberg, Johan; Olsen, Björn; Wallensten, Anders; Haemig, Paul D.; Fransson, Thord; Brudin, Lars; Waldenström, Jonas

    2008-01-01

    The natural reservoir of influenza A virus is waterfowl, particularly dabbling ducks (genus Anas). Although it has long been assumed that waterfowl are asymptomatic carriers of the virus, a recent study found that low-pathogenic avian influenza (LPAI) infection in Bewick's swans (Cygnus columbianus bewickii) negatively affected stopover time, body mass and feeding behaviour. In the present study, we investigated whether LPAI infection incurred ecological or physiological costs to migratory mallards (Anas platyrhynchos) in terms of body mass loss and staging time, and whether such costs could influence the likelihood for long-distance dispersal of the avian influenza virus by individual ducks. During the autumn migrations of 2002–2007, we collected faecal samples (n=10?918) and biometric data from mallards captured and banded at Ottenby, a major staging site in a flyway connecting breeding and wintering areas of European waterfowl. Body mass was significantly lower in infected ducks than in uninfected ducks (mean difference almost 20?g over all groups), and the amount of virus shed by infected juveniles was negatively correlated with body mass. There was no general effect of infection on staging time, except for juveniles in September, in which birds that shed fewer viruses stayed shorter than birds that shed more viruses. LPAI infection did not affect speed or distance of subsequent migration. The data from recaptured individuals showed that the maximum duration of infection was on average 8.3 days (s.e. 0.5), with a mean minimum duration of virus shedding of only 3.1 days (s.e. 0.1). Shedding time decreased during the season, suggesting that mallards acquire transient immunity for LPAI infection. In conclusion, deteriorated body mass following infection was detected, but it remains to be seen whether this has more long-term fitness effects. The short virus shedding time suggests that individual mallards are less likely to spread the virus at continental or intercontinental scales. PMID:19129127

  9. Effects of influenza A virus infection on migrating mallard ducks.

    PubMed

    Latorre-Margalef, Neus; Gunnarsson, Gunnar; Munster, Vincent J; Fouchier, Ron A M; Osterhaus, Albert D M E; Elmberg, Johan; Olsen, Björn; Wallensten, Anders; Haemig, Paul D; Fransson, Thord; Brudin, Lars; Waldenström, Jonas

    2009-03-22

    The natural reservoir of influenza A virus is waterfowl, particularly dabbling ducks (genus Anas). Although it has long been assumed that waterfowl are asymptomatic carriers of the virus, a recent study found that low-pathogenic avian influenza (LPAI) infection in Bewick's swans (Cygnus columbianus bewickii) negatively affected stopover time, body mass and feeding behaviour. In the present study, we investigated whether LPAI infection incurred ecological or physiological costs to migratory mallards (Anas platyrhynchos) in terms of body mass loss and staging time, and whether such costs could influence the likelihood for long-distance dispersal of the avian influenza virus by individual ducks. During the autumn migrations of 2002-2007, we collected faecal samples (n=10918) and biometric data from mallards captured and banded at Ottenby, a major staging site in a flyway connecting breeding and wintering areas of European waterfowl. Body mass was significantly lower in infected ducks than in uninfected ducks (mean difference almost 20 g over all groups), and the amount of virus shed by infected juveniles was negatively correlated with body mass. There was no general effect of infection on staging time, except for juveniles in September, in which birds that shed fewer viruses stayed shorter than birds that shed more viruses. LPAI infection did not affect speed or distance of subsequent migration. The data from recaptured individuals showed that the maximum duration of infection was on average 8.3 days (s.e. 0.5), with a mean minimum duration of virus shedding of only 3.1 days (s.e. 0.1). Shedding time decreased during the season, suggesting that mallards acquire transient immunity for LPAI infection. In conclusion, deteriorated body mass following infection was detected, but it remains to be seen whether this has more long-term fitness effects. The short virus shedding time suggests that individual mallards are less likely to spread the virus at continental or intercontinental scales. PMID:19129127

  10. Pathological changes in Fenneropenaeus indicus experimentally infected with white spot virus and virus morphogenesis

    Microsoft Academic Search

    M. Manjusha; Resmy Varghese; Rosamma Philip; A. Mohandas; I. S. Bright Singh

    2009-01-01

    To demonstrate pathological changes due to white spot virus infection in Fenneropenaeus indicus, a batch of hatchery bred quarantined animals was experimentally infected with the virus. Organs such as gills, foregut, mid-gut, hindgut, nerve, eye, heart, ovary and integument were examined by light and electron microscopy. Histopathological analyses revealed changes hitherto not reported in F. indicus such as lesions to

  11. Influenza Virus Lung Infection Protects from Respiratory Syncytial Virus-induced Immunopathology

    Microsoft Academic Search

    Gerhard Walzl; Sabrina Tafuro; Paul Moss; Peter J. M. Openshaw; Tracy Hussell

    The effect of infection history is ignored in most animal models of infectious disease. The at- tachment protein of respiratory syncytial virus (RSV) induces T helper cell type 2-driven pul- monary eosinophilia in mice similar to that seen in the failed infant vaccinations in the 1960s. We show that previous influenza virus infection of mice: (a) protects against weight loss,

  12. Pathogenic Interactions Between Sorghum Yellow Banding Virus and Other Viruses Infecting Sorghum.

    E-print Network

    Theu, M.P.K.J; Toler, R.W.

    1992-01-01

    Between Sorghum Yellow Banding Virus and Other Viruses Infecting Sorghum M.P.K.J. Theu and R. W. Toler1 Abstract A pathogenic interaction between sorghum yel low banding virus (SYBV) and maize dwarf mosaic (MDMV-A) virus was proved. Inoculation..., MDMV-A was the only virus that was serologically detected. SYBV infected root tissue revealed the presence of SYBV particles in the mitochondria and not in the nucleus. Maize dwarf mosaic strain 0 also produced a patho genic synergistic interaction...

  13. Liver Enlargement Associated with Opportunistic Infections in Patients with Human Immunodeficiency Virus Infection

    Microsoft Academic Search

    Dragica Terzic; Branko Brmbolic; Djordje Jevtovic; Brankica Dupanovic; Milos Kora; Dubravka Selemovic; Neda Svirtlih; Nenad Draskovic; Boban Mugosa; Ivan Boricic; Zoran Terzic

    Background & Aim. Liver disease is commonly present in human immunodeficiency virus (HIV) infection. The aim was to determine the frequency of liver enlargement and its association with opportunistic infections in patients with HIV infection. Patients and methods. A total of 400 HIV-infected patients were investigated. Commercial kits (Ortho EIA; BioRad, ELISA) were used for detection of serum specific antibodies

  14. Hepatitis B virus and hepatitis C virus co-infection: a therapeutic challenge.

    PubMed

    Hamzaoui, Lamine; El Bouchtili, Souheil; Siai, Karima; Mahmoudi, Moufida; Azzouz, Mohamed Msaddak

    2013-02-01

    Hepatitis B virus and hepatitis C virus are the two most common causes of chronic liver disease in the world. Dual infection with hepatitis B virus and hepatitis C virus, whose prevalence is underestimated, is characterized by a more severe liver injury, a higher probability of liver cirrhosis and a higher incidence of hepatocellular carcinoma. Treatment of these patients represents a therapeutic challenge. We report the case of an hepatitis B virus-hepatitis C virus co-infected patient, which particularly illustrates the interactions between these two viruses and therapeutic problems caused by the dual infection. HCV was initially dominant, which indicated a combination therapy by pegylated interferon and ribavirin. This treatment was associated with an early virological response of the HCV but an increase of HBV DNA occurred, requiring the use of a nucleoside analogue. A good response was obtained for the HBV but a relapse of HCV was noted, posing a problem for therapeutic decision. PMID:22959099

  15. Occult hepatitis B virus infection in Egypt

    PubMed Central

    Elbahrawy, Ashraf; Alaboudy, Alshimaa; El Moghazy, Walid; Elwassief, Ahmed; Alashker, Ahmed; Abdallah, Abdallah Mahmoud

    2015-01-01

    The emerging evidence of the potentially clinical importance of occult hepatitis B virus (HBV) infection (OBI) increases the interest in this topic. OBI may impact in several clinical contexts, which include the possible transmission of the infection, the contribution to liver disease progression, the development of hepatocellular carcinoma, and the risk of reactivation. There are several articles that have published on OBI in Egyptian populations. A review of MEDLINE database was undertaken for relevant articles to clarify the epidemiology of OBI in Egypt. HBV genotype D is the only detectable genotype among Egyptian OBI patients. Higher rates of OBI reported among Egyptian chronic HCV, hemodialysis, children with malignant disorders, and cryptogenic liver disease patients. There is an evidence of OBI reactivation after treatment with chemotherapy. The available data suggested that screening for OBI must be a routine practice in these groups of patients. Further studies needed for better understand of the epidemiology of OBI among Egyptian young generations after the era of hepatitis B vaccination.

  16. The persistence of swine vesicular disease virus infection in pigs.

    PubMed Central

    Lin, F.; Mackay, D. K.; Knowles, N. J.

    1998-01-01

    Two groups of pigs were infected with a recent Italian isolate of swine vesicular disease virus (SVDV). Blood, nasal swabs and faeces were collected for up to 6 months after exposure to infection and animals were killed at regular intervals to obtain tissues post-mortem. These samples were examined for virus by conventional means and for viral RNA (vRNA) by reverse transcription-nested polymerase chain reaction (RT-nPCR). Virus was identified intermittently from both clinically and subclinically infected animals in nasal swabs, faeces and tonsillar tissue by either virus isolation or RT-nPCR up to 63 days post infection (dpi). Between 63 and 119 dpi virus was not detected in the secretions, excretions or tissues of any pigs. Following mixing of the two groups of animals at 119 dpi, SVDV was again identified in faeces for up to 7 days suggesting that the stress of mixing reactivated the excretion of virus in pigs from which the agent could no longer be identified. Minor antigenic changes were identified between the parental virus and isolates recovered late in the course of infection. Altered antigenicity corresponded with deduced amino acid substitutions identified from differences in nucleotide sequence between early and late isolates. This investigation demonstrates that SVDV and vRNA can be present in pigs for considerably longer after exposure to infection than has previously been recognized and provides preliminary evidence for a carrier state in swine vesicular disease. PMID:9825800

  17. The persistence of swine vesicular disease virus infection in pigs.

    PubMed

    Lin, F; Mackay, D K; Knowles, N J

    1998-10-01

    Two groups of pigs were infected with a recent Italian isolate of swine vesicular disease virus (SVDV). Blood, nasal swabs and faeces were collected for up to 6 months after exposure to infection and animals were killed at regular intervals to obtain tissues post-mortem. These samples were examined for virus by conventional means and for viral RNA (vRNA) by reverse transcription-nested polymerase chain reaction (RT-nPCR). Virus was identified intermittently from both clinically and subclinically infected animals in nasal swabs, faeces and tonsillar tissue by either virus isolation or RT-nPCR up to 63 days post infection (dpi). Between 63 and 119 dpi virus was not detected in the secretions, excretions or tissues of any pigs. Following mixing of the two groups of animals at 119 dpi, SVDV was again identified in faeces for up to 7 days suggesting that the stress of mixing reactivated the excretion of virus in pigs from which the agent could no longer be identified. Minor antigenic changes were identified between the parental virus and isolates recovered late in the course of infection. Altered antigenicity corresponded with deduced amino acid substitutions identified from differences in nucleotide sequence between early and late isolates. This investigation demonstrates that SVDV and vRNA can be present in pigs for considerably longer after exposure to infection than has previously been recognized and provides preliminary evidence for a carrier state in swine vesicular disease. PMID:9825800

  18. Pathogenic Interactions Between Sorghum Yellow Banding Virus and Other Viruses Infecting Sorghum. 

    E-print Network

    Theu, M.P.K.J; Toler, R.W.

    1992-01-01

    Between Sorghum Yellow Banding Virus and Other Viruses Infecting Sorghum M.P.K.J. Theu and R. W. Toler1 Abstract A pathogenic interaction between sorghum yel low banding virus (SYBV) and maize dwarf mosaic (MDMV-A) virus was proved. Inoculation... of MDMV A 3 days before inoculation with SYBV resulted in a more severe disease and the resultant disease symp toms were different from those caused by either virus alone. Both viruses were serologically detected in a treatment in which MDMV...

  19. Phylogenetic analysis of the haemagglutinin gene of canine distemper virus strains detected from giant panda and raccoon dogs in China

    PubMed Central

    2013-01-01

    Background Canine distemper virus (CDV) infects a variety of carnivores, including wild and domestic Canidae. In this study, we sequenced and phylogenetic analyses of the hemagglutinin (H) genes from eight canine distemper virus (CDV) isolates obtained from seven raccoon dogs (Nyctereutes procyonoides) and a giant panda (Ailuropoda melanoleuca) in China. Results Phylogenetic analysis of the partial hemagglutinin gene sequences showed close clustering for geographic lineages, clearly distinct from vaccine strains and other wild-type foreign CDV strains, all the CDV strains were characterized as Asia-1 genotype and were highly similar to each other (91.5-99.8% nt and 94.4-99.8% aa). The giant panda and raccoon dogs all were 549Y on the HA protein in this study, irrespective of the host species. Conclusions These findings enhance our knowledge of the genetic characteristics of Chinese CDV isolates, and may facilitate the development of effective strategies for monitoring and controlling CDV for wild canids and non-cainds in China. PMID:23566727

  20. Communication Frequent foamy virus infection in free-living

    E-print Network

    direct contact, hunting and consumption of bush meat. Foamy viruses (FVs) belong to the genus Spumavirus with clinical manifestation in animals. FVs infect a broad spectrum of cells in vitro, but, in contrast

  1. INFLUENCE OF ANESTHESIA ON EXPERIMENTAL NEUROTROPIC VIRUS INFECTIONS

    PubMed Central

    Sulkin, S. Edward; Zarafonetis, Christine; Goth, Andres

    1946-01-01

    Anesthesia with diethyl ether significantly alters the course and outcome of experimental infections with the equine encephalomyelitis virus (Eastern or Western type) or with the St. Louis encephalitis virus. No comparable effect is observed in experimental infections produced with rabies or poliomyelitis (Lansing) viruses. The neurotropic virus infections altered by ether anesthesia are those caused by viruses which are destroyed in vitro by this anesthetic, and those infections not affected by ether anesthesia are caused by viruses which apparently are not destroyed by ether in vitro. Another striking difference between these two groups of viruses is their pathogenesis in the animal host; those which are inhibited in vivo by ether anesthesia tend to infect cells of the cortex, basal ganglia, and only occasionally the cervical region of the cord. On the other hand, those which are not inhibited in vivo by ether anesthesia tend to involve cells of the lower central nervous system and in the case of rabies, peripheral nerves. This difference is of considerable importance in view of the fact that anesthetics affect cells of the lower central nervous system only in very high concentrations. It is obvious from the complexity of the problem that no clear-cut statement can be made at this point as to the mechanism of the observed effect of ether anesthesia in reducing the mortality rate in certain of the experimental neurotropic virus infections. Important possibilities include a direct specific effect of diethyl ether upon the virus and a less direct effect of the anesthetic upon the virus through its alteration of the metabolism of the host cell. PMID:19871570

  2. Hepatitis C Virus and HIV Type 1 Co-Infection

    PubMed Central

    Gupta, Priyanka

    2013-01-01

    Around 33 million people worldwide are living with Human Immunodeficiency Virus (HIV) infection, and approximately 20-30% of HIV-infected individuals are also infected with Hepatitis C virus (HCV). The main form of HCV transmission is via the blood borne route; high rates of co-infection are found in intravenous drug users with HCV prevalence rates as high as 90%. Introduction of effective antiretroviral therapy (ART) has led to a significant decline in HIV-related morbidity, but at the same time the incidence of HCV related liver disease is increasing in the co-infected population. Meta analysis has revealed that individuals who are co-infected with HIV/HCV harbor three times greater risk of progression to liver disease than those infected with HCV alone. Increased risk of progression to Acquired Immunodeficiency Syndrome (AIDS) and AIDS-related deaths is shown among the co-infected patients by some studies, suggesting that HCV infection may accelerate the clinical course of HIV infection. HCV may also affect the incidence of liver toxicity associated with ART, affecting the management of HIV infection. There is a lack of optimal therapeutic approaches to treat HCV infection in HIV co-infected patients. This review discusses recent literature pertaining HIV/HCV co-infection, in addition to providing a snapshot of impact of co-infection on human genome at the level of gene expression and its regulation by microRNAs (miRNAs). PMID:24470971

  3. Toscana Virus Central Nervous System Infections in Southern Italy

    Microsoft Academic Search

    Pasquale Pagliano; Sonia Battisti; Maria Starace; Vera Mininni

    Toscana virus was detected by reverse transcription-nested PCR in 5.6% of cerebrospinal fluid (CSF) samples from patients with meningitis and encephalitis during the summer in southern Italy. The central nervous system infections were associated with young adults and with a substantially benign clinical course. Presenting features and CSF findings are also discussed in the present report. Toscana virus (TOSV) is

  4. The naming of Potato virus Y strains infecting potato

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Potato virus Y (PVY) strain groups are based on host-response and resistance-gene interactions. The strain groups PVYO, PVYC and PVYN are well-established for the isolates infecting potato in the field. A switch in the emphasis from host response to nucleotide sequence differences in the virus genom...

  5. The Human Immunodeficiency Virus: Infectivity and Mechanisms of Pathogenesis.

    ERIC Educational Resources Information Center

    Fauci, Anthony S.

    1988-01-01

    Discusses how the infection of the human immunodeficiency virus (HIV) results in a profound immunosuppression due predominantly to a selective depletion of helper/inducer T lymphocytes that express the receptor for the virus, as well as neuropsychiatric abnormalities in the brain. (TW)

  6. EFFECT OF CHLORINE TREATMENT ON INFECTIVITY OF HEPATITIS A VIRUS

    EPA Science Inventory

    This study examined the effect of chlorine treatment on the infectivity of hepatitis A virus (HAV). Prodromal chimpanzee feces, shown to induce hepatitis in marmosets (Saguinus sp.), was clarified, and the virus was precipitated with 7% polyethylene glycol 6000, harvested and res...

  7. Influenza Virus Infection in Guinea Pigs Raised as Livestock, Ecuador

    PubMed Central

    Leyva-Grado, Victor H.; Mubareka, Samira; Krammer, Florian; Cárdenas, Washington B.

    2012-01-01

    To determine whether guinea pigs are infected with influenza virus in nature, we conducted a serologic study in domestic guinea pigs in Ecuador. Detection of antibodies against influenza A and B raises the question about the role of guinea pigs in the ecology and epidemiology of influenza virus in the region. PMID:22710350

  8. EFFECTS OF EXPERIMENTAL PSEUDORABIES VIRUS INFECTION ON VACCINATED PREGNANT SOWS

    E-print Network

    Paris-Sud XI, Université de

    EFFECTS OF EXPERIMENTAL PSEUDORABIES VIRUS INFECTION ON VACCINATED PREGNANT SOWS DIEUZYI, VANNIER P'Aujeszky (MA) de truies vaccinées (vaccin à virus inactivé) avant ou pendant la gestation, a été réalisée normale. Les résultats des inocula- tions intrafoetales indiquent que la vaccination d'une truie ne

  9. Release of Viral Glycoproteins during Ebola Virus Infection

    Microsoft Academic Search

    Viktor E. Volchkov; Valentina A. Volchkova; Werner Slenczka; Hans-Dieter Klenk; Heinz Feldmann

    1998-01-01

    Maturation and release of the Ebola virus glycoprotein GP were studied in cells infected with either Ebola or recombinant vaccinia viruses. Significant amounts of GP were found in the culture medium in nonvirion forms. The major form represented the large subunit GP1that was shed after release of its disulfide linkage to the smaller transmembrane subunit GP2. The minor form were

  10. Human Muscle Satellite Cells as Targets of Chikungunya Virus Infection

    E-print Network

    Paris-Sud XI, Université de

    Human Muscle Satellite Cells as Targets of Chikungunya Virus Infection Simona Ozden1 , Michel antigens were found exclusively inside skeletal muscle progenitor cells (designed as satelllite cells), and not in muscle fibers. To evaluate the ability of CHIK virus to replicate in human satellite cells, we assessed

  11. Powassan virus infection presenting as acute disseminated encephalomyelitis in Tennessee.

    PubMed

    Hicar, Mark D; Edwards, Kathryn; Bloch, Karen

    2011-01-01

    Powassan virus is a rarely diagnosed cause of encephalitis, and is associated with significant neurologic sequelae. Although symptomatic infections with Powassan virus occur primarily in adults, we report a case of confirmed Powassan neuroinvasive disease in a child presenting to a Tennessee hospital, with symptoms and imaging studies suggestive of acute disseminated encephalomyelitis. PMID:20736878

  12. Experimental St. Louis encephalitis virus infection of sloths and cormorants.

    PubMed

    Seymour, C; Kramer, L D; Peralta, P H

    1983-07-01

    Experimental infection of 11 Bradypus variegatus and Choloepus hoffmanni sloths with St. Louis encephalitis (SLE) virus produced detectable viremias of seven to 27 (median 13) days duration and maximum titers of 2.7 to 6.5 (median 5.1) log10 median suckling mouse intracranial lethal doses (SMicLD50) per ml. Experimental SLE viremia onset was delayed and maximum titer depressed in two sloths concurrently infected with naturally acquired viruses. SLE viremias in four experimentally inoculated cormorants Phalacrocorax olivaceus were shorter, and of equal or lower titer, than in sloths. Colonized Culex pipiens quinquefasciatus mosquitoes were infected by feeding on sloths circulating at least 4.8 log10 SMicLD50 of SLE virus per ml, and subsequently transmitted the infection to mice and chicks. An uninoculated baby Bradypus became infected by contact transmission from its mother. The antibody response of sloths to SLE virus was slow, being undetectable until several weeks post-inoculation. However, both sloth species developed high and long-lasting neutralizing and hemagglutination-inhibition antibody titers. The complement-fixation antibody response in Bradypus was lower and slower to develop than in Choloepus. Sloths with naturally acquired SLE virus antibody did not become detectably viremic after experimental inoculation. Neither sloths nor cormorants become overly ill from SLE virus infection. PMID:6881434

  13. Analysis of resistance and tolerance to virus infection in Drosophila.

    PubMed

    Merkling, Sarah H; van Rij, Ronald P

    2015-07-01

    Host defense to virus infection involves both resistance mechanisms that reduce viral burden and tolerance mechanisms that limit detrimental effects of infection. The fruit fly, Drosophila melanogaster, has emerged as a model for identifying and characterizing the genetic basis of resistance and tolerance. This protocol describes how to analyze host responses to virus infection in Drosophila, and it covers the preparation of virus stocks, experimental inoculation of flies and assessment of host survival and virus production, which are indicative of resistance or tolerance. It also provides guidance on how to account for recently identified confounding factors, including natural genetic variation in the pastrel locus and contamination of fly stocks with persistent viruses and the symbiotic bacterium Wolbachia. Our protocol aims to be accessible to newcomers to the field and, although optimized for virus research using Drosophila, some of the techniques could be adapted to other host organisms and/or other microbial pathogens. Preparation of fly stocks requires ?1 month, virus stock preparation requires 17-20 d, virus injection and survival assays require 10-15 d and virus titration requires 14 d. PMID:26110714

  14. Human T-cell lymphotropic virus type III infection of the central nervous system: a preliminary in situ analysis

    SciTech Connect

    Stoler, M.H.; Eskin, T.A.; Benn, S.; Angerer, R.C.; Angerer, L.M.

    1986-11-07

    Patients with acquired immunodeficiency syndrome (AIDS) are subject to a spectrum of central nervous system (CNS) disorders. Recent evidence implicates the human T-cell lymphotropic virus type III (HTLV-III) in the pathogenesis of some of these illnesses, although the cells infected by the virus have yet to be identified. Using in situ hybridization, the authors examined brain tissue from two patients with AIDS encephalopathy for the presence of HTLV-III RNA. In both cases, viral RNA was detected and concentrated in, though not limited to, the white matter. The CNS cells most frequently infected included macrophages, pleomorphic microglia, and multinucleated giant cells. Less frequently, cells morphologically consistent with astrocytes, oligodendroglia, and rarely neurons were also infected. The findings strengthen the association of HTLV-III with the pathogenesis of AIDS encephalopathy. In situ hybridization can be applied to routinely prepared biopsy tissue in the diagnosis of HTLV-III infection of the CNS.

  15. Viral MicroRNAs Targeting Virus Genes Promote Virus Infection in Shrimp In Vivo

    PubMed Central

    He, Yaodong; Yang, Kai

    2014-01-01

    Viral microRNAs (miRNAs), most of which are characterized in cell lines, have been found to play important roles in the virus life cycle to avoid attack by the host immune system or to keep virus in the latency state. Viral miRNAs targeting virus genes can inhibit virus infection. In this study, in vivo findings in Marsupenaeus japonicus shrimp revealed that the viral miRNAs could target virus genes and further promote the virus infection. The results showed that white spot syndrome virus (WSSV)-encoded miRNAs WSSV-miR-66 and WSSV-miR-68 were transcribed at the early stage of WSSV infection. When the expression of WSSV-miR-66 and WSSV-miR-68 was silenced with sequence-specific anti-miRNA oligonucleotides (AMOs), the number of copies of WSSV and the WSSV-infected shrimp mortality were significantly decreased, indicating that the two viral miRNAs had a great effect on virus infection. It was revealed that the WSSV wsv094 and wsv177 genes were the targets of WSSV-miR-66 and that the wsv248 and wsv309 genes were the targets of WSSV-miR-68. The data demonstrate that the four target genes play negative roles in the WSSV infection. The targeting of the four virus genes by WSSV-miR-66 and WSSV-miR-68 led to the promotion of virus infection. Therefore, our in vivo findings show a novel aspect of viral miRNAs in virus-host interactions. PMID:24198431

  16. Reduced Risk of Disease During Postsecondary Dengue Virus Infections

    PubMed Central

    Olkowski, Sandra; Forshey, Brett M.; Morrison, Amy C.; Rocha, Claudio; Vilcarromero, Stalin; Halsey, Eric S.; Kochel, Tadeusz J.; Scott, Thomas W.; Stoddard, Steven T.

    2013-01-01

    Background.?Antibodies induced by infection with any 1 of 4 dengue virus (DENV) serotypes (DENV-1–4) may influence the clinical outcome of subsequent heterologous infections. To quantify potential cross-protective effects, we estimated disease risk as a function of DENV infection, using data from longitudinal studies performed from September 2006 through February 2011 in Iquitos, Peru, during periods of DENV-3 and DENV-4 transmission. Methods.?DENV infections before and during the study period were determined by analysis of serial serum samples with virus neutralization tests. Third and fourth infections were classified as postsecondary infections. Dengue fever cases were detected by door-to-door surveillance for acute febrile illness. Results.?Among susceptible participants, 39% (420/1077) and 53% (1595/2997) seroconverted to DENV-3 and DENV-4, respectively. Disease was detected in 7% of DENV-3 infections and 10% of DENV-4 infections. Disease during postsecondary infections was reduced by 93% for DENV-3 and 64% for DENV-4, compared with primary and secondary infections. Despite lower disease rates, postsecondary infections constituted a significant proportion of apparent infections (14% [for DENV-3 infections], 45% [for DENV-4 infections]). Conclusions.?Preexisting heterotypic antibodies markedly reduced but did not eliminate the risk of disease in this study population. These results improve understanding of how preinfection history can be associated with dengue outcomes and DENV transmission dynamics. PMID:23776195

  17. Characteristics of Mild Dengue Virus Infection in Thai Children

    PubMed Central

    Yoon, In-Kyu; Srikiatkhachorn, Anon; Hermann, Laura; Buddhari, Darunee; Scott, Thomas W.; Jarman, Richard G.; Aldstadt, Jared; Nisalak, Ananda; Thammapalo, Suwich; Bhoomiboonchoo, Piraya; Mammen, Mammen P.; Green, Sharone; Gibbons, Robert V.; Endy, Timothy P.; Rothman, Alan L.

    2013-01-01

    A four-year longitudinal cohort and geographic cluster study in rural Thailand was conducted to characterize the clinical spectrum of dengue virus (DENV) infection. Symptomatic DENV infections in the cohort were detected by active school absence–based surveillance that triggered cluster investigations around ill cohort children. Data from 189 cohort children with symptomatic DENV infection and 126 contact children in the clusters with DENV infection were analyzed. Of infected contacts, only 19% were asymptomatic; 81% were symptomatic, but only 65.9% reported fever. Symptom-based case definitions were unreliable for diagnosis. Symptomatic infections in contacts were milder with lower DENV RNA levels than the cohort. Infections in contacts with fever history were more likely to have detectable DENV RNA than infections without fever history. Mild infections identified by cluster investigations account for a major proportion of all DENV infections. These findings are relevant for disease burden assessments, transmission modeling, and determination of vaccine impact. PMID:24127167

  18. Senescence Affects Endothelial Cells Susceptibility to Dengue Virus Infection

    PubMed Central

    AbuBakar, Sazaly; Shu, Meng-Hooi; Johari, Jefree; Wong, Pooi-Fong

    2014-01-01

    Alteration in the endothelium leading to increased vascular permeability contributes to plasma leakage seen in dengue hemorrhagic fever (DHF) and dengue shock syndrome (DSS). An earlier study showed that senescent endothelial cells (ECs) altered the ECs permeability. Here we investigated the susceptibility of senescing human umbilical vein endothelial cells (HUVECs) to dengue virus infection and determined if dengue virus infection induces HUVECs senescence. Our results suggest that DENV type-2 (DENV-2) foci forming unit (FFU) and extracellular virus RNA copy number were reduced by at least 35% and 85% in infection of the intermediate young and early senescent HUVECs, respectively, in comparison to infection of young HUVECs. No to low infectivity was recovered from infection of late senescent HUVECs. DENV infection also increases the percentage of HUVECs expressing senescence-associated (SA)-?-gal, cells arrested at the G2/M phase or 4N DNA content stage and cells with enlarged morphology, indicative of senescing cells. Alteration of HUVECs morphology was recorded using impedance-based real-time cell analysis system following DENV-2 infection. These results suggest that senescing HUVECs do not support DENV infection and DENV infection induces HUVECs senescence. The finding highlights the possible role of induction of senescence in DENV infection of the endothelial cells. PMID:24782642

  19. Senescence affects endothelial cells susceptibility to dengue virus infection.

    PubMed

    AbuBakar, Sazaly; Shu, Meng-Hooi; Johari, Jefree; Wong, Pooi-Fong

    2014-01-01

    Alteration in the endothelium leading to increased vascular permeability contributes to plasma leakage seen in dengue hemorrhagic fever (DHF) and dengue shock syndrome (DSS). An earlier study showed that senescent endothelial cells (ECs) altered the ECs permeability. Here we investigated the susceptibility of senescing human umbilical vein endothelial cells (HUVECs) to dengue virus infection and determined if dengue virus infection induces HUVECs senescence. Our results suggest that DENV type-2 (DENV-2) foci forming unit (FFU) and extracellular virus RNA copy number were reduced by at least 35% and 85% in infection of the intermediate young and early senescent HUVECs, respectively, in comparison to infection of young HUVECs. No to low infectivity was recovered from infection of late senescent HUVECs. DENV infection also increases the percentage of HUVECs expressing senescence-associated (SA)-?-gal, cells arrested at the G2/M phase or 4N DNA content stage and cells with enlarged morphology, indicative of senescing cells. Alteration of HUVECs morphology was recorded using impedance-based real-time cell analysis system following DENV-2 infection. These results suggest that senescing HUVECs do not support DENV infection and DENV infection induces HUVECs senescence. The finding highlights the possible role of induction of senescence in DENV infection of the endothelial cells. PMID:24782642

  20. Inhalational monkeypox virus infection in cynomolgus macaques

    PubMed Central

    Barnewall, Roy E.; Fisher, David A.; Robertson, Ashley B.; Vales, Pauline A.; Knostman, Katherine A.; Bigger, John E.

    2012-01-01

    An inhalation exposure system was characterized to deliver aerosolized monkeypox virus (MPXV), and a non-human primate (NHP) inhalation monkeypox model was developed in cynomolgus macaques. A head-only aerosol exposure system was characterized, and two sampling methods were evaluated: liquid impingement via an impinger and impaction via a gelatin filter. The aerosol concentrations obtained with the gelatin filter and impinger were virtually identical, indicating that either method is acceptable for sampling aerosols containing MPXV. The mass median aerodynamic diameter (MMAD) for individual aerosol tests in the aerosol system characterization and the NHP study ranged from 1.08 to 1.15 ?m, indicating that the aerosol particles were of a sufficient size to reach the alveoli. Six cynomolgus macaques (four male and two female) were used on study. The animals were aerosol exposed with MPXV and received doses between 2.51 × 104 to 9.28 × 105 plaque forming units (PFUs) inhaled. Four of the six animals died or were euthanized due to their moribund conditions. Both animals that received the lowest exposure doses survived to the end of the observation period. The inhalation LD50 was determined to be approximately 7.8 × 104 pfu inhaled. These data demonstrate that an inhalation MPXV infection model has been developed in the cynomolgus macaque with disease course and lethal dose similar to previously published data. PMID:23061051

  1. [Cellular mediated immunity in virus infections].

    PubMed

    Voiculescu, C; T??ulescu, M

    1978-01-01

    The intervention of cellular immunity in the course of specific antiviral defence is suggested or confirmed by a series of clinical and experimental findings, i.e. the evolution of certain viral diseases following a second contact with viral antigens; discrepancy between the level of antiviral serum antibodies and the clinical course of some viral diseases; pathohistological alterations in some viral diseases, suggesting the intervention of cellular immunity; the clinical aspects of natural or experimental viral diseases in primary and secondary immunodeficiency. Investigations were likewise carried out on certain indices of cellular immunity in human or experimental viral diseases, such as delayed hypersensitivity skin tests; the transfer of immune lymphocytes; lymphocytic blastic transformation; inhibition of macrophage migration; specific cytotoxicity test. The problems concerning the role of cellular immunity in the specific defence against viruses may be grouped as follows: mechanisms of induction of the immune cellular response in viral infections; relationship between cellular and humoral immunity in antiviral resistance; relative independance of systemic and local cellular immunity in the course of viral diseases; the cellular basis of cellular mediated immunity in viral diseases. PMID:353956

  2. Hepatitis E virus chronic infection of swine co-infected with Porcine Reproductive and Respiratory Syndrome Virus.

    PubMed

    Salines, Morgane; Barnaud, Elodie; Andraud, Mathieu; Eono, Florent; Renson, Patricia; Bourry, Olivier; Pavio, Nicole; Rose, Nicolas

    2015-01-01

    In developed countries, most of hepatitis E human cases are of zoonotic origin. Swine is a major hepatitis E virus (HEV) reservoir and foodborne transmissions after pork product consumption have been described. The risk for HEV-containing pig livers at slaughter time is related to the age at infection and to the virus shedding duration. Porcine Reproductive and Respiratory Syndrome Virus (PRRSV) is a virus that impairs the immune response; it is highly prevalent in pig production areas and suspected to influence HEV infection dynamics. The impact of PRRSV on the features of HEV infections was studied through an experimental HEV/PRRSV co-infection of specific-pathogen-free (SPF) pigs. The follow-up of the co-infected animals showed that HEV shedding was delayed by a factor of 1.9 in co-infected pigs compared to HEV-only infected pigs and specific immune response was delayed by a factor of 1.6. HEV shedding was significantly increased with co-infection and dramatically extended (48.6 versus 9.7 days for HEV only). The long-term HEV shedding was significantly correlated with the delayed humoral response in co-infected pigs. Direct transmission rate was estimated to be 4.7 times higher in case of co-infection than in HEV only infected pigs (0.70 and 0.15 per day respectively). HEV infection susceptibility was increased by a factor of 3.3, showing the major impact of PRRSV infection on HEV dynamics. Finally, HEV/PRRSV co-infection - frequently observed in pig herds - may lead to chronic HEV infection which may dramatically increase the risk of pig livers containing HEV at slaughter time. PMID:26048774

  3. Drosophila C Virus Systemic Infection Leads to Intestinal Obstruction

    PubMed Central

    Chtarbanova, Stanislava; Lamiable, Olivier; Lee, Kwang-Zin; Galiana, Delphine; Troxler, Laurent; Meignin, Carine; Hetru, Charles; Hoffmann, Jules A.; Daeffler, Laurent

    2014-01-01

    ABSTRACT Drosophila C virus (DCV) is a positive-sense RNA virus belonging to the Dicistroviridae family. This natural pathogen of the model organism Drosophila melanogaster is commonly used to investigate antiviral host defense in flies, which involves both RNA interference and inducible responses. Although lethality is used routinely as a readout for the efficiency of the antiviral immune response in these studies, virus-induced pathologies in flies still are poorly understood. Here, we characterize the pathogenesis associated with systemic DCV infection. Comparison of the transcriptome of flies infected with DCV or two other positive-sense RNA viruses, Flock House virus and Sindbis virus, reveals that DCV infection, unlike those of the other two viruses, represses the expression of a large number of genes. Several of these genes are expressed specifically in the midgut and also are repressed by starvation. We show that systemic DCV infection triggers a nutritional stress in Drosophila which results from intestinal obstruction with the accumulation of peritrophic matrix at the entry of the midgut and the accumulation of the food ingested in the crop, a blind muscular food storage organ. The related virus cricket paralysis virus (CrPV), which efficiently grows in Drosophila, does not trigger this pathology. We show that DCV, but not CrPV, infects the smooth muscles surrounding the crop, causing extensive cytopathology and strongly reducing the rate of contractions. We conclude that the pathogenesis associated with systemic DCV infection results from the tropism of the virus for an important organ within the foregut of dipteran insects, the crop. IMPORTANCE DCV is one of the few identified natural viral pathogens affecting the model organism Drosophila melanogaster. As such, it is an important virus for the deciphering of host-virus interactions in insects. We characterize here the pathogenesis associated with DCV infection in flies and show that it results from the tropism of the virus for an essential but poorly characterized organ in the digestive tract, the crop. Our results may have relevance for other members of the Dicistroviridae, some of which are pathogenic to beneficial or pest insect species. PMID:25253354

  4. The Aedes aegypti Toll Pathway Controls Dengue Virus Infection

    PubMed Central

    Xi, Zhiyong; Ramirez, Jose L.; Dimopoulos, George

    2008-01-01

    Aedes aegypti, the mosquito vector of dengue viruses, utilizes its innate immune system to ward off a variety of pathogens, some of which can cause disease in humans. To date, the features of insects' innate immune defenses against viruses have mainly been studied in the fruit fly Drosophila melanogaster, which appears to utilize different immune pathways against different types of viruses, in addition to an RNA interference–based defense system. We have used the recently released whole-genome sequence of the Ae. aegypti mosquito, in combination with high-throughput gene expression and RNA interference (RNAi)-based reverse genetic analyses, to characterize its response to dengue virus infection in different body compartments. We have further addressed the impact of the mosquito's endogenous microbial flora on virus infection. Our findings indicate a significant role for the Toll pathway in regulating resistance to dengue virus, as indicated by an infection-responsive regulation and functional assessment of several Toll pathway–associated genes. We have also shown that the mosquito's natural microbiota play a role in modulating the dengue virus infection, possibly through basal-level stimulation of the Toll immune pathway. PMID:18604274

  5. Therapeutic vaccination against chronic hepatitis B virus infection

    Microsoft Academic Search

    Marie Louise Michel; Maryline Mancini-Bourgine

    2005-01-01

    Chronic liver disease and hepatocellular carcinoma due to chronic hepatitis B virus (HBV) infection pose a major public health problem in highly endemic regions. Effective vaccines against HBV exist but more than 370 million people remain chronically infected with HBVFor these patients there is a high risk to develop cirrhosis and hepatocellular carcinoma. Currently available therapies fail to control viral

  6. Eastern Equine Encephalomyelitis Virus Infection in a Horse from California

    Microsoft Academic Search

    Robert P. Franklin; Hailu Kinde; Michele T. Jay; Laura D. Kramer; Emily-Gene N. Green; Robert E. Chiles; Eileen Ostlund; Stan Husted; Jonathan Smith; Michael D. Parker

    2002-01-01

    A yearling quarter horse, which was raised in southern California, received routine vaccinations for pre- vention of infection by Eastern equine encephalomyelitis virus (EEEV). One week later, severe neurologic signs developed, and the horse was humanely destroyed. A vaccine-related encephalomyelitis was later suspected. A final diagnosis of EEEV infection was established on the basis of acute onset of the neuro-

  7. Western blot detection of infectious bursal disease virus infection

    Microsoft Academic Search

    S. R. F. G. Pereira; C. E. P. F. Travassos; A. Huguenim; A. C. C. Guimarães; A. G. Silva; M. A. A. M. Guimarães

    1998-01-01

    In order to evaluate the use of a Western blot methodology for the diagnosis of infectious bursal disease virus (IBDV) infection, chick- ens were experimentally infected with IBDV strains and tested for the presence of viral antigens and antibodies by a blocking Western blot test (bWB). The viral proteins obtained from the bursa of Fabricius (BF) were transferred to a

  8. Vaccinial osteomyelitis in a case of generalized intrauterine virus infection.

    PubMed

    Vorst, E J; Gaillard, J L

    1983-01-01

    We report the case of a 14-week fetus who developed a generalized vaccinia virus infection after primary vaccination of the mother in the 10th week of pregnancy. Special emphasis is given to the skeletal lesions, which have not been previously reported in prenatal vaccinial infection. PMID:6687278

  9. Reye's syndrome associated with respiratory syncytial virus infection

    Microsoft Academic Search

    N Griffin; J W Keeling; A H Tomlinson

    1979-01-01

    An upper respiratory tract infection in a 22-month-old boy was followed by rapid loss of consciousness, hypoglycaemia, uraemia, and death. Necropsy examination showed fatty change of liver and kidneys, severe cerebral oedema, bronchiolitis, and endocardial fibroelastosis affecting the left ventricle. Immunofluorescence staining showed infection with respiratory syncytial virus (RSV). The clinical and pathological findings were those of Reye's syndrome, not

  10. Persistent bovine viral diarrhoea virus infection in US beef herds

    Microsoft Academic Search

    T. E Wittum; D. M Grotelueschen; K. V Brock; W. G Kvasnicka; J. G Floyd; C. L Kelling; K. G Odde

    2001-01-01

    In the summer of 1996, we screened 18,931 calves in 128 beef herds located in five US states for persistent bovine viral diarrhea virus (BVDV) infection. Of these, 76 herds were randomly selected from the client database of collaborating veterinary practices, and 52 herds were suspected by the collaborating veterinarians to have BVDV infection based on history or clinical signs.

  11. Preference by a virus vector for infected plants is reversed after virus acquisition.

    PubMed

    Rajabaskar, Dheivasigamani; Bosque-Pérez, Nilsa A; Eigenbrode, Sanford D

    2014-06-24

    Pathogens and their vectors can interact either directly or indirectly via their shared hosts, with implications for the persistence and spread of the pathogen in host populations. For example, some plant viruses induce changes in host plants that cause the aphids that carry these viruses to settle preferentially on infected plants. Furthermore, relative preference by the vector for infected plants can change to a preference for noninfected plants after virus acquisition by the vector, as has recently been demonstrated in the wheat-Rhopalosiphum padi-Barley yellow dwarf virus pathosystem. Here we document a similar dynamic in the potato-Myzus persicae (Sulzer)-Potato leaf roll virus (PLRV) pathosystem. Specifically, in a dual choice bioassay, nonviruliferous apterous M. persicae settled preferentially on or near potato plants infected with PLRV relative to noninfected (sham-inoculated) control plants, whereas viruliferous M. persicae (carrying PLRV) preferentially settled on or near sham-inoculated potato plants relative to infected plants. The change in preference after virus acquisition also occurred in response to trapped headspace volatiles, and to synthetic mimics of headspace volatile blends from PLRV-infected and sham-inoculated potato plants. The change in preference we document should promote virus spread by increasing rates of virus acquisition and transmission by the vector. PMID:24269348

  12. Neuraminidase inhibitors for influenza B virus infection: efficacy and resistance.

    PubMed

    Burnham, Andrew J; Baranovich, Tatiana; Govorkova, Elena A

    2013-11-01

    Many aspects of the biology and epidemiology of influenza B viruses are far less studied than for influenza A viruses, and one of these aspects is efficacy and resistance to the clinically available antiviral drugs, the neuraminidase (NA) inhibitors (NAIs). Acute respiratory infections are one of the leading causes of death in children and adults, and influenza is among the few respiratory infections that can be prevented and treated by vaccination and antiviral treatment. Recent data has suggested that influenza B virus infections are of specific concern to pediatric patients because of the increased risk of severe disease. Treatment of influenza B is a challenging task for the following reasons: This review presents current knowledge of the efficacy of NAIs for influenza B virus and antiviral resistance in clinical, surveillance, and experimental studies. PMID:24013000

  13. Human Infection with Orf Virus from Goats in China, 2012

    PubMed Central

    Zhang, Keshan; Liu, Yongjie; Kong, Hanjin; Shang, Youjun

    2014-01-01

    Abstract Orf virus, which belongs to the Parapoxvirus genus, induces a zoonotic infectious disease characterized by acute, highly vascularized cutaneous pustular lesions in sheep and goats. A number of Orf outbreaks have been reported in sheep and goats in recent years, but no reports have described an Orf virus strain from humans in China. In this study, we diagnosed Orf virus infection in two people, a mother and son, in the Gansu province of China. The human Orf virus was isolated and its phylogenetic characterization was analyzed based on a complete B2L gene. The results are useful for developing prospective programs to control Orf virus infections in both goats and humans PMID:24745915

  14. Sheep persistently infected with Border disease readily transmit virus to calves seronegative to BVD virus.

    PubMed

    Braun, U; Reichle, S F; Reichert, C; Hässig, M; Stalder, H P; Bachofen, C; Peterhans, E

    2014-01-10

    Bovine viral diarrhea- and Border disease viruses of sheep belong to the highly diverse genus pestivirus of the Flaviviridae. Ruminant pestiviruses may infect a wide range of domestic and wild cloven-hooved mammals (artiodactyla). Due to its economic importance, programs to eradicate bovine viral diarrhea are a high priority in the cattle industry. By contrast, Border disease is not a target of eradication, although the Border disease virus is known to be capable of also infecting cattle. In this work, we compared single dose experimental inoculation of calves with Border disease virus with co-mingling of calves with sheep persistently infected with this virus. As indicated by seroconversion, infection was achieved only in one out of seven calves with a dose of Border disease virus that was previously shown to be successful in calves inoculated with BVD virus. By contrast, all calves kept together with persistently infected sheep readily became infected with Border disease virus. The ease of viral transmission from sheep to cattle and the antigenic similarity of bovine and ovine pestiviruses may become a problem for demonstrating freedom of BVD by serology in the cattle population. PMID:24315041

  15. Immune Modulation in Primary Vaccinia virus Zoonotic Human Infections

    PubMed Central

    Gomes, Juliana Assis Silva; de Araújo, Fernanda Fortes; Trindade, Giliane de Souza; Quinan, Bárbara Resende; Drumond, Betânia Paiva; Ferreira, Jaqueline Maria Siqueira; Mota, Bruno Eduardo Fernandes; Nogueira, Maurício Lacerda; Kroon, Erna Geessien; Abrahão, Jônatas Santos; Côrrea-Oliveira, Rodrigo; da Fonseca, Flávio Guimarães

    2012-01-01

    In 2010, the WHO celebrated the 30th anniversary of the smallpox eradication. Ironically, infections caused by viruses related to smallpox are being increasingly reported worldwide, including Monkeypox, Cowpox, and Vaccinia virus (VACV). Little is known about the human immunological responses elicited during acute infections caused by orthopoxviruses. We have followed VACV zoonotic outbreaks taking place in Brazil and analyzed cellular immune responses in patients acutely infected by VACV. Results indicated that these patients show a biased immune modulation when compared to noninfected controls. Amounts of B cells are low and less activated in infected patients. Although present, T CD4+ cells are also less activated when compared to noninfected individuals, and so are monocytes/macrophages. Similar results were obtained when Balb/C mice were experimentally infected with a VACV sample isolated during the zoonotic outbreaks. Taking together, the data suggest that zoonotic VACVs modulate specific immune cell compartments during an acute infection in humans. PMID:22229039

  16. Multiple Epstein-Barr Virus Infections in Healthy Individuals

    PubMed Central

    Walling, Dennis M.; Brown, Abigail L.; Etienne, Wiguins; Keitel, Wendy A.; Ling, Paul D.

    2003-01-01

    We employed a newly developed genotyping technique with direct representational detection of LMP-1 gene sequences to study the molecular epidemiology of Epstein-Barr virus (EBV) infection in healthy individuals. Infections with up to five different EBV genotypes were found in two of nine individuals studied. These results support the hypothesis that multiple EBV infections of healthy individuals are common. The implications for the development of an EBV vaccine are discussed. PMID:12743312

  17. The pathology of experimental Ebola virus infection in monkeys.

    PubMed

    Baskerville, A; Bowen, E T; Platt, G S; McArdell, L B; Simpson, D I

    1978-07-01

    Six rhesus and two vervet monkeys were infected intraperitoneally with Ebola virus. They developed an acute haemorrhagic fever with skin rash 4 days later and died 6--12 days after infection. Histopathological lesions of acute necrosis were present in the liver, spleen, lymph nodes, lungs and testes. The presence of fibrin thrombi in several organs was suggestive of the occurrence of disseminated intravascular coagulation during the infection. PMID:102747

  18. Respiratory syncitial virus in children with acute respiratory infections

    Microsoft Academic Search

    R. Hemalatha; G. Krishna Swetha; M. Seshacharyulu; K. V. Radhakrishna

    2010-01-01

    Objective  To study the nutritional status of children with Respiratory Syncitial virus infection.\\u000a \\u000a \\u000a \\u000a Methods  One hundred and twenty six children with acute respiratory infection, between the age of 4–24 months, were investigated for\\u000a RSV infection with bronchiolitis, pneumonia and upper respiratory tract infection. Nasopharyngeal aspirates were collected\\u000a and cytokine responses were determined by ELISA. Upper respiratory tract infections were detected in 16.66%,

  19. In vitro infection of primary and retrovirus-infected human leukocytes by human foamy virus.

    PubMed Central

    Mikovits, J A; Hoffman, P M; Rethwilm, A; Ruscetti, F W

    1996-01-01

    The infectivity of human foamy virus (HFV) was examined in primary and cultured human leukocytes. Cell-free infectious viral stocks of HFV were prepared from the human kidney cell line 293 transfected with an infectious molecular clone of HFV. HFV productively infects a variety of human myeloid and lymphoid cell lines. In addition, primary cell cultures enriched for human CD4+, monocytes and brain-derived microglial cells, were readily infected by HFV. Interestingly, while infected primary CD4+ lymphocytes and microglial cells showed marked cytopathology characteristic of foamy virus, HFV-infected monocyte-derived macrophages failed to show any cytopathology. In addition, marked cytotoxicity due to HFV infection was seen in both human T-cell leukemia virus type 1- and human immunodeficiency virus type 1-infected T-cell lines and in human immunodeficiency virus type 1-infected monocytoid cell lines. Thus, HFV infection produces differential cytopathology in a wide host range of primary human leukocytes and hematopoietic cell lines. PMID:8627751

  20. Acute kidney injury in dengue virus infection

    PubMed Central

    Khalil, Muhammad A.M.; Sarwar, Sarfaraz; Chaudry, Muhammad A.; Maqbool, Baila; Khalil, Zarghoona; Tan, Jackson; Yaqub, Sonia; Hussain, Syed A.

    2012-01-01

    Background Dengue is a growing public health problem in Pakistan and acute kidney injury (AKI) is one of the least studied complications of dengue virus infection (DVI). The aim of this study was to determine the frequency, severity and predictors of AKI in patients with DVI and to study the impact of AKI on the length of hospital stay and mortality. Methods We retrospectively reviewed medical records of patients aged ?14 years hospitalized with a primary diagnosis of DVI at Aga Khan University Hospital Karachi between January 2008 and December 2010. Binary logistic regression models were constructed to identify factors associated with the development of AKI and to study the impact of AKI on hospital stays of more than 3 days. Results Out of 532 patients, AKI was present in 13.3% (71/532). Approximately two-thirds (64.8%) of these patients had mild AKI and a third (35.2%) had moderate to severe AKI. Independent predictors for AKI were male gender [odds ratio (OD) 4.43; 95% CI 1.92–10.23], presence of dengue hemorrhagic and dengue shock syndrome (DSS, OD 2.14; 95% CI 1.06–4.32), neurological involvement (OD 12.08; 95% CI 2.82–51.77) and prolonged activated partial thromboplastin time (aPTT, OD 1.81; 95% CI 1.003–3.26). AKI was associated with a length of stay ?3 days when compared with those who did not have AKI (OD 2.98; 95% CI 1.66–5.34). Eight patients (11.3%) with AKI died whereas there were no mortalities in patients without AKI (P < 0.001). Only 5 patients (7%) had persistent kidney dysfunction at discharge. Conclusions AKI in DVI is associated with neurological involvement, prolongation of aPTT, greater length of hospital stay and increased mortality.

  1. Vaccination of chimpanzees against infection by the hepatitis C virus.

    PubMed

    Choo, Q L; Kuo, G; Ralston, R; Weiner, A; Chien, D; Van Nest, G; Han, J; Berger, K; Thudium, K; Kuo, C

    1994-02-15

    A high incidence of community-acquired hepatitis C virus infection that can lead to the progressive development of chronic active hepatitis, liver cirrhosis, and primary hepatocellular carcinoma occurs throughout the world. A vaccine to control the spread of this agent that represents a major cause of chronic liver disease is therefore needed. Seven chimpanzees (Pan troglodytes) have been immunized with both putative envelope glycoproteins [E1 (gp33) and E2 (gp72)] that were copurified from HeLa cells infected with a recombinant vaccinia virus expression vector. Despite the induction of a weak humoral immune response to these viral glycoproteins in experimentally infected chimpanzees, a strong humoral immune response was obtained in all vaccines. The five highest responders showed complete protection against an i.v. challenge with homologous hepatitis C virus 1. The remaining two vaccines became infected, but both infection and disease may have been ameliorated in comparison with four similarly challenged control chimpanzees, all of which developed acute hepatitis and chronic infections. These results provide considerable encouragement for the eventual control of hepatitis C virus infection by vaccination. PMID:7509068

  2. Characterization of the Early Steps of Hepatitis C Virus Infection by Using Luciferase Reporter Viruses

    PubMed Central

    Koutsoudakis, George; Kaul, Artur; Steinmann, Eike; Kallis, Stephanie; Lohmann, Volker; Pietschmann, Thomas; Bartenschlager, Ralf

    2006-01-01

    The lack of an efficient system to produce hepatitis C virus (HCV) particles has impeded the analysis of the HCV life cycle. Recently, we along with others demonstrated that transfection of Huh7 hepatoma cells with a novel HCV isolate (JFH1) yields infectious viruses. To facilitate studies of HCV replication, we generated JFH1-based bicistronic luciferase reporter virus genomes. We found that RNA replication of the reporter construct was only slightly attenuated and that virus titers produced were only three- to fivefold lower compared to the parental virus, making these reporter viruses an ideal tool for quantitative analyses of HCV infections. To expand the scope of the system, we created two chimeric JFH1 luciferase reporter viruses with structural proteins from the Con1 (genotype 1b) and J6CF (genotype 2a) strains. Using these and the authentic JFH1 reporter viruses, we analyzed the early steps of the HCV life cycle. Our data show that the mode of virus entry is conserved between these isolates and involves CD81 as a key receptor for pH-dependent virus entry. Competition studies and time course experiments suggest that interactions of HCV with cell surface-resident glycosaminoglycans aid in efficient infection of Huh7 cells and that CD81 acts during a postattachment step. The reporter viruses described here should be instrumental for investigating the viral life cycle and for the development of HCV inhibitors. PMID:16699011

  3. Virus Enrichment for Single Virus Infection by Using 3D Insulator Based Dielectrophoresis

    PubMed Central

    Masuda, Taisuke; Maruyama, Hisataka; Honda, Ayae; Arai, Fumihito

    2014-01-01

    We developed an active virus filter (AVF) that enables virus enrichment for single virus infection, by using insulator-based dielectrophoresis (iDEP). A 3D-constricted flow channel design enabled the production of an iDEP force in the microfluidic chip. iDEP using a chip with multiple active virus filters (AVFs) was more accurate and faster than using a chip with a single AVF, and improved the efficiency of virus trapping. We utilized maskless photolithography to achieve the precise 3D gray-scale exposure required for fabrication of constricted flow channel. Influenza virus (A PR/8) was enriched by a negative DEP force when sinusoidal wave was applied to the electrodes within an amplitude range of 20 Vp-p and a frequency of 10 MHz. AVF-mediated virus enrichment can be repeated simply by turning the current ON or OFF. Furthermore, the negative AVF can inhibit virus adhesion onto the glass substrate. We then trapped and transported one of the enriched viruses by using optical tweezers. This microfluidic chip facilitated the effective transport of a single virus from AVFs towards the cell-containing chamber without crossing an electrode. We successfully transported the virus to the cell chamber (v?=?10 µm/s) and brought it infected with a selected single H292 cell. PMID:24918921

  4. Virus enrichment for single virus infection by using 3D insulator based dielectrophoresis.

    PubMed

    Masuda, Taisuke; Maruyama, Hisataka; Honda, Ayae; Arai, Fumihito

    2014-01-01

    We developed an active virus filter (AVF) that enables virus enrichment for single virus infection, by using insulator-based dielectrophoresis (iDEP). A 3D-constricted flow channel design enabled the production of an iDEP force in the microfluidic chip. iDEP using a chip with multiple active virus filters (AVFs) was more accurate and faster than using a chip with a single AVF, and improved the efficiency of virus trapping. We utilized maskless photolithography to achieve the precise 3D gray-scale exposure required for fabrication of constricted flow channel. Influenza virus (A PR/8) was enriched by a negative DEP force when sinusoidal wave was applied to the electrodes within an amplitude range of 20 Vp-p and a frequency of 10 MHz. AVF-mediated virus enrichment can be repeated simply by turning the current ON or OFF. Furthermore, the negative AVF can inhibit virus adhesion onto the glass substrate. We then trapped and transported one of the enriched viruses by using optical tweezers. This microfluidic chip facilitated the effective transport of a single virus from AVFs towards the cell-containing chamber without crossing an electrode. We successfully transported the virus to the cell chamber (v = 10 µm/s) and brought it infected with a selected single H292 cell. PMID:24918921

  5. Secondary dengue virus type 4 infections in Vietnam.

    PubMed

    Buchy, Philippe; Vo, Van Luong; Bui, Khanh Toan; Trinh, Thi Xuan Mai; Glaziou, Philippe; Le, Thi Thu Ha; Le, Viet Lo; Bui, Trong Chien

    2005-01-01

    This study was designated to describe clinical and biological features of patients with a suspected diagnosis of dengue fever/dengue hemorrhagic fever during an outbreak in Central Vietnam. One hundred and twenty-five consecutive patients hospitalized at Khanh Hoa and Binh Thuan Provincial hospitals between November 2001 and January 2002 with a diagnosis of suspected dengue infection were included in the present study. Viruses were isolated in C6/36 and VERO E6 cell cultures or detected by RT-PCR. A hemagglutination-inhibition test (HI) was done on each paired sera using dengue antigens type 1-4, Japanese encephalitis (JE) virus antigen, Chickungunya virus antigen and Sindbis virus antigen. Anti-dengue and anti-JE virus IgM were measured by a capture enzyme-linked immunosorbent assay (MAC-ELISA). Anti-dengue and anti-JE virus IgG were measured by an ELISA test. Dengue viruses were isolated in cell culture and/or detected by RT-PCR in 20.8% of blood samples. DEN-4 and DEN-2 serotypes were found in 18.4% and 2.4% of the patients, respectively. A total of 86.4% of individuals had a diagnosis of acute dengue fever by using the HI test and/or dengue virus-specific IgM capture-ELISA and/or virus isolation and/or RT-PCR. The prevalence of primary and secondary acute dengue infection was 4% and 78.4%, respectively. Anti-dengue IgG ELISA test was positive in 88.8% of the patients. In 5 cases (4%), Japanese encephalitis virus infection was positive by serology but the cell culture was negative. No Chickungunya virus or Sindbis virus infection was detected by the HI test. In patients with acute dengue virus infection, the most common presenting symptom was headache, followed by conjunctivitis, petechial rash, muscle and joint pain, nausea and abdominal pain. Four percent of hospitalized patients were classified as dengue hemorrhagic fever. The clinical presentation and blood cell counts were similar between patients hospitalized with acute dengue fever and patients with other febrile illnesses. PMID:15906664

  6. Infection of cells by Sindbis virus at low temperature

    SciTech Connect

    Wang Gongbo [Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, NC 27695 (United States); Hernandez, Raquel [Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, NC 27695 (United States); Weninger, Keith [Department of Physics, North Carolina State University, Raleigh, NC 27695 (United States); Brown, Dennis T. [Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, NC 27695 (United States)]. E-mail: dennis_brown@ncsu.edu

    2007-06-05

    Sindbis virus, which belongs to the family Togaviridae genus Alphavirus infects a variety of vertebrate and invertebrate cells. The initial steps of Sindbis virus infection involve attachment, penetration and uncoating. Two different pathways of infection have been proposed for Alphaviruses. One proposed mechanism involves receptor mediated virion endocytosis followed by membrane fusion triggered by endosome acidification. This virus-host membrane fusion model, well established by influenza virus, has been applied to other unrelated membrane-containing viruses including Alphaviruses. The other mechanism proposes direct penetration of the cell plasma membrane by the virus glycoproteins in the absence of membrane fusion. This alternate model is supported by both ultrastructural [Paredes, A.M., Ferreira, D., Horton, M., Saad, A., Tsuruta, H., Johnston, R., Klimstra, W., Ryman, K., Hernandez, R., Chiu, W., Brown, D.T., 2004. Conformational changes in Sindbis virions resulting from exposure to low pH and interactions with cells suggest that cell penetration may occur at the cell surface in the absence of membrane fusion. Virology 324(2), 373-386] and biochemical [Koschinski, A., Wengler, G., Wengler, G., and Repp, H., 2005. Rare earth ions block the ion pores generated by the class II fusion proteins of alphaviruses and allow analysis of the biological functions of these pores. J. Gen. Virol. 86(Pt. 12), 3311-3320] studies. We have examined the ability of Sindbis virus to infect Baby Hamster Kidney (BHK) cells at temperatures which block endocytosis. We have found that under these conditions Sindbis virus infects cells in a temperature- and time-dependent fashion.

  7. Neuraminidase inhibitors for influenza B virus infection: efficacy and resistance

    PubMed Central

    Burnham, Andrew J.; Baranovich, Tatiana; Govorkova, Elena A.

    2013-01-01

    Many aspects of the biology and epidemiology of influenza B viruses are far less studied than for influenza A viruses, and one of these aspects is effectiveness and resistance to the clinically available antiviral drugs, the neuraminidase (NA) inhibitors (NAIs). Acute respiratory infections are one of the leading causes of death in children and adults, and influenza is among the few respiratory infections that can be prevented and treated by vaccination and antiviral treatment. Recent data has suggested that influenza B virus infections are of specific concern to pediatric patients because of the increased risk of severe disease. Treatment of influenza B is a challenging task for the following reasons: NAIs (e.g., oseltamivir and zanamivir) are the only FDA-approved class of antivirals available for treatment;the data suggest that oseltamivir is less effective than zanamivir in pediatric patients;zanamivir is not prescribed to patients younger than 7;influenza B viruses are less susceptible than influenza A viruses to NAIs in vitro;although the level of resistance to NAIs is low, the number of different molecular markers of resistance is higher than for influenza A viruses, and they are not well defined;the relationship between levels of NAI phenotypic resistance and known molecular markers, frequency of emergence, transmissibility, and fitness of NAI-resistant variants are not well established. This review presents current knowledge of the effectiveness of NAIs for influenza B virus and antiviral resistance in clinical, surveillance, and experimental studies. PMID:24013000

  8. Antiviral activity of lanatoside C against dengue virus infection.

    PubMed

    Cheung, Yan Yi; Chen, Karen Caiyun; Chen, Huixin; Seng, Eng Khuan; Chu, Justin Jang Hann

    2014-11-01

    Dengue infection poses a serious threat globally due to its recent rapid spread and rise in incidence. Currently, there is no approved vaccine or effective antiviral drug for dengue virus infection. In response to the urgent need for the development of an effective antiviral for dengue virus, the US Drug Collection library was screened in this study to identify compounds with anti-dengue activities. Lanatoside C, an FDA approved cardiac glycoside was identified as a candidate anti-dengue compound. Our data revealed that lanatoside C has an IC50 of 0.19?M for dengue virus infection in HuH-7 cells. Dose-dependent reduction in dengue viral RNA and viral proteins synthesis were also observed upon treatment with increasing concentrations of lanatoside C. Time of addition study indicated that lanatoside C inhibits the early processes of the dengue virus replication cycle. Furthermore, lanatoside C can effectively inhibit all four serotypes of dengue virus, flavivirus Kunjin, alphavirus Chikungunya and Sindbis virus as well as the human enterovirus 71. These findings suggest that lanatoside C possesses broad spectrum antiviral activity against several groups of positive-sense RNA viruses. PMID:25251726

  9. Pathogenesis of Lassa fever virus infection: I. Susceptibility of mice to recombinant Lassa Gp/LCMV chimeric virus.

    PubMed

    Lee, Andrew M; Cruite, Justin; Welch, Megan J; Sullivan, Brian; Oldstone, Michael B A

    2013-08-01

    Lassa virus (LASV) is a BSL-4 restricted agent. To allow study of infection by LASV under BSL-2 conditions, we generated a recombinant virus in which the LASV glycoprotein (Gp) was placed on the backbone of lymphocytic choriomeningitis virus (LCMV) Cl13 nucleoprotein, Z and polymerase genes (rLCMV Cl13/LASV Gp). The recombinant virus displayed high tropism for dendritic cells following in vitro or in vivo infection. Inoculation of immunocompetent adults resulted in an acute infection, generation of virus-specific CD8(+) T cells and clearance of the infection. Inoculation of newborn mice with rLCMV Cl13/LASV Gp resulted in a life-long persistent infection. Interestingly, adoptive transfer of rLCMV Cl13/LASV Gp immune memory cells into such persistently infected mice failed to purge virus but, in contrast, cleared virus from mice persistently infected with wt LCMV Cl13. PMID:23684417

  10. Influenza A virus infections in Chinese landbirds

    E-print Network

    Peterson, A. Townsend; Bush, Sarah E.; Spackman, Erica; Swayne, David E.; Ip, Hon S.

    2009-10-01

    occurrence of infl uenza viruses in diverse taxa of Emerging Infectious Diseases • www.cdc.gov/eid • Vol. 14, No. 10, October 2008 1645 Table. Prevalence of influenza A virus in avian orders and families at 5 sites, People’s Republic of China Location, no...

  11. Viruses infecting Passiflora species in Florida

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This report documents multiple viruses in Passiflora spp. in Florida. It also reiterates the risk of movement of vegetatively-propagated plant material. This report provides an overview of this virus for growers, extension workers, crop consultants and research and regulatory scientists....

  12. A case of Ebola virus infection

    Microsoft Academic Search

    R T Emond; B Evans; Etw Bowen; G Lloyd

    1977-01-01

    In November 1976 an investigator at the Microbiological Research Establishment accidentally inoculated himself while processing material from patients in Africa who had been suffering from a haemorrhagic fever of unknown cause. He developed an illness closely resembling Marburg disease, and a virus was isolated from his blood that resembled Marburg virus but was distinct serologically. The course of the illness

  13. Ultrastructural Characterization of the Giant Volcano-like Virus Factory of Acanthamoeba polyphaga Mimivirus

    PubMed Central

    Suzan-Monti, Marie; Scola, Bernard La; Barrassi, Lina; Espinosa, Leon; Raoult, Didier

    2007-01-01

    Acanthamoeba polyphaga Mimivirus is a giant double-stranded DNA virus defining a new genus, the Mimiviridae, among the Nucleo-Cytoplasmic Large DNA Viruses (NCLDV). We used utrastructural studies to shed light on the different steps of the Mimivirus replication cycle: entry via phagocytosis, release of viral DNA into the cell cytoplasm through fusion of viral and vacuolar membranes, and finally viral morphogenesis in an extraordinary giant cytoplasmic virus factory (VF). Fluorescent staining of the AT-rich Mimivirus DNA showed that it enters the host nucleus prior to the generation of a cytoplasmic independent replication centre that forms the core of the VF. Assembly and filling of viral capsids were observed within the replication centre, before release into the cell cytoplasm where progeny virions accumulated. 3D reconstruction from fluorescent and differential contrast interference images revealed the VF emerging from the cell surface as a volcano-like structure. Its size dramatically grew during the 24 h infectious lytic cycle. Our results showed that Mimivirus replication is an extremely efficient process that results from a rapid takeover of cellular machinery, and takes place in a unique and autonomous giant assembly centre, leading to the release of a large number of complex virions through amoebal lysis. PMID:17389919

  14. Viral transcription during Autographa californica nuclear polyhedrosis virus infection

    SciTech Connect

    Fuchs, L.Y.

    1985-01-01

    The purpose of this research has been to study the transcription process during nuclear polyhedrosis virus infection of S. frugiperda cells. The challenge raised at the beginning of the project was to find the RNA polymerases(s) responsible for the viral RNA synthesis. The results reported here provide the probable answer to this question. It was found that the early viral RNA, being alpha-amanitin sensitive, was transcribed by the host RNA polymerase II. However, the switch later in infection implied an amanitin-resistant viral transcription, as shown in the RNA-DNA hybridization experiments between viral DNA and (/sup 3/H)-RNA synthesized in nuclei isolated from infected cells. A major breakthrough came with the purification of RNA polymerases from infected cells. The DEAE-Sephadex profile showed a distinct peak of alpha-amanitin resistant RNA polymerase activity, which was not present in the DEAE-Sephadex RNA polymerase profile of uninfected cells. This novel activity was, therefore, induced by the nuclear polyhedrosis virus infection. RNA polymerases were isolated from both normal and infected cells. The virus-induced polymerase was characterized and its properties were compared to those of the host RNA polymerase. The results obtained so far suggest that the virus-induced RNA polymerase may be the enzyme responsible for the transcription of the viral late genes.

  15. Apoptosis of lymphocytes and monocytes infected with influenza virus might be the mechanism of combating virus and causing secondary infection by influenza.

    PubMed

    Xie, Dongxu; Bai, Hai; Liu, Lihua; Xie, Xiangyu; Ayello, Janet; Ma, Xiaohui; Zhang, Junying

    2009-11-01

    Influenza affects most of the world's population annually, often causing a secondary infection, but pathological mechanisms of influenza virus infection remain unclear. We have found that influenza viruses have a selective preference for infecting monocytes and mature immune effector cells. This paper provides evidence that influenza virus infection increases the expression of granzyme B (GrB) in monocytes, activated T and B cells. All GrB(+) cells had cytolytic function. GrB(+)CD62L(high) central memory (T(CM)) cells were fast response population to virus infection when compared with GrB(+)CD62L(low) population. The influenza virus-infected PBMC could be killed by GrB(+) cells. We propose the following mechanism for influenza: (i) influenza virus within the respiratory tract overcomes humoral defenses; (ii) free virus is directly engulfed by the immune system effector cells and free virus also infects epithelial cells; (iii) virus-infected epithelial cells and the immune system cells are killed by cytotoxic cells. These indicated that an immune system that was combating a virus infection needs to sacrifice some of its immune system cells. Therefore, influenza viruses might temporally destroy the human immune system's line of defense, resulting in susceptibility to a secondary infection. This might be a prevalent mechanism existing in cell-mediated immune responses. PMID:19736294

  16. Persistent infection is a rare sequel following infection of pigs with swine vesicular disease virus.

    PubMed Central

    Lin, F.; Mackay, D. K.; Knowles, N. J.; Kitching, R. P.

    2001-01-01

    Nine isolates from pigs persistently infected with a recent Italian isolate of swine vesicular disease (SVD) virus, ITL/9/93, were collected sequentially over 121 days and were characterized antigenically and biochemically. There was an accumulation of amino acid (aa) substitutions in the capsid proteins throughout the carrier state that could be correlated with alterations in antigenicity in virus isolates collected late stage in infection. The aa substitutions detected mainly occurred in VPI and antigenic changes were detected in late isolates both at antigenic site 1, resulting in loss of binding of Mab 4GO7, and at a closely located site which has not yet been named, recognized by Mab C29. In further experiments groups of pigs were exposed to a range of SVD viruses, but no virus was isolated beyond 16 days post infection (dpi) nor viral RNA detected beyond 42 dpi. Attempts to transfer infection to sentinel pigs introduced some time after initial infection of the original pigs were largely unsuccessful. The carrier state was established in only one out of five experimental infections of pigs with SVD virus and can therefore be considered a rare sequel toinfection with SVD virus and is of limited significance in the epidemiology of the disease. PMID:11561966

  17. Antibody landscapes after influenza virus infection or vaccination

    PubMed Central

    James, S. L.; Fox, A.; Ventresca, M.; Aban, M.; Xue, L.; Jones, T. C.; Le, N. M. H.; Pham, Q. T.; Tran, N. D.; Wong, Y.; Mosterin, A.; Katzelnick, L. C.; Labonte, D.; Le, T. T.; van der Net, G.; Skepner, E.; Russell, C. A.; Kaplan, T. D.; Rimmelzwaan, G. F.; de Jong, J. C.; Palache, A.; Beyer, W. E. P.; Le, Q. M.; Nguyen, T. H.; Wertheim, H. F. L.; Hurt, A. C.; Osterhaus, A. D. M. E.; Barr, I. G.; Fouchier, R. A. M.; Horby, P. W.; Smith, D. J.

    2014-01-01

    We introduce the antibody landscape, a method for the quantitative analysis of antibody-mediated immunity to antigenically variable pathogens, achieved by accounting for antigenic variation among pathogen strains. We generated antibody landscapes to study immune profiles covering 43 years of influenza A/H3N2 virus evolution for 69 individuals monitored for infection over six years and for 225 individuals pre- and post-vaccination. On infection and vaccination titers increased broadly, including previously encountered viruses far beyond the extent of cross-reactivity observed after a primary infection. We explored implications for vaccination, and found that use of an antigenically advanced virus had the dual benefit of inducing antibodies against both advanced and previous antigenic clusters. These results indicate that pre-emptive vaccine updates may improve influenza vaccine efficacy in previously-exposed individuals. PMID:25414313

  18. A Review on JC Virus Infection in Kidney Transplant Recipients

    PubMed Central

    Delbue, Serena; Ferraresso, Mariano; Ghio, Luciana; Carloni, Camilla; Carluccio, Silvia; Belingheri, Mirco; Edefonti, Alberto; Ferrante, Pasquale

    2013-01-01

    The polyomavirus (PyV), JC virus (JCV), is a small nonenveloped DNA virus that asymptomatically infects about 80% of healthy adults and establishes latency in the kidney tissue. In case of immunodeficient hosts, JCV can lytically infect the oligodendrocytes, causing a fatal demyelinating disease, known as progressive multifocal leukoencephalopathy (PML). Although the reactivation of another human PyV, BK virus (BKV), is relatively common and its association with the polyomavirus associated nephropathy (PyVAN) following renal transplantation is proven, JCV replication and its impact on graft function and survival are less well studied. Here we describe the biology of JCV and its pathological features and we review the literature regarding the JCV infection analyzed in the setting of transplantations. PMID:23424601

  19. The first imported case infected with chikungunya virus in Korea.

    PubMed

    Hwang, Jeong-Hwan; Lee, Chang-Seop

    2015-03-01

    Chikungunya is caused by an arbovirus transmitted by Aedes mosquito vector. With the increase of habitat of mosquito by global warming and frequent international travel and interchange, chikungunya reemerged and showed global distribution recently. Until now there has not been reported any case infected with chikungunya virus in Korea. A 23-year-old man has been the Republic of the Philippines for 1 week, and visited our emergency center due to fever and back pain. Chikungunya viral infection was diagnosed by specific IgM for chickungunya virus by enzyme-linked immunosorbent assayin Korea Centers for Disease Control and Prevention. His clinical course was self limited. We introduce the first imported case infected with chikungunya virus in Korea. PMID:25844264

  20. The First Imported Case Infected with Chikungunya Virus in Korea

    PubMed Central

    2015-01-01

    Chikungunya is caused by an arbovirus transmitted by Aedes mosquito vector. With the increase of habitat of mosquito by global warming and frequent international travel and interchange, chikungunya reemerged and showed global distribution recently. Until now there has not been reported any case infected with chikungunya virus in Korea. A 23-year-old man has been the Republic of the Philippines for 1 week, and visited our emergency center due to fever and back pain. Chikungunya viral infection was diagnosed by specific IgM for chickungunya virus by enzyme-linked immunosorbent assayin Korea Centers for Disease Control and Prevention. His clinical course was self limited. We introduce the first imported case infected with chikungunya virus in Korea. PMID:25844264

  1. Endocrinopathies in children infected with human immunodeficiency virus.

    PubMed

    Loomba-Albrecht, Lindsey A; Bregman, Thea; Chantry, Caroline J

    2014-09-01

    Endocrine changes (including adrenal insufficiency, disorders of growth and puberty, thyroid dysfunction, metabolic abnormalities and osteopenia) accompany human immunodeficiency virus (HIV) infection in pediatric patients. The cause of these changes is multifactorial and includes direct viral effects of HIV, and effects of antiretroviral therapy. These effects may be of particular importance in childhood given the critical developmental processes that occur during this time period and the likelihood of prolonged exposure to the virus and medications. PMID:25169569

  2. Low risk of TT virus (TTV) infection in medical workers

    Microsoft Academic Search

    K. Nagano; Y. Fukuda; S. Yokozaki; K. Okada; K. Tanaka; K. Funahashi; T. Hayakawa

    1999-01-01

    The rate of infection with TT virus (TTV), a novel single-strand DNA virus was evaluated and the clinical and laboratory features in affected Japanese medical workers were analysed. TTV DNA was measured in 356 medical workers and in 150 age-matched controls using a semi-nested polymerase chain reaction. TTV DNA was detected in 62 of 356 medical workers (17·4%). There were

  3. BLACK CREEK CANAL VIRUS INFECTION INSIGMODON HISPIDUSIN SOUTHERN FLORIDA

    Microsoft Academic Search

    GREGORY E. GLASS; WALTER LIVINGSTONE; JAMES N. MILLS; W. GARY HLADY; JOSHUA B. FINE; WILLIAM BIGGLER; TREVOR COKE; DWIGHT FRAZIER; STEPHANIE ATHERLEY; PIERRE E. ROLLIN; THOMAS G. KSIAZEK; C. J. PETERS; JAMES E. CHILDS

    1998-01-01

    A total of 1,500 small mammals were collected and tested for antibodies cross-reactive to Sin Nombre virus (Hantavirus: Bunyaviridae) at 89 sites in a 1,600 km2 study area of southern Florida. More than 95% of the 123 seropositive animals were cotton rats (Sigmodon hispidus), suggesting infection by Black Creek Canal Virus, although seroreactive Rattus rattus (5 of 294) and Peromyscus

  4. Human Muscle Satellite Cells as Targets of Chikungunya Virus Infection

    Microsoft Academic Search

    Simona Ozden; Michel Huerre; Jean-Pierre Riviere; Lark L. Coffey; Philippe V. Afonso; Vincent Mouly; Jean de Monredon; Jean-Christophe Roger; Mohamed El Amrani; Jean-Luc Yvin; Marie-Christine Jaffar; Marie-Pascale Frenkiel; Marion Sourisseau; Olivier Schwartz; Gillian Butler-Browne; Philippe Desprès; Antoine Gessain; Pierre-Emmanuel Ceccaldi; Linqi Zhang

    2007-01-01

    BackgroundChikungunya (CHIK) virus is a mosquito-transmitted alphavirus that causes in humans an acute infection characterised by fever, polyarthralgia, head-ache, and myalgia. Since 2005, the emergence of CHIK virus was associated with an unprecedented magnitude outbreak of CHIK disease in the Indian Ocean. Clinically, this outbreak was characterized by invalidating poly-arthralgia, with myalgia being reported in 97.7% of cases. Since the

  5. Occult hepatitis B virus infection among Mexican human immunodeficiency virus-1-infected patients

    PubMed Central

    Alvarez-Muñoz, Ma Teresa; Maldonado-Rodriguez, Angelica; Rojas-Montes, Othon; Torres-Ibarra, Rocio; Gutierrez-Escolano, Fernanda; Vazquez-Rosales, Guillermo; Gomez, Alejandro; Muñoz, Onofre; Torres, Javier; Lira, Rosalia

    2014-01-01

    AIM: To determine the frequency of occult hepatitis B infection (OHBI) in a group of human immunodeficiency virus (HIV)-1+/ hepatitis B surface antigen negative (HBsAg)- patients from Mexico. METHODS: We investigated the presence of OHBI in 49 HIV-1+/HBsAg- patients. Hepatitis B virus (HBV) DNA was analyzed using nested PCR to amplify the Core (C) region and by real-time PCR to amplify a region of the S and X genes. The possible associations between the variables and OHBI were investigated using Pearson’s ?2 and/or Fisher’s exact test. RESULTS: We found that the frequency of OHBI was 49% among the group of 49 HIV-1+/HBsAg- patients studied. The presence of OHBI was significantly associated with the HIV-1 RNA viral load [odds ratio (OR) = 8.75; P = 0.001; 95%CI: 2.26-33.79] and with HIV-antiretroviral treatment with drugs that interfere with HBV replication (lamivudine, tenofovir or emtricitabine) (OR = 0.25; P = 0.05; 95%CI: 0.08-1.05). CONCLUSION: The OHBI frequency is high among 49 Mexican HIV-1+/HBsAg- patients and it was more frequent in patients with detectable HIV RNA, and less frequent in patients who are undergoing HIV-ARV treatment with drugs active against HBV. PMID:25309083

  6. African swine fever virus infection in Ornithodoros ticks.

    PubMed

    Burrage, Thomas G

    2013-04-01

    African swine fever virus (ASFV) is an arbovirus which is vectored by soft ticks of the Ornithodoros spp. and in the sylvatic cycle infects wart hogs and bush pigs. ASFV infection of domestic swine causes a high mortality disease. On the other hand, ASFV infection of the tick can result in a high-titered and persistent infection depending upon the ASFV isolate and the tick combination. Recently, morphological, classical virology (titration) and recombinant ASFV have been used to study the cellular, molecular and genetic interactions that occur between ASFV and its host tick. PMID:23085123

  7. Enhanced infectivity of bluetongue virus in cell culture by centrifugation.

    PubMed Central

    Sundin, D R; Mecham, J O

    1989-01-01

    The effects of centrifugation of the infection of cell culture with bluetongue virus (BTV) were investigated. Baby hamster kidney cells were infected with BTV with or without centrifugation. Viral antigen was detected by immunofluorescence at 24 h in both centrifuged and noncentrifuged cultures. However, after 24 h of infection, the production of PFU in centrifuged cell cultures was 10- to 20-fold greater than that seen in cultures not centrifuged. In addition, centrifugation enhanced the direct detection of PFU from blood samples collected from a sheep experimentally infected with BTV. Images PMID:2549092

  8. Infection of influenza virus neuraminidase-vaccinated mice with homologous influenza virus leads to strong protection against heterologous influenza viruses.

    PubMed

    He, Biao; Chang, Haiyan; Liu, Zhihua; Huang, Chaoyang; Liu, Xueying; Zheng, Dan; Fang, Fang; Sun, Bing; Chen, Ze

    2014-12-01

    Vaccination is the best measure to prevent influenza pandemics. Here, we studied the protective effect against heterologous influenza viruses, including A/reassortant/NYMC X-179A (pH1N1), A/Chicken/Henan/12/2004 (H5N1), A/Chicken/Jiangsu/7/2002 (H9N2) and A/Guizhou/54/89×A/PR/8/34 (A/Guizhou-X) (H3N2), in mice first vaccinated with a DNA vaccine of haemagglutinin (HA) or neuraminidase (NA) of A/PR/8/34 (PR8) and then infected with the homologous virus. We showed that PR8 HA or NA vaccination both protected mice against a lethal dose of the homologous virus; PR8 HA or NA DNA vaccination and then PR8 infection in mice offered poor or excellent protection, respectively, against a second, heterologous influenza virus challenge. In addition, before the second heterologous influenza infection, the highest antibody level against nucleoprotein (NP) and matrix (M1 and M2) proteins was found in the PR8 NA-vaccinated and PR8-infected group. The level of induced cellular immunity against NP and M1 showed a trend consistent with that seen in antibody levels. However, PR8 HA+NA vaccination and then PR8 infection resulted in limited protection against heterologous influenza virus challenge. Results of the present study demonstrated that infection of the homologous influenza virus in mice already immunized with a NA vaccine could provide excellent protection against subsequent infection of a heterologous influenza virus. These findings suggested that NA, a major antigen of influenza virus, could be an important candidate antigen for universal influenza vaccines. PMID:25170051

  9. First study of different insect cells to triatoma virus infection.

    PubMed

    Susevich, María Laura; Marti, Gerardo Aníbal; Metz, Germán Ernesto; Echeverría, María Gabriela

    2015-04-01

    The use of viruses for biological control is a new option to be considered. The family Dicistroviridae, which affects only invertebrates, is one of the families that have been proposed for this purpose. The Triatoma virus (TrV), a member of this family, affects triatomine transmitters of Chagas disease, which is endemic in Latin America but also expanding its worldwide distribution. To this end, we attempted virus replication in Diptera, Aedes albopictus (clone C6/36) and Lepidoptera Spodoptera frugiperda (SF9, SF21) and High Five (H5) cell lines. The methodologies used were transfection process, direct inoculation (purified virus), and inoculation of purified virus with trypsin. Results were confirmed by SDS-PAGE, Western blotting, RT-PCR, electron microscopy, and immunofluorescence. According to the results obtained, further analysis of susceptibility/infection of H5 cells to TrV required to be studied. PMID:25481388

  10. The Human Immunodeficiency Virus: Infectivity and Mechanisms of Pathogenesis

    NASA Astrophysics Data System (ADS)

    Fauci, Anthony S.

    1988-02-01

    Infection with the human immunodeficiency virus (HIV) results in a profound immunosuppression due predominantly to a selective depletion of helper/inducer T lymphocytes that express the receptor for the virus (the CD4 molecule). HIV also has tropism for the brain leading to neuropsychiatric abnormalities. Besides inducing cell death, HIV can interfere with T4 cell function by various mechanisms. The monocyte serves as a reservoir for HIV and is relatively refractory to its cytopathic effects. HIV can exist in a latent or chronic form which can be converted to a productive infection by a variety of inductive signals.

  11. Cowpea viruses: Effect of single and mixed infections on symptomatology and virus concentration

    PubMed Central

    Taiwo, Moni A; Kareem, Kehinde T; Nsa, Imade Y; D'A Hughes, Jackies

    2007-01-01

    Natural multiple viral infections of cultivated cowpeas have been reported in Nigeria. In this study, three Nigerian commercial cowpea cultivars ("Olo 11", "Oloyin" and "White") and two lines from the IITA (IT86D- 719 and TVU 76) were mechanically inoculated with Cowpea aphid-borne mosaic virus (CABMV), Bean southern mosaic virus (SBMV) and Cowpea mottle virus (CMeV) singly, as well as in all possible combinations at 10, 20 and 30 days after planting (DAP). Samples of leaves or stems were collected at 10, 20 and 30 days after inoculation (DAI) and analyzed for relative virus concentration by Enzyme-Linked Immunosrbent Assay. All the cultivars and lines {CVS/L} were susceptible to the viruses but the commercial CVS showed more severe symptoms and had relatively higher viral concentration. In single virus infections, CABMV which induced the most severe symptoms had absorbance values (at 405 nm) of 0.11 to 0.46 while SBMV and CMeV which induced moderate symptoms had virus titre of 0.74 to 1.99 and 0.11 to 0.90 respectively. Plants inoculated 10 DAP had significantly higher virus concentration than those inoculated 30 DAP. In mixed infections involving CABMV (10 DAP) apical necrosis and death were observed in commercial cultivars "Olo 11" and "White". Enhancement of CMeV titers were observed in plants infected with CMeV + CABMV. Multiple viral infections of cowpeas may result in complete yield loss, hence, the availability of seeds of cultivars with a high level of multiple virus resistance is recommended as a means of control. PMID:17900355

  12. First Isolation of a Giant Virus from Wild Hirudo medicinalis Leech: Mimiviridae isolation in Hirudo medicinalis

    PubMed Central

    Boughalmi, Mondher; Pagnier, Isabelle; Aherfi, Sarah; Colson, Philippe; Raoult, Didier; La Scola, Bernard

    2013-01-01

    Giant viruses and amoebae are common in freshwater, where they can coexist with other living multicellular organisms. We screened leeches from the species Hirudo medicinalis for giant viruses. We analyzed five H. medicinalis obtained from Tunisia (3) and France (2). The leeches were decontaminated and then dissected to remove internal parts for co-culture with Acanthamoeba polyphaga. The genomes of isolated viruses were sequenced on a 454 Roche instrument, and a comparative genomics analysis was performed. One Mimivirus was isolated and the strain was named Hirudovirus. The genome assembly generated two scaffolds, which were 1,155,382 and 25,660 base pairs in length. Functional annotations were identified for 47% of the genes, which corresponds to 466 proteins. The presence of Mimividae in the same ecological niche as wild Hirudo may explain the presence of the mimivirus in the digestive tract of the leech, and several studies have already shown that viruses can persist in the digestive tracts of leeches fed contaminated blood. As leeches can be used medically and Mimiviruses have the potential to be an infectious agent in humans, patients treated with leeches should be surveyed to investigate a possible connection. PMID:24287596

  13. Junín Virus Infects Mouse Cells and Induces Innate Immune Responses ?

    PubMed Central

    Cuevas, Christian D.; Lavanya, Madakasira; Wang, Enxiu; Ross, Susan R.

    2011-01-01

    Junín virus is the causative agent for Argentine hemorrhagic fever, and its natural host is the New World rodent Calomys musculinus. The virus is transmitted to humans by aerosolization, and it is believed that many of the clinical symptoms are caused by cytokines produced by sentinel cells of the immune system. Here we used the Junín virus vaccine strain Candid 1 to determine whether mouse cells could be used to study virus entry and antiviral innate immune responses. We show that Candid 1 can infect and propagate in different mouse-derived cell lines through a low-pH-dependent, transferrin receptor 1-independent mechanism, suggesting that there is a second entry receptor. In addition, Candid 1 induced expression of the antiviral cytokines tumor necrosis factor alpha and beta interferon in macrophages, and this induction was independent of viral replication. Using Candid 1, as well as virus-like particles bearing the viral glycoprotein, to infect different primary cells and established macrophage cell lines with deletions in the Toll-like receptor (TLR) pathway, we show that TLR2 is a cellular sensor of both the Parodi and Candid 1 viral glycoproteins. Because Junín virus is highly lethal in humans, the use of an experimentally tractable model system, such as the mouse, could provide a better understanding of the antiviral innate cellular responses to Junín virus and the role of these responses in pathogenesis. PMID:21880772

  14. Experimental rabies virus infection of big brown bats (Eptesicus fuscus).

    PubMed

    Jackson, Felix R; Turmelle, Amy S; Farino, David M; Franka, Richard; McCracken, Gary F; Rupprecht, Charles E

    2008-07-01

    A captive colony of adult Big Brown Bats (Eptesicus fuscus) was experimentally infected with a rabies virus (RABV) variant isolated from the salivary glands of a naturally infected Big Brown Bat and passaged once through murine neuroblastoma cell culture. Bats were divided into 11 groups, which were composed of one to three noninfected and one to three infected individuals each. Twenty of 38 animals were infected intramuscularly into both left and right masseter muscles; they received a total of 10(3.2) median mouse intracerebral lethal dose (MICLD50) of Big Brown Bat RABV variant. Experimental outcome after viral exposure was followed in the bats for 140 days postinoculation (PI). Of 20 infected bats, 16 developed clinical rabies, and the mean incubation period was 24 days (range: 13-52 days). Three infected bats never seroconverted and succumbed early to infection (13 days). Four infected bats that survived until the end of the experiment without any signs of disease maintained detectable antibody titers until the third month PI, peaking between days 13 and 43, and consequent drop-off below the threshold for detection occurred by day 140. Limited excretion of virus in saliva of infected bats during the clinical course of disease was observed in two individuals on days 13 and 15 PI (<24 hr prior to onset of clinical illness). No bat-to-bat transmission of RABV to noninfected bats was detected. PMID:18689646

  15. Virus-host interactions in hepatitis C virus infection: implications for molecular pathogenesis and antiviral strategies.

    PubMed

    Georgel, Philippe; Schuster, Catherine; Zeisel, Mirjam B; Stoll-Keller, Françoise; Berg, Thomas; Bahram, Seiamak; Baumert, Thomas F

    2010-06-01

    With a global burden of 170 million chronically infected patients and a major cause of liver cirrhosis and hepatocellular carcinoma, hepatitis C virus (HCV) is a major public health challenge. Recent discoveries of viral and cellular factors mediating virus-host interactions have allowed scientists to uncover the key molecular mechanisms of viral infection and escape from innate and adaptive immune responses. These include the discovery of tight junction proteins as entry factors and microRNA-122, cyclophilins and lipoproteins as host factors for virus translation, replication and production. Furthermore, global genetic analyses have identified IL-28B as a genetic factor associated with the outcome of HCV infection. These discoveries markedly advance the understanding of the molecular pathogenesis of HCV infection and uncover novel targets for urgently needed antiviral strategies. PMID:20537953

  16. Chikungunya virus and West Nile virus infections imported into Belgium, 2007-2012.

    PubMed

    VAN DEN Bossche, D; Cnops, L; Meersman, K; Domingo, C; VAN Gompel, A; VAN Esbroeck, M

    2015-07-01

    Arboviral infections are emerging among tourists travelling to (sub)tropical regions. This study aims to describe the importation of chikungunya virus (CHIKV) and West Nile virus (WNV) into Belgium over a 6-year period from 2007 to 2012. Clinical samples were obtained from travellers presenting at the outpatient clinic of the Institute of Tropical Medicine (ITM), Antwerp, Belgium or submitted to the Central Laboratory for Clinical Biology of the ITM. Testing was performed by serology and/or by real-time reverse transcriptase-polymerase chain reaction. A total of 1288 returning travellers were investigated for CHIKV infection resulting in 34 confirmed and two probable diagnoses (2·80%). Out of 899 patients, four confirmed and one probable imported WNV infections were diagnosed (0·55%). No locally acquired cases have been registered in Belgium until now and the geographical origin of the imported infections reflects the global locations where the viruses are circulating. PMID:24690286

  17. Antigen-Specific Expansion of Cytotoxic T Lymphocytes in Acute Measles Virus Infection

    Microsoft Academic Search

    JUTHATHIP MONGKOLSAPAYA; ASSAN JAYE; MARGARET F. C. CALLAN; ALBERT F. MAGNUSEN; ANDREW J. MCMICHAEL

    1999-01-01

    Skewing of the T-cell receptor repertoire of CD81 T cells has been shown in some persistent infections with viruses, such as human immunodeficiency virus, simian immunodeficiency virus, and Epstein-Barr virus. We have demonstrated that similar distortions also occur in nonpersistent measles virus infection. In addition, two of four children immunized with live, attenuated measles virus showed larger and more persistent

  18. Oral Conditions Associated with Hepatitis C Virus Infection

    PubMed Central

    Alavian, Seyed-Moayed; Mahboobi, Nastaran; Mahboobi, Nima; Karayiannis, Peter

    2013-01-01

    Hepatitis C virus (HCV) infection in more than 170 million chronically infected patients with no developed preventive vaccine is a globally important issue. In addition to expected hepatic manifestations, a number of extrahepatic manifestations, such as mixed cryoglobulinemia, glomerulonephritis, polyarteritis nodosa, rashes, renal disease, neuropathy, and lymphoma, have been reported following HCV infection, which are believed to be influenced by the virus or the host immune response. HCV combination therapy with pegylated interferon and ribavirin might be associated with side effects as well. The association of HCV with special oral conditions has also been reported recurrently; the mechanism of most of which remains unclear. This article reviews the association of HCV infection with some of the oral conditions such as oral health, Sjogren's syndrome, lichen planus and oral cancer. PMID:24195977

  19. Hepatitis B and human immunodeficiency virus co-infection.

    PubMed

    Phung, Bao-Chau; Sogni, Philippe; Launay, Odile

    2014-12-14

    Hepatitis B and human immunodeficiency virus (HBV and HIV) infection share transmission patterns and risk factors, which explains high prevalence of chronic HBV infection in HIV infected patients. The natural course of HBV disease is altered by the HIV infection with less chance to clear acute HBV infection, faster progression to cirrhosis and higher risk of liver-related death in HIV-HBV co-infected patients than in HBV mono-infected ones. HIV infected patients with chronic hepatitis B should be counseled for liver damage and surveillance of chronic hepatitis B should be performed to screen early hepatocellular carcinoma. Noninvasive tools are now available to evaluate liver fibrosis. Isolated hepatitis B core antibodies (anti-HBc) are a good predictive marker of occult HBV infection. Still the prevalence and significance of occult HBV infection is controversial, but its screening may be important in the management of antiretroviral therapy. Vaccination against HBV infection is recommended in non-immune HIV patients. The optimal treatment for almost all HIV-HBV co-infected patients should contain tenofovir plus lamivudine or emtricitabine and treatment should not be stopped to avoid HBV reactivation. Long term tenofovir therapy may lead to significant decline in hepatitis B surface Antigen. The emergence of resistant HBV strains may compromise the HBV therapy and vaccine therapy. PMID:25516647

  20. Epstein–Barr virus infection–Related hemophagocytic lymphohistiocytosis

    PubMed Central

    Kumar, Navin; Mehta, Chitra; Sarma, Smita; Singh, Sumit; Mehta, Yatin

    2015-01-01

    We report a case of 27-year-old female diagnosed with hemophagocytic lymphohistiocytosis (HLH) following a recent Epstein–Barr virus (EBV) infection. A known case of relapsing remitting multiple sclerosis on corticosteroids for last 6 months presented to the critical care unit with fever, maculopapular rash and difficulty in breathing. A rapid and correct diagnosis with the precise treatment led to complete recovery of this patient. The HLH is a rare complication of primary EBV infection.

  1. Optic Neuritis Associated With Chikungunya Virus Infection in South India

    Microsoft Academic Search

    Apoorva Mittal; Saurabh Mittal; M. Jayahar Bharati; Rengappa Ramakrishnan; Sankarlingam Saravanan; Padmakar S. Sathe

    Objective:Todefineopticneuritisassociatedwithchikun- gunya virus (CHIKV) infection in a clinical setting. Methods:This observational case series includes 14 pa- tients with clinical features of CHIKV infection and as- sociated optic neuritis. Complete ophthalmic evalua- tions were performed, as well as other examinations, including Mantoux test, Widal test, blood profile, color vision, neuroimaging, visual fields, visual evoked poten- tials, VDRL test, and enzyme-linked immunosorbent

  2. Prevention of human papilloma virus infection with vaccines.

    PubMed

    Azam, Faisal; Shams-ul-Islam, Mohammad

    2010-08-01

    Human Papilloma virus (HPV) is present in all the cases of cervical cancer. It can also cause other diseases like genital warts, condylomata accuminata, cervical intraepithelial neoplasia and Anogenital cancers. Cervical cancer is the second most common cause of death from cancer. To improve the mortality from cervical cancers it is extremely important to prevent the HPV infection. In this review we have discussed the role of HPV vaccines in preventing the HPV infections and so the cervical cancer. PMID:20726203

  3. Previous infection with a mesogenic strain of newcastle disease virus prevents infection with a highly pathogenic avian influenza virus in chickens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Avian influenza virus (AIV) and Newcastle disease virus (NDV) are two of the most important viruses affecting poultry worldwide. Co-infections of poultry with AIV and NDV are a problem from both the clinical point of view and the diagnosis of these viruses, but little is known on the interactions b...

  4. Management of hepatitis C virus infection in HIV/HCV co-infected patients: clinical review.

    PubMed

    Singal, Ashwani-K; Anand, Bhupinderjit S

    2009-08-14

    Nearly one fourth of individuals with human immunodeficiency virus (HIV) infection have hepatitis C virus (HCV) infection in the US and Western Europe. With the availability of highly active antiretroviral therapy and the consequent reduction in opportunistic infections, resulting in the prolongation of the life span of HIV-infected patients, HCV co-infection has emerged as a significant factor influencing the survival of HIV patients. Patients with HIV/HCV co-infection have a faster rate of fibrosis progression resulting in more frequent occurrences of cirrhosis, end-stage liver disease, and hepatocellular carcinoma. However, the mechanism of interaction between the two viruses is not completely understood. The treatment for HCV in co-infected patients is similar to that of HCV mono-infection; i.e., a combination of pegylated interferon and ribavirin. The presence of any barriers to anti-HCV therapy should be identified and eliminated in order to recruit all eligible patients. The response to treatment in co-infected patients is inferior compared to the response in patients with HCV mono-infection. The sustained virologic response rate is only 38% for genotype-1 and 75% for genotype-2 and -3 infections. Liver transplantation is no longer considered a contraindication for end-stage liver disease in co-infected patients. However, the 5 year survival rate is lower in co-infected patients compared to patients with HCV mono-infection (33% vs 72%, P = 0.07). A better understanding of liver disease in co-infected patients is needed to derive new strategies for improving outcome and survival. PMID:19673011

  5. Nanogram quantities of plasmid DNA encoding the rabies virus glycoprotein protect mice against lethal rabies virus infection

    Microsoft Academic Search

    Nancy B. Ray; Larry C. Ewalt; Donald L. Lodmell

    1997-01-01

    Vaccination against virus infections has proven to be an effective strategy in the improvement of human health. In this study, we evaluated two plasmid DNA vaccines expressing the glycoprotein (G) gene of the challenge virus standard (CVS) rabies virus for their ability to elicit neutralizing antibody and protect BALB\\/cByJ mice against lethal rabies virus challenge. A single inoculation of 10

  6. The role of IKK? in Venezuelan equine encephalitis virus infection.

    PubMed

    Amaya, Moushimi; Voss, Kelsey; Sampey, Gavin; Senina, Svetlana; de la Fuente, Cynthia; Mueller, Claudius; Calvert, Valerie; Kehn-Hall, Kylene; Carpenter, Calvin; Kashanchi, Fatah; Bailey, Charles; Mogelsvang, Soren; Petricoin, Emanuel; Narayanan, Aarthi

    2014-01-01

    Venezuelan equine encephalitis virus (VEEV) belongs to the genus Alphavirus, family Togaviridae. VEEV infection is characterized by extensive inflammation and studies from other laboratories implicated an involvement of the NF-?B cascade in the in vivo pathology. Initial studies indicated that at early time points of VEEV infection, the NF-?B complex was activated in cells infected with the TC-83 strain of VEEV. One upstream kinase that contributes to the phosphorylation of p65 is the IKK? component of the IKK complex. Our previous studies with Rift valley fever virus, which exhibited early activation of the NF-?B cascade in infected cells, had indicated that the IKK? component underwent macromolecular reorganization to form a novel low molecular weight form unique to infected cells. This prompted us to investigate if the IKK complex undergoes a comparable macromolecular reorganization in VEEV infection. Size-fractionated VEEV infected cell extracts indicated a macromolecular reorganization of IKK? in VEEV infected cells that resulted in formation of lower molecular weight complexes. Well-documented inhibitors of IKK? function, BAY-11-7082, BAY-11-7085 and IKK2 compound IV, were employed to determine whether IKK? function was required for the production of infectious progeny virus. A decrease in infectious viral particles and viral RNA copies was observed with inhibitor treatment in the attenuated and virulent strains of VEEV infection. In order to further validate the requirement of IKK? for VEEV replication, we over-expressed IKK? in cells and observed an increase in viral titers. In contrast, studies carried out using IKK?(-/-) cells demonstrated a decrease in VEEV replication. In vivo studies demonstrated that inhibitor treatment of TC-83 infected mice increased their survival. Finally, proteomics studies have revealed that IKK? may interact with the viral protein nsP3. In conclusion, our studies have revealed that the host IKK? protein may be critically involved in VEEV replication. PMID:24586253

  7. Impact of Chikungunya Virus Infection on Health Status and Quality of Life: A Retrospective Cohort Study

    E-print Network

    Paris-Sud XI, Université de

    Impact of Chikungunya Virus Infection on Health Status and Quality of Life: A Retrospective Cohort several months after Chikungunya virus (CHIKV) infection. Their frequency and their impact on quality. (2009) Impact of Chikungunya Virus Infection on Health Status and Quality of Life: A Retrospective

  8. Innate immune responses in raccoons after raccoon rabies virus infection.

    PubMed

    Srithayakumar, Vythegi; Sribalachandran, Hariharan; Rosatte, Rick; Nadin-Davis, Susan A; Kyle, Christopher J

    2014-01-01

    Zoonotic wildlife diseases pose significant health risks not only to their primary vectors but also to humans and domestic animals. Rabies is a lethal encephalitis caused by rabies virus (RV). This RNA virus can infect a range of terrestrial mammals but each viral variant persists in a particular reservoir host. Active management of these host vectors is needed to minimize the negative impacts of this disease, and an understanding of the immune response to RV infection aids strategies for host vaccination. Current knowledge of immune responses to RV infection comes primarily from rodent models in which an innate immune response triggers activation of several genes and signalling pathways. It is unclear, however, how well rodent models represent the immune response of natural hosts. This study investigates the innate immune response of a primary host, the raccoon, to a peripheral challenge using the raccoon rabies virus (RRV). The extent and temporal course of this response during RRV infection was analysed using genes predicted to be upregulated during infection (IFNs; IFN regulatory factors; IL-6; Toll like receptor-3; TNF receptor). We found that RRV activated components of the innate immune system, with changes in levels of transcripts correlated with presence of viral RNA. Our results suggest that natural reservoirs of rabies may not mimic the immune response triggered in rodent models, highlighting the need for further studies of infection in primary hosts. PMID:24085257

  9. Diminished Intracellular Invariant Chain Expression Following Vaccinia Virus Infection

    PubMed Central

    Wang, Nan; Weber, Ekkehard; Blum, Janice S.

    2010-01-01

    Vaccinia virus (VV) has been used as a vaccine to eradicate smallpox and as a vaccine for HIV and tumors. However, the immunoevasive properties of VV, have raised safety concerns. VV infection of APC perturbs MHC class II-mediated Ag presentation. Exposure of human B cell lines to VV induced a dramatic reduction in cellular expression of the class II chaperone, invariant chain (Ii) during the late stages (i.e. 8–10 h) of infection. Yet, cell viability and surface expression of MHC class II molecules were maintained up to 24 h after exposure to virus. Reductions in Ii and class II mRNA levels were detected as early as 6 h after VV infection of APC. To examine whether VV was acting solely to disrupt host protein synthesis, B cells were treated with an inhibitor of translation, cycloheximide (CHX). Within 1 h of B cell CHX treatment, Ii protein expression decreased coupled with a loss of class II presentation. Analysis of Ii degradation in VV or CHX treated cells, revealed on-going Ii proteolysis contributing to reduced steady state Ii levels in these APC. Yet in contrast with CHX, VV infection of APC altered lysosomal protease expression and Ii degradation. Virus infection induced cellular cathepsin L expression while reducing the levels of other lysosomal proteases. These results demonstrate that at late stages of VV infection, reductions in cellular Ii levels coupled with changes in lysosomal protease activity, contribute in part to defects in class II presentation. PMID:19592662

  10. Thyroid disorders in chronic hepatitis C virus infection.

    PubMed

    Antonelli, Alessandro; Ferri, Clodoveo; Fallahi, Poupak; Ferrari, Silvia Martina; Ghinoi, Alessandra; Rotondi, Mario; Ferrannini, Ele

    2006-06-01

    The prevalence of thyroid disorders has been evaluated in patients with hepatitis C virus (HCV) infection by many studies. From a review of the published controlled studies, it is possible to observe that: (1) most investigated patients with chronic HCV hepatitis, while a minority evaluated hepatitis C virus antibody (HCVAb)- seropositive patients (the two conditions are not comparable with regards to thyroidal repercussions, in fact, HCVAb-seropositive patients do not necessarily display changes of the immune system present in chronically infected HCV patients); and (2) some authors selected as internal control hepatitis B virus (HBV)-infected patients, while others selected apparently healthy controls or HCVAb-negative subjects. Pooling all data about HCV-positive patients (with chronic hepatitis or HCVAb positivity) and using as control the sum of healthy controls, HBV-infected patients and sera negative for HCVAb, a significant increase of the prevalence has been observed both for thyroid autoimmune disorders (odds ratio [OR] = 1.6; 95% confidence interval = [C]) 1.4-1.9) as well as for hypothyroidism (OR = 2.9; 95% CI = 2.0-4.1). The results of the epidemiologic studies showing an association between HCV infection and thyroid cancer need to be confirmed. The abovementioned evidences seem sufficient to suggest careful thyroid monitoring during the follow-up of patients with HCV infection. PMID:16839258

  11. Reduction of Influenza Virus Titer and Protection against Influenza Virus Infection in Infant Mice Fed Lactobacillus casei Shirota

    Microsoft Academic Search

    Hisako Yasui; Junko Kiyoshima; Tetsuji Hori

    2004-01-01

    We investigated whether oral administration of Lactobacillus casei strain Shirota to neonatal and infant mice ameliorates influenza virus (IFV) infection in the upper respiratory tract and protects against influenza infection. In a model of upper respiratory IFV infection, the titer of virus in the nasal washings of infant mice administered L. casei Shirota (L. casei Shirota group) was significantly (P

  12. Heterologous RNA-silencing suppressors from both plant- and animal-infecting viruses support plum pox virus infection.

    PubMed

    Maliogka, Varvara I; Calvo, María; Carbonell, Alberto; García, Juan Antonio; Valli, Adrian

    2012-07-01

    HCPro, the RNA-silencing suppressor (RSS) of viruses belonging to the genus Potyvirus in the family Potyviridae, is a multifunctional protein presumably involved in all essential steps of the viral infection cycle. Recent studies have shown that plum pox potyvirus (PPV) HCPro can be replaced successfully by cucumber vein yellowing ipomovirus P1b, a sequence-unrelated RSS from a virus of the same family. In order to gain insight into the requirement of a particular RSS to establish a successful potyviral infection, we tested the ability of different heterologous RSSs from both plant- and animal-infecting viruses to substitute for HCPro. Making use of engineered PPV chimeras, we show that PPV HCPro can be replaced functionally by some, but not all, unrelated RSSs, including the NS1 protein of the mammal-infecting influenza A virus. Interestingly, the capacity of a particular RSS to replace HCPro does not correlate strictly with its RNA silencing-suppression strength. Altogether, our results suggest that not all suppression strategies are equally suitable for efficient escape of PPV from the RNA-silencing machinery. The approach followed here, based on using PPV chimeras in which an under-consideration RSS substitutes for HCPro, could further help to study the function of diverse RSSs in a 'highly sensitive' RNA-silencing context, such as that taking place in plant cells during the process of a viral infection. PMID:22513385

  13. Epidemiology and natural history of hepatitis C virus infection

    PubMed Central

    Lee, Mei-Hsuan; Yang, Hwai-I; Yuan, Yong; L’Italien, Gilbert; Chen, Chien-Jen

    2014-01-01

    Hepatitis C virus (HCV) affects 130-210 million people worldwide and is one of the major risk factors for hepatocellular carcinoma. Globally, at least one third of hepatocellular carcinoma cases are attributed to HCV infection, and 350000 people died from HCV related diseases per year. There is a great geographical variation of HCV infection globally, with risk factors for the HCV infection differing in various countries. The progression of chronic hepatitis C to end-stage liver disease also varies in different study populations. A long-term follow-up cohort enrolling participants with asymptomatic HCV infection is essential for elucidating the natural history of HCV-caused hepatocellular carcinoma, and for exploring potential seromarkers that have high predictability for risk of hepatocellular carcinoma. However, prospective cohorts comprising individuals with HCV infection are still uncommon. The risk evaluation of viral load elevation and associated liver disease/cancer in HCV (REVEAL-HCV) study has followed a cohort of 1095 residents seropositive for antibodies against hepatitis C virus living in seven townships in Taiwan for more than fifteen years. Most of them have acquired HCV infection through iatrogenic transmission routes. As the participants in the REVEAL-HCV study rarely receive antiviral therapies, it provides a unique opportunity to study the natural history of chronic HCV infection. In this review, the prevalence, risk factors and natural history of HCV infection are comprehensively reviewed. The study cohort, data collection, and findings on liver disease progression of the REVEAL-HCV study are described. PMID:25071320

  14. Virus-inhibiting surgical glove to reduce the risk of infection by enveloped viruses.

    PubMed

    Bricout, Fernand; Moraillon, Anne; Sonntag, Philippe; Hoerner, Pierre; Blackwelder, William; Plotkin, Stanley

    2003-04-01

    Needle puncture and other accidents that occur during surgery and other procedures may lead to viral infections of medical personnel, notably by hepatitis C (HCV) and human immunodeficiency virus (HIV), now that hepatitis B can be prevented by vaccination. A new surgical glove called G-VIR, which contains a disinfecting agent for enveloped viruses, has been developed. Herpes simplex type 1 (HSV) was used as a standard enveloped virus in both in vitro and in vivo tests of the virucidal capacity of the glove. Bovine viral diarrhea virus (BVDV) and feline immunodeficiency virus (FIV) were used as models for HCV and HIV, respectively. For in vitro study, a contaminated needle was passed through a glove and residual virus was titrated; for in vivo studies, animals were stuck with a contaminated needle through a glove. Despite variation in virus enumeration inherent in the puncture technique, statistical evaluation showed that infection was reproducibly and substantially reduced by passage through the virucidal layer. For BVDV, the amount of virus passing through the virucidal glove was reduced in 82% of pairwise comparisons with control gloves that lacked the virucidal agent; when plaque counts were adjusted to a common dilution, the median count for the virucidal glove was on the average reduced >10-fold. In experiments in which the proportion of wells infected with FIV was measured, the ratio of TCID(50) values (control glove to G-VIR) was >15, and probably much higher. For HSV, the amount of virus passing through the virucidal glove was reduced in 81% of comparisons with control gloves; the median of adjusted plaque counts was reduced on the average approximately eightfold or ninefold. In vivo tests with FIV and HSV in cats and mice, respectively, found smaller percentage reductions in infection than the in vitro tests but confirmed the virucidal effect of the gloves. PMID:12601762

  15. Treatment of Venezuelan equine encephalitis virus infection with (-)-carbodine.

    PubMed

    Julander, Justin G; Bowen, Richard A; Rao, Jagadeeshwar R; Day, Craig; Shafer, Kristiina; Smee, Donald F; Morrey, John D; Chu, Chung K

    2008-12-01

    Venezuelan equine encephalitis virus (VEEV) may cause encephalitis in humans, for which no FDA-approved antiviral treatment is available. Carbocyclic cytosine (carbodine) has broad-spectrum activity but toxicity has limited its utility. It was anticipated that one of the enantiomers of carbodine would show enhanced activity and reduced toxicity. The activity of the d-(-) enantiomer of carbodine [(-)-carbodine] was evaluated by infectious cell culture assay and was found to have a 50% effective concentration (EC50) of 0.2 microg/ml against the TC-83 vaccine strain of VEEV in Vero cells, while the l-(+) enantiomer had no activity. Virus titer inhibition correlated with intracellular cytidine triphosphate reduction after treatment with (-)-carbodine, as determined by HPLC analysis. Pre-treatment with 200 mg/(kgd) resulted in significant improvement in survival, virus load in the brain, weight change, and mean day-to-death in a mouse model of TC-83 VEEV disease. A single dose of (-)-carbodine resulted in a slight extension of mean time to death in mice infected with wild-type VEEV. Post-virus exposure treatment with (-)-carbodine was effective in significantly improving disease parameters in mice infected with TC-83 VEEV when treatment was initiated as late as 4 days post-virus installation (dpi). It is remarkable that (-)-carbodine is effective when initiated after the establishment of brain infection. PMID:18675850

  16. Hepatitis B virus and hepatitis C virus infection among HIV-1-infected injection drug users in Dali, China: prevalence and infection status in a cross-sectional study.

    PubMed

    Dong, Yuan; Qiu, Chao; Xia, Xueshan; Wang, Jing; Zhang, Haiyan; Zhang, Xiaoyan; Xu, Jianqing

    2015-04-01

    To assess the prevalence of hepatitis B virus (HBV) and hepatitis C virus (HCV) infection and to investigate their mutual influences on infection status among human immunodeficiency virus type 1 (HIV-1)-seropositive injection drug users (IDUs). A cross-sectional study was conducted among HIV infected IDUs in Dali, China. The participants were tested for serological markers of HBV and HCV infection, alanine transaminase (ALT) activity and CD4(+) T cell count. HCV genotype was determined by sequencing. Of 529 patients, 498 (94.1 %) HIV infected IDUs agreed to participate. The overall prevalence of HCV infection (anti-HCV antibody positive) and spontaneous HCV clearance were 90.8 % (452/498) and 21.5 % (97/452), respectively. Of 411 subjects who had not received HBV vaccine, 296 (72.0 %) were positive for antibody against HBV core antigen (HBcAb), while 274 (66.7 %) were positive for both HCV antibody and HBcAb. HBV antigens were detected in 52 of the HBV-infected subjects (17.6 %). HCV clearance was associated with HBV antigenemia (p = 0.0002) and higher CD4(+) T cell count (p = 0.0294). Resolved HBV infection was associated with HCV genotype 3 (p = 0.0365). HBV and HCV infection are highly prevalent and mutually influence infection status in HIV-1 infected IDUs in Dali, China. PMID:25616842

  17. Dynamics of Hepatitis B Virus Infection: What Causes Viral Clearance?

    Microsoft Academic Search

    STANCA M. CIUPE; ANNE J. CATLLÁ; JONATHAN FORDE; DAVID G. SCHAEFFER

    2011-01-01

    The virus Hepatitis B infects liver cells, leading to either acute or chronic liver disease. Immune responses involve both curing and killing of cells. Stability analyses show that viral clearance depends only on the strength of the combined killing and curing, independent of the characteristics of the cured cells.

  18. The mortality of neonatal herpes simplex virus infection.

    PubMed

    Lopez-Medina, Eduardo; Cantey, Joseph B; Sánchez, Pablo J

    2015-06-01

    This retrospective study characterized the clinical course of 13 neonates who died with herpes simplex virus infection from 2001 to 2011, representing a 26% case-fatality rate. Fatal disease developed at ?48 hours of age in one-third of infants, was mostly disseminated disease, and occurred despite early administration of high-dose acyclovir therapy. PMID:25868428

  19. Epidemiology of Genital Herpes Simplex Virus Infection in Developed Countries

    Microsoft Academic Search

    J Standardized; Jean-Elie Malkin

    SUMMARY Comparisons of the seroepidemiology of genital herpes simplex virus (HSV) infection within and between countries are hampered by variations in tests, methods and populations sampled. Differences in seroprevalence may partly reflect variability in diagnostic efforts and healthcare awareness, expectations and utilization. To allow comparison between surveys and to improve their performance, seroepidemiological studies should use validated HSV type-specific tests,

  20. Hepatitis E virus infection prevalence among selected populations in Iowa

    Microsoft Academic Search

    Yuory V. Karetnyi; Mary J. R. Gilchrist

    1999-01-01

    Background: HEV causes an enteric infectious disease endemic in developing areas with hot climate. A case of endogenous HEV infection has been reported in the US. Recently, HEV-like virus was isolated from swine in Iowa. Swine production is a major industry in Iowa with the potential for human exposure to swine in and around industrial and family farm operations. Objective:

  1. WEST NILE VIRUS INFECTION IN REINDEER (RANGIFER TARANDUS)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    West Nile virus (WNV) is a mosquito-borne member of the Flaviviridae family (genus Flavivirus) transmitted among bird populations by mosquitoes and incidentally infecting mammals. First recognized in the United States in 1999, WNV has spread across the United States in subsequent years. Numerous cas...

  2. Measles Virus Infection in the Placenta of Monozygotic Twins

    Microsoft Academic Search

    Makiko Ohyama; Tomoko Fukui; Yukichi Tanaka; Keisuke Kato; Rikuo Hoshino; Tomoka Sugawara; Michiko Yamanaka; Rieko Ijiri; Tetsutaro Sata; Yasufumi Itani

    2001-01-01

    We report a case of monozygotic twins whose mother was infected with measles at 19 weeks' gestation. One of the twins died in utero at 32 weeks' gestation. The placenta of the stillbirth showed massive fibrin deposition, and some residual trophoblasts contained many inclusion bodies positive for measles virus antigen. Fetal organs and cells other than a few splenic lymphocytes

  3. Protective effect of dietary xylitol on influenza A virus infection.

    PubMed

    Yin, Sun Young; Kim, Hyoung Jin; Kim, Hong-Jin

    2014-01-01

    Xylitol has been used as a substitute for sugar to prevent cavity-causing bacteria, and most studies have focused on its benefits in dental care. Meanwhile, the constituents of red ginseng (RG) are known to be effective in ameliorating the symptoms of influenza virus infection when they are administered orally for 14 days. In this study, we investigated the effect of dietary xylitol on influenza A virus infection (H1N1). We designed regimens containing various fractions of RG (RGs: whole extract, water soluble fraction, saponin and polysaccharide) and xylitol, and combination of xylitol with the RG fractions. Mice received the various combinations orally for 5 days prior to lethal influenza A virus infection. Almost all the mice died post challenge when xylitol or RGs were administered separately. Survival was markedly enhanced when xylitol was administered along with RGs, pointing to a synergistic effect. The effect of xylitol plus RG fractions increased with increasing dose of xylitol. Moreover, dietary xylitol along with the RG water soluble fraction significantly reduced lung virus titers after infection. Therefore, we suggest that dietary xylitol is effective in ameliorating influenza-induced symptoms when it is administered with RG fractions, and this protective effect of xylitol should be considered in relation to other diseases. PMID:24392148

  4. West Nile Virus Infection in Humans and Horses, Cuba

    PubMed Central

    Guzmán, Maria Guadalupe; Fernández, Roberto; Llop, Alina; Dickinson, Félix Orlando; Pérez, Daniel; Cruz, Raúl; González, Tayri; Estévez, Gonzalo; González, Hiram; Santos, Paulino; Kourí, Gustavo; Andonova, Maya; Lindsay, Robbin; Artsob, Harvey; Drebot, Michael

    2006-01-01

    A surveillance system to detect West Nile virus (WNV) was established in Cuba in 2002. WNV infection was confirmed by serologic assays in 4 asymptomatic horses and 3 humans with encephalitis in 2003 and 2004. These results are the first reported evidence of WNV activity in Cuba. PMID:16707068

  5. Chikungunya Virus and Central Nervous System Infections in Children, India

    Microsoft Academic Search

    Penny Lewthwaite; Ravi Vasanthapuram; Jane C. Osborne; Ashia Begum; Jenna L. M. Plank; M. Veera Shankar; Roger Hewson; Anita Desai; Nick J. Beeching; Ravi Ravikumar; Tom Solomon

    2009-01-01

    Chikungunya virus (CHIKV) is a mosquito-borne al- phavirus best known for causing fever, rash, arthralgia, and occasional neurologic disease. By using real-time reverse transcription-PCR, we detected CHIKV in plasma samples of 8 (14%) of 58 children with suspected central nervous system infection in Bellary, India. CHIKV was also detected in the cerebrospinal fl uid of 3 children.

  6. Autochthonous Infections with Hepatitis E Virus Genotype 4, France

    PubMed Central

    Romanet, Pauline; Moal, Valérie; Borentain, Patrick; Purgus, Raj; Benezech, Alban; Motte, Anne; Gérolami, René

    2012-01-01

    During January–March 2011, diagnoses of hepatitis E virus (HEV) infection increased in Marseille University hospitals in southeastern France. HEV genotype 4, which is described almost exclusively in Asia, was recovered from 2 persons who ate uncooked pork liver sausage. Genetic sequences were 96.7% identical to those recently described in swine in Europe. PMID:22840196

  7. Rapid Diagnosis of Respiratory Syncytial Virus Infections in Immunocompromised Adults

    Microsoft Academic Search

    JANET A. ENGLUND; PEDRO A. PIEDRA; ALAN JEWELL; KIRTI PATEL; BARBARA B. BAXTER; ANDESTELLA WHIMBEY

    1996-01-01

    Although rapid antigen detection methods for the documentation of respiratory syncytial virus (RSV) infections are widely used with pediatric patients, these tests have not been prospectively evaluated in immunocompromised (IC) adults. For bone marrow transplant recipients and adult patients undergoing chemotherapy for leukemia who had recent onset of respiratory symptoms, respiratory samples (combined nasal wash (NW)-throat swab (TS), endotracheal tube

  8. Testosterone correlates with Venezuelan equine encephalitis virus infection in macaques

    Microsoft Academic Search

    Michael P Muehlenbein; Frank B Cogswell; Mark A James; James Koterski; George V Ludwig

    2006-01-01

    Here we briefly report testosterone and cytokine responses to Venezuelan equine encephalitis virus (VEEV) in macaques which were used as part of a larger study conducted by the Department of Defense to better characterize pathological responses to aerosolized VEEV in non-human primates. Serial samples were collected and analyzed for testosterone and cytokines prior to and during infection in 8 captive

  9. Dual infection with dengue virus 3 and human immunodeficiency virus 1 in Havana, Cuba.

    PubMed

    Gonzalez, Daniel; Limonta, Daniel; Bandera, Juan Francisco; Perez, Jorge; Kouri, Gustavo; Guzman, Maria G

    2009-01-01

    Although dengue virus (DEN) endemic regions overlap with human immunodeficiency virus 1 (HIV) high incidence areas, little has been documented on HIV and DEN mixed infection. Here we report DEN/HIV concurrent infections recorded during the DEN-3 epidemic in 2001-2002 in Havana. Serologic-confirmed DEN is described in two HIV-infected subjects with dengue fever symptoms. Although patients had dengue disease, the CD4+ cells remained within normal levels and no accelerated progression of HIV disease was observed. To our knowledge, DEN cases caused by DEN-3 in HIV-infected individuals have not been reported previously. Further research is needed to diagnose this likely underreported mixed viral infection in DEN endemic areas. PMID:19759497

  10. Persistent equine arteritis virus infection in HeLa cells.

    PubMed

    Zhang, Jianqiang; Timoney, Peter J; MacLachlan, N James; McCollum, William H; Balasuriya, Udeni B R

    2008-09-01

    The horse-adapted virulent Bucyrus (VB) strain of equine arteritis virus (EAV) established persistent infection in high-passage-number human cervix cells (HeLa-H cells; passages 170 to 221) but not in low-passage-number human cervix cells (HeLa-L cells; passages 95 to 115) or in several other cell lines that were evaluated. However, virus recovered from the 80th passage of the persistently infected HeLa-H cells (HeLa-H-EAVP80) readily established persistent infection in HeLa-L cells. Comparative sequence analysis of the entire genomes of the VB and HeLa-H-EAVP80 viruses identified 16 amino acid substitutions, including 4 in the replicase (nsp1, nsp2, nsp7, and nsp9) and 12 in the structural proteins (E, GP2, GP3, GP4, and GP5). Reverse genetic studies clearly showed that substitutions in the structural proteins but not the replicase were responsible for the establishment of persistent infection in HeLa-L cells by the HeLa-H-EAVP80 virus. It was further demonstrated that recombinant viruses with substitutions in the minor structural proteins E and GP2 or GP3 and GP4 were unable to establish persistent infection in HeLa-L cells but that recombinant viruses with combined substitutions in the E (Ser53-->Cys and Val55-->Ala), GP2 (Leu15-->Ser, Trp31-->Arg, Val87-->Leu, and Ala112-->Thr), GP3 (Ser115-->Gly and Leu135-->Pro), and GP4 (Tyr4-->His and Ile109-->Phe) proteins or with a single point mutation in the GP5 protein (Pro98-->Leu) were able to establish persistent infection in HeLa-L cells. In summary, an in vitro model of EAV persistence in cell culture was established for the first time. This system can provide a valuable model for studying virus-host cell interactions, especially virus-receptor interactions. PMID:18579588

  11. The Variegate Neurological Manifestations of Varicella Zoster Virus Infection

    PubMed Central

    Nagel, Maria A.; Cohrs, Randall J.; Mahalingam, Ravi

    2014-01-01

    Varicella zoster virus (VZV) is an exclusively human neurotropic alphaherpesvirus. Primary infection causes varicella (chickenpox), after which the virus becomes latent in ganglionic neurons along the entire neuraxis. With advancing age or immunosuppression, cell-mediated immunity to VZV declines, and the virus reactivates to cause zoster (shingles), dermatomal distribution, pain, and rash. Zoster is often followed by chronic pain (postherpetic neuralgia), cranial nerve palsies, zoster paresis, vasculopathy, meningoencephalitis, and multiple ocular disorders. This review covers clinical, laboratory, and pathological features of neurological complications of VZV reactivation, including diagnostic testing to verify active VZV infection in the nervous system. Additional perspectives are provided by discussions of VZV latency, animal models to study varicella pathogenesis and immunity, and of the value of vaccination of elderly individuals to boost cell-mediated immunity to VZV and prevent VZV reactivation. PMID:23884722

  12. Equine Influenza A(H3N8) Virus Infection in Cats

    PubMed Central

    Su, Shuo; Wang, Lifang; Fu, Xinliang; He, Shuyi; Hong, Malin; Zhou, Pei; Gray, Gregory

    2014-01-01

    Interspecies transmission of equine influenza A(H3N8) virus has resulted in establishment of a canine influenza virus. To determine if something similar could happen with cats, we experimentally infected 14 cats with the equine influenza A(H3N8) virus. All showed clinical signs, shed virus, and transmitted the virus to a contact cohort. PMID:25417790

  13. Respiratory Syncytial Virus Infection: From Biology to Therapy A Perspective

    PubMed Central

    2008-01-01

    Respiratory syncytial virus (RSV) is responsible for significant morbidity and mortality, particularly in infants younger than 18 months and in the elderly. To date, there are few effective treatment options available to prevent or treat RSV infections. Attractive therapeutic strategies include targeting host epithelial adhesion molecules required for RSV infection, enhancing localized cell-mediated immunity, interfering with RSV viral gene expression and developing a multigene DNA vaccine. The most recent data supporting the advantages and limitations of each of these approaches are discussed in detail. Several promising strategies offer hope for safe and effective prophylaxis and treatment of RSV infection. PMID:23283306

  14. Human papilloma virus (HPV) infection in children and adolescents.

    PubMed

    Mammas, Ioannis N; Sourvinos, George; Spandidos, Demetrios A

    2009-03-01

    Human papilloma viruses (HPV) are common pathogens associated with a wide range of cutaneous and mucosal infections in childhood. Different HPV types can cause common warts, genital warts, low-grade as well as high-grade squamous intraepithelial lesions. Anogenital warts represent an issue with legal and clinical implications and evaluation of children for the possibility of sexual abuse should be considered in all cases. Recurrent respiratory papillomatosis has also been associated with HPV infection in a variety of studies. The recently introduced HPV vaccination is expected to prevent HPV-related cervical cancer in adulthood; however, HPV infection will continue to affect children. PMID:19050916

  15. Human Ebola virus infection results in substantial immune activation

    PubMed Central

    McElroy, Anita K.; Akondy, Rama S.; Davis, Carl W.; Ellebedy, Ali H.; Mehta, Aneesh K.; Kraft, Colleen S.; Lyon, G. Marshall; Ribner, Bruce S.; Varkey, Jay; Sidney, John; Sette, Alessandro; Campbell, Shelley; Ströher, Ute; Damon, Inger; Nichol, Stuart T.; Spiropoulou, Christina F.; Ahmed, Rafi

    2015-01-01

    Four Ebola patients received care at Emory University Hospital, presenting a unique opportunity to examine the cellular immune responses during acute Ebola virus infection. We found striking activation of both B and T cells in all four patients. Plasmablast frequencies were 10–50% of B cells, compared with less than 1% in healthy individuals. Many of these proliferating plasmablasts were IgG-positive, and this finding coincided with the presence of Ebola virus-specific IgG in the serum. Activated CD4 T cells ranged from 5 to 30%, compared with 1–2% in healthy controls. The most pronounced responses were seen in CD8 T cells, with over 50% of the CD8 T cells expressing markers of activation and proliferation. Taken together, these results suggest that all four patients developed robust immune responses during the acute phase of Ebola virus infection, a finding that would not have been predicted based on our current assumptions about the highly immunosuppressive nature of Ebola virus. Also, quite surprisingly, we found sustained immune activation after the virus was cleared from the plasma, observed most strikingly in the persistence of activated CD8 T cells, even 1 mo after the patients’ discharge from the hospital. These results suggest continued antigen stimulation after resolution of the disease. From these convalescent time points, we identified CD4 and CD8 T-cell responses to several Ebola virus proteins, most notably the viral nucleoprotein. Knowledge of the viral proteins targeted by T cells during natural infection should be useful in designing vaccines against Ebola virus. PMID:25775592

  16. A virus-like particle vaccine for epidemic Chikungunya virus protects nonhuman primates against infection.

    PubMed

    Akahata, Wataru; Yang, Zhi-Yong; Andersen, Hanne; Sun, Siyang; Holdaway, Heather A; Kong, Wing-Pui; Lewis, Mark G; Higgs, Stephen; Rossmann, Michael G; Rao, Srinivas; Nabel, Gary J

    2010-03-01

    Chikungunya virus (CHIKV) has infected millions of people in Africa, Europe and Asia since this alphavirus reemerged from Kenya in 2004. The severity of the disease and the spread of this epidemic virus present a serious public health threat in the absence of vaccines or antiviral therapies. Here, we describe a new vaccine that protects against CHIKV infection of nonhuman primates. We show that selective expression of viral structural proteins gives rise to virus-like particles (VLPs) in vitro that resemble replication-competent alphaviruses. Immunization with these VLPs elicited neutralizing antibodies against envelope proteins from alternative CHIKV strains. Monkeys immunized with VLPs produced high-titer neutralizing antibodies that protected against viremia after high-dose challenge. We transferred these antibodies into immunodeficient mice, where they protected against subsequent lethal CHIKV challenge, indicating a humoral mechanism of protection. Immunization with alphavirus VLP vaccines represents a strategy to contain the spread of CHIKV and related pathogenic viruses in humans. PMID:20111039

  17. Giant viruses coexisted with the cellular ancestors and represent a distinct supergroup along with superkingdoms Archaea, Bacteria and Eukarya

    PubMed Central

    2012-01-01

    Background The discovery of giant viruses with genome and physical size comparable to cellular organisms, remnants of protein translation machinery and virus-specific parasites (virophages) have raised intriguing questions about their origin. Evidence advocates for their inclusion into global phylogenomic studies and their consideration as a distinct and ancient form of life. Results Here we reconstruct phylogenies describing the evolution of proteomes and protein domain structures of cellular organisms and double-stranded DNA viruses with medium-to-very-large proteomes (giant viruses). Trees of proteomes define viruses as a ‘fourth supergroup’ along with superkingdoms Archaea, Bacteria, and Eukarya. Trees of domains indicate they have evolved via massive and primordial reductive evolutionary processes. The distribution of domain structures suggests giant viruses harbor a significant number of protein domains including those with no cellular representation. The genomic and structural diversity embedded in the viral proteomes is comparable to the cellular proteomes of organisms with parasitic lifestyles. Since viral domains are widespread among cellular species, we propose that viruses mediate gene transfer between cells and crucially enhance biodiversity. Conclusions Results call for a change in the way viruses are perceived. They likely represent a distinct form of life that either predated or coexisted with the last universal common ancestor (LUCA) and constitute a very crucial part of our planet’s biosphere. PMID:22920653

  18. Cryo-Electron Microscopy of Viruses Infecting Bacterium

    NASA Astrophysics Data System (ADS)

    Chiu, Wah

    2010-03-01

    Single particle cryo-EM can yield structures of infectious bacterial viruses with and without imposed icosahedral symmetry at subnanometer resolution. Reconstructions of infectious and empty phage particles show substantial differences in the portal vertex protein complex at one of the 12 pentameric vertices in the icosahedral virus particle through which the viral genomes are packaged or released. In addition, electron cryo-tomography of viruses during infecting its bacterial host cell displayed multiple conformations of the tail fiber of the virus. Our structural observations by single particle and tomographic reconstructions suggest a mechanism whereby the viral tail fibers, upon binding to the host cell, induce a cascade of structural alterations of the portal vertex protein complex that triggers DNA release.

  19. In vivo imaging of cidofovir treatment of cowpox virus infection.

    PubMed

    Goff, Arthur; Twenhafel, Nancy; Garrison, Aura; Mucker, Eric; Lawler, James; Paragas, Jason

    2007-09-01

    Variola virus and other members of the genus Orthopoxviruses constitute a prominent bioterrorism and public health threat. Treatment with the anti-viral drug cidofovir inhibits replication of orthopoxviruses in vitro and in vivo. In this study, we visualized the effect of cidofovir on viral kinetics in orthopoxvirus infected mice by using whole-body fluorescence imaging (FI). We engineered a cowpox virus (CPV) expressing the enhanced green fluorescent protein (GFP). Single-step growth curves and calculated 50% lethal doses (LD(50)) of wild-type CPX (Wt-CPV) and GFP-expressing CPX (GFP-CPV) were comparable. Whole-body FI first detected GFP fluorescence in the mesenteric tissue of untreated animals on post-infection day (PID) 1. On PID 3 GFP signal was detected throughout the mesentery, in all abdominal organs by PID 5 and in most major organs, except for the heart and brain by PID 6. Infected animals treated with 25mg/kg of cidofovir also began showing signs of viral replication on PID 1, however, the fluorescent signal was limited only to discrete foci throughout the course of the infection. This work describes the first use of an established Orthopox model of infection to evaluate drug efficacy and track virus progression on a macroscopic level. PMID:17524511

  20. Experimental West Nile virus infection in jungle crows (Corvus macrorhynchos).

    PubMed

    Shirafuji, Hiroaki; Kanehira, Katsushi; Kubo, Masanori; Shibahara, Tomoyuki; Kamio, Tsugihiko

    2008-05-01

    We experimentally infected jungle crows (Corvus macrorhynchos), which are representative corvids in East Asia, with West Nile virus (WNV) to study their susceptibility toward WNV infection. Six jungle crows were subcutaneously inoculated with 1,000 plaque-forming units (PFU) of the WNV NY99 strain. Within 7 days after inoculation, five of the six infected crows died, and peak viremias ranged from 10(6.5) to 10(10.9) PFU/mL serum. In addition, infected crows shed WNV in the oral cavity and cloaca, and the virus was widely disseminated in the organs of the crows. Based on these findings, we conclude that jungle crows are highly susceptible to WNV infection, and they could serve as amplifying hosts in the transmission of WNV. Although WNV has not been detected in East Asia, the virus could spread rapidly on introduction into this region because of the large number of potential amplifying hosts and vector mosquitoes that inhabit this region. PMID:18458322

  1. Immune responses of ducks infected with duck Tembusu virus

    PubMed Central

    Li, Ning; Wang, Yao; Li, Rong; Liu, Jiyuan; Zhang, Jinzhou; Cai, Yumei; Liu, Sidang; Chai, Tongjie; Wei, Liangmeng

    2015-01-01

    Duck Tembusu virus (DTMUV) can cause serious disease in ducks, characterized by reduced egg production. Although the virus has been isolated and detection methods developed, the host immune responses to DTMUV infection are unclear. Therefore, we systematically examined the expression of immune-related genes and the viral distribution in DTMUV-infected ducks, using quantitative real-time PCR. Our results show that DTMUV replicates quickly in many tissues early in infection, with the highest viral titers in the spleen 1 day after infection. Rig-1, Mda5, and Tlr3 are involved in the host immune response to DTMUV, and the expression of proinflammatory cytokines (Il-1?, –2, –6, Cxcl8) and antiviral proteins (Mx, Oas, etc.) are also upregulated early in infection. The expression of Il-6 increased most significantly in the tissues tested. The upregulation of Mhc-I was observed in the brain and spleen, but the expression of Mhc-II was upregulated in the brain and downregulated in the spleen. The expression of the interferons was also upregulated to different degrees in the spleen but that of the brain was various. Our study suggests that DTMUV replicates rapidly in various tissues and that the host immune responses are activated early in infection. However, the overexpression of cytokines may damage the host. These results extend our understanding of the immune responses of ducks to DTMUV infection, and provide insight into the pathogenesis of DTMUV attributable to host factors. PMID:26005441

  2. Role of macrophages and monocytes in hepatitis C virus infections

    PubMed Central

    Revie, Dennis; Salahuddin, Syed Zaki

    2014-01-01

    A number of studies conducted over many years have shown that hepatitis C virus (HCV) can infect a variety of cell types. In vivo infection of monocytes, macrophages, and dendritic cells by HCV has been frequently shown by a number of researchers. These studies have demonstrated replication of HCV by detecting the presence of both negative genomic strands and a variety of non-structural HCV proteins in infected cells. In addition, analyses of genome sequences have also shown that different cell types can harbor different HCV variants. Investigators have also done preliminary studies of which cellular genes are affected by HCV infection, but there have not yet been a sufficient number of these studies to understand the effects of infection on these cells. Analyses of in vitro HCV replication have shown that monocytes, macrophages and dendritic cells can be infected by HCV from patient sera or plasma. These studies suggest that entry and cellular locations may vary between different cell types. Some studies suggest that macrophages may preferentially allow HCV genotype 1 to replicate, but macrophages do not appear to select particular hypervariable regions. Overall, these studies agree with a model where monocytes and macrophages act as an amplification system, in which these cells are infected and show few cytopathic effects, but continuously produce HCV. This allows them to produce virus over an extended time and allows its spread to other cell types. PMID:24659871

  3. Bovine viral diarrhea virus infection induces autophagy in MDBK cells.

    PubMed

    Fu, Qiang; Shi, Huijun; Ren, Yan; Guo, Fei; Ni, Wei; Qiao, Jun; Wang, Pengyan; Zhang, Hui; Chen, Chuangfu

    2014-07-01

    Bovine viral diarrhea virus (BVDV) is an enveloped, positive-sense, single-stranded RNA virus that belongs to the genus Pestivirus (Flaviviridae). The signaling pathways and levels of signaling molecules are altered in Madin-Darby Bovine Kidney (MDBK) cells infected with BVDV. Autophagy is a conservative biological degradation pathway that mainly eliminates and degrades damaged or superfluous organelles and macromolecular complexes for intracellular recycling in eukaryotic cells. Autophagy can also be induced as an effective response to maintain cellular homeostasis in response to different stresses, such as nutrient or growth factor deprivation, hypoxia, reactive oxygen species exposure and pathogen infection. However, the effects of BVDV infection on autophagy in MDBK cells remain unclear. Therefore, we performed an analysis of autophagic activity after BVDV NADL infection using real-time PCR, electron microscopy, laser confocal microscopy, and Western blotting analysis. The results demonstrated that BVDV NADL infection increased autophagic activity and significantly elevated the expression levels of the autophagy-related genes Beclin1 and ATG14 in MDBK cells. However, the knockdown of Beclin1 and ATG14 by RNA interference (RNAi) did not affect BVDV NADL infection-related autophagic activity. These findings provided a novel perspective to elaborate the effects of viral infection on the host cells. PMID:24972811

  4. Chronic social stress impairs virus specific adaptive immunity during acute Theiler’s virus infection

    PubMed Central

    Young, Erin E.; Vichaya, Elisabeth G.; Reusser, Nicole M.; Cook, Jennifer L.; Steelman, Andrew R.; Welsh, C. Jane R.; Meagher, Mary W.

    2012-01-01

    Prior exposure to social disruption (SDR) stress exacerbates Theiler’s murine encephalomyelitis virus (TMEV) infection, a model of multiple sclerosis. Here we examined the impact of SDR on T cell responses to TMEV infection in SJL mice. SDR impaired viral clearance and exacerbated acute disease. Moreover, TMEV infection alone increased CD4 and CD8 mRNA expression in brain and spleen while SDR impaired this response. SDR decreased both CD4+ and CD8+ virus-specific T cells in CNS, but not spleen. These findings suggest that SDR-induced suppression of virus-specific T cell responses contributes to impairments in viral clearance and exacerbation of acute disease. PMID:23021485

  5. Virus Infections and Type 1 Diabetes Risk

    Microsoft Academic Search

    Merja Roivainen; Karin Klingel

    2010-01-01

    Common intestinal infections caused by human enteroviruses (HEVs) are considered major environmental factors predisposing\\u000a to type 1 diabetes (T1D). In spite of the active research of the field, the HEV-induced pathogenetic processes are poorly\\u000a understood. Recently, after the first documented report on HEV infections in the pancreatic islets of deceased T1D patients,\\u000a several groups became interested in the issue and

  6. MICA and recovery from hepatitis C virus and hepatitis B virus infections

    Microsoft Academic Search

    P S Karacki; X Gao; C L Thio; D L Thomas; J J Goedert; D Vlahov; R A Kaslow; S Strathdee; M W Hilgartner; S J O'Brien; M Carrington

    2004-01-01

    The polymorphic MHC class I chain-related A (MICA) gene encodes a ligand that has different binding affinities for the NKG2D activating receptor of CD8+ T cells and natural killer (NK) cells. We hypothesized that MICA heterogeneity would affect recovery from hepatitis C virus (HCV) and hepatitis B virus (HBV) infections. To test the hypothesis, we initially typed known MICA polymorphisms

  7. Virus antibody dynamics in primary and secondary dengue infections.

    PubMed

    Gujarati, Tanvi P; Ambika, G

    2014-12-01

    Dengue viral infections show unique infection patterns arising from its four serotypes, (DENV-1,2,3,4). Its effects range from simple fever in primary infections to potentially fatal secondary infections. We analytically and numerically analyse virus dynamics and humoral response in a host during primary and secondary dengue infection for long periods using micro-epidemic models. The models presented here incorporate time delays, antibody dependent enhancement, a dynamic switch and a correlation factor between different DENV serotypes. We find that the viral load goes down to undetectable levels within 7-14 days as is observed for dengue infection, in both cases. For primary infection, the stability analysis of steady states shows interesting dependence on the time delay involved in the production of antibodies from plasma cells. We demonstrate the existence of a critical value for the immune response parameter, beyond which the infection gets completely cured. For secondary infections with a different serotype, the homologous antibody production is enhanced due to the influence of heterologous antibodies. The antibody production is also controlled by the correlation factor, which is a measure of similarities between the different DENV serotypes involved. Our results agree with clinically observed humoral responses for primary and secondary infections. PMID:24384697

  8. Hepatitis B virus infection and primary hepatocellular carcinoma.

    PubMed Central

    Feitelson, M

    1992-01-01

    For many years, epidemiological studies have demonstrated a strong link between chronic hepatitis B virus (HBV) infection and the development of primary hepatocellular carcinoma (PHC). Other hepatocarcinogens such as hepatitis C virus and aflatoxin also contribute to hepatocarcinogenesis either in conjunction with HBV infection or alone. Cellular and molecular biological studies are providing explanations for the HBV-PHC relationship, and models are now being formulated to further test the relative importance of various factors such as viral DNA integration, activation of oncogenes, genetic instability, loss of tumor suppressor genes, and trans-activating properties of HBV to the pathogenesis of PHC. Further research will probably define more than a single mechanism whereby chronic HBV infection results in PHC. PMID:1323384

  9. CD81 and Hepatitis C Virus (HCV) Infection

    PubMed Central

    Fénéant, Lucie; Levy, Shoshana; Cocquerel, Laurence

    2014-01-01

    Hepatitis C Virus (HCV) infection is a global public health problem affecting over 160 million individuals worldwide. Its symptoms include chronic hepatitis, liver cirrhosis and hepatocellular carcinoma. HCV is an enveloped RNA virus mainly targeting liver cells and for which the initiation of infection occurs through a complex multistep process involving a series of specific cellular entry factors. This process is likely mediated through the formation of a tightly orchestrated complex of HCV entry factors at the plasma membrane. Among HCV entry factors, the tetraspanin CD81 is one of the best characterized and it is undoubtedly a key player in the HCV lifecycle. In this review, we detail the current knowledge on the involvement of CD81 in the HCV lifecycle, as well as in the immune response to HCV infection. PMID:24509809

  10. The Innate Immune Playbook for Restricting West Nile Virus Infection

    PubMed Central

    Quicke, Kendra M.; Suthar, Mehul S.

    2013-01-01

    West Nile virus (WNV) is an emerging mosquito-borne flavivirus that causes annual epidemics of encephalitic disease throughout the world. Despite the ongoing risk to public health, no approved vaccines or therapies exist for use in humans to prevent or combat WNV infection. The innate immune response is critical for controlling WNV replication, limiting virus-induced pathology, and programming protective humoral and cell-mediated immunity to WNV infection. The RIG-I like receptors, Toll-like receptors, and Nod-like receptors detect and respond to WNV by inducing a potent antiviral defense program, characterized by production of type I IFN, IL-1? and expression of antiviral effector genes. Recent research efforts have focused on uncovering the mechanisms of innate immune sensing, antiviral effector genes that inhibit WNV, and countermeasures employed by WNV to antagonize innate immune cellular defenses. In this review, we highlight the major research findings pertaining to innate immune regulation of WNV infection. PMID:24178712

  11. A Cellular Model to Explain the Pathogenesis of Infection by the Hepatitis B Virus

    E-print Network

    Nowak, Martin A.

    A Cellular Model to Explain the Pathogenesis of Infection by the Hepatitis B Virus ROBERT J. H; revised 10 November 1993 ABSTRACT The natural history of infection by the hepatitis B virus (HBV) depends transient infection to subclinical chronic hepatitis. Persistent infection often leads to the development

  12. Antiviral activity of ginseng extract against respiratory syncytial virus infection

    PubMed Central

    LEE, JONG SEOK; KO, EUN-JU; HWANG, HYE SUK; LEE, YU-NA; KWON, YOUNG-MAN; KIM, MIN-CHUL; KANG, SANG-MOO

    2014-01-01

    Panax ginseng has been known to have a number of immuno-modulatory effects. In this study, we investigated whether Panax Korean red ginseng extract (KRGE) has in vitro and in vivo antiviral effects on respiratory syncytial virus (RSV) infection. KRGE improved the survival of human lung epithelial cells against RSV infection and inhibited RSV replication. In addition, KRGE treatment suppressed the expression of RSV-induced inflammatory cytokine genes (IL-6 and IL-8) and the formation of reactive oxygen species in epithelial cell cultures. Oral administration of mice with KRGE resulted in lowering lung viral loads after RSV infection. Additionally, the in vivo effects of KRGE showed an enhanced level of interferon-? (IFN-?) producing dendritic cells subsequent to RSV infection. Taken together, these results suggested that KRGE has antiviral activity against RSV infection. PMID:24756136

  13. Dermatological manifestations of hepatitis C virus infection in Saudi Arabia.

    PubMed

    Halawani, Mona R

    2014-06-01

    The Saudi Ministry of Health data indicates that almost 32% of viral hepatitis cases were caused by hepatitis C virus (HCV). It has been widely reported that chronic HCV infection is associated with and may trigger or exacerbate many skin manifestations in 20-40% of patients visiting dermatologists. The most commonly encountered dermatological manifestations of HCV infection globally include mixed cryoglobulinemia, porphyria cutanea tarda, cutaneous and/or oral lichen planus, urticaria, pruritus, thrombocytopenic purpura, and psoriasis. The current article indicates that HCV infection is increasing in Saudi Arabia and approximately 12% of the reported dermatological manifestations are caused by HCV infection. We recommend the urgent need for large-scale, case-control studies to understand the impact of HCV infection in patients with skin disease. PMID:24888650

  14. Health care-associated hepatitis C virus infection.

    PubMed

    Pozzetto, Bruno; Memmi, Meriam; Garraud, Olivier; Roblin, Xavier; Berthelot, Philippe

    2014-12-14

    Hepatitis C virus (HCV) is a blood-borne pathogen that has a worldwide distribution and infects millions of people. Care-associated HCV infections represented a huge part of hepatitis C burden in the past via contaminated blood and unsafe injections and continue to be a serious problem of public health. The present review proposes a panorama of health care-associated HCV infections via the three mode of contamination that have been identified: (1) infected patient to non-infected patient; (2) infected patient to non-infected health care worker (HCW); and (3) infected HCW to non infected patient. For each condition, the circumstances of contamination are described together with the means to prevent them. As a whole, the more important risk is represented by unsafe practices regarding injections, notably with the improper use of multidose vials used for multiple patients. The questions of occupational exposures and infected HCWs are also discussed. In terms of prevention and surveillance, the main arm for combating care-associated HCV infections is the implementation of standard precautions in all the fields of cares, with training programs and audits to verify their good application. HCWs must be sensitized to the risk of blood-borne pathogens, notably by the use of safety devices for injections and good hygiene practices in the operating theatre and in all the invasive procedures. The providers performing exposed-prone procedures must monitor their HCV serology regularly in order to detect early any primary infection and to treat it without delay. With the need to stay vigilant because HCV infection is often a hidden risk, it can be hoped that the number of people infected by HCV via health care will decrease very significantly in the next years. PMID:25516637

  15. Health care-associated hepatitis C virus infection

    PubMed Central

    Pozzetto, Bruno; Memmi, Meriam; Garraud, Olivier; Roblin, Xavier; Berthelot, Philippe

    2014-01-01

    Hepatitis C virus (HCV) is a blood-borne pathogen that has a worldwide distribution and infects millions of people. Care-associated HCV infections represented a huge part of hepatitis C burden in the past via contaminated blood and unsafe injections and continue to be a serious problem of public health. The present review proposes a panorama of health care-associated HCV infections via the three mode of contamination that have been identified: (1) infected patient to non-infected patient; (2) infected patient to non-infected health care worker (HCW); and (3) infected HCW to non infected patient. For each condition, the circumstances of contamination are described together with the means to prevent them. As a whole, the more important risk is represented by unsafe practices regarding injections, notably with the improper use of multidose vials used for multiple patients. The questions of occupational exposures and infected HCWs are also discussed. In terms of prevention and surveillance, the main arm for combating care-associated HCV infections is the implementation of standard precautions in all the fields of cares, with training programs and audits to verify their good application. HCWs must be sensitized to the risk of blood-borne pathogens, notably by the use of safety devices for injections and good hygiene practices in the operating theatre and in all the invasive procedures. The providers performing exposed-prone procedures must monitor their HCV serology regularly in order to detect early any primary infection and to treat it without delay. With the need to stay vigilant because HCV infection is often a hidden risk, it can be hoped that the number of people infected by HCV via health care will decrease very significantly in the next years. PMID:25516637

  16. Mouse Models of Hepatitis B Virus Infection Comprising Host-Virus Immunologic Interactions

    PubMed Central

    Inuzuka, Tadashi; Takahashi, Ken; Chiba, Tsutomu; Marusawa, Hiroyuki

    2014-01-01

    Hepatitis B virus (HBV) infection is one of the most prevalent infectious diseases associated with various human liver diseases, including acute, fulminant and chronic hepatitis; liver cirrhosis; and hepatocellular carcinoma. Despite the availability of an HBV vaccine and the development of antiviral therapies, there are still more than 350 million chronically infected people worldwide, approximately 5% of the world population. To understand the virus biology and pathogenesis in HBV-infected patients, several animal models have been developed to mimic hepatic HBV infection and the immune response against HBV, but the narrow host range of HBV infection and lack of a full immune response spectrum in animal models remain significant limitations. Accumulating evidence obtained from studies using a variety of mouse models that recapitulate hepatic HBV infection provides several clues for understanding host-virus immunologic interactions during HBV infection, whereas the determinants of the immune response required for HBV clearance are poorly defined. Therefore, adequate mouse models are urgently needed to elucidate the mechanism of HBV elimination and identify novel targets for antiviral therapies. PMID:25437805

  17. Disease course and viral shedding in experimental Norwalk virus and Snow Mountain virus infection.

    PubMed

    Kirby, A E; Shi, J; Montes, J; Lichtenstein, M; Moe, C L

    2014-12-01

    Norovirus is the most common cause of acute infectious gastroenteritis, causing approximately 21 million cases annually in the USA. The virus is highly contagious and resistant to decontamination, making outbreaks difficult to control. To facilitate the development of better control methods, this study characterized the viral shedding patterns in stools from subjects experimentally infected with genogroup I or II norovirus. Viral stool titers were determined by quantitative real-time RT-PCR for all stools produced in the first 7 days post-challenge and representative stools through day 35 post-challenge. The shedding titers and disease course were analyzed with respect to virus type, illness, and subject demographics. Infection with GII.2 Snow Mountain (SMV) resulted in more symptoms and a higher frequency of painful symptoms compared to GI.1 Norwalk (NV) infection. However, NV infection produced stool viral titers approximately 2 logs higher than those seen in SMV infections. Both NV and SMV were shed in stools for up to 3 weeks after the resolution of symptoms, but long shedding durations were more common in NV infections. For each challenge virus, shedding titers and patterns were not correlated with subject demographics or clinical course. This is the first study to report shedding dynamics in experimental GII norovirus infection. PMID:24531909

  18. Interleukin-4 causes delayed virus clearance in influenza virus-infected mice.

    PubMed Central

    Moran, T M; Isobe, H; Fernandez-Sesma, A; Schulman, J L

    1996-01-01

    Two different subsets of T cells, Th1 and Th2 cells, have been demonstrated to secrete different profiles of cytokines and to influence various infections in different ways. Whereas cytokines secreted by Th1 cells, particularly gamma interferon, promote the generation of cell-mediated immunity, Th2 cells and their cytokines (interleukin-4 [IL-4], IL-5, IL-10, and IL-13) have been shown to function in recovery from parasitic infections and in antibody responses. In this study, we analyzed the effects of the dominant Th2 cytokine, IL-4, on immunity to virus infection. We assessed the effects of IL-4 on both secondary immune responses by an adoptive transfer assay and primary immune responses by in vivo treatment of influenza virus-infected mice with IL-4. The results demonstrated that IL-4 can function to inhibit antiviral immunity at both stages. We found that IL-4 treatment of sensitized cells during secondary stimulation in vitro had little effect on their ability to lyse virus-infected target cells in a 51Cr release assay. Nevertheless, the clearance of influenza A/PR/8/34 (H1N1) virus from the lungs of infected BALB/c mice was significantly delayed after the transfer of virus-specific T cells secondarily stimulated in the presence of IL-4 in comparison to virus clearance in recipients of cells stimulated in the absence of IL-4. In contrast to the adoptive transfer results, the treatment of PR8 virus-infected mice with IL-4 during primary infection greatly suppressed the generation of cytotoxic T-cell precursors, as assessed by secondary stimulation in vitro. In addition, culture supernatants of secondarily stimulated spleen cells from IL-4-treated mice contained significantly less gamma interferon and more IL-4 than did spleen cells from controls. More importantly, the treatment of mice with IL-4 resulted in an extremely significant delay in virus clearance. Thus, IL-4 can inhibit both primary and secondary antiviral immune responses. PMID:8764032

  19. Intranasal Sendai virus vaccine protects African green monkeys from infection with human parainfluenza virus-type one

    Microsoft Academic Search

    Julia L. Hurwitz; Kenneth F. Soike; Mark Y. Sangster; Allen Portner; Robert E. Sealy; Dawn H. Dawson; Christopher Coleclough

    1997-01-01

    Human parainfluenza virus-type 1 (hPIV-1) infections are a common cause of “croup” and hospitalizations among young children. Here we address the possibility of using the xenotropic Sendai virus [a mouse parainfluenza virus (PIV)] as a vaccine for hPIV-1. Sendai virus was administered to six African green monkeys (Cercopithecus aethiops) by the intranasal (i.n.) route. A long lasting virus-specific antibody response

  20. Varicella Zoster Virus in Temporal Arteries of Patients With Giant Cell Arteritis.

    PubMed

    Gilden, Don; Nagel, Maria

    2015-07-15

    Giant cell arteritis (GCA) is an immune-mediated disease of unknown etiology. Varicella zoster virus (VZV) antigen was found in all of 4 GCA-positive temporal arteries (TAs) but was not present in any of 13 normal TAs. All 4 GCA-positive TAs contained viral antigen in skip areas, mostly in the adventitia and media and least in the intima. Despite formalin fixation, VZV DNA was detected in 2 of 4 GCA-positive, VZV antigen-positive TAs. Skeletal muscle was attached to 3 of 4 TAs, and VZV antigen was found in 2 and VZV DNA in 1. VZV may cause GCA. PMID:26116729

  1. Molecular diagnosis of Baylisascaris schroederi infections in giant panda (Ailuropoda melanoleuca) feces using PCR.

    PubMed

    Zhou, Xuan; Yu, Hua; Wang, Ning; Xie, Yue; Liang, Yi-nan; Li, De-sheng; Wang, Cheng-dong; Chen, Si-jie; Yan, Yu-bo; Gu, Xiao-bin; Wang, Shu-xian; Peng, Xue-rong; Yang, Guang-you

    2013-10-01

    The helminth Baylisascaris schroederi is one of the most harmful parasites infecting giant pandas (Ailuropoda melanoleuca). It is therefore important to develop an exact diagnostic technique to detect this parasite. Using a known number (1, 2, 3, 4, 5, 10, 25, 50, 100) of feces-isolated B. schroederi egg and adult DNA, we developed a PCR to detect a portion of the mitochondrial 12S rRNA and applied it to giant panda fecal samples. The method was sufficiently sensitive to detect B. schroederi DNA from isolated eggs in a fecal sample with a detection threshold of one egg. We detected B. schroederi in 88% of fecal samples, 30% higher than the conventional flotation technique. No cross-reactivity with other common nematode DNA was detected. Our PCR assay may constitute a valuable alternative for the diagnosis of B. schroederi infections. PMID:24502740

  2. [The diagnosis of hepatitis C virus infection].

    PubMed

    Gervain, Judit

    2014-06-29

    The successful therapy of hepatitis C viral infection requires that the illness is diagnosed before the development of structural changes of the liver. Testing is stepwise consisting of screening, diagnosis, and anti-viral therapy follow-up. For these steps there are different biochemical, serological, histological and molecular biological methods available. For screening, alanine aminotransferase and anti-HCV tests are used. The diagnosis of infection is confirmed using real-time polymerase chain reaction of the viral nucleic acid. Before initiation of the therapy liver biopsy is recommended to determine the level of structural changes in the liver. Alternatively, transient elastography or blood biomarkers may be also used for this purpose. Differential diagnosis should exclude the co-existence of other viral infections and chronic hepatitis due to other origin, with special attention to the presence of autoantibodies. The outcome of the antiviral therapy and the length of treatment are mainly determined by the viral genotype. In Hungary, most patients are infected with genotype 1, subtype b. The polymorphism type that occurs in the single nucleotide located next to the interleukin 28B region in chromosome 19 and the viral polymorphism type Q80K for infection with HCV 1a serve as predictive therapeutic markers. The follow-up of therapy is based on the quantitative determination of viral nucleic acid according to national and international protocols and should use the same method and laboratory throughout the treatment of an individual patient. PMID:24954143

  3. Preparation and efficacy of an inactivated subunit vaccine (NFUIBHK) against type 2 Herpes simplex virus infection.

    PubMed

    Skinner, G R; Williams, D R; Buchan, A; Whitney, J; Harding, M; Bodfish, K

    1978-11-17

    A vaccine against Herpes simplex virus infection was prepared by Nonidet NP 40 and formalin treatment of a type 1, infected-cell extract; virus particles were removed by ultracentrifugation over sucrose. These procedures were not detrimental to the antigenic quality of the vaccine preparation. The vaccine afforded significant protection to experimental type 2 genital herpes virus infection in mice, as adjudged by clinical observations, cytopathological change, and virus yields. PMID:214676

  4. Early street rabies virus infection in striated muscle and later progression to the central nervous system.

    PubMed

    Murphy, F A; Bauer, S P

    1974-01-01

    Twelve isolates of street rabies virus were inoculated intramuscularly into young hamsters and the course of infection was followed by frozen section immunofluorescence. Animals infected with 10 of the 12 viruses had antigen in striated muscle at day 3, but involvement of other tissues was absent or extremely sparse. Muscle infection was still most pronounced at day 6, but neuromuscular spindle, nerve, and brain infections were also detected in a majority of animals. Progression of infection was continuous, with striking terminal accumulations of antigen. The early myotropism of rabies virus may yield the virus which invades the peripheral nervous system, and may represent a phase of infection vulnerable to postexposure intervention. PMID:4282379

  5. Kinetics and Immunodominance of Virus-Specific T Cell Responses During Hantaan Virus Infection.

    PubMed

    Wang, Meiliang; Wang, Jiuping; Kang, Zhenhua; Zhao, Qiuling; Wang, Xiaohui; Hui, Ling

    2015-06-01

    Immunodominant T cell responses are important for protection against virus challenge. However, studies screening for the immunodominant T cell responses and following their kinetics in acute Hantaan virus (HTNV) infection are very limited. Herein, the HTNV nucleocapsid protein-specific T cell responses were longitudinally screened in 15 patients with acute HTNV infection, eight of whom had a particularly severe hemorrhagic fever with renal syndrome (HFRS). An extremely impaired IFN-?-producing T cell response was observed in patients with severe HFRS at the early stage of infection, especially to the immunodominant epitopes detected in the mild to moderate group, namely peptides N127-141, N139-153, N241-255, and N355-369. The initially insufficient T cell response to the immunodominant epitopes may play a role in influencing the severity of HTNV infection. These findings provide information that may aid the design of future vaccines against hantaviruses. PMID:25945718

  6. Bacterial vaginosis and human immunodeficiency virus infection

    PubMed Central

    Spear, Gregory T; St John, Elizabeth; Zariffard, M Reza

    2007-01-01

    Epidemiologic studies indicate that bacterial vaginosis (BV), a common alteration of lower genital tract flora in women, is associated with increased susceptibility to HIV infection. Other recent studies show that HIV is detected more frequently and at higher levels in the lower genital tract of HIV-seropositive women with BV. In vitro studies show that genital tract secretions from women with BV or flora associated with BV induce HIV expression in infected cells. The increased HIV expression appears to be due at least in part to activation through Toll-like receptors (TLR), specifically TLR2. Further research is needed to elucidate how BV contributes to HIV acquisition and transmission. PMID:17953761

  7. Frontiers in the Treatment of Hepatitis C Virus Infection

    PubMed Central

    Ahn, Joseph

    2014-01-01

    In the United States, chronic hepatitis C virus (HCV) infection is the leading cause of blood-borne, virus-associated death related to advanced liver disease and the leading indication for liver transplantation. Although the diagnostic test for HCV has been available for more than 20 years, the majority of persons with HCV infection still have not received a diagnosis. This has led to a recent change in screening recommendations by the Centers for Disease Control and Prevention. Moreover, new medications were approved in 2011 after nearly a decade of minimal progress in the development of treatments for HCV infection. This was followed by the highly anticipated approval of sofosbuvir and simeprevir in 201 3. In the past 3 years, there has been an explosion of reports on medications from different classes, promising a dramatic expansion to an all-oral regimen for the treatment of HCV genotype 1 infection within the next few years. This article reviews the current screening recommendations and standard of care for treatment of HCV infection and highlights specific agents in the pipeline that should change the landscape of how HCV infection is treated in the near future. PMID:24803873

  8. Multiple roles of the coagulation protease cascade during virus infection

    PubMed Central

    Antoniak, Silvio

    2014-01-01

    The coagulation cascade is activated during viral infections. This response may be part of the host defense system to limit spread of the pathogen. However, excessive activation of the coagulation cascade can be deleterious. In fact, inhibition of the tissue factor/factor VIIa complex reduced mortality in a monkey model of Ebola hemorrhagic fever. Other studies showed that incorporation of tissue factor into the envelope of herpes simplex virus increases infection of endothelial cells and mice. Furthermore, binding of factor X to adenovirus serotype 5 enhances infection of hepatocytes but also increases the activation of the innate immune response to the virus. Coagulation proteases activate protease-activated receptors (PARs). Interestingly, we and others found that PAR1 and PAR2 modulate the immune response to viral infection. For instance, PAR1 positively regulates TLR3-dependent expression of the antiviral protein interferon ?, whereas PAR2 negatively regulates expression during coxsackievirus group B infection. These studies indicate that the coagulation cascade plays multiple roles during viral infections. PMID:24632711

  9. Multiple roles of the coagulation protease cascade during virus infection.

    PubMed

    Antoniak, Silvio; Mackman, Nigel

    2014-04-24

    The coagulation cascade is activated during viral infections. This response may be part of the host defense system to limit spread of the pathogen. However, excessive activation of the coagulation cascade can be deleterious. In fact, inhibition of the tissue factor/factor VIIa complex reduced mortality in a monkey model of Ebola hemorrhagic fever. Other studies showed that incorporation of tissue factor into the envelope of herpes simplex virus increases infection of endothelial cells and mice. Furthermore, binding of factor X to adenovirus serotype 5 enhances infection of hepatocytes but also increases the activation of the innate immune response to the virus. Coagulation proteases activate protease-activated receptors (PARs). Interestingly, we and others found that PAR1 and PAR2 modulate the immune response to viral infection. For instance, PAR1 positively regulates TLR3-dependent expression of the antiviral protein interferon ?, whereas PAR2 negatively regulates expression during coxsackievirus group B infection. These studies indicate that the coagulation cascade plays multiple roles during viral infections. PMID:24632711

  10. Naturally Occurring Animal Models of Human Hepatitis E Virus Infection

    PubMed Central

    Yugo, Danielle M.; Cossaboom, Caitlin M.; Meng, Xiang-Jin

    2014-01-01

    Hepatitis E virus (HEV) is a single-stranded, positive-sense RNA virus in the family Hepeviridae. Hepatitis E caused by HEV is a clinically important global disease. There are currently four well-characterized genotypes of HEV in mammalian species, although numerous novel strains of HEV likely belonging to either new genotypes or species have recently been identified from several other animal species. HEV genotypes 1 and 2 are limited to infection in humans, whereas genotypes 3 and 4 infect an expanding host range of animal species and are zoonotic to humans. Historical animal models include various species of nonhuman primates, which have been indispensable for the discovery of human HEV and for understanding its pathogenesis and course of infection. With the genetic identification and characterization of animal strains of HEV, a number of naturally occurring animal models such as swine, chicken, and rabbit have recently been developed for various aspects of HEV research, including vaccine trials, pathogenicity, cross-species infection, mechanism of virus replication, and molecular biology studies. Unfortunately, the current available animal models for HEV are still inadequate for certain aspects of HEV research. For instance, an animal model is still lacking to study the underlying mechanism of severe and fulminant hepatitis E during pregnancy. Also, an animal model that can mimic chronic HEV infection is critically needed to study the mechanism leading to chronicity in immunocompromised individuals. Genetic identification of additional novel animal strains of HEV may lead to the development of better naturally occurring animal models for HEV. This article reviews the current understanding of animal models of HEV infection in both natural and experimental infection settings and identifies key research needs and limitations. PMID:24936039

  11. Hepatitis G virus infection in fulminant hepatic failure

    PubMed Central

    Saiz, J; Sans, M; Mas, A; Olmedo, E; Forns, X; Lopez-Labrador, F; Restrepo, J; Costa, J; Salmeron, J; Guilera, M; Ampurdanes, S; Sanchez-Tapias, J; de Anta, M T J.; Rodes, J

    1997-01-01

    Background—RNA sequences of the recently identified hepatitis GB virus C (HGBV-C), also named hepatitis G virus (HGV), have been detected in patients with idiopathic fulminant hepatic failure (FHF) but the role of this agent in the disease remains controversial. ?Aims—To investigate the presence and implications of HGV infection in a large series of Spanish patients with FHF. ?Patients—Sixty eight patients with FHF, including 19 with idiopathic disease, were studied. In 28 cases, studies were performed before and after liver transplantation. For comparison 200 volunteer blood donors and 22 patients transplanted for chronic liver disease were also studied. ?Methods—HGV RNA was measured in serum by reverse transcriptase polymerase chain reaction of the 5' non-coding region. ?Results—Evidence of HGV infection was found in 3% (6/200) of blood donors and in 19% (13/68) of patients with FHF. HGV infection was more frequent in patients with hepatitis B (24%, 6/25) or hepatitis D (42%, 5/12), than in patients with idiopathic disease (11%, 2/19). Half of the patients with HGV infection used illicit intravenous drugs. Specific clinical features associated with HGV infection were not identified. A very high rate of infection with HGV was observed in patients who underwent liver transplantation, either for FHF (60%, 15/24) or chronic liver disease (45%, 9/20). ?Conclusions—In our geographical area, HGV infection is relatively frequent in FHF, but it does not seem to play a major role in idiopathic cases. ?? Keywords: viral hepatitis; hepatitis G virus; fulminant hepatic failure; liver transplantation PMID:9414981

  12. mRNA maturation in giant viruses: variation on a theme.

    PubMed

    Priet, Stéphane; Lartigue, Audrey; Debart, Françoise; Claverie, Jean-Michel; Abergel, Chantal

    2015-04-20

    Giant viruses from the Mimiviridae family replicate entirely in their host cytoplasm where their genes are transcribed by a viral transcription apparatus. mRNA polyadenylation uniquely occurs at hairpin-forming palindromic sequences terminating viral transcripts. Here we show that a conserved gene cluster both encode the enzyme responsible for the hairpin cleavage and the viral polyA polymerases (vPAP). Unexpectedly, the vPAPs are homodimeric and uniquely self-processive. The vPAP backbone structures exhibit a symmetrical architecture with two subdomains sharing a nucleotidyltransferase topology, suggesting that vPAPs originate from an ancestral duplication. A Poxvirus processivity factor homologue encoded by Megavirus chilensis displays a conserved 5'-GpppA 2'O methyltransferase activity but is also able to internally methylate the mRNAs' polyA tails. These findings elucidate how the arm wrestling between hosts and their viruses to access the translation machinery is taking place in Mimiviridae. PMID:25779049

  13. Clinical evaluation of a rapid immunochromatographic test for the diagnosis of dengue virus infection.

    PubMed

    Sang, C T; Hoon, L S; Cuzzubbo, A; Devine, P

    1998-05-01

    A rapid immunochromatographic test was compared to the hemagglutination inhibition assay for separate determinations of dengue virus-specific immunoglobulin M (IgM) and IgG levels in paired serum specimens from 92 patients (34 with primary dengue virus infection, 35 with secondary dengue virus infection, and 23 without dengue virus infection). The rapid test showed 99% sensitivity in the diagnosis of dengue virus infection. The majority (30 of 34 [88%]) of patients with primary infection showed positive IgM but negative IgG, while 34 of 35 (97%) patients with secondary infection showed positive IgG with or without IgM. Specificity in nonflavivirus infections was 96% (1 of 23 positive). The rapid test should be a useful aid in rapid diagnosis of dengue virus infection. PMID:9606000

  14. Inhibition of a plant virus infection by analogs of melittin.

    PubMed Central

    Marcos, J F; Beachy, R N; Houghten, R A; Blondelle, S E; Pérez-Payá, E

    1995-01-01

    An approach that enables identification of specific synthetic peptide inhibitors of plant viral infection is reported. Synthetic analogs of melittin that have sequence and structural similarities to an essential domain of tobacco mosaic virus coat protein were found to possess highly specific antiviral activity. This approach involves modification of residues located at positions analogous to those that are critical for virus assembly. The degree of inhibition found correlates well with sequence similarities between the viral capsid protein and the melittin analogs studied as well as with the induced conformational changes that result upon interaction of the peptides and ribonucleic acid. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 PMID:8618922

  15. Chayote mosaic virus, a New Tymovirus Infecting Cucurbitaceae.

    PubMed

    Bernal, J J; Jiménez, I; Moreno, M; Hord, M; Rivera, C; Koenig, R; Rodríguez-Cerezo, E

    2000-10-01

    ABSTRACT Chayote mosaic virus (ChMV) is a putative tymovirus isolated from chayote crops in Costa Rica. ChMV was characterized at the host range, serological, and molecular levels. ChMV was transmitted mechanically and induced disease symptoms mainly in Cucurbitaceae hosts. Asymptomatic infections were detected in other host families. Serologically, ChMV is related to the Andean potato latent virus (APLV) and the Eggplant mosaic virus (EMV), both members of the genus Tymovirus infecting solanaceous hosts in the Caribbean Basin and South America. The sequence of the genomic RNA of ChMV was determined and its genetic organization was typical of tymoviruses. Comparisons with other tymoviral sequences showed that ChMV was a new member of the genus Tymovirus. The phylogenetic analyses of the coat protein gene were consistent with serological comparisons and positioned ChMV within a cluster of tymoviruses infecting mainly cucurbit or solanaceous hosts, including APLV and EMV. Phylogenetic analyses of the replicase protein gene confirmed the close relationship of ChMV and EMV. Our results suggest that ChMV is related to two tymoviruses (APLV and EMV) of proximal geographical provenance but with different natural host ranges. ChMV is the first cucurbit-infecting tymovirus to be fully characterized at the genomic level. PMID:18944472

  16. Virus-neutralizing antibody response of mice to consecutive infection with human and avian influenza A viruses.

    PubMed

    Janulíková, J; Stropkovská, A; Bobišová, Z; Košík, I; Mucha, V; Kostolanský, F; Vare?ková, E

    2015-06-01

    In this work we simulated in a mouse model a naturally occurring situation of humans, who overcame an infection with epidemic strains of influenza A, and were subsequently exposed to avian influenza A viruses (IAV). The antibody response to avian IAV in mice previously infected with human IAV was analyzed. We used two avian IAV (A/Duck/Czechoslovakia/1956 (H4N6) and the attenuated virus rA/Viet Nam/1203-2004 (H5N1)) as well as two human IAV isolates (virus A/Mississippi/1/1985 (H3N2) of medium virulence and A/Puerto Rico/8/1934 (H1N1) of high virulence). Two repeated doses of IAV of H4 or of H5 virus elicited virus-specific neutralizing antibodies in mice. Exposure of animals previously infected with human IAV (of H3 or H1 subtype) to IAV of H4 subtype led to the production of antibodies neutralizing H4 virus in a level comparable with the level of antibodies against the human IAV used for primary infection. In contrast, no measurable levels of virus-neutralizing (VN) antibodies specific to H5 virus were detected in mice infected with H5 virus following a previous infection with human IAV. In both cases the secondary infection with avian IAV led to a significant increase of the titer of VN antibodies specific to the corresponding human virus used for primary infection. Moreover, cross-reactive HA2-specific antibodies were also induced by sequential infection. By virtue of these results we suggest that the differences in the ability of avian IAV to induce specific antibodies inhibiting virus replication after previous infection of mice with human viruses can have an impact on the interspecies transmission and spread of avian IAV in the human population. PMID:26104333

  17. Serological evidence of Ebola virus infection in Indonesian orangutans.

    PubMed

    Nidom, Chairul A; Nakayama, Eri; Nidom, Reviany V; Alamudi, Mohamad Y; Daulay, Syafril; Dharmayanti, Indi N L P; Dachlan, Yoes P; Amin, Mohamad; Igarashi, Manabu; Miyamoto, Hiroko; Yoshida, Reiko; Takada, Ayato

    2012-01-01

    Ebola virus (EBOV) and Marburg virus (MARV) belong to the family Filoviridae and cause severe hemorrhagic fever in humans and nonhuman primates. Despite the discovery of EBOV (Reston virus) in nonhuman primates and domestic pigs in the Philippines and the serological evidence for its infection of humans and fruit bats, information on the reservoirs and potential amplifying hosts for filoviruses in Asia is lacking. In this study, serum samples collected from 353 healthy Bornean orangutans (Pongo pygmaeus) in Kalimantan Island, Indonesia, during the period from December 2005 to December 2006 were screened for filovirus-specific IgG antibodies using a highly sensitive enzyme-linked immunosorbent assay (ELISA) with recombinant viral surface glycoprotein (GP) antigens derived from multiple species of filoviruses (5 EBOV and 1 MARV species). Here we show that 18.4% (65/353) and 1.7% (6/353) of the samples were seropositive for EBOV and MARV, respectively, with little cross-reactivity among EBOV and MARV antigens. In these positive samples, IgG antibodies to viral internal proteins were also detected by immunoblotting. Interestingly, while the specificity for Reston virus, which has been recognized as an Asian filovirus, was the highest in only 1.4% (5/353) of the serum samples, the majority of EBOV-positive sera showed specificity to Zaire, Sudan, Cote d'Ivoire, or Bundibugyo viruses, all of which have been found so far only in Africa. These results suggest the existence of multiple species of filoviruses or unknown filovirus-related viruses in Indonesia, some of which are serologically similar to African EBOVs, and transmission of the viruses from yet unidentified reservoir hosts into the orangutan populations. Our findings point to the need for risk assessment and continued surveillance of filovirus infection of human and nonhuman primates, as well as wild and domestic animals, in Asia. PMID:22815803

  18. Immunization with Solid Matrix-Antibody-Antigen Complexes Containing Surface or Internal Virus Structural Proteins Protects Mice from Infection with the Paramyxovirus, Simian Virus 5

    Microsoft Academic Search

    R. E. Randall; D. F. Young

    1988-01-01

    SUMMARY A mouse model system has been developed to examine the ability of purified virus proteins to protect mice from infection with the paramyxovirus simian virus 5. The system is based on the infection of mouse lungs by intranasal administration of infectious virus. The relative amounts of virus proteins and nucleic acid present within infected lungs were estimated either by

  19. Genetic resistance to Infectious Bronchitis Virus infection 

    E-print Network

    Dzielawa, Jennifer Ann

    2001-01-01

    An IBV infectivity study was conducted using inbred lines of White Leghorn chickens homozygous at the B-complex, or MHC genes. One heterozygous haplotype was also included. Of the groups examined, based on clinical illness, the B5/B5 haplotype...

  20. [Acute myelocytic leukemia in immunodeficiency virus infection].

    PubMed

    Pulik, M; Lionnet, F; Genet, P; Jary, L; Jondeau, K

    1998-12-01

    B lineage-derived malignant proliferation is a well recognized complication of HIV infection. Acute myeloid leukemias have been reported but no complete review of these cases has been performed. The Medline database was reviewed for the years 1980-1997. Eighteen cases of AML have been reported. When previously known, HIV infection was present for 40 months. In 7 patients HIV infection and AML were diagnosed simultaneously. According to the FAB classification, 5 cases were M2, 8 M4, 5 M5. Extramedullary localizations (skin, testis, spleen) were noticed in 10 patients. Non-treated patients had a survival of 2.7 weeks versus 9.8 months in patients treated with chemotherapy. Pathophysiologic studies were performed in 3 cases: reverse transcriptase activity and p24 antigen were noted in tumoral cultured cells in 1 case; absence of viral particules in culture in another one; absence of cloned DNA provirus integration in blasts cells in a third patient. Based on the observed high rate of M4/M5 (72%) versus 19-36% expected in a non HIV-infected population, we postulate that the association of AML and HIV is not coincidental. The monocytotropism of HIV, the chronic cytokines-mediated activation of monocyte/macrophages, the immunodeficiency may explain this association. PMID:10021898

  1. Hepatitis G virus infection in chronic liver disease

    PubMed Central

    Guilera, M; Saiz, J; Lopez-Labrador, F; Olmedo, E; Ampurdanes, S; Forns, X; Bruix, J; Pares, A; Sanchez-Tapias, J; de Anta, M T J.; Rodes, J

    1998-01-01

    Background—The hepatitis G virus (HGV), a recently identified member of the Flaviviridae family, can cause chronic infection in man but the role of this agent in chronic liver disease is poorly understood. ?Aims—To evaluate the prevalence and meaning of HGV infection in a large series of patients with chronic liver disease. ?Subjects—Two hundred volunteer blood donors, 179 patients with chronic hepatitis C, 111 with chronic hepatitis B, 104 with alcoholic liver disease, 136 with hepatocellular carcinoma, and 24 with cryptogenic chronic liver disease were studied. ?Methods—HGV RNA was investigated in serum samples by reverse transcription and polymerase chain reaction amplification of the 5' non-coding region of HCV and hybridisation to a specific probe. The main features of HGV RNA seropositive and seronegative patients were compared. ?Results—The prevalence of HGV infection was 3% in blood donors, 7% in chronic hepatitis C, 8% in chronic hepatitis B, 2% in alcoholic liver disease, 4% in hepatocellular carcinoma, and 8% in cryptogenic chronic liver disease. HGV infected patients tended to be younger than non-infected patients but no differences concerning sex, possible source of infection, clinical manifestations, biochemical and virological parameters, or severity of liver lesions were found. ?Conclusions—The prevalence of HGV infection in chronic liver disease seems to be relatively low in our area. Infection with HGV does not seem to play a significant pathogenic role in patients with chronic liver disease related to chronic HBV or HCV infection or to increased alcohol consumption, or in those with cryptogenic chronic liver disease. ?? Keywords: chronic liver disease; hepatitis G virus PMID:9505895

  2. Neuropathology of H5N1 virus infection in ferrets.

    PubMed

    Peng, Bi-Hung; Yun, Nadezhda; Chumakova, Olga; Zacks, Michele; Campbell, Gerald; Smith, Jeanon; Smith, Jennifer; Linde, Seth; Linde, Jenna; Paessler, Slobodan

    2012-05-01

    Highly pathogenic H5N1 virus remains a potential threat to humans. Over 289 fatalities have been reported in WHO confirmed human cases since 2003, and lack of effective vaccines and early treatments contribute to increasing numbers of cases and fatalities. H5N1 encephalitis is a recognized cause of death in Vietnamese cases, and brain pathology is described in other human cases and naturally infected animals. However, neither pathogenesis of H5N1 viral infection in human brain nor post-infection effects in survivors have been fully investigated. We report the brain pathology in a ferret model for active infection and 18-day survival stages. This model closely resembles the infection pattern and progression in human cases of influenza A, and our report is the first description of brain pathology for longer term (18-day) survival in ferrets. We analyzed viral replication, type and severity of meningoencephalitis, infected cell types, and cellular responses to infection. We found viral replication to very high titers in ferret brain, closely correlating with severity of meningoencephalitis. Viral antigens were detected predominantly in neurons, correlating with inflammatory lesions, and less frequently in astrocytes and ependymal cells during active infection. Mononuclear cell infiltrates were observed in early stages predominantly in cerebral cortex, brainstem, and leptomeninges, and less commonly in cerebellum and other areas. Astrogliosis was mild at day 4 post-infection, but robust by day 18. Early and continuous treatment with an antiviral agent (peramivir) inhibited virus production to non-detectable levels, reduced severity of brain injury, and promoted higher survival rates. PMID:22176758

  3. Interferon Gamma Prolongs Survival of Varicella-Zoster Virus-Infected Human Neurons In Vitro.

    PubMed

    Baird, Nicholas L; Bowlin, Jacqueline L; Hotz, Taylor J; Cohrs, Randall J; Gilden, Don

    2015-07-15

    Infection of human neurons in vitro with varicella-zoster virus (VZV) at a low multiplicity of infection does not result in a cytopathic effect (CPE) within 14 days postinfection (dpi), despite production of infectious virus. We showed that by 28 dpi a CPE ultimately developed in infected neurons and that interferon gamma inhibited not only the CPE but also VZV DNA accumulation, transcription, and virus production, thereby prolonging the life of VZV-infected neurons. PMID:25948748

  4. Infection with strains of Citrus tristeza virus does not exclude superinfection by other strains of the virus.

    PubMed

    Folimonova, Svetlana Y; Robertson, Cecile J; Shilts, Turksen; Folimonov, Alexey S; Hilf, Mark E; Garnsey, Stephen M; Dawson, William O

    2010-02-01

    Superinfection exclusion or homologous interference, a phenomenon in which a primary viral infection prevents a secondary infection with the same or closely related virus, has been observed commonly for viruses in various systems, including viruses of bacteria, plants, and animals. With plant viruses, homologous interference initially was used as a test of virus relatedness to define whether two virus isolates were "strains" of the same virus or represented different viruses, and subsequently purposeful infection with a mild isolate was implemented as a protective measure against isolates of the virus causing severe disease. In this study we examined superinfection exclusion of Citrus tristeza virus (CTV), a positive-sense RNA closterovirus. Thirteen naturally occurring isolates of CTV representing five different virus strains and a set of isolates originated from virus constructs engineered based on an infectious cDNA clone of T36 isolate of CTV, including hybrids containing sequences from different isolates, were examined for their ability to prevent superinfection by another isolate of the virus. We show that superinfection exclusion occurred only between isolates of the same strain and not between isolates of different strains. When isolates of the same strain were used for sequential plant inoculation, the primary infection provided complete exclusion of the challenge isolate, whereas isolates from heterologous strains appeared to have no effect on replication, movement or systemic infection by the challenge virus. Surprisingly, substitution of extended cognate sequences from isolates of the T68 or T30 strains into T36 did not confer the ability of resulting hybrid viruses to exclude superinfection by those donor strains. Overall, these results do not appear to be explained by mechanisms proposed previously for other viruses. Moreover, these observations bring an understanding of some previously unexplained fundamental features of CTV biology and, most importantly, build a foundation for the strategy of selecting mild isolates that would efficiently exclude severe virus isolates as a practical means to control CTV diseases. PMID:19923189

  5. Hepatitis B virus coinfection in human immunodeficiency virus-infected patients: A review

    PubMed Central

    Sun, Hsin-Yun; Sheng, Wang-Huei; Tsai, Mao-Song; Lee, Kuan-Yeh; Chang, Sui-Yuan; Hung, Chien-Ching

    2014-01-01

    Hepatitis B virus (HBV) infection is a leading cause of chronic hepatitis, liver cirrhosis, and hepatocellular carcinoma worldwide. Due to the shared modes of transmission, coinfection with HBV and human immunodeficiency virus (HIV) is not uncommon. It is estimated that 10% of HIV-infected patients worldwide are coinfected with HBV. In areas where an HBV vaccination program is implemented, the HBV seroprevalence has declined significantly. In HIV/HBV-coinfected patients, HBV coinfection accelerates immunologic and clinical progression of HIV infection and increases the risk of hepatotoxicity when combination antiretroviral therapy (cART) is initiated, while HIV infection increases the risk of hepatitis events, cirrhosis, and end-stage liver disease related to chronic HBV infection. With the advances in antiviral therapy, concurrent, successful long-term suppression of HIV and HBV replication can be achieved in the cART era. To reduce the disease burden of HBV infection among HIV-infected patients, adoption of safe sex practices, avoidance of sharing needles and diluent, HBV vaccination and use of cART containing tenofovir disoproxil fumarate plus emtricitabine or lamivudine are the most effective approaches. However, due to HIV-related immunosuppression, using increased doses of HBV vaccine and novel approaches to HBV vaccination are needed to improve the immunogenicity of HBV vaccine among HIV-infected patients. PMID:25356024

  6. M-protein-positive chronic active Epstein–Barr virus infection: features mimicking HIV1 infection

    Microsoft Academic Search

    Shinsaku Imashuku; Naoto Azuma; Hirokazu Kanegane; Yoshihito Kasahara

    2009-01-01

    Chronic active Epstein–Barr virus infection (CAEBV) is a unique and fatal lymphoproliferative disease (LPD), which often shows\\u000a high serum IgG and\\/or IgE. The significance of such immunoglobulin abnormalities in CAEBV has not been fully evaluated and\\u000a discussed. In addition, such clinical features mimic HIV-1 infection. We report here a case of CAEBV with M-protein detected\\u000a which may shed a new

  7. Alteration of cell cycle progression by Sindbis virus infection.

    PubMed

    Yi, Ruirong; Saito, Kengo; Isegawa, Naohisa; Shirasawa, Hiroshi

    2015-07-10

    We examined the impact of Sindbis virus (SINV) infection on cell cycle progression in a cancer cell line, HeLa, and a non-cancerous cell line, Vero. Cell cycle analyses showed that SINV infection is able to alter the cell cycle progression in both HeLa and Vero cells, but differently, especially during the early stage of infection. SINV infection affected the expression of several cell cycle regulators (CDK4, CDK6, cyclin E, p21, cyclin A and cyclin B) in HeLa cells and caused HeLa cells to accumulate in S phase during the early stage of infection. Monitoring SINV replication in HeLa and Vero cells expressing cell cycle indicators revealed that SINV which infected HeLa cells during G1 phase preferred to proliferate during S/G2 phase, and the average time interval for viral replication was significantly shorter in both HeLa and Vero cells infected during G1 phase than in cells infected during S/G2 phase. PMID:25976675

  8. Ovine Fetal Immune Response to Cache Valley Virus Infection

    PubMed Central

    Dorniak, Piotr; Filant, Justyna; Dunlap, Kathrin A.; Bazer, Fuller W.; de la Concha-Bermejillo, Andres; Welsh, Christabel Jane; Varner, Patricia

    2013-01-01

    Cache Valley virus (CVV)-induced malformations have been previously reproduced in ovine fetuses. To evaluate the development of the antiviral response by the early, infected fetus, before the development of immunocompetency, ovine fetuses at 35 days of gestation were inoculated in utero with CVV and euthanized at 7, 10, 14, 21, and 28 days postinfection. The antiviral immune response in immature fetuses infected with CVV was evaluated. Gene expression associated with an innate, immune response was quantified by real-time quantitative PCR. The upregulated genes in infected fetuses included ISG15, Mx1, Mx2, IL-1, IL-6, TNF-?, TLR-7, and TLR-8. The amount of Mx1 protein, an interferon-stimulated GTPase capable of restricting growth of bunyaviruses, was elevated in the allantoic and amniotic fluid in infected fetuses. ISG15 protein expression was significantly increased in target tissues of infected animals. B lymphocytes and immunoglobulin-positive cells were detected in lymphoid tissues and in the meninges of infected animals. These results demonstrated that the infected ovine fetus is able to initiate an innate and adaptive immune response much earlier than previously known, which presumably contributes to viral clearance in infected animals. PMID:23468505

  9. Ovine fetal immune response to Cache Valley virus infection.

    PubMed

    Rodrigues Hoffmann, Aline; Dorniak, Piotr; Filant, Justyna; Dunlap, Kathrin A; Bazer, Fuller W; de la Concha-Bermejillo, Andres; Welsh, Christabel Jane; Varner, Patricia; Edwards, John Francis

    2013-05-01

    Cache Valley virus (CVV)-induced malformations have been previously reproduced in ovine fetuses. To evaluate the development of the antiviral response by the early, infected fetus, before the development of immunocompetency, ovine fetuses at 35 days of gestation were inoculated in utero with CVV and euthanized at 7, 10, 14, 21, and 28 days postinfection. The antiviral immune response in immature fetuses infected with CVV was evaluated. Gene expression associated with an innate, immune response was quantified by real-time quantitative PCR. The upregulated genes in infected fetuses included ISG15, Mx1, Mx2, IL-1, IL-6, TNF-?, TLR-7, and TLR-8. The amount of Mx1 protein, an interferon-stimulated GTPase capable of restricting growth of bunyaviruses, was elevated in the allantoic and amniotic fluid in infected fetuses. ISG15 protein expression was significantly increased in target tissues of infected animals. B lymphocytes and immunoglobulin-positive cells were detected in lymphoid tissues and in the meninges of infected animals. These results demonstrated that the infected ovine fetus is able to initiate an innate and adaptive immune response much earlier than previously known, which presumably contributes to viral clearance in infected animals. PMID:23468505

  10. Epstein-Barr Virus Infection of Human Astrocyte Cell Lines

    PubMed Central

    Menet, Anne; Speth, Cornelia; Larcher, Clara; Prodinger, Wolfgang M.; Schwendinger, Michael G.; Chan, Philippe; Jäger, Michael; Schwarzmann, Fritz; Recheis, Heidrun; Fontaine, Marc; Dierich, Manfred P.

    1999-01-01

    Epstein-Barr virus (EBV) is implicated in different central nervous system syndromes. The major cellular receptor for EBV, complement receptor type 2 (CR2) (CD21), is expressed by different astrocyte cell lines and human fetal astrocytes, suggesting their susceptibility to EBV infection. We demonstrated the infection of two astrocyte cell lines, T98 and CB193, at low levels. As infection was mediated by CR2, we used two stable CR2 transfectant astrocyte cell lines (T98CR2 and CB193CR2) to achieve a more efficient infection. We have monitored EBV gene expression for 2 months and observed the transient infection of T98 and T98CR2 cells and persistent infection of CB193 and CB193CR2 cells. The detection of BZLF1, BALF2, and BcLF1 mRNA expression suggests that the lytic cycle is initiated at early time points postinfection. At later time points the pattern of mRNA expressed (EBER1, EBNA1, EBNA2, and LMP1) differs from latency type III in the absence of LMP2A transcription and in the expression of BALF2 and BcLF1 but not BZLF1. A reactivation of the lytic cycle was achieved in CB193CR2 cells by the addition of phorbol esters. These studies identify astrocyte cell lines as targets for EBV infection and suggest that this infection might play a role in the pathology of EBV in the brain. PMID:10438862

  11. Prevention and management of neonatal herpes simplex virus infections

    PubMed Central

    Allen, Upton D; Robinson, Joan L

    2014-01-01

    Human herpes simplex virus (HSV) infection in neonates can result in devastating outcomes, including mortality and significant morbidity. All infants are potentially at risk for neonatal HSV infection. This position statement reviews epidemiology, transmission and risk factors, with a focus on intrapartum infection. It considers diagnosis and prognosis according to infection category, along with testing modalities and limitations. Recommendations for managing newborns known to have been exposed intrapartum to HSV are based on expert opinion because a randomized trial to compare management options is not feasible. Guidance is provided for the empirical management of infants with suspected clinical sepsis, including those who do not respond to antibacterial therapy. The present statement replaces a 2006 position statement by the Canadian Paediatric Society. PMID:24855418

  12. Influence of different hepatitis C virus genotypes on the course of asymptomatic hepatitis C virus infection

    Microsoft Academic Search

    D Prati; C Capelli; A Zanella; F Mozzi; P Bosoni; M Pappalettera; F Zanuso; L Vianello; E Locatelli; C de Fazio; G Ronchi; E del Ninno; M Colombo; G Sirchia

    1996-01-01

    BACKGROUND & AIMS: The association of liver disease with hepatitis C virus (HCV) genotypes mainly refers to patients with serious liver damage; little information is available on symptomless carriers. The aim of this study was to investigate the correlation of genotypes with clinical course, risk factors for infection, and antibody to HCV reactivity in asymptomatic subjects. METHODS: One hundred nine

  13. Lack of evidence of measles virus shedding in people with inapparent measles virus infections.

    PubMed

    Lievano, Fabio A; Papania, Mark J; Helfand, Rita F; Harpaz, Rafael; Walls, Laura; Katz, Russell S; Williams, Irene; Villamarzo, Yvonne S; Rota, Paul A; Bellini, William J

    2004-05-01

    Serological evidence of measles virus infection has been detected among people exposed to measles who do not exhibit classical clinical symptoms. Throat swabs, lymphocytes, and serum and urine samples were collected from contacts of individuals with confirmed measles 12-16 days after exposure, during measles outbreaks occurring in 1998. Follow-up serum samples were drawn 2 weeks later. Samples were tested for measles IgM antibody by enzyme immunoassays and plaque reduction neutralization testing. Virus isolation and reverse transcriptase-polymerase chain reaction testing was attempted for all samples. None of the 133 contacts developed classical measles disease; 11 (8%) had serological evidence of infection. Duration of exposure of >or=3 h was the only significant risk factor for developing serological response (24% vs. 4% among contacts exposed for 1-2 h; relative risk, 6.0; 95% confidence interval, 1.9-19.2). None of the 133 contacts had virological evidence of infection by culture or polymerase chain reaction. We found no evidence that persons with inapparent measles virus infections shed measles virus. PMID:15106106

  14. Inhibition of African swine fever virus binding and infectivity by purified recombinant virus attachment protein p12.

    PubMed Central

    Angulo, A; Viñuela, E; Alcamí, A

    1993-01-01

    The African swine fever virus protein p12, involved in virus attachment to the host cell, has an apparent molecular mass of 17 kDa in sodium dodecyl sulfate-polyacrylamide gel electrophoresis under nonreducing conditions. We have also identified 12- and 10-kDa forms of the p12 protein in infected Vero cells and found that the mature 17-kDa protein is the only form present in virus particles. The p12 protein has been produced in large amounts in Spodoptera frugiperda insect cells infected with a recombinant baculovirus. A 17-kDa protein that possessed the biological properties of the viral protein was produced, since it bound to susceptible Vero cells and not to receptor-negative L cells, which do not support virus replication. The binding of the baculovirus-expressed protein p12 to Vero cells was specifically blocked by virus particles. In addition, the recombinant protein purified by immunoaffinity chromatography blocked the specific binding of virus particles to susceptible cells and prevented infection, demonstrating that the p12 protein mediates the attachment of virions to specific receptors and indicating that blocking the p12-mediated interaction between African swine fever virus and receptors in Vero cells can inhibit infection. However, although antibodies specific for protein p12 are induced in natural infections and in animals inoculated with inactivated virus or recombinant protein p12, these antisera did not inhibit virus binding to the host cell or neutralize virus infectivity. Images PMID:8350406

  15. Resistance to vaginal or systemic infection with herpes simplex virus type 2

    Microsoft Academic Search

    Mary C. Breinig; L. L. Wright; Margaret B. McGeorge; P. S. MORAItAN

    1978-01-01

    Summary Mortality due to vaginal or intravenous infection of female BALB\\/c mice with herpes simplex virus type 2 (HSV-2) was significantly reduced by treatment of mice with the immunomodulator pyran. Following intravaginal inoculation with virus, the incidence of vaginal infection and titers of virus present in the vaginal secretions were significantly reduced in pyran treated as compared with control mice.

  16. Gene expression responses to highly pathogenic avian influenza H5N1 virus infections in ducks

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Differences in host response to infection with avian influenza (AI) viruses were investigated by identifying genes differentially expressed in tissues of infected ducks. Clear differences in pathogenicity were observed among ducks inoculated with five H5N1 HPAI viruses. Virus titers in tissues cor...

  17. A Mathematical Model for Virus Infection in a System of Interacting Computers

    E-print Network

    Cipolatti, Rolci

    A Mathematical Model for Virus Infection in a System of Interacting Computers J. L´opez Gondar & R are explored and enlightened in this paper. 1. Introduction The infection of computers by virtual viruses of virtual viruses in a system of interacting computers could be compared with a disease transmitted

  18. Subclinical Highly Pathogenic Avian Influenza Virus Infection among Vaccinated Chickens, China

    PubMed Central

    Ma, Qing-Xia; Jiang, Wen-Ming; Liu, Shuo; Wang, Su-Chun; Zhuang, Qing-Ye; Hou, Guang-Yu; Liu, Xiang-Ming; Sui, Zheng-Hong

    2014-01-01

    Subclinical infection of vaccinated chickens with a highly pathogenic avian influenza A(H5N2) virus was identified through routine surveillance in China. Investigation suggested that the virus has evolved into multiple genotypes. To better control transmission of the virus, we recommend a strengthened program of education, biosecurity, rapid diagnostics, surveillance, and elimination of infected poultry. PMID:25418710

  19. A SAP30 Complex Inhibits IFN-b Expression in Rift Valley Fever Virus Infected Cells

    E-print Network

    Paris-Sud XI, Université de

    A SAP30 Complex Inhibits IFN-b Expression in Rift Valley Fever Virus Infected Cells Nicolas Le May1, Institut Pasteur, Paris, France Rift Valley fever virus (RVFV) nonstructural protein NSs acts as the major Valley Fever Virus infected cells. PLoS Pathog 4(1): e13. doi:10.1371/journal.ppat.0040013 Introduction

  20. Artificial Receptors in Serologic Tests for the Early Diagnosis of Dengue Virus Infection

    Microsoft Academic Search

    Dar-Fu Tai; Chung-Yin Lin; Tzong-Zeng Wu; Jyh-Hsiung Huang; Pei-Yun Shu

    2006-01-01

    Background: Because of the range and nonspecificity of clinical presentations of dengue virus infections, we felt there was a need to create diagnostic tests. We used artificial receptors for the virus to develop serologic assays to detect dengue virus infection. Methods: We coated a quartz crystal microbalance (QCM) with molecularly imprinted polymers specific for nonstructural protein 1 of flavivirus. These

  1. Two distinct variants of simian foamy virus in naturally infected mandrills (Mandrillus sphinx)

    E-print Network

    Paris-Sud XI, Université de

    Two distinct variants of simian foamy virus in naturally infected mandrills (Mandrillus sphinx variants of simian foamy virus in naturally infected mandrills (Mandrillus sphinx) and cross evaluated the natural history of the virus in a free-ranging colony of mandrills and investigated possible

  2. Infection and Dissemination of Venezuelan Equine Encephalitis Virus in the Epidemic Mosquito Vector, Aedes taeniorhynchus

    Microsoft Academic Search

    Darci R. Smith; Nicole C. Arrigo; Grace Leal; Linda E. Muehlberger; Scott C. Weaver

    The mosquito Aedes taeniorhynchus is an important epidemic vector of Venezuelan equine encephalitis virus (VEEV), but detailed studies of its infection are lacking. We compared infection by an epidemic VEEV strain to that by an enzootic strain using virus titrations, immunohistochemistry, and a virus expressing the green fluorescent protein. Ae. taeniorhynchus was more susceptible to the epidemic strain, which initially

  3. Co-infections with hepatitis B and C viruses in human immunodeficiency virus-infected patients in Morocco.

    PubMed

    Rebbani, K; Ouladlahsen, A; Bensghir, A; Akil, A; Lamdini, H; Issouf, H; Brahim, I; Kitab, B; Fakhir, F Z; Wakrim, L; Marhoum El Filali, K; Himmich, H; Ezzikouri, S; Benjelloun, S

    2013-10-01

    Human immunodeficiency virus (HIV), hepatitis B virus (HBV) and hepatitis C virus (HCV) are major public health concerns. We aimed to determine the prevalence of HBV and HCV infections among HIV-infected patients, and to identify the main circulating hepatitis strains in Morocco. The study was carried out in 503 HIV-infected patients. Our survey indicated that the prevalence of HIV/hepatitis co-infection was 10.6%; 5.2% of patients were HBV surface antigen positive, and 5.4% of patients were anti-HCV positive. Among the HBV surface antigen-positive group, HBV DNA sequencing identified exclusively genotype D (D1: 26.7%; D7: 73.3%) in accordance with what is found in the general population. In contrast, sequencing of HCV isolates produced an unusual subtype distribution with a decreasing order of prevalence: 1a, 3a (both 23.5%), 1b, 4a (both 17.6%), 1c (11.8%) and 6h (6%). PMID:23731409

  4. Innate Immune Responses in Hepatitis C Virus Infection1

    PubMed Central

    Li, Kui; Lemon, Stanley M.

    2013-01-01

    Hepatitis C virus (HCV) is a major causative agent of chronic hepatitis and hepatocellular carcinoma worldwide and thus poses a significant public health threat. A hallmark of HCV infection is the extraordinary ability of the virus to persist in a majority of infected people. Innate immune responses represent the front line of defense of the human body against HCV immediately after infection. They also play a crucial role in orchestrating subsequent HCV-specific adaptive immunity that is pivotal for viral clearance. Accumulating evidence suggests that the host has evolved multifaceted innate immune mechanisms to sense HCV infection and elicit defense responses, while HCV has developed elaborate strategies to circumvent many of these. Defining the interplay of HCV with host innate immunity reveals mechanistic insights into hepatitis C pathogenesis and informs approaches to therapy. In this review, we summarize recent advances in understanding innate immune responses to HCV infection, focusing on induction and effector mechanisms of the interferon antiviral response as well as the evasion strategies of HCV. PMID:22868377

  5. BOVINE VIRAL DIARRHEA VIRUS PERSISTENT INFECTIONS IN BEEF BREEDING HERDS: UTILIZATION OF IMMUNOHISTOCHEMISTRY AND ANTIGEN CAPTIVE ELISA ON EAR NOTCHES

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bovine viral diarrhea virus (BVDV) infections represent significant disease manifestations in cattle. Persistently infected (PI) cattle resulting from fetal infections are considered the major reservoir of virus for susceptible cattle. Beef cattle in stocker and feedlot operations are often where ...

  6. Systems biology unravels interferon responses to respiratory virus infections

    PubMed Central

    Kroeker, Andrea L; Coombs, Kevin M

    2014-01-01

    Interferon production is an important defence against viral replication and its activation is an attractive therapeutic target. However, it has long been known that viruses perpetually evolve a multitude of strategies to evade these host immune responses. In recent years there has been an explosion of information on virus-induced alterations of the host immune response that have resulted from data-rich omics technologies. Unravelling how these systems interact and determining the overall outcome of the host response to viral infection will play an important role in future treatment and vaccine development. In this review we focus primarily on the interferon pathway and its regulation as well as mechanisms by which respiratory RNA viruses interfere with its signalling capacity. PMID:24600511

  7. Bluetongue virus infection in India: a review.

    PubMed

    Prasad, G; Jain, N C; Gupta, Y

    1992-09-01

    The history and epizootiology of bluetongue (BT) in India are reviewed. BT has become endemic in India. The first outbreak of BT in sheep and goats in the country was recorded in 1964 in Maharashtra State. Since then, several outbreaks of BT have been reported in sheep. Exotic sheep are more susceptible than indigenous and cross-bred sheep. A serological survey has indicated the presence of bluetongue virus (BTV) antibodies in cattle and buffalo in several states in India. However, clinical BT has not been observed in cattle or buffalo to date. Of the 24 known serotypes of BTV, 18 have been reported in India. Although BTV has been isolated from Culicoides midges, the particular species responsible for transmission has not yet been identified. PMID:1335304

  8. A model for persistent infection with Epstein-Barr virus: The stealth virus of human B cells

    Microsoft Academic Search

    David A. Thorley-Lawson; Gregory J. Babcock

    1999-01-01

    Most adult humans are infected benignly and for life with the herpesvirus Epstein-Barr virus. EBV has been a focus of research because of its status as a candidate tumor virus for a number of lymphomas and carcinomas. In vitro EBV has the ability to establish a latent infection in proliferating B lymphoblasts. This is the only system available for studying

  9. The role of varroa mites in infections of Kashmir bee virus (KBV) and deformed wing virus (DWV) in honey bees

    Microsoft Academic Search

    Miaoqing Shen; Xiaolong Yang; Diana Cox-Foster; Liwang Cui

    2005-01-01

    To determine the roles of varroa mites in activating or vectoring viral infections, we performed quantitative comparison of viral infections between bees with and without mites by dot blot analysis and enzyme-linked immunosorbent assay (ELISA). Under natural and artificial mite infestations, bee pupae contained significantly higher levels of Kashmir bee virus (KBV) and deformed wing virus (DWV) RNAs and KBV

  10. Experimental infection of laying turkeys with Rhinotracheitis virus: Distribution of virus in the tissues and serological response

    Microsoft Academic Search

    R. C. Jones; R. A. Williams; C. E. Savage; G. P. Wilding

    1988-01-01

    Twenty?four laying turkey hens shown to be free of antibodies to turkey rhinotracheitis virus were inoculated intranasally with an isolate of the virus. A mild respiratory disease developed between 5 and 9 days post infection (pi). Two birds were selected at random at intervals between days 1 and 20 pi, killed and tissues examined for the presence of virus. At

  11. Hepatitis E virus infection in acute hepatitis in Spain

    Microsoft Academic Search

    Maria Buti; Rosendo Jardí; Montserrat Cotrina; Francisco Rodríguez-Frías; Hugo Troonen; Luis Viladomiu; J. I. Esteban; Rafael Esteban; Jaime Guardia

    1995-01-01

    In order to study the prevalence of hepatitis E virus (HEV) infection in developed countries, IgG and IgM anti-HEV were determined in serum samples from 382 patients with acute viral hepatitis (244 hepatitis A, 48 hepatitis B and\\/or D, and 90 non-A, non-B, non-C hepatitis), 76 healthy subjects, 55 hemophiliacs and 50 patients on hemodialysis. IgG anti-HEV antibodies were detected

  12. Lessons for tuberculosis vaccines from respiratory virus infection.

    PubMed

    Beverley, Peter Charles Leonard; Tchilian, Elma Zaven

    2008-10-01

    There is a worldwide epidemic of increasingly drug-resistant TB. Bacillus Calmette-Guérin vaccination provides partial protection against disseminated disease in infants but poor protection against later pulmonary TB. Cell-mediated protection against respiratory virus infections requires the presence of T cells in lung tissues, and the most effective prime-boost immunizations for Mycobacterium tuberculosis also induce lung-resident lymphocytes. These observations need to be taken into account when designing future vaccines against M. tuberculosis. PMID:18844591

  13. Antibody landscapes after influenza virus infection or vaccination

    E-print Network

    Fonville, J. M.; Wilks, S. H.; James, S. L.; Fox, A.; Ventresca, M.; Aban, M.; Xue, L.; Jones, T. C.; Le, N. M. H.; Pham, Q. T.; Tran, N. D.; Wong, Y.; Mosterin, A.; Katzelnick, L. C.; Labonte, D.; Le, T. T.; van der Net, G.; Skepner, E.; Russell, C. A.; Kaplan, T. D.; Rimmelzwaan, G. F.; Masurel, N.; de Jong, J. C.; Palache, A.; Beyer, W. E. P.; Le, Q. M.; Nguyen, T. H.; Wertheim, H. F. L.; Hurt, A. C.; Osterhaus, A. D. M. E.; Barr, I. G.; Fouchier, R. A. M.; Horby, P. W.; Smith, D. J.

    2014-01-01

    of differing background immunity and to use this information 73 as the basis for improved vaccine strain selection and evaluation. Indeed, such data are used in 74 4 the vaccine strain selection process. Unfortunately, immunological patterns in human... of original antigenic sin after infection or vaccination with the 2009 303 pandemic H1N1 influenza virus. Clin. Vaccine Immunol. 21, 737-746 (2014). 304 18. J. Wrammert et al., Rapid cloning of high-affinity human monoclonal antibodies against 305...

  14. Protracted viremia during acute sporadic hepatitis E virus infection

    Microsoft Academic Search

    Santosh Kumar Nanda; Israrul Haque Ansari; Subrat Kumar Acharya; Shahid Jameel; Subrat Kumar Panda

    1995-01-01

    Background\\/Aims: Hepatitis E virus (HEV) is associated with epidemic and sporadic hepatitis in developing countries. The disease is largely self-limited with no long-term sequelae. The source of HEV for maintenance of the disease in an endemic area is unknown. This study investigated the occurrence and duration of viremia in patients with acute sporadic HEV infection. Methods: In 26 of 37

  15. Epidemiology of hepatitis C virus infection in Australia

    Microsoft Academic Search

    Gregory J Dore; Matthew Law; Margaret MacDonald; John M Kaldor

    2003-01-01

    Background: Since the discovery in 1989 of hepatitis C virus (HCV) as the infectious agent responsible for the vast majority of post-transfusion non-A non-B hepatitis the patterns of transmission and clinical consequences of this highly prevalent flavivirus have been widely studied. Objective: This paper reviews available evidence on the epidemiology of HCV infection in Australia, including HCV notification data obtained

  16. Occult Hepatitis B Virus Infection in Chacma Baboons, South Africa

    PubMed Central

    Dickens, Caroline; Kew, Michael C.; Purcell, Robert H.

    2013-01-01

    During previous studies of susceptibility to hepatitis B virus (HBV) infection, HBV DNA was detected in 2/6 wild-caught baboons. In the present study, HBV DNA was amplified from 15/69 wild-caught baboons. All animals were negative for HBV surface antigen and antibody against HBV core antigen. Liver tissue from 1 baboon was immunohistochemically negative for HBV surface antigen but positive for HBV core antigen. The complete HBV genome of an isolate from this liver clustered with subgenotype A2. Reverse transcription PCR of liver RNA amplified virus precore and surface protein genes, indicating replication of virus in baboon liver tissue. Four experimentally naive baboons were injected with serum from HBV DNA–positive baboons. These 4 baboons showed transient seroconversion, and HBV DNA was amplified from serum at various times after infection. The presence of HBV DNA at relatively low levels and in the absence of serologic markers in the baboon, a nonhuman primate, indicates an occult infection. PMID:23631817

  17. Index Cluster Study of Dengue Virus Infection in Nicaragua

    PubMed Central

    Reyes, Miguel; Mercado, Juan Carlos; Standish, Katherine; Matute, Juan Carlos; Ortega, Oscar; Moraga, Berman; Avilés, William; Henn, Matthew R.; Balmaseda, Angel; Kuan, Guillermina; Harris, Eva

    2010-01-01

    Traditional study designs do not identify acute asymptomatic or pre-symptomatic dengue virus (DENV) infections, thus limiting our understanding of immunologic and viral factors that modulate infection outcome. In the 2006 and 2007 dengue seasons, we conducted a pilot index cluster study in Managua, Nicaragua, in which 442 persons living within 50 meters of 22 index cases identified through an ongoing pediatric cohort study were evaluated for DENV infection. Post-enrollment and pre-enrollment DENV infections were confirmed in 12 (2.7%) and 19 (4.3%) contacts, respectively. Five (42%) post-enrollment infections were asymptomatic, and DENV-2 was identified in 9 (75%) infections. Phylogenetic analysis with full-length DENV genomic sequence from contacts, index cases, and cohort dengue cases indicated focal transmission and infection outside the local area. We demonstrate the feasibility of identification of acute asymptomatic and pre-symptomatic cases in urban Latin America, the first report of such a study in the Americas, and identify age and concomitant immunity to DENV of contacts as a key factor in index cluster study design. PMID:20810839

  18. Testicular dysfunction in human immunodeficiency virus-infected men.

    PubMed

    Poretsky, L; Can, S; Zumoff, B

    1995-07-01

    This review pertains to gonadal function in men with human immunodeficiency virus (HIV) infection, who often exhibit clinical and biochemical evidence of hypogonadism. Hypogonadotropic hypogonadism appears to be the most commonly encountered abnormality, although complete anterior pituitary insufficiency and primary gonadal failure have been reported. Levels of sex hormone-binding globulin (SHBG) are either unchanged or increased. Plasma levels of estrogens, progesterone, androstenedione, dehydroepiandrosterone sulfate (DHEA-S), and prolactin vary. Pathologically, except for involvement by opportunistic infections, no significant abnormality in the hypothalamic-pituitary area has been described, but evidence of orchitis is commonly present. The cause(s) of these abnormalities remains unclear. The possible factors leading to hypogonadism in HIV-infected men include HIV infection itself, opportunistic infections, chronic debilitating illness, and effects of cytokines on the hypothalamic-pituitary-gonadal axis. Further studies are needed to clarify the cause(s) of testicular dysfunction in HIV-infected men and its clinical significance, treatment, relevance to the progression of HIV infection, and influence on the immune system. PMID:7616856

  19. Pathophysiology of hepatitis C virus infection and related liver disease.

    PubMed

    Pawlotsky, Jean-Michel

    2004-02-01

    Hepatitis C virus (HCV) infects over 170 million people worldwide. Chronic infection occurs in 50-80% of cases and eventually leads to cirrhosis and hepatocellular carcinoma. The HCV lifecycle is only partly understood owing to the lack of a productive cell culture system. Several molecules have been implicated in the receptor complex at the surface of target cells, but the mode of HCV entry remains unknown. Persistent infection appears to be due to weak CD4+and CD8+ T-cell responses during acute infection, which fail to control viral replication. When chronic infection is established, HCV does not appear to be cytopathic. Liver lesions appear to result from locally driven immune responses, which are mainly non-specific. Local inflammation triggers fibrogenesis, in which hepatic stellate cells play a major role. Cirrhosis is facilitated by external factors, such as chronic alcohol consumption and viral co-infections. Patients with cirrhosis are at high risk of developing hepatocellular carcinoma. The role of HCV proteins in hepatocarcinogenesis is unknown. Further progress in our understanding of HCV infection and pathogenesis awaits the advent of new model systems and technologies. PMID:15036326

  20. Autonomic Nervous Dysfunction in Hamsters Infected with West Nile Virus

    PubMed Central

    Wang, Hong; Siddharthan, Venkatraman; Hall, Jeffery O.; Morrey, John D.

    2011-01-01

    Clinical studies and case reports clearly document that West Nile virus (WNV) can cause respiratory and gastrointestinal (GI) complications. Other functions controlled by the autonomic nervous system may also be directly affected by WNV, such as bladder and cardiac functions. To investigate how WNV can cause autonomic dysfunctions, we focused on the cardiac and GI dysfunctions of rodents infected with WNV. Infected hamsters had distension of the stomach and intestines at day 9 after viral challenge. GI motility was detected by a dye retention assay; phenol red dye was retained more in the stomachs of infected hamsters as compared to sham-infected hamsters. The amplitudes of electromygraphs (EMGs) of intestinal muscles were significantly reduced. Myenteric neurons that innervate the intestines, in addition to neurons in the brain stem, were identified to be infected with WNV. These data suggest that infected neurons controlling autonomic function were the cause of GI dysfunction in WNV-infected hamsters. Using radiotelemetry to record electrocardiograms and to measure heart rate variability (HRV), a well-accepted readout for autonomic function, we determined that HRV and autonomic function were suppressed in WNV-infected hamsters. Cardiac histopathology was observed at day 9 only in the right atrium, which was coincident with WNV staining. A subset of WNV infected cells was identified among cells with hyperplarization-activated cyclic nucleotide-gated potassium channel 4 (HCN4) as a marker for cells in the sinoatrial (SA) and atrioventricular (AV) nodes. The unique contribution of this study is the discovery that WNV infection of hamsters can lead to autonomic dysfunction as determined by reduced HRV and reduced EMG amplitudes of the GI tract. These data may model autonomic dysfunction of the human West Nile neurological disease. PMID:21573009

  1. Recombination Every Day: Abundant Recombination in a Virus during a Single MultiCellular Host Infection

    Microsoft Academic Search

    Remy Froissart; Denis Roze; Marilyne Uzest; Lionel Galibert; Stephane Blanc; Yannis Michalakis

    2005-01-01

    Viral recombination can dramatically impact evolution and epidemiology. In viruses, the recombination rate depends on the frequency of genetic exchange between different viral genomes within an infected host cell and on the frequency at which such co-infections occur. While the recombination rate has been recently evaluated in experimentally co-infected cell cultures for several viruses, direct quantification at the most biologically

  2. Identification of cell membrane proteins linked to susceptibility to bovine viral diarrhoea virus infection

    Microsoft Academic Search

    C. Schelp; I. Greiser-Wilke; G. Wolf; M. Beer; V. Moennig; B. Liess

    1995-01-01

    Summary Three monoclonal antibodies directed against cell surface molecules of bovine cells inhibited subsequent infections with bovine viral diarrhoea virus (BVDV). They specifically blocked the infectivity of three non-cytopathogenic and three cytopathogenic BVDV strains. These results showed that an important mechanism for virus uptake was inhibited. The ligand of the monoclonal antibody BVD\\/CA 17, which blocked infectivity most efficiently, was

  3. Social stress alters the severity and onset of the chronic phase of Theiler's virus infection

    E-print Network

    Meagher, Mary

    Social stress alters the severity and onset of the chronic phase of Theiler's virus infection Robin form 3 February 2006; accepted 27 February 2006 Abstract Social stress alters the acute phase of Theiler's virus infection (TMEV), a model of multiple sclerosis. Stress applied prior to infection had

  4. Interplay Between Viral and Cellular Factors Determines the Fate of Herpes Simplex Virus type I Infection

    E-print Network

    Mabrouk-Mostafa, Heba

    2014-05-31

    The herpes simplex virus type I (HSV-1) is a major human pathogen that infects the majority of the world's population. The life cycle of HSV-1 is controlled by interactions with its hosts. Understanding virus-host interactions ...

  5. Symptomatic cytomegalovirus infection in seropositive kidney recipients: reinfection with donor virus rather than reactivation of recipient virus.

    PubMed

    Grundy, J E; Lui, S F; Super, M; Berry, N J; Sweny, P; Fernando, O N; Moorhead, J; Griffiths, P D

    1988-07-16

    74 patients receiving cadaver kidney grafts were investigated prospectively for cytomegalovirus (CMV) infection. Among seropositive recipients CMV infection, especially symptomatic and disseminated infection, occurred significantly more frequently when kidneys came from seropositive than from seronegative donors. Since seropositive recipients can become infected with donor virus, the excess is probably accounted for by reinfection. This conclusion was supported by restriction enzyme typing of virus isolates from recipient pairs receiving kidneys from the same donor; proven reinfection with donor strain virus was significantly commoner than proven reactivation of recipient virus. Furthermore, symptoms occurred only in the proven reinfection group. Although the proportion of reinfections that caused symptoms was less than that seen in primary infections, prior natural infection with CMV clearly does not prevent symptomatic reinfection in seropositive recipients, a point which has profound implications for future vaccination strategies in renal allograft recipients and choice of donors. PMID:2899189

  6. Sharka: how do plants respond to Plum pox virus infection?

    PubMed

    Clemente-Moreno, María J; Hernández, José A; Diaz-Vivancos, Pedro

    2015-01-01

    Plum pox virus (PPV), the causal agent of sharka disease, is one of the most studied plant viruses, and major advances in detection techniques, genome characterization and organization, gene expression, transmission, and the description of candidate genes involved in PPV resistance have been described. However, information concerning the plant response to PPV infection is very scarce. In this review, we provide an updated summary of the research carried out to date in order to elucidate how plants cope with PPV infection and their response at different levels, including the physiological, biochemical, proteomic, and genetic levels. Knowledge about how plants respond to PPV infection can contribute to the development of new strategies to cope with this disease. Due to the fact that PPV induces an oxidative stress in plants, the bio-fortification of the antioxidative defences, by classical or biotechnological approaches, would be a useful tool to cope with PPV infection. Nevertheless, there are still some gaps in knowledge related to PPV-plant interaction that remain to be filled, such as the effect of PPV on the hormonal profile of the plant or on the plant metabolome. PMID:25336685

  7. Antiviral strategies in hepatitis C virus infection.

    PubMed

    Sarrazin, Christoph; Hézode, Christophe; Zeuzem, Stefan; Pawlotsky, Jean-Michel

    2012-01-01

    Resolution of the three-dimensional structures of several hepatitis C virus (HCV) proteins, together with the development of replicative cell culture systems, has led to the identification of a number of potential targets for direct-acting antiviral (DAA) agents. Numerous families of drugs that potently inhibit the HCV lifecycle in vitro have been identified, and some of these molecules have reached early to late clinical development. Two NS3/4A protease inhibitors, telaprevir and boceprevir, were approved in Europe and the United States in 2011 in combination with pegylated interferon (IFN)-? and ribavirin for the treatment of chronic hepatitis C related to HCV genotype 1, in both treatment-naïve and treatment-experienced patients. Sustained virological response rates in the range of 6675% and 5966% (2988% if the response to the first course of therapy is taken into account) have been achieved in these two patient populations, respectively, with treatment durations of 24 to 48 weeks. A number of other DAAs are at the clinical developmental stage in combination with pegylated IFN-? and ribavirin or with other DAAs in IFN-free regimens, with or without ribavirin. They include second-wave, first-generation, and second-generation NS3/4A protease inhibitors, nucleoside/nucleotide analogue inhibitors and non-nucleoside inhibitorsof HCVRNA-dependent RNA polymerase, inhibitors of nonstructural protein 5A (NS5A) and host-targeted compounds, such as cyclophilin inhibitors and silibinin. The proof of concept that IFN-free regimens may lead to HCV eradication has recently been brought. However, new drugs may be associated with troublesome side effects and drugdrug interactions, and the ideal IFN-free DAA combination remains to be found. PMID:22300469

  8. Medical management of human immunodeficiency virus infection.

    PubMed

    Kempen, John H

    2008-01-01

    The human immunodeficiency virus (HIV)/ acquired immune deficiency syndrome (AIDS) pandemic has pervasive effects on culture, economics, policy, and human development. All organs can be affected by complications of HIV/AIDS, including the eye. When sufficient resources are available and widespread antiretroviral resistance does not exist, the four available classes of antiretroviral agents - nucleoside/nucleotide reverse transcriptase inhibitors, non-nucleoside reverse transcriptase inhibitors, protease inhibitors, and fusion inhibitors - can be combined to provide highly active antiretroviral therapy (HAART). For many (not all) patients, HAART converts an inexorably fatal disease into a chronic disease with a fairly good prognosis. Use of HAART often induces partial immune recovery, which has predominantly beneficial effects on ocular complications of AIDS. However, HAART-induced immune recovery sometimes results in immune recovery inflammatory syndromes, such as immune recovery uveitis. Use of HAART is the single most useful intervention for most patients with ocular complications of AIDS. However, specific ocular therapy is also critical to avoid blindness in the early months before immune recovery can occur, or if HAART is unavailable. Increasing availability of HAART worldwide shows great promise to alleviate one of the world's greatest plagues. However, predictable secular trends in the AIDS epidemic make it likely that the number of cases of ocular complications of AIDS will increase substantially before they decrease. Ophthalmologists worldwide should be familiar with the diagnosis and management of cytomegalovirus retinitis - the most common ocular complication of AIDS - and should establish partnerships with physicians who are able to provide HAART. Research is needed to determine the optimal approach for managing cytomegalovirus retinitis in resource-constrained settings. PMID:18711266

  9. Cloned cytotoxic T cells specific for lymphocytic choriomeningitis virus induce acute disease and primary footpad swelling in infected mice

    Microsoft Academic Search

    J. Baenziger; H. Hengartner; R. M. Zinkernagel

    1986-01-01

    Lymphocytic choriomeningitis virus (LCMV) infection in mice causes a wide spectrum of diseases with various symptoms, dependent upon virus isolate, virus dose, route of infection, and the immune status of the infected host [4]. When given intravenously (i.v.) or intraperitoneally to immunocompetent mice, it causes acute disease and the virus is usually efficiently eliminated. Major histocompatibility complex (MHC) class I-restricted

  10. Recovery of immunodeficient mice from a vaccinia virus/IL-2 recombinant infection.

    PubMed

    Ramshaw, I A; Andrew, M E; Phillips, S M; Boyle, D B; Coupar, B E

    Vaccinia virus recombinants that express cloned genes encoding antigens of unrelated infectious agents, such as hepatitis B virus and human immunodeficiency virus (HIV), provide a new approach to the development of live vaccines. Although there is evidence that genetically engineered vaccinia viruses have reduced pathogenicity a major obstacle to their use as vaccines is that severe complications can occur after vaccination, especially in immunodeficient individuals. We describe here a recombinant vaccinia virus expressing murine interleukin-2 (IL-2) and show that athymic nude mice infected with the recombinant virus resolve the virus infection rapidly whereas mice infected with control virus develop a progressive vaccinal disease. By incorporating the gene for IL-2 in live virus vaccines it may be possible to prevent the severe complications that arise in recipients with an impaired immune system. PMID:3498904

  11. Differing Effects of Herpes Simplex Virus 1 and Pseudorabies Virus Infections on Centrosomal Function

    PubMed Central

    Labetoulle, Marc; Rixon, Frazer J.

    2013-01-01

    Efficient intracellular transport of the capsid of alphaherpesviruses, such as herpes simplex virus 1 (HSV-1), is known to be dependent upon the microtubule (MT) network. Typically, the MT network radiates from an MT-organizing center (MTOC), which is, in most cases, the centrosome. During herpesvirus egress, it has been assumed that capsids travel first from the nucleus to the centrosome and then from the centrosome to the site of envelopment. Here we report that the centrosome is no longer a primary MTOC in HSV-1-infected cells, but it retains this function in cells infected by another alphaherpesvirus, pseudorabies virus (PrV). As a result, MTs formed at late times after infection with PrV grow from a major, centralized MTOC, while those formed after HSV-1 infection arise from dispersed locations in the cytoplasm, indicating the presence of alternative and minor MTOCs. Thus, loss of the principal MT nucleating center in cells following HSV-1 infection raises questions about the mechanism of HSV-1 capsid egress. It is possible that, rather than passing via the centrosome, capsids may travel directly to the site of envelopment after exiting the nucleus. We suggest that, in HSV-1-infected cells, the disruption of centrosomal functions triggers reorganization of the MT network to favor noncentrosomal MTs and promote efficient viral spread. PMID:23596303

  12. Molecular evidence of simian virus 40 infections in children

    NASA Technical Reports Server (NTRS)

    Butel, J. S.; Arrington, A. S.; Wong, C.; Lednicky, J. A.; Finegold, M. J.

    1999-01-01

    Recent studies have detected simian virus 40 (SV40) DNA in certain human tumors and normal tissues. The significance of human infections by SV40, which was first discovered as a contaminant of poliovirus vaccines used between 1955 and 1963, remains unknown. The occurrence of SV40 infections in unselected hospitalized children was evaluated. Polymerase chain reaction and DNA sequence analyses were done on archival tissue specimens from patients positive for SV40 neutralizing antibody. SV40 DNA was identified in samples from 4 of 20 children (1 Wilms' tumor, 3 transplanted kidney samples). Sequence variation among SV40 regulatory regions ruled out laboratory contamination of specimens. This study shows the presence of SV40 infections in pediatric patients born after 1982.

  13. Experimental Infections of Wild Birds with West Nile Virus

    PubMed Central

    Pérez-Ramírez, Elisa; Llorente, Francisco; Jiménez-Clavero, Miguel Ángel

    2014-01-01

    Avian models of West Nile virus (WNV) disease have become pivotal in the study of infection pathogenesis and transmission, despite the intrinsic constraints that represents this type of experimental research that needs to be conducted in biosecurity level 3 (BSL3) facilities. This review summarizes the main achievements of WNV experimental research carried out in wild birds, highlighting advantages and limitations of this model. Viral and host factors that determine the infection outcome are analyzed in detail, as well as recent discoveries about avian immunity, viral transmission, and persistence achieved through experimental research. Studies of laboratory infections in the natural host will help to understand variations in susceptibility and reservoir competence among bird species, as well as in the epidemiological patterns found in different affected areas. PMID:24531334

  14. Innate Immune Control of West Nile Virus Infection

    PubMed Central

    Arjona, Alvaro; Wang, Penghua; Montgomery, Ruth R.; Fikrig, Erol

    2011-01-01

    West Nile virus (WNV), from the Flaviviridae family, is a re-emerging zoonotic pathogen of medical importance. In humans, WNV infection may cause life-threatening meningoencephalitis or long-term neurologic sequelae. WNV is transmitted by Culex spp mosquitoes and both the arthropod vector and the mammalian host are equipped with antiviral innate immune mechanisms sharing a common phylogeny. As far as the current evidence is able to demonstrate, mosquitoes primarily rely on RNA interference, Toll, Imd and JAK-STAT signaling pathways for limiting viral infection, while mammals are provided with these and other more complex antiviral mechanisms involving antiviral effectors, inflammatory mediators, and cellular responses triggered by highly specialized pathogen detection mechanisms that often resemble their invertebrate ancestry. This mini-review summarizes our current understanding of how the innate immune systems of the vector and the mammalian host react to WNV infection and shape its pathogenesis. PMID:21790942

  15. Testosterone correlates with Venezuelan equine encephalitis virus infection in macaques.

    PubMed

    Muehlenbein, Michael P; Cogswell, Frank B; James, Mark A; Koterski, James; Ludwig, George V

    2006-01-01

    Here we briefly report testosterone and cytokine responses to Venezuelan equine encephalitis virus (VEEV) in macaques which were used as part of a larger study conducted by the Department of Defense to better characterize pathological responses to aerosolized VEEV in non-human primates. Serial samples were collected and analyzed for testosterone and cytokines prior to and during infection in 8 captive male macaques. Infected animals exhibited a febrile response with few significant changes in cytokine levels. Baseline testosterone levels were positively associated with viremia following exposure and were significantly higher than levels obtained during infection. Such findings suggest that disease-induced androgen suppression is a reasonable area for future study. Decreased androgen levels during physiological perturbations may function, in part, to prevent immunosuppression by high testosterone levels and to prevent the use of energetic resources for metabolically-expensive anabolic functions. PMID:16571136

  16. Chronic actinic dermatitis associated with human immunodeficiency virus infection.

    PubMed

    Meola, T; Sanchez, M; Lim, H W; Buchness, M R; Soter, N A

    1997-09-01

    Chronic actinic dermatitis is a photodistributed, eczematous dermatitis that preferentially affects elderly men and persists for months to years. Its occurrence in individuals infected with human immunodeficiency virus (HIV) has been described in five patients. We report four additional cases of this uncommon, chronic photodermatosis associated with HIV infection. In two of the patients, photosensitivity was a presenting disorder leading to the diagnosis of HIV infection. All patients were men of skin type VI with a mean age of 50 years, all had decreased minimal erythema doses to ultraviolet B, three of the four patients had decreased minimal erythema doses to ultraviolet A and all had CD4 cell counts of < 200 x 10(6)/L. PMID:9349344

  17. HIV-1 Infection of DC: Evidence for the Acquisition of Virus Particles from Infected T Cells by Antigen Uptake Mechanism

    PubMed Central

    Venkatachari, Narasimhan J.; Alber, Sean; Watkins, Simon C.; Ayyavoo, Velpandi

    2009-01-01

    Dendritic cells (DC) play a pivotal role in transmission and dissemination of HIV-1. Earlier studies reported that DC present at the site of infection trap virus particles via DC-SIGN and transfer the virus to the interacting naïve T cells. This prompted us to ask the question whether DC could acquire virus from infected T cells during DC-T cell interaction. To address this, we investigated the likely transfer of virus from HIV-1 infected T cells to DC and the underlying mechanisms involved. Results indicate that DC acquire virus from infected T cells via antigen uptake mechanism and this results in infection of DC with expression of proteins directed by viral DNA. Further studies with HIV-1 lacking the Env protein also resulted in infection of DC. The use of antibodies against DC-SIGN and DC-SIGN-R ruled out a role for receptor in the infection of DC. Additional data show that DC infection is directly correlated with the ability of DC to take up antigen from infected T cells. Overall, these studies provide evidence to suggest that HIV-1, besides infecting immune cells, also utilizes immunological mechanism(s) to acquire and disseminate virus. PMID:19829715

  18. Infection of XC Cells by MLVs and Ebola Virus Is Endosome-Dependent but Acidification-Independent

    Microsoft Academic Search

    Haruka Kamiyama; Katsura Kakoki; Hiroaki Yoshii; Masatomo Iwao; Tsukasa Igawa; Hideki Sakai; Hideki Hayashi; Toshifumi Matsuyama; Naoki Yamamoto; Yoshinao Kubo; Robert J. Geraghty

    2011-01-01

    Inhibitors of endosome acidification or cathepsin proteases attenuated infections mediated by envelope proteins of xenotropic murine leukemia virus-related virus (XMRV) and Ebola virus, as well as ecotropic, amphotropic, polytropic, and xenotropic murine leukemia viruses (MLVs), indicating that infections by these viruses occur through acidic endosomes and require cathepsin proteases in the susceptible cells such as TE671 cells. However, as previously

  19. Vector infection determinants of Venezuelan equine encephalitis virus reside within the E2 envelope glycoprotein.

    PubMed

    Brault, Aaron C; Powers, Ann M; Weaver, Scott C

    2002-06-01

    Epizootic subtype IAB and IC Venezuelan equine encephalitis viruses (VEEV) readily infect the epizootic mosquito vector Aedes taeniorhynchus. The inability of enzootic subtype IE viruses to infect this mosquito species provides a model system for the identification of natural viral determinants of vector infectivity. To map mosquito infection determinants, reciprocal chimeric viruses generated from epizootic subtype IAB and enzootic IE VEEV were tested for mosquito infectivity. Chimeras containing the IAB epizootic structural gene region and, more specifically, the IAB PE2 envelope glycoprotein E2 precursor gene demonstrated an efficient infection phenotype. Introduction of the PE2 gene from an enzootic subtype ID virus into an epizootic IAB or IC genetic backbone resulted in lower infection rates than those of the epizootic parent. The finding that the E2 envelope glycoprotein, the site of epitopes that define the enzootic and epizootic subtypes, also encodes mosquito infection determinants suggests that selection for efficient infection of epizootic mosquito vectors may mediate VEE emergence. PMID:12021373

  20. Mixed infections of Pepino mosaic virus strains modulate the evolutionary dynamics of this emergent virus.

    PubMed

    Gómez, P; Sempere, R N; Elena, S F; Aranda, M A

    2009-12-01

    Pepino mosaic virus (PepMV) is an emerging pathogen that causes severe economic losses in tomato crops (Solanum lycopersicum L.) in the Northern hemisphere, despite persistent attempts of control. In fact, it is considered one of the most significant viral diseases for tomato production worldwide, and it may constitute a good model for the analysis of virus emergence in crops. We have combined a population genetics approach with an analysis of in planta properties of virus strains to explain an observed epidemiological pattern. Hybridization analysis showed that PepMV populations are composed of isolates of two types (PepMV-CH2 and PepMV-EU) that cocirculate. The CH2 type isolates are predominant; however, EU isolates have not been displaced but persist mainly in mixed infections. Two molecularly cloned isolates belonging to each type have been used to examine the dynamics of in planta single infections and coinfection, revealing that the CH2 type has a higher fitness than the EU type. Coinfections expand the range of susceptible hosts, and coinfected plants remain symptomless several weeks after infection, so a potentially important problem for disease prevention and management. These results provide an explanation of the observed epidemiological pattern in terms of genetic and ecological interactions among the different viral strains. Thus, mixed infections appear to be contributing to shaping the genetic structure and dynamics of PepMV populations. PMID:19759144

  1. Mixed Infections of Pepino Mosaic Virus Strains Modulate the Evolutionary Dynamics of this Emergent Virus ? †

    PubMed Central

    Gómez, P.; Sempere, R. N.; Elena, S. F.; Aranda, M. A.

    2009-01-01

    Pepino mosaic virus (PepMV) is an emerging pathogen that causes severe economic losses in tomato crops (Solanum lycopersicum L.) in the Northern hemisphere, despite persistent attempts of control. In fact, it is considered one of the most significant viral diseases for tomato production worldwide, and it may constitute a good model for the analysis of virus emergence in crops. We have combined a population genetics approach with an analysis of in planta properties of virus strains to explain an observed epidemiological pattern. Hybridization analysis showed that PepMV populations are composed of isolates of two types (PepMV-CH2 and PepMV-EU) that cocirculate. The CH2 type isolates are predominant; however, EU isolates have not been displaced but persist mainly in mixed infections. Two molecularly cloned isolates belonging to each type have been used to examine the dynamics of in planta single infections and coinfection, revealing that the CH2 type has a higher fitness than the EU type. Coinfections expand the range of susceptible hosts, and coinfected plants remain symptomless several weeks after infection, so a potentially important problem for disease prevention and management. These results provide an explanation of the observed epidemiological pattern in terms of genetic and ecological interactions among the different viral strains. Thus, mixed infections appear to be contributing to shaping the genetic structure and dynamics of PepMV populations. PMID:19759144

  2. Differential Proteome Analysis of Chikungunya Virus Infection on Host Cells

    PubMed Central

    Thio, Christina Li-Ping; Yusof, Rohana; Abdul-Rahman, Puteri Shafinaz Akmar; Karsani, Saiful Anuar

    2013-01-01

    Background Chikungunya virus (CHIKV) is an emerging mosquito-borne alphavirus that has caused multiple unprecedented and re-emerging outbreaks in both tropical and temperate countries. Despite ongoing research efforts, the underlying factors involved in facilitating CHIKV replication during early infection remains ill-characterized. The present study serves to identify host proteins modulated in response to early CHIKV infection using a proteomics approach. Methodology and Principal Findings The whole cell proteome profiles of CHIKV-infected and mock control WRL-68 cells were compared and analyzed using two-dimensional gel electrophoresis (2-DGE). Fifty-three spots were found to be differentially modulated and 50 were successfully identified by MALDI-TOF/TOF. Eight were significantly up-regulated and 42 were down-regulated. The mRNA expressions of 15 genes were also found to correlate with the corresponding protein expression. STRING network analysis identified several biological processes to be affected, including mRNA processing, translation, energy production and cellular metabolism, ubiquitin-proteasome pathway (UPP) and cell cycle regulation. Conclusion/Significance This study constitutes a first attempt to investigate alteration of the host cellular proteome during early CHIKV infection. Our proteomics data showed that during early infection, CHIKV affected the expression of proteins that are involved in mRNA processing, host metabolic machinery, UPP, and cyclin-dependent kinase 1 (CDK1) regulation (in favour of virus survival, replication and transmission). While results from this study complement the proteomics results obtained from previous late host response studies, functional characterization of these proteins is warranted to reinforce our understanding of their roles during early CHIKV infection in humans. PMID:23593481

  3. Human genes involved in hepatitis B virus infection

    PubMed Central

    Zeng, Zheng

    2014-01-01

    Persistent hepatitis B virus (HBV) infection is a significant public health problem because it is a major cause of chronic liver disease, cirrhosis, and hepatocellular carcinoma (HCC). Roughly one-third of the world population has been infected with HBV and there are about 350 million (5%-6%) persistent carriers. HBV causes 80% of all liver cancer cases and is the second most important carcinogen, after smoking tobacco. There is an approximate 90% risk of becoming a persistent carrier following perinatal infection in infants born to e antigen positive carrier mothers and a 30% risk in pre-school children. Only 5%-10% of adults become persistent carriers following infection. Of individuals persistently infected with HBV, 10%-30% will develop liver cirrhosis and HCC. These highly variable outcomes in both clearance rates and disease outcomes in persistently infected individuals cannot be fully explained by differences in immunological, viral or environmental factors. Thus, differences in host genetic factors may affect the natural history of hepatitis B. PMID:24976707

  4. Innate immune responses against Epstein Barr virus infection

    PubMed Central

    Chijioke, Obinna; Azzi, Tarik; Nadal, David; Münz, Christian

    2013-01-01

    EBV persists life-long in >95% of the human adult population. Whereas it is perfectly immune-controlled in most infected individuals, a minority develops EBV-associated diseases, primarily malignancies of B cell and epithelial cell origin. In recent years, it has become apparent that the course of primary infection determines part of the risk to develop EBV-associated diseases. Particularly, the primary symptomatic EBV infection or IM, which is caused by exaggerated T cell responses, resulting in EBV-induced lymphocytosis, predisposes for EBV-associated diseases. The role of innate immunity in the development of IM remains unknown. Therefore, it is important to understand how the innate immune response to this virus differs between symptomatic and asymptomatic primary EBV infection. Furthermore, the efficiency of innate immune compartments might determine the outcome of primary infection and could explain why some individuals are susceptible to IM. We will discuss these aspects in this review with a focus on intrinsic immunity in EBV-infected B cells, as well as innate immune responses by DCs and NK cells, which constitute promising immune compartments for the understanding of early immune control against EBV and potential targets for EBV-specific immunotherapies. PMID:23812328

  5. Virology of hepatitis C virus infection.

    PubMed

    Chevaliez, Stéphane; Pawlotsky, Jean-Michel

    2012-08-01

    The multiple steps of the HCV lifecycle have been recently unravelled, thanks to the development of a number of cell-free or cell culture-based model systems. The HCV lifecycle offers a very large number of potential targets of intervention for specific anti-HCV drugs, including direct-acting antiviral drugs and host-targeted agents. HCV virological tools include enzyme immunoassays (EIAs) that detect anti-HCV antibodies and detect/quantify HCV core antigen, and molecular biology-based assays that are used to detect and quantify HCV RNA and to determine the HCV genotype. Recently, point-of-care tests and alternatives to laboratory tests that require whole-blood samples have been developed to improve access to screening, diagnosis and care. Virological tools are used in clinical practice to diagnose acute and chronic HCV infection, to decide who should be treated, to select the optimal therapy and to monitor treatment responses in order to tailor treatment duration. PMID:23199498

  6. Using small RNA sequences to diagnose, sequence, and investigate the infectivity characteristics of vegetable-infecting viruses

    Microsoft Academic Search

    Charles Hagen; Alessandra Frizzi; John Kao; Lijie Jia; Mingya Huang; Yuanji Zhang; Shihshieh Huang

    2011-01-01

    In a virus-infected plant, small interfering RNAs (siRNAs) corresponding to the viral genome form a large proportion of the\\u000a small RNA population. It is possible to reassemble significant portions of the virus sequence from overlapping siRNA sequences\\u000a and use these to identify the virus. We tested this technique with a resistance-breaking and a non-resistance-breaking strain\\u000a of tomato spotted wilt virus

  7. Behavioral and neurophysiological hallmarks of simian immunodeficiency virus infection in macaque monkeys

    Microsoft Academic Search

    P. D. Cheney; M. Riazi; J. M. Marcario

    2008-01-01

    Macaque monkeys infected with various neurovirulent forms of simian immunodeficiency virus (SIV) represent highly effective\\u000a models, not only of systemic acquired immunodeficiency virus (AIDS), but also neuroAIDS. Behavioral studies with this model\\u000a have clearly established that SIV-infected monkeys show both cognitive and motor impairments resembling those that have been\\u000a reported in human immunodeficiency virus (HIV)-infected humans. This paper combines data

  8. Primary Simian Immunodeficiency Virus SIVmnd-2 Infection in Mandrills (Mandrillus sphinx)

    Microsoft Academic Search

    Richard Onanga; Sandrine Souquiere; Maria Makuwa; Augustin Mouinga-Ondeme; Francois Simon; Cristian Apetrei; Pierre Roques

    2006-01-01

    Mandrills are the only nonhuman primate (NHP) naturally infected by two types of simian immunodefi- ciency virus (SIV): SIVmnd-1 and SIVmnd-2. We have already reported that the high SIVmnd-1 replication during primary infection contrasts with only transient changes in CD4 and CD8 cell counts. Since early virus-host interactions predict viral control and disease progression in human immunodeficiency virus- infected patients,

  9. Inhibition of lytic infection of pseudorabies virus by arginine depletion

    SciTech Connect

    Wang, H.-C. [Department of Veterinary Medicine, College of Veterinary Medicine, National Chung-Hsing University, Taichung 402, Taiwan (China); Kao, Y.-C. [Department of Veterinary Medicine, College of Veterinary Medicine, National Chung-Hsing University, Taichung 402, Taiwan (China); Chang, T-J. [Department of Veterinary Medicine, College of Veterinary Medicine, National Chung-Hsing University, Taichung 402, Taiwan (China); Wong, M.-L. [Department of Veterinary Medicine, College of Veterinary Medicine, National Chung-Hsing University, Taichung 402, Taiwan (China)]. E-mail: mlwong@dragon.nchu.edu.tw

    2005-08-26

    Pseudorabies virus (PRV) is a member of Alphahepesviruses; it is an enveloped virus with a double-stranded DNA genome. Polyamines (such as spermine and spermidine) are ubiquitous in animal cells and participate in cellular proliferation and differentiation. Previous results of our laboratory showed that the PRV can accomplish lytic infection either in the presence of exogenous spermine (or spermidine) or depletion of cellular polyamines. The amino acid arginine is a precursor of polyamine biosynthesis. In this work, we investigated the role of arginine in PRV infection. It was found that the plaque formation of PRV was inhibited by arginase (enzyme catalyzing the conversion of arginine into ornithine and urea) treatment whereas this inhibition can be reversed by exogenous arginine, suggesting that arginine is essential for PRV proliferation. Western blotting was conducted to study the effect of arginine depletion on the levels of structural proteins of PRV in virus-infected cells. Four PRV structural proteins (gB, gE, UL47, and UL48) were chosen for examination, and results revealed that the levels of viral proteins were obviously reduced in long time arginase treatment. However, the overall protein synthesis machinery was apparently not influenced by arginase treatment either in mock or PRV-infected cells. Analyzing with native gel, we found that arginase treatment affected the mobility of PRV structural proteins, suggesting the conformational change of viral proteins by arginine depletion. Heat shock proteins, acting as molecular chaperons, participate in protein folding and translocation. Our results demonstrated that long time arginase treatment could reduce the expression of cellular heat shock proteins 70 (hsc70 and hsp70), and transcriptional suppression of heat shock protein 70 gene promoter was one of the mechanisms involved in this reduced expression.

  10. GB virus C infection in Indonesian HIV-positive patients.

    PubMed

    Anggorowati, Nungki; Yano, Yoshihiko; Subronto, Yanri Wijayanti; Utsumi, Takako; Heriyanto, Didik Setyo; Mulya, Deshinta Putri; Rinonce, Hanggoro Tri; Widasari, Dewiyani Indah; Lusida, Maria Inge; Soetjipto; Hayashi, Yoshitake

    2013-04-01

    GB virus C (GBV-C), a human virus of the Flaviviridae family that is structurally and epidemiologically closest to hepatitis C virus (HCV), has been reported to confer beneficial outcomes in HIV-positive patients. However, the prevalence of GBV-C in HIV-positive individuals in Indonesia is unknown. Since GBV-C is more prevalent in anti-HCV positive patients than in anti-HCV negative subjects, transmission of GBV-C and HCV could be by the same method. This study examined the prevalence and molecular characteristics of GBV-C infection in HIV patients in Yogyakarta, Indonesia. The prevalence of GBV-C among HIV patients (n = 125, median age 31 years) based on the 5'UTR region was 111/125 (88.8%), including 39/48 (81.3%) and 72/77 (93.5%) HIV-infected patients with and without HCV infection, respectively. GBV-C isolates were of genotype 2a, 3 and 6 in 58.3%, 12.6% and 28.4% of patients, respectively. Patients with genotype 3 were significantly younger than those with genotypes 2a or 6 (P = 0.001 and P = 0.012, respectively). Genotypes 3 and 6 were significantly associated with injection drug use (P = 0.004 and P = 0.002, respectively) and HCV co-infection (P < 0.001 for both genotypes), indicating a shared transmission route with HCV. In conclusion, the prevalence of GBV-C among HIV-positive patients in Indonesia is high, and three genotypes were detected, namely genotype 2a, 3 and 6. PMID:23590588

  11. GB virus C infection in Indonesian HIV-positive patients.

    PubMed

    Anggorowati, Nungki; Yano, Yoshihiko; Subronto, Yanri Wijayanti; Utsumi, Takako; Heriyanto, Didik Setyo; Mulya, Deshinta Putri; Rinonce, Hanggoro Tri; Widasari, Dewiyani Indah; Lusida, Maria Inge; Soetjipto; Hayashi, Yoshitake

    2013-02-01

    GB virus C (GBV-C) is a human virus of the Flaviviridae family that is structurally and epidemiologically closest to hepatitis C virus (HCV), and has been reported to confer beneficial outcomes in HIV-positive patients. However, the presence of GBV-C in HIV-positive individuals in Indonesia was unknown. Since the prevalence of GBV-C was higher in the patients with anti-HCV positive, the transmission of GBV-C and HCV could be by the same method. This study examined the prevalence and molecular characteristics of GBV-C infection in HIV patients in Yogyakarta, Indonesia. The prevalence of GBV-C among HIV patients (n?=?125, median age 31 years) based on 5'UTR region was 111 of 125 (88.8%), including 39/48 (81.3%) and 72/77 (93.5%) of HIV-infected patients with and without HCV infection, respectively. GBV-C isolates were classified into genotypes 2a, 3, and 6 in 58.3%, 12.6%, and 28.4% of patients, respectively. Patients with genotype 3 were significantly younger than those with genotypes 2a or 6 (P?=?0.001 and P?=?0.012, respectively). Genotypes 3 and 6 were significantly associated with injection drug use (P?=?0.004 and P?=?0.002, respectively) and HCV co-infection (P?

  12. Within-Host Spatiotemporal Dynamics of Plant Virus Infection at the Cellular Level

    PubMed Central

    Lafforgue, Guillaume; Elena, Santiago F.

    2014-01-01

    A multicellular organism is not a monolayer of cells in a flask; it is a complex, spatially structured environment, offering both challenges and opportunities for viruses to thrive. Whereas virus infection dynamics at the host and within-cell levels have been documented, the intermediate between-cell level remains poorly understood. Here, we used flow cytometry to measure the infection status of thousands of individual cells in virus-infected plants. This approach allowed us to determine accurately the number of cells infected by two virus variants in the same host, over space and time as the virus colonizes the host. We found a low overall frequency of cellular infection (<0.3), and few cells were coinfected by both virus variants (<0.1). We then estimated the cellular contagion rate (R), the number of secondary infections per infected cell per day. R ranged from 2.43 to values not significantly different from zero, and generally decreased over time. Estimates of the cellular multiplicity of infection (MOI), the number of virions infecting a cell, were low (<1.5). Variance of virus-genotype frequencies increased strongly from leaf to cell levels, in agreement with a low MOI. Finally, there were leaf-dependent differences in the ease with which a leaf could be colonized, and the number of virions effectively colonizing a leaf. The modeling of infection patterns suggests that the aggregation of virus-infected cells plays a key role in limiting spread; matching the observation that cell-to-cell movement of plant viruses can result in patches of infection. Our results show that virus expansion at the between-cell level is restricted, probably due to the host environment and virus infection itself. PMID:24586207

  13. Peginterferon Alfa-2a plus Ribavirin for Chronic Hepatitis C Virus Infection in HIV-Infected Patients

    Microsoft Academic Search

    Francesca J. Torriani; Maribel Rodriguez-Torres; Jürgen K. Rockstroh; Eduardo Lissen; Juan Gonzalez-García; Adriano Lazzarin; Giampiero Carosi; Joseph Sasadeusz; Christine Katlama; Julio Montaner; Hoel Sette; Sharon Passe; Jean De Pamphilis; Frank Duff; Uschi Marion Schrenk; Douglas T. Dieterich

    2004-01-01

    background Hepatitis C virus (HCV) infection is highly prevalent and is associated with substan- tial morbidity and mortality among persons infected with the human immunodefi- ciency virus (HIV). We compared the efficacy and safety of pegylated interferon alfa-2a (peginterferon alfa-2a) plus either ribavirin or placebo with those of interferon alfa-2a plus ribavirin for the treatment of chronic HCV infection in

  14. Interferon alfacon-1 protects hamsters from lethal pichinde virus infection.

    PubMed

    Gowen, Brian B; Barnard, Dale L; Smee, Donald F; Wong, Min-Hui; Pace, Anne M; Jung, Kie-Hoon; Winslow, Scott G; Bailey, Kevin W; Blatt, Lawrence M; Sidwell, Robert W

    2005-06-01

    Hemorrhagic fever of arenaviral origin is a frequently fatal infectious disease of considerable priority to the biodefense mission. Historically, the treatment of arenaviral infections with alpha interferons has not yielded favorable results. Here we present evidence that interferon alfacon-1, a nonnaturally occurring bioengineered alpha interferon approved for the treatment of chronic hepatitis C, is active against Pichinde and Tacaribe arenaviruses in cell culture. In the hamster model of Pichinde virus (PCV) infection, interferon alfacon-1 treatment significantly protected animals from death, prolonged the survival of those that eventually died, reduced virus titers, and limited liver damage characteristic of PCV-induced disease. Moreover, interferon alfacon-1 also demonstrated therapeutic activity, to a lesser degree, when the initiation of treatment was delayed up to 2 days post-virus challenge. Despite the observed advantages of interferon alfacon-1 therapy, efforts to stimulate the immune system with the known interferon inducer poly(I:C12U) (Ampligen) offered only limited protection against lethal PCV challenge. Taken together, these data suggest that the increased potency of the bio-optimized interferon alfacon-1 molecule may be critical to the observed antiviral effects. These data are the first report demonstrating efficacious treatment of acute arenaviral disease with alpha interferon therapy, and further study is warranted. PMID:15917537

  15. Experimental Infection of Raccoons (Procyon lotor) with West Nile Virus

    PubMed Central

    Root, J. Jeffrey; Bentler, Kevin T.; Nemeth, Nicole M.; Gidlewski, Thomas; Spraker, Terry R.; Franklin, Alan B.

    2010-01-01

    To characterize the responses of raccoons to West Nile virus (WNV) infection, we subcutaneously exposed them to WNV. Moderately high viremia titers (? 104.6 plaque forming units [PFU]/mL of serum) were noted in select individuals; however, peak viremia titers were variable and viremia was detectable in some individuals as late as 10 days post-inoculation (DPI). In addition, fecal shedding was prolonged in some animals (e.g., between 6 and 13 DPI in one individual), with up to105.0 PFU/fecal swab detected. West Nile virus was not detected in tissues collected on 10 or 16 DPI, and no histologic lesions attributable to WNV infection were observed. Overall, viremia profiles suggest that raccoons are unlikely to be important WNV amplifying hosts. However, this species may occasionally shed significant quantities of virus in feces. Considering their behavioral ecology, including repeated use of same-site latrines, high levels of fecal shedding could potentially lead to interspecies fecal-oral WNV transmission. PMID:20889868

  16. Protein Synthesis in Simian Virus 40-Infected Monkey Cells

    PubMed Central

    Walter, Gernot; Roblin, Richard; Dulbecco, Renato

    1972-01-01

    The proteins of purified Simian virus 40 (SV40) were examined by sodium dodecyl sulfate-acrylamide gel electrophoresis and compared with the polypeptides synthesized in SV40-infected monkey cells. Purified virions contain two major components, with molecular weights of 44,000 and 31,000. Together they make up 83% of the total virion proteins. In addition, the virus contains 12 minor polypeptides, which are believed to be cellular proteins, or peptides derived from proteolytic degradation of the 44,000 molecular weight polypeptide. Pulse-label experiments show that about 90% of the polypeptides synthesized after SV40 infection are host-cell proteins; 10% represent the two major structural components of the virion. A small fraction (about 0.5%) consists of three polypeptides (molecular weights 70,000, 60,000, and 8,000) that are neither part of the virion nor detectable in uninfected cells. They are either virus-induced cellular proteins or, more likely, proteins coded for by the SV40 genome. PMID:4337247

  17. Ascorbic Acid Inhibits Replication and Infectivity of Avian RNA Tumor Virus

    NASA Astrophysics Data System (ADS)

    Bissell, Mina J.; Hatie, Carroll; Farson, Deborah A.; Schwarz, Richard I.; Soo, Whai-Jen

    1980-05-01

    Ascorbic acid, at nontoxic concentrations, causes a substantial reduction in the ability of avian tumor viruses to replicate in both primary avian tendon cells and chicken embryo fibroblasts. The virus-infected cultures appear to be less transformed in the presence of ascorbic acid by the criteria of morphology, reduced glucose uptake, and increased collagen synthesis. The vitamin does not act by altering the susceptibility of the cells to initial infection and transformation, but instead appears to interfere with the spread of infection through a reduction in virus replication and virus infectivity. The effect is reversible and requires the continuous presence of the vitamin in the culture medium.

  18. Serum Ferritin as a Predictor of Host Response to Hepatitis B Virus Infection

    NASA Astrophysics Data System (ADS)

    Lustbader, Edward D.; Hann, Hie-Won L.; Blumberg, Baruch S.

    1983-04-01

    With hemodialysis patients, a high serum ferritin before there was serological evidence of hepatitis B virus infection increased the likelihood that the infection would be persistent. This finding suggested that hepatitis B virus is likely to infect and actively replicate in liver cells with the propensity for increased ferritin synthesis. The virus itself could stimulate the synthesis of ferritin in a cyclic positive feedback mechanism that increases intracellular ferritin concentration and, eventually, intracellular iron. Transformed liver cells have low iron content, do not replicate hepatitis B virus, and require iron for growth. Infected, nonmalignant liver cells could supply iron to the transformed cells and nourish their expansion.

  19. Bovine viral diarrhea virus infections: manifestations of infection and recent advances in understanding pathogenesis and control.

    PubMed

    Brodersen, B W

    2014-03-01

    Bovine viral diarrhea virus (BVDV) continues to be of economic significance to the livestock industry in terms of acute disease and fetal loss. Many of the lesions relating to BVDV infection have been well described previously. The virus is perpetuated in herds through the presence of calves that are persistently infected. Relationships between various species and biotypes of BVDV and host defenses are increasingly understood. Understanding of the host defense mechanisms of innate immunity and adaptive immunity continues to improve, and the effects of the virus on these immune mechanisms are being used to explain how persistent infection develops. The noncytopathic biotype of BVDV plays the major role in its effects on the host defenses by inhibiting various aspects of the innate immune system and creation of immunotolerance in the fetus during early gestation. Recent advances have allowed for development of affordable test strategies to identify and remove persistently infected animals. With these improved tests and removal strategies, the livestock industry can begin more widespread effective control programs. PMID:24476940

  20. Experimental infection of mice with bovine viral diarrhea virus.

    PubMed

    Seong, Giyong; Oem, Jae-Ku; Lee, Kyung-Hyun; Choi, Kyoung-Seong

    2015-06-01

    The objective of this study was to test the ability of bovine viral diarrhea virus (BVDV) to infect mice. Two mice each were either mock infected or inoculated with one of three BVDV strains by the intraperitoneal (IP) (n = 8) or intranasal (IN) (n = 8) route. All mice were euthanized at day 7 postinfection (p.i.). None of the infected mice exhibited any clinical signs of illness; however, the tissues harvested after BVDV challenge showed significant histopathological changes. Blood samples from five mice that were injected IP and one mouse that was inoculated IN were positive for BVDV by reverse transcription polymerase chain reaction (RT-PCR). Immunohistochemistry (IHC) was used to assess the presence of viral antigen in the organs of mice infected with three BVDV strains. In IP-injected mice, BVDV antigen was detected in the spleen (5/6), mesenteric lymph nodes (4/6), lymphatic tissue of the lung (3/6), lung (1/6), and stomach (1/6) of the infected mice; however, it was not detected in the liver (0/6) or kidney (0/6). In IN-inoculated mice, BVDV antigen was detected in the lung and mesenteric lymph nodes of one BVDV-infected mouse but was not detected in other tissues. The results of this study suggest that the spleen is the most reliable tissue for BVDV antigen detection using IHC in the IP-injected group. Our study demonstrates that mice can be infected by BVDV. This is the first report of BVDV infection in mice. PMID:25850760

  1. Persistent Rat Virus Infection in Smooth Muscle of Euthymic and Athymic Rats

    PubMed Central

    Jacoby, Robert O.; Johnson, Elizabeth A.; Paturzo, Frank X.; Ball-Goodrich, Lisa

    2000-01-01

    Rat virus (RV) infection can cause disease or disrupt responses that rely on cell proliferation. Therefore, persistent infection has the potential to amplify RV interference with research. As a step toward determining underlying mechanisms of persistence, we compared acute and persistent RV infections in infant euthymic and athymic rats inoculated oronasally with the University of Massachusetts strain of RV. Rats were assessed by virus isolation, in situ hybridization, and serology. Selected tissues also were analyzed by Southern blotting or immunohistochemistry. Virus was widely disseminated during acute infection in rats of both phenotypes, whereas vascular smooth muscle cells (SMC) were the primary targets during persistent infection. The prevalence of virus-positive cells remained moderate to high in athymic rats through 8 weeks but decreased in euthymic rats by 2 weeks, coincident with seroconversion and perivascular infiltration of mononuclear cells. Virus-positive pneumocytes and renal tubular epithelial cells also were detected through 8 weeks, implying that kidney and lung excrete virus during persistent infection. Viral mRNA was detected in SMC of both phenotypes through 8 weeks, indicating that persistent infection includes virus replication. However, only half of the SMC containing viral mRNA at 4 weeks stained for proliferating cell nuclear antigen, a protein expressed in cycling cells. The results demonstrate that vasculotropism is a significant feature of persistent infection, that virus replication continues during persistent infection, and that host immunity reduces, but does not eliminate, infection. PMID:11090184

  2. Requirement for shrimp caspase in apoptosis against virus infection.

    PubMed

    Wang, Lei; Zhi, Bin; Wu, Wenlin; Zhang, Xiaobo

    2008-01-01

    Caspases are central effectors in apoptosis. In this investigation, a novel caspase gene (designated as PjCaspase) obtained from the marine shrimp Marsupenaeus japonicus was found to be significantly upregulated in survivors of WSSV-challenged shrimp, suggesting that it might be involved in shrimp antiviral immunity. As revealed by RNAi assays, when the PjCaspase gene was silenced by gene-specific siRNA, the WSSV-induced apoptosis was significantly inhibited. The results showed that the PjCaspase gene was essential in the virus-induced apoptosis of shrimp. Based on the quantitative PCR detection, it was shown that the PjCaspase gene silencing resulted in the increase of virus copies, indicating that apoptosis played a key role in antiviral process of shrimp. As well known, caspase-3 and -8 are crucial caspases in apoptosis. The discovery of PjCaspase in this study would contribute another essential caspase involved in apoptosis against virus infection, which might reveal an ancient mechanism of caspase activation in invertebrate immunity against viruses. PMID:18068223

  3. Prevalence of rabies virus and Hantaan virus infections in commensal rodents and shrews trapped in Bangkok.

    PubMed

    Kantakamalakul, Wannee; Siritantikorn, Sontana; Thongcharoen, Prasert; Singchai, Chantra; Puthavathana, Pilaipan

    2003-11-01

    Five hundred rodents and shrews (Rattus norvegicus: 458, Rattus rattus: 28, Rattus exulans: 5, Mus musculus: 4 and Suncus murine: 5) trapped from the fresh food markets around Bangkok area were investigated for rabies virus and Hantaan virus infections. No rabies viral antigens in the animals' brains were detected by direct immunofluorescence. On the other hand, antibodies to Hantaan virus were demonstrated in the sera of 7 (1.53%) R. norvegicus caught in various markets using a particle agglutination technique. Further determination of the viral genome in rat lung tissue was performed by reverse transcriptase-polymerase chain reaction (RT-PCR) and nested PCR, 3 (0.66%) out of 7 were positive. HindIII and HifI restriction enzyme analyses showed the pattern of the Hantaan virus genome in 2 samples and that of the Seoul virus genome in the other. The results of the present study suggest that rodents from Bangkok's fresh food markets did not carry rabies. Thus, getting rid of rabies in dogs or cats in the Bangkok area may be easier than anticipated because there are no sources of asymptomatic reservoirs. This may result in the low incidence of rabies patients observed in Bangkok. On the contrary, the presence of antibodies and the Hantaan virus genome and Seoul virus genome in R. norvegicus will definitely provide evidence for physicians to be aware of hemorrhagic fever with renal syndrome (HFRS) and other clinical settings of Hantaan/Seoul virus disease in patients with a history of having contact with rats or their excreta. PMID:14696782

  4. Occult hepatitis B virus infection and blood transfusion

    PubMed Central

    Seo, Dong Hee; Whang, Dong Hee; Song, Eun Young; Han, Kyou Sup

    2015-01-01

    Transfusion-transmitted infections including hepatitis B virus (HBV) have been a major concern in transfusion medicine. Implementation of HBV nucleic acid testing (NAT) has revealed occult HBV infection (OBI) in blood donors. In the mid-1980s, hepatitis B core antibody (HBc) testing was introduced to screen blood donors in HBV non-endemic countries to prevent transmission of non-A and non-B hepatitis. That test remains in use for preventing of potential transmission of HBV from hepatitis B surface antigen (HBsAg)-negative blood donors, even though anti-hepatitis C virus tests have been introduced. Studies of anti-HBc-positive donors have revealed an HBV DNA positivity rate of 0%-15%. As of 2012, 30 countries have implemented HBV NAT. The prevalence of OBI in blood donors was estimated to be 8.55 per 1 million donations, according to a 2008 international survey. OBI is transmissible by blood transfusion. The clinical outcome of occult HBV transmission primarily depends on recipient immune status and the number of HBV DNA copies present in the blood products. The presence of donor anti-HBs reduces the risk of HBV infection by approximately five-fold. The risk of HBV transmission may be lower in endemic areas than in non-endemic areas, because most recipients have already been exposed to HBV. Blood safety for HBV, including OBI, has substantially improved, but the possibility for OBI transmission remains. PMID:25848484

  5. Occult hepatitis B virus infection and blood transfusion.

    PubMed

    Seo, Dong Hee; Whang, Dong Hee; Song, Eun Young; Han, Kyou Sup

    2015-03-27

    Transfusion-transmitted infections including hepatitis B virus (HBV) have been a major concern in transfusion medicine. Implementation of HBV nucleic acid testing (NAT) has revealed occult HBV infection (OBI) in blood donors. In the mid-1980s, hepatitis B core antibody (HBc) testing was introduced to screen blood donors in HBV non-endemic countries to prevent transmission of non-A and non-B hepatitis. That test remains in use for preventing of potential transmission of HBV from hepatitis B surface antigen (HBsAg)-negative blood donors, even though anti-hepatitis C virus tests have been introduced. Studies of anti-HBc-positive donors have revealed an HBV DNA positivity rate of 0%-15%. As of 2012, 30 countries have implemented HBV NAT. The prevalence of OBI in blood donors was estimated to be 8.55 per 1 million donations, according to a 2008 international survey. OBI is transmissible by blood transfusion. The clinical outcome of occult HBV transmission primarily depends on recipient immune status and the number of HBV DNA copies present in the blood products. The presence of donor anti-HBs reduces the risk of HBV infection by approximately five-fold. The risk of HBV transmission may be lower in endemic areas than in non-endemic areas, because most recipients have already been exposed to HBV. Blood safety for HBV, including OBI, has substantially improved, but the possibility for OBI transmission remains. PMID:25848484

  6. Virus and Host Factors Affecting the Clinical Outcome of Bluetongue Virus Infection

    PubMed Central

    Caporale, Marco; Di Gialleonorado, Luigina; Janowicz, Anna; Wilkie, Gavin; Shaw, Andrew; Savini, Giovanni; Van Rijn, Piet A.; Mertens, Peter; Di Ventura, Mauro

    2014-01-01

    ABSTRACT Bluetongue is a major infectious disease of ruminants caused by bluetongue virus (BTV), an arbovirus transmitted by Culicoides. Here, we assessed virus and host factors influencing the clinical outcome of BTV infection using a single experimental framework. We investigated how mammalian host species, breed, age, BTV serotypes, and strains within a serotype affect the clinical course of bluetongue. Results obtained indicate that in small ruminants, there is a marked difference in the susceptibility to clinical disease induced by BTV at the host species level but less so at the breed level. No major differences in virulence were found between divergent serotypes (BTV-8 and BTV-2). However, we observed striking differences in virulence between closely related strains of the same serotype collected toward the beginning and the end of the European BTV-8 outbreak. As observed previously, differences in disease severity were also observed when animals were infected with either blood from a BTV-infected animal or from the same virus isolated in cell culture. Interestingly, with the exception of two silent mutations, full viral genome sequencing showed identical consensus sequences of the virus before and after cell culture isolation. However, deep sequencing analysis revealed a marked decrease in the genetic diversity of the viral population after passaging in mammalian cells. In contrast, passaging in Culicoides cells increased the overall number of low-frequency variants compared to virus never passaged in cell culture. Thus, Culicoides might be a source of new viral variants, and viral population diversity can be another factor influencing BTV virulence. IMPORTANCE Bluetongue is one of the major infectious diseases of ruminants. It is caused by an arbovirus known as bluetongue virus (BTV). The clinical outcome of BTV infection is extremely variable. We show that there are clear links between the severity of bluetongue and the mammalian host species infected, while at the breed level differences were less evident. No differences were observed in the virulence of two different BTV serotypes (BTV-8 and BTV-2). In contrast, we show that the European BTV-8 strain isolated at the beginning of the bluetongue outbreak in 2006 was more virulent than a strain isolated toward the end of the outbreak. In addition, we show that there is a link between the variability of the BTV population as a whole and virulence, and our data also suggest that Culicoides cells might function as an “incubator” of viral variants. PMID:24991012

  7. Immunodominance Changes as a Function of the Infecting Dengue Virus Serotype and Primary versus Secondary Infection

    PubMed Central

    Angelo, Michael A.; Sidney, John; Peters, Bjoern; Shresta, Sujan; Sette, Alessandro

    2014-01-01

    ABSTRACT Dengue virus (DENV) is the causative agent of dengue fever (DF). This disease can be caused by any of four DENV serotypes (DENV1 to -4) which share 67 to 75% sequence homology with one another. The effect of subsequent infections with different serotypes on the T cell repertoire is not fully understood. We utilized mice transgenic for human leukocyte antigens (HLA) lacking the alpha/beta interferon (IFN-?/?) receptor to study responses to heterologous DENV infection. First, we defined the primary T cell response to DENV3 in the context of a wide range of HLA molecules. The primary DENV3 immune response recognized epitopes derived from all 10 DENV proteins, with a significant fraction of the response specific for structural proteins. This is in contrast to primary DENV2 infection, in which structural proteins are a minor component of the response, suggesting differential antigen immunodominance as a function of the infecting serotype. We next investigated the effect of secondary heterologous DENV infection on the T cell repertoire. In the case of both DENV2/3 and DENV3/2 heterologous infections, recognition of conserved/cross-reactive epitopes was either constant or expanded compared to that in homologous infection. Furthermore, in heterologous infection, previous infection with a different serotype impaired the development of responses directed to serotype-specific but not conserved epitopes. Thus, a detrimental effect of previous heterotypic responses might not be due to dysfunctional and weakly cross-reactive epitopes dominating the response. Rather, responses to the original serotype might limit the magnitude of responses directed against epitopes that are either cross-reactive to or specific for the most recently infecting serotype. IMPORTANCE DENV transmission occurs in more than 100 countries and is an increasing public health problem in tropical and subtropical regions. At present, no effective antiviral therapy or licensed vaccine exists, and treatment is largely supportive in nature. Disease can be caused by any of the four DENV serotypes (DENV1 to -4), which share a high degree of sequence homology with one another. In this study, we have addressed the question of how the T cell repertoire changes as a function of infections with different serotypes and of subsequent heterologous secondary infections. This is of particular interest in the field of dengue viruses, in which secondary infections with different DENV serotypes increase the risk of severe disease. Our results on the evolution of the immune response after primary and secondary infections provide new insights into HLA-restricted T cell responses against DENV relevant for the design of a vaccine against DENV. PMID:25056881

  8. Interleukin 28B genetic polymorphism and hepatitis B virus infection

    PubMed Central

    Takahashi, Toru

    2014-01-01

    Interleukin (IL) 28B genetic polymorphism is significantly associated with the sustained virological response rate in patients with chronic hepatitis C treated with pegylated interferon-? (PEG-IFN) plus ribavirin and with spontaneous hepatitis C virus clearance. However, a consensus on the relationship between IL28B genetic polymorphism and the favorable outcome of chronic hepatitis B virus infection defined by hepatitis B e antigen seroconversion, and/or hepatitis B surface antigen seroclearance in patients treated with interferon or PEG-IFN has not been reached. Several reports failed to show a positive association, while some studies demonstrated a positive association in certain subject settings. More prospective studies including large cohorts are needed to determine the possible association between IL28B genetic polymorphism and the outcome of interferon or PEG-IFN treatment for chronic hepatitis B. PMID:25232239

  9. Metagenomic next-generation sequencing of viruses infecting grapevines.

    PubMed

    Burger, Johan T; Maree, Hans J

    2015-01-01

    Next-generation sequencing (NGS) technologies, for the first time, provide a truly "complete" representation of the viral (and other) pathogens present in a host organism. This is achieved in an unbiased way, and without any prior biological or molecular knowledge of these pathogen(s). During recent years a number of broad approaches, for most of the popular NGS platforms, have been developed. Here we describe such a protocol-one that accurately and reliably analyze viruses (and viroids) infecting grapevine. Our strategy relies on the synthesis of cDNA sequencing libraries from dsRNA, extracted from diseased grapevine tissues; the sequencing of these on an Illumina platform, and a streamlined bioinformatics pipeline to analyze the NGS data, yielding the virus composition (virome) of a specific grapevine tissue type, organ, entire plant, or even a vineyard. PMID:25981264

  10. Interleukin 28B genetic polymorphism and hepatitis B virus infection.

    PubMed

    Takahashi, Toru

    2014-09-14

    Interleukin (IL) 28B genetic polymorphism is significantly associated with the sustained virological response rate in patients with chronic hepatitis C treated with pegylated interferon-? (PEG-IFN) plus ribavirin and with spontaneous hepatitis C virus clearance. However, a consensus on the relationship between IL28B genetic polymorphism and the favorable outcome of chronic hepatitis B virus infection defined by hepatitis B e antigen seroconversion, and/or hepatitis B surface antigen seroclearance in patients treated with interferon or PEG-IFN has not been reached. Several reports failed to show a positive association, while some studies demonstrated a positive association in certain subject settings. More prospective studies including large cohorts are needed to determine the possible association between IL28B genetic polymorphism and the outcome of interferon or PEG-IFN treatment for chronic hepatitis B. PMID:25232239

  11. Innate immune recognition of respiratory syncytial virus infection.

    PubMed

    Kim, Tae Hoon; Lee, Heung Kyu

    2014-04-01

    Respiratory syncytial virus (RSV) is the leading cause of respiratory infection in infants and young children. Severe clinical manifestation of RSV infection is a bronchiolitis, which is common in infants under six months of age. Recently, RSV has been recognized as an important cause of respiratory infection in older populations with cardiovascular morbidity or immunocompromised patients. However, neither a vaccine nor an effective antiviral therapy is currently available. Moreover, the interaction between the host immune system and the RSV pathogen during an infection is not well understood. The innate immune system recognizes RSV through multiple mechanisms. The first innate immune RSV detectors are the pattern recognition receptors (PRRs), including toll-like receptors (TLRs), retinoic acid-inducible gene-I (RIG-I)-like receptors (RLRs), and nucleotide-biding oligomerization domain (NOD)-like receptors (NLRs). The following is a review of studies associated with various PRRs that are responsible for RSV virion recognition and subsequent induction of the antiviral immune response during RSV infection. PMID:24568879

  12. Differential tropism in roots and shoots infected by Citrus tristeza virus.

    PubMed

    Harper, S J; Cowell, S J; Robertson, C J; Dawson, W O

    2014-07-01

    Virus tropism is a result of interactions between virus, host and vector species, and determines the fate of an infection. In this study, we examined the infection process of Citrus tristeza virus (CTV) in susceptible and resistant species, and found that the tropism of CTV is not simply phloem limited, but tissue specific. In resistant species, virus infection was not prevented, but mostly restricted to the roots. This phenomenon was also observed after partial replacement of genes of one CTV strain from another, despite both parental strains being capable of systemic infection. Finally, the roots remained susceptible in the absence of viral gene products needed for systemic infection of shoots. Our results suggest that all phloem cells within a plant are not equally susceptible and that changes in host or virus may produce a novel tropism: restriction by the host to a location where further virus spread is prevented. PMID:25010274

  13. The saga of XMRV: a virus that infects human cells but is not a human virus

    PubMed Central

    Arias, Maribel; Fan, Hung

    2014-01-01

    Xenotropic murine leukemia virus-related virus (XMRV) was discovered in 2006 in a search for a viral etiology of human prostate cancer (PC). Substantial interest in XMRV as a potentially new pathogenic human retrovirus was driven by reports that XMRV could be detected in a significant percentage of PC samples, and also in tissues from patients with chronic fatigue syndrome (CFS). After considerable controversy, etiologic links between XMRV and these two diseases were disproven. XMRV was determined to have arisen during passage of a human PC tumor in immunocompromised nude mice, by activation and recombination between two endogenous murine leukemia viruses from cells of the mouse. The resulting XMRV had a xentropic host range, which allowed it replicate in the human tumor cells in the xenograft. This review describes the discovery of XMRV, and the molecular and virological events leading to its formation, XMRV infection in animal models and biological effects on infected cells. Lessons from XMRV for other searches of viral etiologies of cancer are discussed, as well as cautions for researchers working on human tumors or cell lines that have been passed through nude mice, includingpotential biohazards associated with XMRV or other similar xenotropic murine leukemia viruses (MLVs). PMID:26038516

  14. Zucchini yellow mosaic virus (ZYMV, Potyvirus): vertical transmission, seed infection and cryptic infections.

    PubMed

    Simmons, H E; Dunham, J P; Zinn, K E; Munkvold, G P; Holmes, E C; Stephenson, A G

    2013-09-01

    The role played by seed transmission in the evolution and epidemiology of viral crop pathogens remains unclear. We determined the seed infection and vertical transmission rates of zucchini yellow mosaic virus (ZYMV), in addition to undertaking Illumina sequencing of nine vertically transmitted ZYMV populations. We previously determined the seed-to-seedling transmission rate of ZYMV in Cucurbita pepo ssp. texana (a wild gourd) to be 1.6%, and herein observed a similar rate (1.8%) in the subsequent generation. We also observed that the seed infection rate is substantially higher (21.9%) than the seed-to-seedling transmission rate, suggesting that a major population bottleneck occurs during seed germination and seedling growth. In contrast, that two thirds of the variants present in the horizontally transmitted inoculant population were also present in the vertically transmitted populations implies that the bottleneck at vertical transmission may not be particularly severe. Strikingly, all of the vertically infected plants were symptomless in contrast to those infected horizontally, suggesting that vertical infection may be cryptic. Although no known virulence determining mutations were observed in the vertically infected samples, the 5' untranslated region was highly variable, with at least 26 different major haplotypes in this region compared to the two major haplotypes observed in the horizontally transmitted population. That the regions necessary for vector transmission are retained in the vertically infected populations, combined with the cryptic nature of vertical infection, suggests that seed transmission may be a significant contributor to the spread of ZYMV. PMID:23845301

  15. BOVINE VIRAL DIARRHEA VIRUS PERSISTENTLY INFECTED AND ACUTELY INFECTED CALVES: ASSAYS FOR VIRAL INFECTIVITY, POLYMERASE CHAIN REACTION ANALYSIS, AND ANTIGEN DETECTION

    Technology Transfer Automated Retrieval System (TEKTRAN)

    There are numerous assays for bovine viral diarrhea virus (BVDV) detecting infectious virus, nucleic material, and antigen. Persistently infected (PI) and acutely/transiently infected calves with BVDV represent two different manifestations. Diagnostic test results impact on differentiation of PI o...

  16. Persistence and Emergence of X4 Virus in HIV Infection

    PubMed Central

    Weinberger, Ariel D.; Perelson, Alan S.

    2011-01-01

    Approximately 50% of late-stage HIV patients develop CXCR4-tropic (X4) virus in addition to CCR5-tropic (R5) virus. X4 emergence occurs with a sharp decline in CD4+ T cell counts and accelerated time to AIDS. Why this “phenotypic switch” to X4 occurs is not well understood. Previously, we used numerical simulations of a mathematical model to show that across much of parameter space a promising new class of antiretroviral treatments, CCR5 inhibitors, can accelerate X4 emergence and immunodeficiency. Here, we show that mathematical model to be a minimal activation-based HIV model that produces a spontaneous switch to X4 virus at a clinically-representative time point, while also matching in vivo data showing X4 and R5 coexisting and competing to infect memory CD4+ T cells. Our analysis shows that X4 avoids competitive exclusion from an initially fitter R5 virus due to X4’s unique ability to productively infect naïve CD4+ T cells. We further justify the generalized conditions under which this minimal model holds, implying that a phenotypic switch can even occur when the fraction of activated naïve CD4+ T cells increases at a slower rate than the fraction of activated memory CD4+ T cells. We find that it is the ratio of the fractions of activated naïve and memory CD4+ T cells that must increase above a threshold to produce a switch. This occurs as the concentration of CD4+ T cells drops beneath a threshold. Thus, highly active antiretroviral therapy (HAART), which increases CD4+ T cell counts and decreases cellular activation levels, inhibits X4 viral growth. However, we show here that even in the simplest dual-strain framework, competition between R5 and X4 viruses often results in accelerated X4 emergence in response to CCR5 inhibition, further highlighting the potential danger of anti-CCR5 monotherapy in multi-strain HIV infection. PMID:21631149

  17. Effects of genetic resistance against Herpes simplex virus in vaginally infected mice

    Microsoft Academic Search

    K. E. Schneweis; M. Olbrich; V. Saftig; R. Scholz

    1982-01-01

    In order to take the conditions of naturalHerpes simplex virus (HSV) infection into consideration, the genetic resistance of C57-B1 mice, which was established by intraperitoneal HSV-1 infection [Lopez, 1975], was investigated in vaginally infected mice. The course of infection in the mucous membranes did not differ in sensitive (NMRI) and resistant (C57-B1) mice: both number of takes and virus elimination

  18. Dendritic Cells in Dengue Virus Infection: Targets of Virus Replication and Mediators of Immunity

    PubMed Central

    Schmid, Michael A.; Diamond, Michael S.; Harris, Eva

    2014-01-01

    Dendritic cells (DCs) are sentinels of the immune system and detect pathogens at sites of entry, such as the skin. In addition to the ability of DCs to control infections directly via their innate immune functions, DCs help to prime adaptive B- and T-cell responses by processing and presenting antigen in lymphoid tissues. Infected Aedes aegypti or Aedes albopictus mosquitoes transmit the four dengue virus (DENV) serotypes to humans while probing for small blood vessels in the skin. DENV causes the most prevalent arthropod-borne viral disease in humans, yet no vaccine or specific therapeutic is currently licensed. Although primary DENV infection confers life-long protective immunity against re-infection with the same DENV serotype, secondary infection with a different DENV serotype can lead to increased disease severity via cross-reactive T-cells or enhancing antibodies. This review summarizes recent findings in humans and animal models about DENV infection of DCs, monocytes, and macrophages. We discuss the dual role of DCs as both targets of DENV replication and mediators of innate and adaptive immunity, and summarize immune evasion strategies whereby DENV impairs the function of infected DCs. We suggest that DCs play a key role in priming DENV-specific neutralizing or potentially harmful memory B- and T-cell responses, and that future DC-directed therapies may help induce protective memory responses and reduce dengue pathogenesis. PMID:25566258

  19. Rabbitpox Virus and Vaccinia Virus Infection of Rabbits as a Model for Human Smallpox?

    PubMed Central

    Adams, Mathew M.; Rice, Amanda D.; Moyer, R. W.

    2007-01-01

    The threat of smallpox release and use as a bioweapon has encouraged the search for new vaccines and antiviral drugs, as well as development of new small-animal models in which their efficacy can be determined. Here, we reinvestigate a rabbit model in which the intradermal infection of rabbits with very low doses of either rabbitpox virus (RPV) or vaccinia virus Western Reserve (VV-WR) recapitulates many of the clinical features of human smallpox. Following intradermal inoculation with RPV, rabbits develop systemic disease characterized by extensive viremia, numerous secondary lesions on the skin and mucocutaneous tissues, severe respiratory disease, death by 9 days postinfection, and, importantly, natural aerosol transmission between animals. Contrary to previous reports, intradermal infection with VV-WR also resulted in a very similar lethal systemic disease in rabbits, again with natural aerosol transmission between animals. When sentinel and index animals were cohoused, transmission rates approached 100% with either virus, with sentinel animals exhibiting a similar, severe disease. Lower rates of transmission were observed when index and sentinel animals were housed in separate cages. Sentinel animals infected with RPV with one exception succumbed to the disease. However, the majority of VV-WR-infected sentinel animals, while becoming seriously ill, survived. Finally, we tested the efficacy of the drug 1-O-hexadecyloxypropyl-cidofovir in the RPV/rabbit model and found that an oral dose of 5 mg/kg twice a day for 5 days beginning 1 day before infection was able to completely protect rabbits from lethal disease. PMID:17686856

  20. MiR-122 in hepatitis B virus and hepatitis C virus dual infection.

    PubMed

    Song, Kyoungsub; Han, Chang; Dash, Srikanta; Balart, Luis A; Wu, Tong

    2015-03-27

    Hepatitis B virus (HBV) and hepatitis C virus (HCV) infections are the most common causes of chronic liver diseases and hepatocelluar carcinomas. Over the past few years, the liver-enriched microRNA-122 (miR-122) has been shown to differentially regulate viral replication of HBV and HCV. It is notable that the level of miR-122 is positively and negatively regulated by HCV and HBV, respectively. Consistent with the well-documented phenomenon that miR-122 promotes HCV accumulation, inhibition of miR-122 has been shown as an effective therapy for the treatment of HCV infection in both chimpanzees and humans. On the other hand, miR-122 is also known to block HBV replication, and HBV has recently been shown to inhibit miR-122 expression; such a reciprocal inhibition between miR-122 and HBV suggests an intriguing possibility that miR-122 replacement may represent a potential therapy for treatment of HBV infection. As HBV and HCV have shared transmission routes, dual infection is not an uncommon scenario, which is associated with more advanced liver disease than either HBV or HCV mono-infection. Thus, there is a clear need to further understand the interaction between HBV and HCV and to delineate the role of miR-122 in HBV/HCV dual infection in order to devise effective therapy. This review summarizes the current understanding of HBV/HCV dual infection, focusing on the pathobiological role and therapeutic potential of miR-122. PMID:25848473

  1. The green tea catechin, epigallocatechin gallate inhibits chikungunya virus infection.

    PubMed

    Weber, Christopher; Sliva, Katja; von Rhein, Christine; Kümmerer, Beate M; Schnierle, Barbara S

    2015-01-01

    Chikungunya virus (CHIKV) is a mosquito-transmitted alphavirus that causes chikungunya fever and has infected millions of people mainly in developing countries. The associated disease is characterized by rash, high fever and severe arthritis that can persist for years. CHIKV has adapted to Aedes albopictus, which also inhabits temperate regions, including Europe and the United States of America and might cause new, large outbreaks there. No treatment or licensed CHIKV vaccine exists. Epigallocatechin-3-gallate (EGCG), the major component of green tea, has, among other beneficial properties, antiviral activities. Therefore, we examined if EGCG has antiviral activity against CHIKV. EGCG inhibited CHIKV infection in vitro, blocked entry of CHIKV Env-pseudotyped lentiviral vectors and inhibited CHIKV attachment to target cells. Thus EGCG might be used as a lead structure to develop more effective antiviral drugs. PMID:25446334

  2. Daclatasvir for the treatment of chronic hepatitis C virus infection.

    PubMed

    Temesgen, Z; Rizza, S A

    2015-05-01

    Daclatasvir is a nonstructural protein 5A (NS5A) replication complex inhibitor that has shown potent in vitro activity against multiple hepatitis C virus (HCV) genotypes (GT). It is currently in advanced clinical development as a component of combination treatment regimens in a variety of HCV-infected patient populations. In studies conducted thus far, it has been generally well tolerated. It has been approved for the treatment of HCV GTs 1-4 in the European Union. The combination of daclatasvir and asunaprevir (an HCV NS3/4A protease inhibitor) has been approved in Japan for the treatment of patients with GT1 HCV infection. Here we review the available literature on daclatasvir, including its information on its discovery, mechanism of action, pharmacology, preclinical and clinical activity, resistance and safety. PMID:26097901

  3. Progressive outer retinal necrosis: manifestation of human immunodeficiency virus infection.

    PubMed

    Lo, Phey Feng; Lim, Rongxuan; Antonakis, Serafeim N; Almeida, Goncalo C

    2015-01-01

    We present the case of a 54-year-old man who developed progressive outer retinal necrosis (PORN) as an initial manifestation of HIV infection without any significant risk factors for infection with HIV. PORN is usually found as a manifestation of known AIDS late in the disease. Our patient presented with transient visual loss followed by decrease in visual acuity and facial rash. Subsequent investigation revealed anterior chamber tap positive for varicella zoster virus (VZV), as well as HIV positivity, with an initial CD4 count of 48 cells/µL. Systemic and intravitreal antivirals against VZV, and highly active antiretroviral therapy against HIV were started, which halted further progression of retinal necrosis. This case highlights the importance of suspecting PORN where there is a rapidly progressive retinitis, and also testing the patient for HIV, so appropriate treatment can be started. PMID:25948844

  4. Genomic comparison of closely related Giant Viruses supports an accordion-like model of evolution

    PubMed Central

    Filée, Jonathan

    2015-01-01

    Genome gigantism occurs so far in Phycodnaviridae and Mimiviridae (order Megavirales). Origin and evolution of these Giant Viruses (GVs) remain open questions. Interestingly, availability of a collection of closely related GV genomes enabling genomic comparisons offer the opportunity to better understand the different evolutionary forces acting on these genomes. Whole genome alignment for five groups of viruses belonging to the Mimiviridae and Phycodnaviridae families show that there is no trend of genome expansion or general tendency of genome contraction. Instead, GV genomes accumulated genomic mutations over the time with gene gains compensating the different losses. In addition, each lineage displays specific patterns of genome evolution. Mimiviridae (megaviruses and mimiviruses) and Chlorella Phycodnaviruses evolved mainly by duplications and losses of genes belonging to large paralogous families (including movements of diverse mobiles genetic elements), whereas Micromonas and Ostreococcus Phycodnaviruses derive most of their genetic novelties thought lateral gene transfers. Taken together, these data support an accordion-like model of evolution in which GV genomes have undergone successive steps of gene gain and gene loss, accrediting the hypothesis that genome gigantism appears early, before the diversification of the different GV lineages.

  5. Herpes simplex virus infections among rural residents in eastern China

    PubMed Central

    2011-01-01

    Background Herpes simplex virus (HSV) has two types: HSV-1 and HSV-2. Both infect epithelial cells and establish latent infections in neurons causing an infection that persists for life. Information on age- and gender-specific seroprevalence of HSV-1 and HSV-2 is valuable for understanding HSV transmission dynamics and designing population-based prevention and intervention programs for HSV. However, such information is not available for China. Methods Cryopreserved serum samples of all subjects aged 5 to 60 years from two randomly selected rural villages in Zhejiang province in Eastern China who had participated in the China national seroepidemiological survey of hepatitis B virus (HBV) infection conducted in 2006 were tested. Seroprevalence of HSV-1 and HSV-2 infections were determined by type-specific IgG antibody tests using an ELISA technique. Their 95% confidence intervals adjusted for the sampling fraction were calculated according to the Clopper-Pearson method. Results A total of 2,141 residents participated in the survey, with a response rate of 82.3%. HSV-1 seroprevalence was 92.0% overall, 89.1% for males and 94.2% for females. HSV-1 seroprevalence was 61.6% among children aged 5-9 years, 90.3% among 25-29 years, and nearly 100% among those aged > = 40 years. HSV-2 seroprevalence was 13.2% overall, 10.5% for males and 15.3% for females. No children aged 5-14 years were HSV-2 positive, and HSV-2 seroprevalence was 7.1% among 15-19 years and peaked at 24.3% among those aged 45-49 years. Neither HSV-1 nor HSV-2 infections were significantly different by gender. About 11.8% of study subjects were co-infected with both types of HSV. Among 549 participating couples, 8.6% were HSV-1 serodiscordant and 11.8% were HSV-2 serodiscordant. No one tested positive for HIV. The overall prevalence of HBsAg was 16.2%, 16.9% for males and 15.4% for females. Conclusions HSV-1 was highly prevalent among all rural residents aged between 5-60 years in Eastern China, whereas HSV-2 was prevalent among sexually active people. HSV-1 and HSV-2 have different transmission modes and dynamics. Future HSV prevention and control programs in China should be type specific. PMID:21414231

  6. WEST NILE VIRUS AND GREATER SAGE-GROUSE: ESTIMATING INFECTION RATE IN A WILD BIRD POPULATION

    Microsoft Academic Search

    BRETT L. WALKER; DAVID E. NAUGLE; A Kevin; E. Doherty

    2007-01-01

    SUMMARY. Understanding impacts of disease on wild bird populations requires knowing not only susceptibility to mortality following infection, but also the proportion of the population that is infected. Greater sage-grouse (Centrocercus urophasianus )i n western North America are known to be extremely susceptible to mortality following infection with West Nile virus (WNv), but actual infection rates in wild populations remain

  7. Virus interference between H7N2 low pathogenic avian influenza virus and lentogenic Newcastle disease virus in experimental co-infections in chickens and turkeys

    PubMed Central

    2014-01-01

    Low pathogenicity avian influenza virus (LPAIV) and lentogenic Newcastle disease virus (lNDV) are commonly reported causes of respiratory disease in poultry worldwide with similar clinical and pathobiological presentation. Co-infections do occur but are not easily detected, and the impact of co-infections on pathobiology is unknown. In this study chickens and turkeys were infected with a lNDV vaccine strain (LaSota) and a H7N2 LPAIV (A/turkey/VA/SEP-67/2002) simultaneously or sequentially three days apart. No clinical signs were observed in chickens co-infected with the lNDV and LPAIV or in chickens infected with the viruses individually. However, the pattern of virus shed was different with co-infected chickens, which excreted lower titers of lNDV and LPAIV at 2 and 3 days post inoculation (dpi) and higher titers at subsequent time points. All turkeys inoculated with the LPAIV, whether or not they were exposed to lNDV, presented mild clinical signs. Co-infection effects were more pronounced in turkeys than in chickens with reduction in the number of birds shedding virus and in virus titers, especially when LPAIV was followed by lNDV. In conclusion, co-infection of chickens or turkeys with lNDV and LPAIV affected the replication dynamics of these viruses but did not affect clinical signs. The effect on virus replication was different depending on the species and on the time of infection. These results suggest that infection with a heterologous virus may result in temporary competition for cell receptors or competent cells for replication, most likely interferon-mediated, which decreases with time. PMID:24393488

  8. Mathematical models of immune effector responses to viral infections: Virus control versus the development of pathology

    NASA Astrophysics Data System (ADS)

    Wodarz, Dominik

    2005-12-01

    This article reviews mathematical models which have investigated the importance of lytic and non-lytic immune responses for the control of viral infections. Lytic immune responses fight the virus by killing infected cells, while non-lytic immune responses fight the virus by inhibiting viral replication while leaving the infected cell alive. The models suggest which types or combinations of immune responses are required to resolve infections which vary in their characteristics, such as the rate of viral replication and the rate of virus-induced target cell death. This framework is then applied to persistent infections and viral evolution. It is investigated how viral evolution and antigenic escape can influence the relative balance of lytic and non-lytic responses over time, and how this might correlate with the transition from an asymptomatic infection to pathology. This is discussed in the specific context of hepatitis C virus infection.

  9. In ovo and in vitro susceptibility of American alligators (Alligator mississippiensis) to avian influenza virus infection.

    PubMed

    Temple, Bradley L; Finger, John W; Jones, Cheryl A; Gabbard, Jon D; Jelesijevic, Tomislav; Uhl, Elizabeth W; Hogan, Robert J; Glenn, Travis C; Tompkins, S Mark

    2015-01-01

    Avian influenza has emerged as one of the most ubiquitous viruses within our biosphere. Wild aquatic birds are believed to be the primary reservoir of all influenza viruses; however, the spillover of H5N1 highly pathogenic avian influenza (HPAI) and the recent swine-origin pandemic H1N1 viruses have sparked increased interest in identifying and understanding which and how many species can be infected. Moreover, novel influenza virus sequences were recently isolated from New World bats. Crocodilians have a slow rate of molecular evolution and are the sister group to birds; thus they are a logical reptilian group to explore susceptibility to influenza virus infection and they provide a link between birds and mammals. A primary American alligator (Alligator mississippiensis) cell line, and embryos, were infected with four, low pathogenic avian influenza (LPAI) strains to assess susceptibility to infection. Embryonated alligator eggs supported virus replication, as evidenced by the influenza virus M gene and infectious virus detected in allantoic fluid and by virus antigen staining in embryo tissues. Primary alligator cells were also inoculated with the LPAI viruses and showed susceptibility based upon antigen staining; however, the requirement for trypsin to support replication in cell culture limited replication. To assess influenza virus replication in culture, primary alligator cells were inoculated with H1N1 human influenza or H5N1 HPAI viruses that replicate independent of trypsin. Both viruses replicated efficiently in culture, even at the 30 C temperature preferred by the alligator cells. This research demonstrates the ability of wild-type influenza viruses to infect and replicate within two crocodilian substrates and suggests the need for further research to assess crocodilians as a species potentially susceptible to influenza virus infection. PMID:25380354

  10. Proteinuria in paediatric patients with human immunodeficiency virus infection.

    PubMed

    Giacomet, Vania; Erba, Paola; Di Nello, Francesca; Coletto, Sonia; Viganò, Alessandra; Zuccotti, Gianvincenzo

    2013-04-16

    In human immunodeficiency virus (HIV)-infected people kidney disease is as an important cause of morbidity and mortality. Clinical features of kidney damage in HIV-infected patients range from asymptomatic microalbuminuria to nephrotic syndrome. The lack of specific clinical features despite the presence of heavy proteinuria may mask the renal involvement. Indeed, it is important in HIV patients to monitor renal function to early discover a possible kidney injury. After the introduction of antiretroviral therapy, mortality and morbidity associated to HIV-infection have shown a substantial reduction, although a variety of side effects for long-term use of highly active antiretroviral therapy, including renal toxicity, has emerged. Among more than 20 currently available antiretroviral agents, many of them can occasionally cause reversible or irreversible nephrotoxicity. At now, three antiretroviral agents, i.e., indinavir, atazanavir and tenofovir disoproxil fumarate have a well established association with direct nephrotoxicity. This review focuses on major causes of proteinuria and other pathological findings related to kidney disease in HIV-infected children and adolescents. PMID:24303454

  11. Human immunodeficiency virus type 1 infection of the brain.

    PubMed Central

    Atwood, W J; Berger, J R; Kaderman, R; Tornatore, C S; Major, E O

    1993-01-01

    Direct infection of the central nervous system by human immunodeficiency virus type 1 (HIV-1), the causative agent of AIDS, was not appreciated in the early years of the AIDS epidemic. Neurological complications associated with AIDS were largely attributed to opportunistic infections that arose as a result of the immunocompromised state of the patient and to depression. In 1985, several groups succeeded in isolating HIV-1 directly from brain tissue. Also that year, the viral genome was completely sequenced, and HIV-1 was found to belong to a neurotropic subfamily of retrovirus known as the Lentivirinae. These findings clearly indicated that direct HIV-1 infection of the central nervous system played a role in the development of AIDS-related neurological disease. This review summarizes the clinical manifestations of HIV-1 infection of the central nervous system and the related neuropathology, the tropism of HIV-1 for specific cell types both within and outside of the nervous system, the possible mechanisms by which HIV-1 damages the nervous system, and the current strategies for diagnosis and treatment of HIV-1-associated neuropathology. Images PMID:8269391

  12. Giant DNA Virus Mimivirus Encodes Pathway for Biosynthesis of Unusual Sugar 4-Amino-4,6-dideoxy-d-glucose (Viosamine)*

    PubMed Central

    Piacente, Francesco; Marin, Margherita; Molinaro, Antonio; De Castro, Cristina; Seltzer, Virginie; Salis, Annalisa; Damonte, Gianluca; Bernardi, Cinzia; Claverie, Jean-Michel; Abergel, Chantal; Tonetti, Michela

    2012-01-01

    Mimivirus is one the largest DNA virus identified so far, infecting several Acanthamoeba species. Analysis of its genome revealed the presence of a nine-gene cluster containing genes potentially involved in glycan formation. All of these genes are co-expressed at late stages of infection, suggesting their role in the formation of the long fibers covering the viral surface. Among them, we identified the L136 gene as a pyridoxal phosphate-dependent sugar aminotransferase. This enzyme was shown to catalyze the formation of UDP-4-amino-4,6-dideoxy-d-glucose (UDP-viosamine) from UDP-4-keto-6-deoxy-d-glucose, a key compound involved also in the biosynthesis of l-rhamnose. This finding further supports the hypothesis that Mimivirus encodes a glycosylation system that is completely independent of the amoebal host. Viosamine, together with rhamnose, (N-acetyl)glucosamine, and glucose, was found as a major component of the viral glycans. Most of the sugars were associated with the fibers, confirming a capsular-like nature of the viral surface. Phylogenetic analysis clearly indicated that L136 was not a recent acquisition from bacteria through horizontal gene transfer, but it was acquired very early during evolution. Implications for the origin of the glycosylation machinery in giant DNA virus are also discussed. PMID:22157758

  13. Cirrhosis, Liver Transplantation and HIV Infection Are Risk Factors Associated with Hepatitis E Virus Infection

    PubMed Central

    Riveiro-Barciela, Mar; Buti, María; Homs, María; Campos-Varela, Isabel; Cantarell, Carmen; Crespo, Manuel; Castells, Lluís; Tabernero, David; Quer, Josep; Esteban, Rafael; Rodriguez-Frías, Francisco

    2014-01-01

    Background Acute and chronic hepatitis E have been associated with high mortality and development of cirrhosis, particularly in solid-organ recipients and patients infected by human immunodeficiency virus. However, data regarding the epidemiology of hepatitis E in special populations is still limited. Aims Investigate seroprevalence and possible factors associated with HEV infection in a large cohort of immunosuppressed patients. Methods Cross-sectional study testing IgG anti-HEV in serum samples from 1373 consecutive individuals: 332 liver-transplant, 296 kidney-transplant, 6 dual organ recipients, 301 non-transplanted patients with chronic liver disease, 238 HIV-infected patients and 200 healthy controls. Results IgG anti-HEV was detected in 3.5% controls, 3.7% kidney recipients, 7.4% liver transplant without cirrhosis and 32.1% patients who developed post-transplant cirrhosis (p<0.01). In patients with chronic liver disease, IgG anti-HEV was also statistically higher in those with liver cirrhosis (2% vs 17.5%, p<0.01). HIV-infected patients showed an IgG anti-HEV rate of 9.2%, higher than those patients without HIV infection (p<0.03). Multivariate analysis showed that the factors independently associated with anti-HEV detection were liver cirrhosis, liver transplantation and HIV infection (OR: 7.6, 3.1 and 2.4). HCV infection was a protective factor for HEV infection (OR: 0.4). Conclusions HEV seroprevalence was high in liver transplant recipients, particularly those with liver cirrhosis. The difference in anti-HEV prevalence between Liver and Kidney transplanted cases suggests an association with advanced liver disease. Further research is needed to ascertain whether cirrhosis is a predisposing factor for HEV infection or whether HEV infection may play a role in the pathogeneses of cirrhosis. PMID:25068388

  14. Genetic Characterization of Simian Foamy Viruses Infecting Humans

    PubMed Central

    Rua, Réjane; Betsem, Edouard; Calattini, Sara; Saib, Ali

    2012-01-01

    Simian foamy viruses (SFVs) are retroviruses that are widespread among nonhuman primates (NHPs). SFVs actively replicate in their oral cavity and can be transmitted to humans after NHP bites, giving rise to a persistent infection even decades after primary infection. Very few data on the genetic structure of such SFVs found in humans are available. In the framework of ongoing studies searching for SFV-infected humans in south Cameroon rainforest villages, we studied 38 SFV-infected hunters whose times of infection had presumably been determined. By long-term cocultures of peripheral blood mononuclear cells with BHK-21 cells, we isolated five new SFV strains and obtained complete genomes of SFV strains from chimpanzee (Pan troglodytes troglodytes; strains BAD327 and AG15), monkey (Cercopithecus nictitans; strain AG16), and gorilla (Gorilla gorilla; strains BAK74 and BAD468). These zoonotic strains share a very high degree of similarity with their NHP counterparts and have a high degree of conservation of the genetic elements important for viral replication. Interestingly, analysis of FV DNA sequences obtained before cultivation revealed variants with deletions in both the U3 region and tas that may correlate with in vivo chronicity in humans. Genomic changes in bet (a premature stop codon) and gag were also observed. To determine if such changes were specific to zoonotic strains, we studied local SFV-infected chimpanzees and found the same genomic changes. Our study reveals that natural polymorphism of SFV strains does exist at both the intersubspecies level (gag, bet) and the intrasubspecies (U3, tas) levels but does not seem to reflect a viral adaptation specific to zoonotic SFV strains. PMID:23015714

  15. Sequential Seasonal H1N1 Influenza Virus Infections Protect Ferrets against Novel 2009 H1N1 Influenza Virus

    PubMed Central

    Carter, Donald M.; Bloom, Chalise E.; Nascimento, Eduardo J. M.; Marques, Ernesto T. A.; Craigo, Jodi K.; Cherry, Joshua L.; Lipman, David J.

    2013-01-01

    Individuals <60 years of age had the lowest incidence of infection, with ?25% of these people having preexisting, cross-reactive antibodies to novel 2009 H1N1 influenza. Many people >60 years old also had preexisting antibodies to novel H1N1. These observations are puzzling because the seasonal H1N1 viruses circulating during the last 60 years were not antigenically similar to novel H1N1. We therefore hypothesized that a sequence of exposures to antigenically different seasonal H1N1 viruses can elicit an antibody response that protects against novel 2009 H1N1. Ferrets were preinfected with seasonal H1N1 viruses and assessed for cross-reactive antibodies to novel H1N1. Serum from infected ferrets was assayed for cross-reactivity to both seasonal and novel 2009 H1N1 strains. These results were compared to those of ferrets that were sequentially infected with H1N1 viruses isolated prior to 1957 or more-recently isolated viruses. Following seroconversion, ferrets were challenged with novel H1N1 influenza virus and assessed for viral titers in the nasal wash, morbidity, and mortality. There was no hemagglutination inhibition (HAI) cross-reactivity in ferrets infected with any single seasonal H1N1 influenza viruses, with limited protection to challenge. However, sequential H1N1 influenza infections reduced the incidence of disease and elicited cross-reactive antibodies to novel H1N1 isolates. The amount and duration of virus shedding and the frequency of transmission following novel H1N1 challenge were reduced. Exposure to multiple seasonal H1N1 influenza viruses, and not to any single H1N1 influenza virus, elicits a breadth of antibodies that neutralize novel H1N1 even though the host was never exposed to the novel H1N1 influenza viruses. PMID:23115287

  16. Drug-resistant and immune-escape hepatitis B virus mutants in HIV-infected hosts

    E-print Network

    1/11 Drug-resistant and immune-escape hepatitis B virus mutants in HIV-infected hosts K. Lacombe1 to hepatitis B immunoglobulin (i.e. "immune-escape" S mutants), or treatment-induced mutations from overlapping-infected with hepatitis B virus (HBV) and there is now strong evidence of higher AIDS-events and death rates

  17. EXPERIMENTAL INFECTION OF NEONATAL STRIPED SKUNKS (Mephitis mephitis) WITH INFECTIOUS BOVINE RHINOTRACHEITIS VIRUS

    Microsoft Academic Search

    HAROLD W. LUPTON; RICHARD D. JORGENSON; DAVID E. REED

    Experimental infection of neonatal skunks (Mephitis mephitis) with infectious bovine rhinotracheitis virus (IBRV) caused fatal systemic infection. Virus isolation and immunofluorescence testswere used todemonstrate a direct association between IBRV and the lesions.Histopathologic studies revealed multiple focal necrosis in the liverand the adrenal glands.

  18. Swine Influenza A(H3N2) Virus Infection in Immunocompromised Man, Italy, 2014.

    PubMed

    Piralla, Antonio; Moreno, Ana; Orlandi, Maria Ester; Percivalle, Elena; Chiapponi, Chiara; Vezzoli, Fausto; Baldanti, Fausto

    2015-07-01

    Because swine influenza virus infection is seldom diagnosed in humans, its frequency might be underestimated. We report a immunocompromised hematologic patient with swine influenza A(H3N2) virus in 2014 in Italy. Local pigs were the source of this human infection. PMID:26079745

  19. Multiplication of soilborne wheat mosaic virus (SBWMV) in wheat roots infected by a soil

    E-print Network

    Paris-Sud XI, Université de

    Multiplication of soilborne wheat mosaic virus (SBWMV) in wheat roots infected by a soil carrying SBWMV and wheat yellow mosaic virus (WYMV) Djabbar HARIRI, Michel COURTILLOT Pascal ZAOUI, Hervé winter wheat cultivars were infected in the field or in a growth chamber with an inoculum consisting

  20. Annulate lamellae in phloem cells of virus-infected Sonchus plants

    Microsoft Academic Search

    M. P. Steinkamp; L. L. HOEFERT

    1977-01-01

    The occurrence of annulate lamellae (AL) in differentiating phloem of Sonchus oleraceus (Compositae) singly infected with sowthistle yellow vein virus (SYVV) and doubly infected with a combination of SYVV and beet yellow stunt virus is documented by electron microscopy. Cell types in which AL were found were immature sieve elements and phloem parenchyma cells. AL were found only in cells

  1. Identification of gene biomarkers for respiratory synctial virus infection in a bronchical epithelial cell line

    EPA Science Inventory

    Abstract: Respiratory syncytial virus (RSV) infection involves complex virus-host interplay. In this study, we analyzed gene expression in RSV-infected BEAS-2B cells to discover novel signaling pathways and biomarkers. We hybridized RNAs from RSV- or vehicle-treated BEAS-2B to ...

  2. Monoclonal anti-claudin 1 antibodies prevent hepatitis C virus infection of primary human hepatocytes

    E-print Network

    Paris-Sud XI, Université de

    1 Monoclonal anti-claudin 1 antibodies prevent hepatitis C virus infection of primary human virus; HCVcc - cell culture-derived HCV; HCVpp - HCV pseudoparticles; mAb - monoclonal antibody; Ig. The monoclonal15 antibodies against CLDN1 efficiently inhibited infection by HCV of all major genotypes as well

  3. Dramatic caspase-dependent apoptosis in antibody-enhanced dengue virus infection of human mast cells

    Microsoft Academic Search

    Michael G. Brown; Yan Y. Huang; Jean S. Marshall; Christine A. King; David W. Hoskin; Robert Anderson

    2008-01-01

    Severe forms of dengue virus disease, known as dengue hemorrhagic fever and dengue shock syndrome, result from an aberrant immune response involving antibody-dependent enhance- ment of infection, thrombocytopenia, and a loss of vascular integrity, culminating in hemorrhage, shock, and in some cases, death. Several studies have indicated that dengue virus infection results in the induction of apoptosis of certain cells

  4. Influenza Virus Directly Infects Human Natural Killer Cells and Induces Cell Apoptosis

    Microsoft Academic Search

    Huawei Mao; Wenwei Tu; Gang Qin; H. K. W. Law; S. F. Sia; P.-L. Chan; Y. Liu; K.-T. Lam; J. Zheng; M. Peiris; Y.-L. Lau

    2009-01-01

    Influenza is an acute respiratory viral disease that is transmitted in the first few days of infection. Evasion of host innate immune defenses, including natural killer (NK) cells, is important for the virus's success as a pathogen of humans and other animals. NK cells encounter influenza viruses within the microenvironment of infected cells and are important for host innate immunity

  5. Physiological response of yellow vein mosaic virus-infected bhendi [ Abelmoschus esculentus] leaves

    Microsoft Academic Search

    Parimala Palanisamy; Prabhu Inbaraj Michael; Muthuchelian Krishnaswamy

    2009-01-01

    The effect of okra yellow vein mosaic virus infection on PS II efficiency and thylakoid membrane protein changes in field-grown bhendi (Abelmoschus esculentus) leaves was studied. The degree of virus infection was determined by means of the ratio of variable to maximum chlorophyll fluorescence (Fv\\/Fm). Changes in photosynthetic pigments, soluble proteins, nitrate reductase, photosynthetic activities and thylakoid membrane proteins were

  6. Multiple virus infections occur in individual polygyne and monogyne Solenopsis invicta ants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Concurrent infections of Solenopsis invicta colonies with Solenopsis invicta virus 1 to 3 (SINV-1, SINV-2 and SINV-3) has been reported. However, whether individual ants were capable of supporting multiple virus infections simultaneously was not known, nor whether the social form of the colony (pol...

  7. Swine Influenza A(H3N2) Virus Infection in Immunocompromised Man, Italy, 2014

    PubMed Central

    Piralla, Antonio; Moreno, Ana; Orlandi, Maria Ester; Percivalle, Elena; Chiapponi, Chiara; Vezzoli, Fausto

    2015-01-01

    Because swine influenza virus infection is seldom diagnosed in humans, its frequency might be underestimated. We report a immunocompromised hematologic patient with swine influenza A(H3N2) virus in 2014 in Italy. Local pigs were the source of this human infection. PMID:26079745

  8. Global transcriptional response of pig brain and lung to natural infection by Pseudorabies virus

    Microsoft Academic Search

    JF Yuan; SJ Zhang; O Jafer; RA Furlong; OE Chausiaux; CA Sargent; GH Zhang; NA Affara

    2009-01-01

    BACKGROUND: Pseudorabies virus (PRV) is an alphaherpesviruses whose native host is pig. PRV infection mainly causes signs of central nervous system disorder in young pigs, and respiratory system diseases in the adult. RESULTS: In this report, we have analyzed native host (piglets) gene expression changes in response to acute pseudorabies virus infection of the brain and lung using a printed

  9. Mycophenolic Acid Inhibits Dengue Virus Infection by Preventing Replication of Viral RNA

    Microsoft Academic Search

    Michael S. Diamond; Marcus Zachariah; Eva Harris

    2002-01-01

    Dengue fever is a mosquito-borne viral disease of global importance with no available antiviral therapy. We assessed the ability of mycophenolic acid (MPA), a drug currently used as an immunosuppressive agent, to inhibit dengue virus (DV) antigen expression, RNA replication, and virus production. Pharmacological concentrations of MPA effectively blocked DV infection, decreasing the percentage of infected cells by 99% and

  10. Host and viral factors in the immunopathogenesis of primary hepatitis C virus infection

    E-print Network

    Cai, Long

    REVIEW Host and viral factors in the immunopathogenesis of primary hepatitis C virus infection and Rosemary A Ffrench3 Individuals infected with hepatitis C virus (HCV) have two possible outcomes.1038/sj.icb.7100010; published online 28 November 2006 Keywords: hepatitis C; cellular immunity; innate

  11. Influenza Virus Respiratory Infection and Transmission Following Ocular Inoculation in Ferrets

    PubMed Central

    Belser, Jessica A.; Gustin, Kortney M.; Maines, Taronna R.; Pantin-Jackwood, Mary J.; Katz, Jacqueline M.; Tumpey, Terrence M.

    2012-01-01

    While influenza viruses are a common respiratory pathogen, sporadic reports of conjunctivitis following human infection demonstrates the ability of this virus to cause disease outside of the respiratory tract. The ocular surface represents both a potential site of virus replication and a portal of entry for establishment of a respiratory infection. However, the properties which govern ocular tropism of influenza viruses, the mechanisms of virus spread from ocular to respiratory tissue, and the potential differences in respiratory disease initiated from different exposure routes are poorly understood. Here, we established a ferret model of ocular inoculation to explore the development of virus pathogenicity and transmissibility following influenza virus exposure by the ocular route. We found that multiple subtypes of human and avian influenza viruses mounted a productive virus infection in the upper respiratory tract of ferrets following ocular inoculation, and were additionally detected in ocular tissue during the acute phase of infection. H5N1 viruses maintained their ability for systemic spread and lethal infection following inoculation by the ocular route. Replication-independent deposition of virus inoculum from ocular to respiratory tissue was limited to the nares and upper trachea, unlike traditional intranasal inoculation which results in virus deposition in both upper and lower respiratory tract tissues. Despite high titers of replicating transmissible seasonal viruses in the upper respiratory tract of ferrets inoculated by the ocular route, virus transmissibility to naïve contacts by respiratory droplets was reduced following ocular inoculation. These data improve our understanding of the mechanisms of virus spread following ocular exposure and highlight differences in the establishment of respiratory disease and virus transmissibility following use of different inoculation volumes and routes. PMID:22396651

  12. Blood Feeding Behavior of Vesicular Stomatitis Virus Infected Culicoides Sonorensis (Diptera: Ceratopogonidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Culicoides sonorensis (Diptera: Ceratopogonidae) is the primary vector of Bluetongue virus in North America and a competent vector of Vesicular Stomatitis virus (VSV). Little is known about how viral infection of this midge affects blood feeding behavior and how this might affect virus transmission....

  13. Comparison of Proteins Induced in Cells Infected with Rinderpest and Peste des Petits Ruminants Viruses

    Microsoft Academic Search

    A. Diallo; T. Barrett; P.-C. Lefevre; W. P. Taylor

    1987-01-01

    SUMMARY The two morbilliviruses rinderpest virus (RPV) and peste des petits ruminants virus (PPRV) are closely related and cause severe disease in large and small ruminants, respectively. They show distinct epidemiological patterns and are distinguishable by reciprocal cross-neutralization tests. We have analysed the proteins induced by these viruses in infected cells and have shown that they can be distinguished by

  14. Influenza virus respiratory infection and transmission following ocular inoculation in ferrets

    Technology Transfer Automated Retrieval System (TEKTRAN)

    While influenza viruses are a common respiratory pathogen, sporadic reports of conjunctivitis following human infection demonstrates the ability of this virus to cause disease outside of the respiratory tract. The ocular surface represents both a potential site of virus replication and a portal of e...

  15. Honeybee Sacbrood virus infects adult small hive beetles, Aethina tumida (Coleoptera: Nitidulidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Small Hive Beetle (SHB) is a recently discovered pest that invades honey bee colonies and causes damage to comb, stored honey and pollen. A laboratory experiment was conducted to investigate whether SHB could harbor honey bee virus(es) via feeding on virus infected brood and thereby serving as ...

  16. Complete Genome Sequence of a Hop Latent Virus Infecting Hop Plants

    PubMed Central

    Jo, Yeonhwa; Choi, Hoseong

    2015-01-01

    The hop latent virus is a single-stranded RNA virus that mainly infects hop plants. Here, we report the complete genome sequence of a hop latent virus, which was de novo assembled by RNA sequencing (RNA-seq). Our study indicates that transcriptome data are useful for identifying a complete viral genome. PMID:25908127

  17. Complete genome sequence of a hop latent virus infecting hop plants.

    PubMed

    Jo, Yeonhwa; Choi, Hoseong; Cho, Won Kyong

    2015-01-01

    The hop latent virus is a single-stranded RNA virus that mainly infects hop plants. Here, we report the complete genome sequence of a hop latent virus, which was de novo assembled by RNA sequencing (RNA-seq). Our study indicates that transcriptome data are useful for identifying a complete viral genome. PMID:25908127

  18. Can Preening Contribute to Influenza A Virus Infection in Wild Waterbirds?

    Microsoft Academic Search

    Mauro Delogu; Maria A. De Marco; Livia Di Trani; Elisabetta Raffini; Claudia Cotti; Simona Puzelli; Fabio Ostanello; Robert G. Webster; Antonio Cassone; Isabella Donatelli

    2010-01-01

    Wild aquatic birds in the Orders Anseriformes and Charadriiformes are the main reservoir hosts perpetuating the genetic pool of all influenza A viruses, including pandemic viruses. High viral loads in feces of infected birds permit a fecal-oral route of transmission. Numerous studies have reported the isolation of avian influenza viruses (AIVs) from surface water at aquatic bird habitats. These isolations

  19. Localization of viral proteins in cells infected with bovine viral diarrhoea virus

    Microsoft Academic Search

    B. Grummer; M. Beer; E. Liebler-Tenorio; I. Greiser-Wilke

    Bovine viral diarrhoea virus (BVDV) is a member of the genus Pestivirus within the family Flaviviridae. In this report, protein localization studies were performed to assess the mechanism for the release of mature virus particles from infected cells. Since BVDV is an enveloped virus, budding from either intra- or extracellular membranes is feasible. A prerequisite for the latter mechanism is

  20. Laboratory diagnostic investigations for bovine viral diarrhoea virus infections in cattle

    Microsoft Academic Search

    Torstein Sandvik

    1999-01-01

    There are no pathognomonic clinical signs of infection with bovine viral diarrhoea virus (BVDV) in cattle. Diagnostic investigations therefore rely on laboratory-based detection of the virus, or of virus-induced antigens or antibodies in submitted samples. In unvaccinated dairy herds, serological testing of bulk milk is a convenient method for BVDV prevalence screening. Alternatively, serological testing of young stock may indicate

  1. Immune response of white shrimp, Litopenaeus vannamei, after a concurrent infection with white spot syndrome virus and infectious hypodermal and hematopoietic necrosis virus

    Microsoft Academic Search

    Shinn-Pyng Yeh; Ying-Nan Chen; Shu-Ling Hsieh; Winton Cheng; Chun-Hung Liu

    2009-01-01

    In the present study, we investigated immunological changes in viral-infected white shrimp, Litopenaeus vannamei. White shrimp were infected with white spot syndrome virus (WSSV) or co-infected with WSSV and infectious hypodermal and hematopoietic necrosis virus (IHHNV) as detected by polymerase chain reaction (PCR). The complete (100%) mortality rate of shrimp was caused by viral infection due to immune parameters being

  2. Transmission of respiratory syncytial virus infection within families.

    PubMed

    Heikkinen, Terho; Valkonen, Heikki; Waris, Matti; Ruuskanen, Olli

    2015-01-01

    Background. ?Because the production of an effective respiratory syncytial virus (RSV) vaccine for infants is challenging, vaccination of other family members is one viable alternative to prevent severe RSV illnesses in infants. Methods. ?In a prospective study, we enrolled all family members of children who were hospitalized with RSV infection. Nasal swabs for RSV detection were obtained from all participating family members. Data on respiratory symptoms in the family members prior to and after the child's admission were collected using standardized questionnaires. Results. ?At the time of or within 1 week after the index child's hospitalization, RSV was detected in 40 (77%) of the 52 families and in 60 (47%) of 129 family members. Forty-nine (82%) of RSV detections in the family members were associated with respiratory symptoms. A sibling or a parent was the probable primary case of RSV in 30 (58%) families. Respiratory syncytial virus loads in the nasal swabs were significantly higher (10(7.7)) in index children than in their parents (10(5.1), P < .0001). Conclusions. ?In most cases, the likely source of an infant's RSV infection is an older sibling or a parent. These findings support the strategy of reducing the burden of RSV in infants by vaccination of their family members. PMID:25884006

  3. Transmission of Respiratory Syncytial Virus Infection Within Families

    PubMed Central

    Heikkinen, Terho; Valkonen, Heikki; Waris, Matti; Ruuskanen, Olli

    2015-01-01

    Background.?Because the production of an effective respiratory syncytial virus (RSV) vaccine for infants is challenging, vaccination of other family members is one viable alternative to prevent severe RSV illnesses in infants. Methods.?In a prospective study, we enrolled all family members of children who were hospitalized with RSV infection. Nasal swabs for RSV detection were obtained from all participating family members. Data on respiratory symptoms in the family members prior to and after the child's admission were collected using standardized questionnaires. Results.?At the time of or within 1 week after the index child's hospitalization, RSV was detected in 40 (77%) of the 52 families and in 60 (47%) of 129 family members. Forty-nine (82%) of RSV detections in the family members were associated with respiratory symptoms. A sibling or a parent was the probable primary case of RSV in 30 (58%) families. Respiratory syncytial virus loads in the nasal swabs were significantly higher (107.7) in index children than in their parents (105.1, P < .0001). Conclusions.?In most cases, the likely source of an infant's RSV infection is an older sibling or a parent. These findings support the strategy of reducing the burden of RSV in infants by vaccination of their family members. PMID:25884006

  4. Immune surveillance and response to JC virus infection and PML

    PubMed Central

    Beltrami, Sarah; Gordon, Jennifer

    2014-01-01

    The ubiquitous human polyomavirus JC virus (JCV) is the established etiological agent of the debilitating and often fatal demyelinating disease, progressive multifocal leukoencephalopathy (PML). Most healthy individuals have been infected with JCV and generate an immune response to the virus, yet remain persistently infected at subclinical levels. The onset of PML is rare in the general population, but has become an increasing concern in immunocompromised patients, where reactivation of JCV leads to uncontrolled replication in the CNS. Understanding viral persistence and the normal immune response to JCV provides insight into the circumstances which could lead to viral resurgence. Further, clues on the potential mechanisms of reactivation may be gleaned from the crosstalk among JCV and HIV-1, as well as the impact of monoclonal antibody therapies used for the treatment of autoimmune disorders, including multiple sclerosis, on the development of PML. In this review, we will discuss what is known about viral persistence and the immune response to JCV replication in immunocompromised individuals to elucidate the deficiencies in viral containment that permit viral reactivation and spread. PMID:24297501

  5. Homogeneity of Powassan virus populations in naturally infected Ixodes scapularis

    SciTech Connect

    Brackney, Doug E.; Brown, Ivy K.; Nofchissey, Robert A.; Fitzpatrick, Kelly A. [University of New Mexico School of Medicine, Department of Pathology, Albuquerque, New Mexico (United States); Ebel, Gregory D., E-mail: gebel@salud.unm.ed [University of New Mexico School of Medicine, Department of Pathology, Albuquerque, New Mexico (United States)

    2010-07-05

    Powassan virus (POWV, Flaviviridae: Flavivirus) is the sole North American member of the tick-borne encephalitis complex and consists of two distinct lineages that are maintained in ecologically discrete enzootic transmission cycles. The underlying genetic mechanisms that lead to niche partitioning in arboviruses are poorly understood. Therefore, intra- and interhost genetic diversity was analyzed to determine if POWV exists as a quasispecies in nature and quantify selective pressures within and between hosts. In contrast to previous reports for West Nile virus (WNV), significant intrahost genetic diversity was not observed. However, pN (0.238) and d{sub N}/d{sub S} ratios (0.092) for interhost diversity were similar to those of WNV. Combined, these data suggest that purifying selection and/or population bottlenecks constrain quasispecies diversity within ticks. These same selective and stochastic mechanisms appear to drive minor sequence changes between ticks. Moreover, Powassan virus populations seem not to be structured as quasispecies in naturally infected adult deer ticks.

  6. Virus Infection Suppresses Nicotiana benthamiana Adaptive Phenotypic Plasticity

    PubMed Central

    Bedhomme, Stéphanie; Elena, Santiago F.

    2011-01-01

    Competition and parasitism are two important selective forces that shape life-histories, migration rates and population dynamics. Recently, it has been shown in various pathosystems that parasites can modify intraspecific competition, thus generating an indirect cost of parasitism. Here, we investigated if this phenomenon was present in a plant-potyvirus system using two viruses of different virulence (Tobacco etch virus and Turnip mosaic virus). Moreover, we asked if parasitism interacted with the shade avoidance syndrome, the plant-specific phenotypic plasticity in response to intraspecific competition. Our results indicate that the modification of intraspecific competition by parasitism is not present in the Nicotiana benthamiana – potyvirus system and suggests that this phenomenon is not universal but depends on the peculiarities of each pathosystem. However, whereas the healthy N. benthamiana presented a clear shade avoidance syndrome, this phenotypic plasticity totally disappeared when the plants were infected with TEV and TuMV, very likely resulting in a fitness loss and being another form of indirect cost of parasitism. This result suggests that the suppression or the alteration of adaptive phenotypic plasticity might be a component of virulence that is often overlooked. PMID:21359142

  7. Serosurveillance for Japanese encephalitis virus infection among equines in India

    PubMed Central

    Singha, Harisankar; Singh, Birendra K.; Virmani, Nitin; Khurana, Sandip K.; Singh, Raj K.

    2011-01-01

    The seroprevalence of Japanese encephalitis virus (JEV) among equines was evaluated from January 2006 to December 2009 in 13 different states of India by hemagglutination inhibition (HI) test and virus neutralization test (VNT). Antibodies against JEV were detected in 327 out of 3,286 (10%) equines with a maximum prevalence reported in the state of Manipur (91.7%) followed by Gujarat (18.5%), Madhya Pradesh (14.4%), and Uttar Pradesh (11.6%). Evidence of JEV infection was observed in equines in Indore (Madhya Pradesh) where a 4-fold or higher rise in antibody titer was observed in 21 out of 34 horses in November 2007 to October 2006. In March 2008, seven of these horses had a subsequent 4-fold rise in JEV antibody titers while this titer decreased in nine animals. JEV-positive horse sera had a JEV/WNV (West Nile virus) ratio over 2.0 according to the HI and/or VNT. These results indicated that JEV is endemic among equines in India. PMID:22122900

  8. Homogeneity of Powassan virus populations in naturally infected Ixodes scapularis.

    PubMed

    Brackney, Doug E; Brown, Ivy K; Nofchissey, Robert A; Fitzpatrick, Kelly A; Ebel, Gregory D

    2010-07-01

    Powassan virus (POWV, Flaviviridae: Flavivirus) is the sole North American member of the tick-borne encephalitis complex and consists of two distinct lineages that are maintained in ecologically discrete enzootic transmission cycles. The underlying genetic mechanisms that lead to niche partitioning in arboviruses are poorly understood. Therefore, intra- and interhost genetic diversity was analyzed to determine if POWV exists as a quasispecies in nature and quantify selective pressures within and between hosts. In contrast to previous reports for West Nile virus (WNV), significant intrahost genetic diversity was not observed. However, pN (0.238) and d(N)/d(S) ratios (0.092) for interhost diversity were similar to those of WNV. Combined, these data suggest that purifying selection and/or population bottlenecks constrain quasispecies diversity within ticks. These same selective and stochastic mechanisms appear to drive minor sequence changes between ticks. Moreover, Powassan virus populations seem not to be structured as quasispecies in naturally infected adult deer ticks. PMID:20434750

  9. Cell-specific temporal infection of the brain in a simian immunodeficiency virus model of human immunodeficiency virus encephalitis

    Microsoft Academic Search

    Katherine A. Thompson; John J. Varrone; Tanja Jankovic-Karasoulos; Steven L. Wesselingh; Catriona A. McLean

    2009-01-01

    Increasing evidence supports early brain infection by human immunodeficiency virus (HIV). Definitive temporal studies determining\\u000a when and within which brain cells viral DNA is present are lacking. This study utilized simian immunodeficiency virus (SIV)-infected\\u000a macaques sacrificed at days 10, 21, 56, and 84 post inoculation. Laser-microdissection isolated pure perivascular macrophage,\\u000a parenchymal microglia, and astrocyte populations. Nested polymerase chain reaction (PCR)

  10. Passiflora virus Y, a novel virus infecting Passiflora spp. in Australia and the Indonesian Province of Papua

    Microsoft Academic Search

    J. N. Parry; R. I. Davis; J. E. Thomas

    2004-01-01

    A novel potyvirus is first described from Passiflora foetida from the Indonesian province of Papua, the Torres Strait Islands and Cape York Peninsula, Queensland. Infected plants had\\u000a yellow\\/green mosaic symptoms, sometimes ringspots and chlorotic spots, and were not infected by other known viruses. The virus\\u000a was transmitted by Aphis gossypii in a non-persistent manner. Analysis of the core and 3?

  11. Fetal calf serum inhibits virus genome expression in Madin-Darby canine kidney cells persistently infected with influenza A virus

    Microsoft Academic Search

    Isamu Mori; Li Dong; Beixing Liu; Yoshinobu Kimura

    2008-01-01

    A cell line of Madin-Darby canine kidney (MDCK) cells persistently infected with human influenza A virus has been established\\u000a and designated as MDCK-IVpi cells. Production of progeny virus in MDCK-IVpi cells was suppressed when the cells were incubated\\u000a in the presence of 10% fetal calf serum (FCS). FCS impaired virus mRNA synthesis in MDCK-IVpi cells, which resulted in a scarcity

  12. Contribution of Trafficking Signals in the Cytoplasmic Tail of the Infectious Bronchitis Virus Spike Protein to Virus Infection

    Microsoft Academic Search

    Soonjeon Youn; Ellen W. Collisson; Carolyn E. Machamer

    2005-01-01

    Coronavirus spike (S) proteins are responsible for binding and fusion with target cells and thus play an essential role in virus infection. Recently, we identified a dilysine endoplasmic reticulum (ER) retrieval signal and a tyrosine-based endocytosis signal in the cytoplasmic tail of the S protein of infectious bronchitis virus (IBV). Here, an infectious cDNA clone of IBV was used to

  13. Animal models for Ebola and Marburg virus infections

    PubMed Central

    Nakayama, Eri; Saijo, Masayuki

    2013-01-01

    Ebola and Marburg hemorrhagic fevers (EHF and MHF) are caused by the Filoviridae family, Ebolavirus and Marburgvirus (ebolavirus and marburgvirus), respectively. These severe diseases have high mortality rates in humans. Although EHF and MHF are endemic to sub-Saharan Africa. A novel filovirus, Lloviu virus, which is genetically distinct from ebolavirus and marburgvirus, was recently discovered in Spain where filoviral hemorrhagic fever had never been reported. The virulence of this virus has not been determined. Ebolavirus and marburgvirus are classified as biosafety level-4 (BSL-4) pathogens and Category A agents, for which the US government requires preparedness in case of bioterrorism. Therefore, preventive measures against these viral hemorrhagic fevers should be prepared, not only in disease-endemic regions, but also in disease-free countries. Diagnostics, vaccines, and therapeutics need to be developed, and therefore the establishment of animal models for EHF and MHF is invaluable. Several animal models have been developed for EHF and MHF using non-human primates (NHPs) and rodents, which are crucial to understand pathophysiology and to develop diagnostics, vaccines, and therapeutics. Rhesus and cynomolgus macaques are representative models of filovirus infection as they exhibit remarkably similar symptoms to those observed in humans. However, the NHP models have practical and ethical problems that limit their experimental use. Furthermore, there are no inbred and genetically manipulated strains of NHP. Rodent models such as mouse, guinea pig, and hamster, have also been developed. However, these rodent models require adaptation of the virus to produce lethal disease and do not mirror all symptoms of human filovirus infection. This review article provides an outline of the clinical features of EHF and MHF in animals, including humans, and discusses how the animal models have been developed to study pathophysiology, vaccines, and therapeutics. PMID:24046765

  14. Endophytic fungus decreases plant virus infections in meadow ryegrass (Lolium pratense).

    PubMed

    Lehtonen, Päivi T; Helander, Marjo; Siddiqui, Shahid A; Lehto, Kirsi; Saikkonen, Kari

    2006-12-22

    We studied the effects of fungal endophyte infection of meadow ryegrass (Lolium pratense=Festuca pratensis) on the frequency of the barley yellow dwarf virus (BYDV). The virus is transferred by aphids, which may be deterred by endophyte-origin alkaloids within the plant. In our experiment, we released viruliferous aphid vectors on endophyte-infected and endophyte-free plants in a common garden. The number of aphids and the percentage of BYDV infections were lower in endophyte-infected plants compared to endophyte-free plants, indicating that endophyte infection may protect meadow ryegrass from BYDV infections. PMID:17148304

  15. Characterization of human influenza A (H5N1) virus infection in mice: neuro-, pneumo- and adipotropic infection.

    PubMed

    Nishimura, H; Itamura, S; Iwasaki, T; Kurata, T; Tashiro, M

    2000-10-01

    Mice (ddY strain, 4 weeks old) were infected intranasally with the H5N1 influenza viruses A/Hong Kong/156/97 (HK156) and A/Hong Kong/483/97 (HK483) isolated from humans. HK156 and HK483 required 200 and 5 p.f.u. of virus, respectively, to give a 50% lethal dose to the mice when the volume of inoculum was set at 10 microl. Both viruses caused encephalitis and severe bronchopneumonia in infected mice. The severity of lung lesions caused by the viruses was essentially similar, whereas HK483 caused more extensive lesions in the brain than did HK156. This was supported by the results of virus titration of organ homogenates, which showed that the virus titres in brains of HK483-infected mice were more than 100-fold higher than those of HK156-infected mice, while those in lungs were almost equivalent. Both viruses were detected in homogenates of the heart, liver, spleen and kidney and blood of the infected mice. Virus antigen was detected by immunohistology in the heart and liver, albeit sporadically, but caused no degenerative change in these organs. The antigen was not detected in the thymus, spleen, pancreas, kidney or gastrointestinal tract. In contrast, virus antigen was found frequently in adipose tissues attached to those organs. The adipose tissues showed severe degenerative change and the virus titres in the tissues were high and comparable to those in lungs. Thus, infection of HK156 and HK483 in our mouse model was pneumo-, neuro- and adipotropic, but not pantropic. Furthermore, HK483 showed higher neurotropism than HK156, which may account for its higher lethality. PMID:10993940

  16. White Spot Syndrome Virus Envelope Protein VP28 Is Involved in the Systemic Infection of Shrimp

    Microsoft Academic Search

    Mariëlle C. W van Hulten; Jeroen Witteveldt; Marjolein Snippe; Just M Vlak

    2001-01-01

    White spot syndrome virus (WSSV) is a large DNA virus infecting shrimp and other crustaceans. The virus particles contain at least five major virion proteins, of which three (VP26, VP24, and VP15) are present in the rod-shaped nucleocapsid and two (VP28 and VP19) reside in the envelope. The mode of entry and systemic infection of WSSV in the black tiger

  17. BOVINE LEUKEMIA VIRUS (BLV) SPECIFIC RNA IN INFECTED CELLS T. ASTIER R. MAMOUN B. GUILLEMAIN J.F. DUPLAN

    E-print Network

    Paris-Sud XI, Université de

    BOVINE LEUKEMIA VIRUS (BLV) SPECIFIC RNA IN INFECTED CELLS T. ASTIER R. MAMOUN B. GUILLEMAIN J and Baumgartener, 1976). The so-called bovine leukemia virus (BLV) displays morphological and biochemical and virus Fetal lamb kidney cells chronically infected with bovine leukemia virus (FLK-BLV) were kindly

  18. Global stability of infection-free state and endemic infection state of a modified human immunodeficiency virus infection model.

    PubMed

    Sun, Qilin; Min, Lequan; Kuang, Yang

    2015-06-01

    This study proposes a modified human immunodeficiency virus (HIV) infection differential equation model with a saturated infection rate. This model has an infection-free equilibrium point and an endemic infection equilibrium point. Using Lyapunov functions and LaSalle's invariance principle shows that if the model's basic reproductive number R0 < 1, the infection-free equilibrium point is globally asymptotically stable, otherwise the endemic infection equilibrium point is globally asymptotically stable. It is shown that a forward bifurcation will occur when R0 = 1. The basic reproductive number R0 of the modified model is independent of plasma total CD4(+) T cell counts and thus the modified model is more reasonable than the original model proposed by Buonomo and Vargas-De-León. Based on the clinical data from HIV drug resistance database of Stanford University, using the proposed model simulates the dynamics of two group patients' anti-HIV infection treatments. The simulation results have shown that the first 4 weeks' treatments made the two group patients' R'0 < 1, respectively. After the period, drug resistance made the two group patients' R'0 > 1. The results explain why the two group patients' mean CD4(+) T cell counts raised and mean HIV RNA levels declined in the first period, but contrary in the following weeks. PMID:26021330

  19. Influence of body condition on influenza a virus infection in mallard ducks: Experimental infection data

    USGS Publications Warehouse

    Arsnoe, D.M.; Ip, H.S.; Owen, J.C.

    2011-01-01

    Migrating waterfowl are implicated in the global spread of influenza A viruses (IAVs), and mallards (Anas platyrhynchos) are considered a particularly important IAV reservoir. Prevalence of IAV infection in waterfowl peaks during autumn pre-migration staging and then declines as birds reach wintering areas. Migration is energetically costly and birds often experience declines in body condition that may suppress immune function. We assessed how body condition affects susceptibility to infection, viral shedding and antibody production in wild-caught and captive-bred juvenile mallards challenged with low pathogenic avian influenza virus (LPAIV) H5N9. Wild mallards (n = 30) were separated into three experimental groups; each manipulated through food availability to a different condition level (-20%, -10%, and normal ??5% original body condition), and captive-bred mallards (n = 10) were maintained at normal condition. We found that wild mallards in normal condition were more susceptible to LPAIV infection, shed higher peak viral loads and shed viral RNA more frequently compared to birds in poor condition. Antibody production did not differ according to condition. We found that wild mallards did not differ from captive-bred mallards in viral intensity and duration of infection, but they did exhibit lower antibody titers and greater variation in viral load. Our findings suggest that reduced body condition negatively influences waterfowl host competence to LPAIV infection. This observation is contradictory to the recently proposed condition-dependent hypothesis, according to which birds in reduced condition would be more susceptible to IAV infection. The mechanisms responsible for reducing host competency among birds in poor condition remain unknown. Our research indicates body condition may influence the maintenance and spread of LPAIV by migrating waterfowl. ?? 2011 Arsnoe et al.

  20. Influence of body condition on influenza A virus infection in mallard ducks: Experimental infection data

    USGS Publications Warehouse

    Arsnoe, Dustin M.; Ip, Hon S.; Owen, Jennifer C.

    2011-01-01

    Migrating waterfowl are implicated in the global spread of influenza A viruses (IAVs), and mallards (Anas platyrhynchos) are considered a particularly important IAV reservoir. Prevalence of IAV infection in waterfowl peaks during autumn pre-migration staging and then declines as birds reach wintering areas. Migration is energetically costly and birds often experience declines in body condition that may suppress immune function. We assessed how body condition affects susceptibility to infection, viral shedding and antibody production in wild-caught and captive-bred juvenile mallards challenged with low pathogenic avian influenza virus (LPAIV) H5N9. Wild mallards (n = 30) were separated into three experimental groups; each manipulated through food availability to a different condition level (-20%, -10%, and normal ±5% original body condition), and captive-bred mallards (n = 10) were maintained at normal condition. We found that wild mallards in normal condition were more susceptible to LPAIV infection, shed higher peak viral loads and shed viral RNA more frequently compared to birds in poor condition. Antibody production did not differ according to condition. We found that wild mallards did not differ from captive-bred mallards in viral intensity and duration of infection, but they did exhibit lower antibody titers and greater variation in viral load. Our findings suggest that reduced body condition negatively influences waterfowl host competence to LPAIV infection. This observation is contradictory to the recently proposed condition-dependent hypothesis, according to which birds in reduced condition would be more susceptible to IAV infection. The mechanisms responsible for reducing host competency among birds in poor condition remain unknown. Our research indicates body condition may influence the maintenance and spread of LPAIV by migrating waterfowl.

  1. Giant magnetoimpedance-based microchannel system for quick and parallel genotyping of human papilloma virus type 16/18

    NASA Astrophysics Data System (ADS)

    Yang, Hao; Chen, Lei; Lei, Chong; Zhang, Ju; Li, Ding; Zhou, Zhi-Min; Bao, Chen-Chen; Hu, Heng-Yao; Chen, Xiang; Cui, Feng; Zhang, Shuang-Xi; Zhou, Yong; Cui, Da-Xiang

    2010-07-01

    Quick and parallel genotyping of human papilloma virus (HPV) type 16/18 is carried out by a specially designed giant magnetoimpedance (GMI) based microchannel system. Micropatterned soft magnetic ribbon exhibiting large GMI ratio serves as the biosensor element. HPV genotyping can be determined by the changes in GMI ratio in corresponding detection region after hybridization. The result shows that this system has great potential in future clinical diagnostics and can be easily extended to other biomedical applications based on molecular recognition.

  2. Prevention of vaccinia virus infection in immunodeficient mice by vector-directed IL-2 expression.

    PubMed

    Flexner, C; Hügin, A; Moss, B

    Recombinant vaccinia viruses have been proposed as live vaccines against a variety of infectious diseases, including AIDS (acquired immune deficiency syndrome). Objections have been concerned primarily with side effects of the vaccinia virus vector itself. Recently it has been shown that inactivation of the vaccinia virus thymidine kinase gene or deletion of certain other non-essential genes is associated with a marked reduction in pathogenicity. Nevertheless, the ability of vaccinia virus to produce a progressive infection in immunodeficient individuals remains a most serious problem. Indeed, an incident of this type in a vaccinated man seropositive for human immunodeficiency virus was recently reported. We have used immunodeficient athymic nude mice to establish a model of disseminated vaccinia virus infection, and to demonstrate a novel approach to virus attenuation which involves insertion of a gene encoding human interleukin-2 into the genome of vaccinia virus vectors. PMID:3118219

  3. Prevalence of hepatitis C virus infection among human immunodeficiency virus-1-infected pregnant women in Malawi: The BAN study?

    PubMed Central

    Chasela, Charles S.; Wall, Patrick; Drobeniuc, Jan; King, Caroline C.; Teshale, Eyasu; Hosseinipour, Mina C.; Ellington, Sascha R.; Codd, Mary; Jamieson, Denise J.; Knight, Rodney J.; Fitzpatrick, Patricia; Kourtis, Athena P.; Hoffman, Irving F.; Kayira, Dumbani; Mumba, Noel; Kamwendo, Deborah D.; Martinson, Francis; Powderly, William; van der Horst, Charles; Kamili, Saleem

    2013-01-01

    Background In Sub-Saharan Africa, prevalence estimates of hepatitis C virus (HCV) vary widely. Objectives To assess the prevalence of HCV infection among HIV-infected, pregnant women screened for a large clinical trial in Lilongwe, Malawi. Study design Plasma from 2041 HIV-infected, pregnant women was screened for anti-HCV IgG using a chemiluminiscent immunometric assay (CIA). Specimens with a signal-cut-off ratio ? 1.00 were considered reactive and those with S/Co ratio < 1.00 non-reactive. All CIA-reactive specimens were tested by a recombinant immunoblot assay (RIBA) for anti-HCV and by PCR for HCV RNA. Results Of 2041 specimens, 110 (5.3%, 95% CI: 4.5–6.5%) were CIA reactive. Of the 109 CIA reactive specimens available for RIBA testing, 2 (1.8%) were positive, 28 (25.7%) were indeterminate, and 79 (72.5%) were negative. All CIA-reactive specimens were HCV RNA negative (n = 110). The estimated HCV prevalence based on the screening assay alone was 5.3%; based on supplemental RIBA testing, the status of HCV infection remained indeterminate in 1.4% (28/2040, 95% CI: 0.1–2.0) and the prevalence of confirmed HCV infections was 0.1% (2/2040, 95% CI: 0–0.4%). Conclusions HCV seroprevalence among HIV-infected, pregnant women in Malawi confirmed by supplemental RIBA HCV 3.0 is low (0.1%); CIA showed a high false-reactivity rate in this population. PMID:22658797

  4. Intracellular Cytokine Production by Dengue Virus–specific T cells Correlates with Subclinical Secondary Infection

    PubMed Central

    Hatch, Steven; Endy, Tim P.; Thomas, Stephen; Mathew, Anuja; Potts, James; Pazoles, Pamela; Libraty, Daniel H.; Gibbons, Robert

    2011-01-01

    The pathophysiology of dengue virus infection remains poorly understood, although secondary infection is strongly associated with more severe disease. In the present study, we performed a nested, case-control study comparing the responses of pre-illness peripheral blood mononuclear cells between children who would subsequently develop either subclinical or symptomatic secondary infection 6–11 months after the baseline blood samples were obtained and frozen. We analyzed intracellular cytokine production by CD4+ and CD8+ cells in response to stimulation with dengue antigen. We found higher frequencies of dengue virus–specific TNF?, IFN?-, and IL-2–producing T cells among schoolchildren who subsequently developed subclinical infection, compared with those who developed symptomatic secondary dengue virus infection. Although other studies have correlated immune responses during secondary infection with severity of disease, to our knowledge this is the first study to demonstrate a pre-infection dengue-specific immune response that correlates specifically with a subclinical secondary infection. PMID:21335561

  5. The role of infections and coinfections with newly identified and emerging respiratory viruses in children

    PubMed Central

    2012-01-01

    Acute respiratory infections are a major cause of morbidity in children both in developed and developing countries. A wide range of respiratory viruses, including respiratory syncytial virus (RSV), influenza A and B viruses, parainfluenza viruses (PIVs), adenovirus, rhinovirus (HRV), have repeatedly been detected in acute lower respiratory tract infections (LRTI) in children in the past decades. However, in the last ten years thanks to progress in molecular technologies, newly discovered viruses have been identified including human Metapneumovirus (hMPV), coronaviruses NL63 (HcoV-NL63) and HKU1 (HcoV-HKU1), human Bocavirus (HBoV), new enterovirus (HEV), parechovirus (HpeV) and rhinovirus (HRV) strains, polyomaviruses WU (WUPyV) and KI (KIPyV) and the pandemic H1N1v influenza A virus. These discoveries have heavily modified previous knowledge on respiratory infections mainly highlighting that pediatric population is exposed to a variety of viruses with similar seasonal patterns. In this context establishing a causal link between a newly identified virus and the disease as well as an association between mixed infections and an increase in disease severity can be challenging. This review will present an overview of newly recognized as well as the main emerging respiratory viruses and seek to focus on the their contribution to infection and co-infection in LRTIs in childhood. PMID:23102237

  6. TIM-family Proteins Promote Infection of Multiple Enveloped Viruses through Virion-associated Phosphatidylserine

    PubMed Central

    Jemielity, Stephanie; Wang, Jinyize J.; Chan, Ying Kai; Ahmed, Asim A.; Li, Wenhui; Monahan, Sheena; Bu, Xia; Farzan, Michael; Freeman, Gordon J.; Umetsu, Dale T.; DeKruyff, Rosemarie H.; Choe, Hyeryun

    2013-01-01

    Human T-cell Immunoglobulin and Mucin-domain containing proteins (TIM1, 3, and 4) specifically bind phosphatidylserine (PS). TIM1 has been proposed to serve as a cellular receptor for hepatitis A virus and Ebola virus and as an entry factor for dengue virus. Here we show that TIM1 promotes infection of retroviruses and virus-like particles (VLPs) pseudotyped with a range of viral entry proteins, in particular those from the filovirus, flavivirus, New World arenavirus and alphavirus families. TIM1 also robustly enhanced the infection of replication-competent viruses from the same families, including dengue, Tacaribe, Sindbis and Ross River viruses. All interactions between TIM1 and pseudoviruses or VLPs were PS-mediated, as demonstrated with liposome blocking and TIM1 mutagenesis experiments. In addition, other PS-binding proteins, such as Axl and TIM4, promoted infection similarly to TIM1. Finally, the blocking of PS receptors on macrophages inhibited the entry of Ebola VLPs, suggesting that PS receptors can contribute to infection in physiologically relevant cells. Notably, infection mediated by the entry proteins of Lassa fever virus, influenza A virus and SARS coronavirus was largely unaffected by TIM1 expression. Taken together our data show that TIM1 and related PS-binding proteins promote infection of diverse families of enveloped viruses, and may therefore be useful targets for broad-spectrum antiviral therapies. PMID:23555248

  7. Complete Genome Sequences of Serotype O Foot-and-Mouth Disease Viruses Recovered from Experimental Persistently Infected Cattle

    PubMed Central

    Parthiban, AravindhBabu R.; Mahapatra, Mana

    2015-01-01

    For the first time, the complete genome sequences of the six serotype O foot-and-mouth disease viruses from persistently infected carrier cattle are reported here. No consistent amino acid changes were found in these viruses obtained from persistently infected cattle compared with the complete genome of the parent virus that was used to infect the cattle. PMID:26159521

  8. Complete Genome Sequences of Serotype O Foot-and-Mouth Disease Viruses Recovered from Experimental Persistently Infected Cattle.

    PubMed

    Parthiban, AravindhBabu R; Mahapatra, Mana; Parida, Satya

    2015-01-01

    For the first time, the complete genome sequences of the six serotype O foot-and-mouth disease viruses from persistently infected carrier cattle are reported here. No consistent amino acid changes were found in these viruses obtained from persistently infected cattle compared with the complete genome of the parent virus that was used to infect the cattle. PMID:26159521

  9. Preparation and efficacy of an inactivated subunit vaccine (NFU I BHK) against type 2 Herpes simplex virus infection

    Microsoft Academic Search

    G. R. B. Skinner; D. R. Williams; A. Buchan; J. Whitney; M. Harding; K. Bodfish

    1978-01-01

    A vaccine againstHerpes simplex virus infection was prepared by Nonidet NP 40 and formalin treatment of a type 1, infected-cell extract; virus particles were removed by ultracentrifugation over sucrose. These procedures were not detrimental to the antigenic quality of the vaccine preparation. The vaccine afforded significant protection to experimental type 2 genital herpes virus infection in mice, as adjudged by

  10. Qualitatively different memory CD8+ T cells are generated after lymphocytic choriomeningitis virus and influenza virus infections.

    PubMed

    Mueller, Scott N; Langley, William A; Li, Guimei; García-Sastre, Adolfo; Webby, Richard J; Ahmed, Rafi

    2010-08-15

    Viral infections often induce robust T cell responses that are long-lived and protective. However, it is unclear to what degree systemic versus mucosal infection influences the generation of effector and memory T cells. In this study, we characterized memory CD8(+) T cells generated after respiratory influenza virus infection and compared the phenotypic and functional qualities of these cells with memory T cells generated after systemic infection with lymphocytic choriomeningitis virus (LCMV). Using a recombinant influenza virus expressing the LCMV gp(33-41) epitope and TCR transgenic CD8(+) T cells with a fixed TCR, we compared responses to the same Ag delivered by mucosal or systemic viral infection. Memory cells generated postinfection with either virus showed only a few phenotypic differences. Yet, influenza memory T cells produced lower amounts of effector cytokines upon restimulation and displayed reduced proliferation compared with LCMV-induced memory cells. Strikingly, we observed reduced expansion of spleen- and, in particular, lung-derived influenza memory cells after recall in vivo, which correlated with reduced early protection from secondary infection. These findings suggest that qualitatively different memory CD8(+) T cells are generated after respiratory or systemic virus infections. PMID:20639484

  11. Infection on a chip: a microscale platform for simple and sensitive cell-based virus assays.

    PubMed

    Zhu, Ying; Warrick, Jay W; Haubert, Kathryn; Beebe, David J; Yin, John

    2009-06-01

    The plaque assay has long served as the "gold standard" to measure virus infectivity and test antiviral drugs, but the assay is labor-intensive, lacks sensitivity, uses excessive reagents, and is hard to automate. Recent modification of the assay to exploit flow-enhanced virus spread with quantitative imaging has increased its sensitivity. Here we performed flow-enhanced infection assays in microscale channels, employing passive fluid pumping to inoculate cell monolayers with virus and drive infection spread. Our test of an antiviral drug (5-fluorouracil) against vesicular stomatitis virus infections of BHK cell monolayers yielded a two-fold improvement in sensitivity, relative to the standard assay based on plaque counting. The reduction in scale, simplified fluid handling, image-based quantification, and higher assay sensitivity will enable infection measurements for high-throughput drug screening, sero-conversion testing, and patient-specific diagnosis of viral infections. PMID:19142734

  12. Wild-type and attenuated influenza virus infection of the neonatal rat brain

    Microsoft Academic Search

    Steven A. Rubin; Dong Liu; Mikhail Pletnikov; Jonathan A. McCullers; Zhiping Ye; Roland A. Levandowski; Jan Johannessen; Kathryn M. Carbone

    2004-01-01

    Although influenza virus infection of humans has been associated with a wide spectrum of clinical neurological syndromes,\\u000a the pathogenesis of influenza virus associated central nervous system (CNS) disease in humans remains controversial. To better\\u000a study influenza virus neuropathogenesis, an animal model of influenza-associated CNS disease using human virus isolates without\\u000a adaptation to an animal host was developed. This neonatal rat

  13. Antibody escape kinetics of equine infectious anemia virus infection of horses.

    PubMed

    Schwartz, Elissa J; Nanda, Seema; Mealey, Robert H

    2015-07-01

    Lentivirus escape from neutralizing antibodies (NAbs) is not well understood. In this work, we quantified antibody escape of a lentivirus, using antibody escape data from horses infected with equine infectious anemia virus. We calculated antibody blocking rates of wild-type virus, fitness costs of mutant virus, and growth rates of both viruses. These quantitative kinetic estimates of antibody escape are important for understanding lentiviral control by antibody neutralization and in developing NAb-eliciting vaccine strategies. PMID:25878104

  14. Treatment of hepatitis C virus genotype 3-infection.

    PubMed

    Pol, Stanislas; Vallet-Pichard, Anaïs; Corouge, Marion

    2014-02-01

    The treatment of hepatitis C virus (HCV) infection with pegylated interferon (PEG-IFN) alfa and ribavirin (800 mg daily) (RBV) is the standard of care (SOC) for hepatitis C virus genotype 3-infection leading to a sustained virological response (SVR) in around 65% of patients. A better understanding of the HCV life-cycle has recently resulted in the development of several potential direct-acting antiviral drugs (DAAs) targeting viral proteins (NS3/4A protease, NS5B nucleos(t)idic and non-nucleos(t)idic polymerase, NS5A viral replication complex). First generation protease inhibitors in combination with PEG-IFN/RBV are not efficient in genotype 3-infected patients. The combination of PEG-IFN/RBV with Daclatasvir, a NS5A inhibitor for 12-24 weeks results in a SVR in around 75% while the triple combination of PEG-IFN/RBV with the oral nucleotidic polymerase inhibitor Sofosbuvir (GS-7977) for 12 weeks in naïve patients results in a SVR in more than 95%. The results of the first oral combination of Sofosbuvir and RBV for 12 weeks in genotype 3-infected patients have been rather disappointing with a slightly lower SVR than after 24 weeks of PEG-IFN: around 60%, and only 30% in patients with cirrhosis. Extending treatment from 12 to 16 weeks in treatment experienced patients doubled the SVR rate and an 80% SVR rate is expected by extending treatment to 24 weeks. The best oral combination of new DAAs is probably the combination of Sofosbuvir and a NS5A inhibitor (Daclatasvir, Ledipasvir…) for 24 weeks, which resulted in a 100% SVR rate in a limited series. The use of cyclophilin inhibitors, a host-targeted antiviral, in association with DAAs and/or RBV may also be of interest. The oral combination of new DAAs (dual or triple combination of different antivirals) or of DAAs and host targets such as cyclophilin will probably become the SOC for genotype 3-infected treatment-naïve or -experienced patients. PMID:24373074

  15. Impact of Simian Immunodeficiency Virus Infection on Chimpanzee Population Dynamics

    PubMed Central

    Rudicell, Rebecca S.; Holland Jones, James; Wroblewski, Emily E.; Learn, Gerald H.; Li, Yingying; Robertson, Joel D.; Greengrass, Elizabeth; Grossmann, Falk; Kamenya, Shadrack; Pintea, Lilian; Mjungu, Deus C.; Lonsdorf, Elizabeth V.; Mosser, Anna; Lehman, Clarence; Collins, D. Anthony; Keele, Brandon F.; Goodall, Jane; Hahn, Beatrice H.; Pusey, Anne E.; Wilson, Michael L.

    2010-01-01

    Like human immunodeficiency virus type 1 (HIV-1), simian immunodeficiency virus of chimpanzees (SIVcpz) can cause CD4+ T cell loss and premature death. Here, we used molecular surveillance tools and mathematical modeling to estimate the impact of SIVcpz infection on chimpanzee population dynamics. Habituated (Mitumba and Kasekela) and non-habituated (Kalande) chimpanzees were studied in Gombe National Park, Tanzania. Ape population sizes were determined from demographic records (Mitumba and Kasekela) or individual sightings and genotyping (Kalande), while SIVcpz prevalence rates were monitored using non-invasive methods. Between 2002–2009, the Mitumba and Kasekela communities experienced mean annual growth rates of 1.9% and 2.4%, respectively, while Kalande chimpanzees suffered a significant decline, with a mean growth rate of ?6.5% to ?7.4%, depending on population estimates. A rapid decline in Kalande was first noted in the 1990s and originally attributed to poaching and reduced food sources. However, between 2002–2009, we found a mean SIVcpz prevalence in Kalande of 46.1%, which was almost four times higher than the prevalence in Mitumba (12.7%) and Kasekela (12.1%). To explore whether SIVcpz contributed to the Kalande decline, we used empirically determined SIVcpz transmission probabilities as well as chimpanzee mortality, mating and migration data to model the effect of viral pathogenicity on chimpanzee population growth. Deterministic calculations indicated that a prevalence of greater than 3.4% would result in negative growth and eventual population extinction, even using conservative mortality estimates. However, stochastic models revealed that in representative populations, SIVcpz, and not its host species, frequently went extinct. High SIVcpz transmission probability and excess mortality reduced population persistence, while intercommunity migration often rescued infected communities, even when immigrating females had a chance of being SIVcpz infected. Together, these results suggest that the decline of the Kalande community was caused, at least in part, by high levels of SIVcpz infection. However, population extinction is not an inevitable consequence of SIVcpz infection, but depends on additional variables, such as migration, that promote survival. These findings are consistent with the uneven distribution of SIVcpz throughout central Africa and explain how chimpanzees in Gombe and elsewhere can be at equipoise with this pathogen. PMID:20886099

  16. Isolation and identification of African horsesickness virus from naturally infected dogs in Upper Egypt.

    PubMed Central

    Salama, S A; Dardiri, A H; Awad, F I; Soliman, A M; Amin, M M

    1981-01-01

    African horsesickness virus was isolated from blood samples of street dogs in Aswan Province in Arab Republic of Egypt. Of six isolated "dog strain" African horsesickness viruses, three viruses designated D2, D6 and D10 have been identified as type 9 African horsesickness virus. Methods of isolation, tissue culture adaptation, serological indentification and typing are described. Horses experimentally infected with dog viruses showed febrile reaction and characteristic clinical and pathological signs of African horsesickness. Reisolation of African horsesickness virus type 9 was achieved from the horses during serial passages. PMID:7337871

  17. Viral DNA in horses infected with equine infectious anemia virus.

    PubMed Central

    Rice, N R; Lequarre, A S; Casey, J W; Lahn, S; Stephens, R M; Edwards, J

    1989-01-01

    The amount and distribution of viral DNA were established in a horse acutely infected with the Wyoming strain of equine infectious anemia virus (EIAV). The highest concentration of viral DNA were found in the liver, lymph nodes, bone marrow, and spleen. The kidney, choroid plexus, and peripheral blood leukocytes also contained viral DNA, but at a lower level. It is estimated that at day 16 postinoculation, almost all of the viral DNA was located in the tissues, with the liver alone containing about 90 times more EIAV DNA than the peripheral blood leukocytes did. Assuming a monocyte-macrophage target, each infected cell contained multiple copies of viral DNA (between 6 and 60 copies in liver Kupffer cells). At day 16 postinoculation, most of the EIAV DNA was not integrated into host DNA, but existed in both linear and circular unintegrated forms. In contrast to acute infection, viral DNA was not detectable in tissues from asymptomatic horses with circulating antibody to EIAV. Images PMID:2555550

  18. Rift Valley fever virus infection in golden Syrian hamsters.

    PubMed

    Scharton, Dionna; Van Wettere, Arnaud J; Bailey, Kevin W; Vest, Zachary; Westover, Jonna B; Siddharthan, Venkatraman; Gowen, Brian B

    2015-01-01

    Rift Valley fever virus (RVFV) is a formidable pathogen that causes severe disease and abortion in a variety of livestock species and a range of disease in humans that includes hemorrhagic fever, fulminant hepatitis, encephalitis and blindness. The natural transmission cycle involves mosquito vectors, but exposure can also occur through contact with infected fluids and tissues. The lack of approved antiviral therapies and vaccines for human use underlies the importance of small animal models for proof-of-concept efficacy studies. Several mouse and rat models of RVFV infection have been well characterized and provide useful systems for the study of certain aspects of pathogenesis, as well as antiviral drug and vaccine development. However, certain host-directed therapeutics may not act on mouse or rat pathways. Here, we describe the natural history of disease in golden Syrian hamsters challenged subcutaneously with the pathogenic ZH501 strain of RVFV. Peracute disease resulted in rapid lethality within 2 to 3 days of RVFV challenge. High titer viremia and substantial viral loads were observed in most tissues examined; however, histopathology and immunostaining for RVFV antigen were largely restricted to the liver. Acute hepatocellular necrosis associated with a strong presence of viral antigen in the hepatocytes indicates that fulminant hepatitis is the likely cause of mortality. Further studies to assess the susceptibility and disease progression following respiratory route exposure are warranted. The use of the hamsters to model RVFV infection is suitable for early stage antiviral drug and vaccine development studies. PMID:25607955

  19. Chemokine production predominates in human monocytes infected with Tula virus.

    PubMed

    Cebalo, L; Markoti?, A

    2007-01-01

    Many reports suggest the hypothesis of a complex immune response accompanying hantaviral infections. However, little is known about the immunopathogenesis of nonpathogenic hantaviruses, especially Tula virus (TULV). The aim of our study was to determine the cytokine/chemokine profile induced after the infection of human macrophages with TULV and the role of viral replication in this process. Also, we wanted to establish how the study of TULV is relevant to our previous study of pathogenic hantaviruses. We showed that TULV-infected macrophages produced chemokines (interleukin-8, macrophage chemoattractant protein-1, and macrophage inflammatory protein-1beta) important for recruiting inflammatory cells, whereas no significant changes were recorded in the tested cytokine levels. This property was not influenced by ultraviolet inactivation. There were some differences in chemokine production compared with our previous study with pathogenic hantaviruses. A possible explanation could be a different way of entering host cells found in the pathogenic and nonpathogenic hantaviruses and activation of different intracellular signaling pathways. PMID:17425435

  20. Predicting human West Nile virus infections with mosquito surveillance data.

    PubMed

    Kilpatrick, A Marm; Pape, W John

    2013-09-01

    West Nile virus (WNV) has become established across the Americas with recent heightened activity causing significant human illness. Surveillance methods to predict the risk of human infection are urgently needed to initiate timely preventative measures and justify the expense of implementing costly or unpopular control measures, such as aerial spraying or curfews. We quantified the links between mosquito surveillance data and the spatiotemporal patterns of 3,827 human WNV cases reported over 5 years in Colorado from 2003 to 2007. Mosquito data were strongly predictive of variation in the number of human WNV infections several weeks in advance in both a spatiotemporal statewide analysis and temporal variation within counties with substantial numbers of human cases. We outline several ways to further improve the predictive power of these data and we quantify the loss of information if no funds are available for testing mosquitoes for WNV. These results demonstrate that mosquito surveillance provides a valuable public health tool for assessing the risk of human arboviral infections, allocating limited public health resources, and justifying emergency control actions. PMID:23825164