Science.gov

Sample records for choriomeningitis virus-induced immunopathology

  1. Lymphocytic Choriomeningitis Virus Differentially Affects the Virus-Induced Type I Interferon Response and Mitochondrial Apoptosis Mediated by RIG-I/MAVS

    PubMed Central

    Pythoud, Christelle; Rothenberger, Sylvia; Martínez-Sobrido, Luis; de la Torre, Juan Carlos

    2015-01-01

    ABSTRACT Arenaviruses are important emerging human pathogens maintained by noncytolytic persistent infection in their rodent reservoir hosts. Despite high levels of viral replication, persistently infected carrier hosts show only mildly elevated levels of type I interferon (IFN-I). Accordingly, the arenavirus nucleoprotein (NP) has been identified as a potent IFN-I antagonist capable of blocking activation of interferon regulatory factor 3 (IRF3) via the retinoic acid inducible gene (RIG)-I/mitochondrial antiviral signaling (MAVS) pathway. Another important mechanism of host innate antiviral defense is represented by virus-induced mitochondrial apoptosis via RIG-I/MAVS and IRF3. In the present study, we investigated the ability of the prototypic Old World arenavirus lymphocytic choriomeningitis virus (LCMV) to interfere with RIG-I/MAVS-dependent apoptosis. We found that LCMV does not induce apoptosis at any time during infection. While LCMV efficiently blocked induction of IFN-I via RIG-I/MAVS in response to superinfection with cytopathic RNA viruses, virus-induced mitochondrial apoptosis remained fully active in LCMV-infected cells. Notably, in LCMV-infected cells, RIG-I was dispensable for virus-induced apoptosis via MAVS. Our study reveals that LCMV infection efficiently suppresses induction of IFN-I but does not interfere with the cell's ability to undergo virus-induced mitochondrial apoptosis as a strategy of innate antiviral defense. The RIG-I independence of mitochondrial apoptosis in LCMV-infected cells provides the first evidence that arenaviruses can reshape apoptotic signaling according to their needs. IMPORTANCE Arenaviruses are important emerging human pathogens that are maintained in their rodent hosts by persistent infection. Persistent virus is able to subvert the cellular interferon response, a powerful branch of the innate antiviral defense. Here, we investigated the ability of the prototypic arenavirus lymphocytic choriomeningitis virus (LCMV) to

  2. COPD immunopathology.

    PubMed

    Caramori, Gaetano; Casolari, Paolo; Barczyk, Adam; Durham, Andrew L; Di Stefano, Antonino; Adcock, Ian

    2016-07-01

    The immunopathology of chronic obstructive pulmonary disease (COPD) is based on the innate and adaptive inflammatory immune responses to the chronic inhalation of cigarette smoking. In the last quarter of the century, the analysis of specimens obtained from the lower airways of COPD patients compared with those from a control group of age-matched smokers with normal lung function has provided novel insights on the potential pathogenetic role of the different cells of the innate and acquired immune responses and their pro/anti-inflammatory mediators and intracellular signalling pathways, contributing to a better knowledge of the immunopathology of COPD both during its stable phase and during its exacerbations. This also has provided a scientific rationale for new drugs discovery and targeting to the lower airways. This review summarises and discusses the immunopathology of COPD patients, of different severity, compared with control smokers with normal lung function.

  3. COPD immunopathology.

    PubMed

    Caramori, Gaetano; Casolari, Paolo; Barczyk, Adam; Durham, Andrew L; Di Stefano, Antonino; Adcock, Ian

    2016-07-01

    The immunopathology of chronic obstructive pulmonary disease (COPD) is based on the innate and adaptive inflammatory immune responses to the chronic inhalation of cigarette smoking. In the last quarter of the century, the analysis of specimens obtained from the lower airways of COPD patients compared with those from a control group of age-matched smokers with normal lung function has provided novel insights on the potential pathogenetic role of the different cells of the innate and acquired immune responses and their pro/anti-inflammatory mediators and intracellular signalling pathways, contributing to a better knowledge of the immunopathology of COPD both during its stable phase and during its exacerbations. This also has provided a scientific rationale for new drugs discovery and targeting to the lower airways. This review summarises and discusses the immunopathology of COPD patients, of different severity, compared with control smokers with normal lung function. PMID:27178410

  4. The Lymphocytic Choriomeningitis Virus Matrix Protein PPXY Late Domain Drives the Production of Defective Interfering Particles

    PubMed Central

    Ziegler, Christopher M.; Eisenhauer, Philip; Bruce, Emily A.; Weir, Marion E.; King, Benjamin R.; Klaus, Joseph P.; Krementsov, Dimitry N.; Shirley, David J.; Ballif, Bryan A.; Botten, Jason

    2016-01-01

    Arenaviruses cause severe diseases in humans but establish asymptomatic, lifelong infections in rodent reservoirs. Persistently-infected rodents harbor high levels of defective interfering (DI) particles, which are thought to be important for establishing persistence and mitigating virus-induced cytopathic effect. Little is known about what drives the production of DI particles. We show that neither the PPXY late domain encoded within the lymphocytic choriomeningitis virus (LCMV) matrix protein nor a functional endosomal sorting complex transport (ESCRT) pathway is absolutely required for the generation of standard infectious virus particles. In contrast, DI particle release critically requires the PPXY late domain and is ESCRT-dependent. Additionally, the terminal tyrosine in the PPXY motif is reversibly phosphorylated and our findings indicate that this posttranslational modification may regulate DI particle formation. Thus we have uncovered a new role for the PPXY late domain and a possible mechanism for its regulation. PMID:27010636

  5. Immunopathology of Schistosoma mansoni infection.

    PubMed Central

    Boros, D L

    1989-01-01

    Schistosomiasis mansoni is a chronic helminthic disease that affects about 100 million people in the tropics. The worms have a life span of 5 to 10 years, and they live in the mesenteric veins of the host. Lightly infected individuals are asymptomatic or manifest mild intestinal symptoms. Heavily infected individuals often develop severe morbidity with hepatosplenomegaly, sometimes with a fatal outcome. Morbidity is attributed to the strong humoral and T-cell-mediated host immune responses developed to a variety of parasite antigens and expressed as tissue inflammations. The immunopathology includes dermatitis, immune complex-mediated kidney disease, and, chiefly, T-cell-mediated granuloma formation and fibrosis around disseminated parasite eggs. This review describes the mechanisms of induction and expression of immunopathology in infected persons and experimental animals. Immunoregulatory mechanisms that modulate the enhanced immune responses and may ameliorate excessive morbidity are discussed. PMID:2504481

  6. Experimental models of virus-induced demyelination of the central nervous system.

    PubMed

    Dal Canto, M C; Rabinowitz, S G

    1982-02-01

    One of the arguments in favor of a viral pathogenesis for multiple sclerosis is the existence of several experimental and natural animal models of virus-induced primary demyelination. This review deals comprehensively with such models. Well-known examples of demyelinating viral infections in their natural host are JHM, Theiler, visna, and canine distemper encephalomyelitides. Recent reports of experimental murine infections with pathogens such as vesicular stomatitis, Chandipura, herpes simplex, Venezuelan equine encephalomyelitis, and Semliki Forest viruses are also discussed. The thrust of the review is to include viral models suspected of producing primary demyelination on an immunopathological basis.

  7. Virus-associated immunopathology: animal models and implications for human disease

    PubMed Central

    1972-01-01

    Part 2 of this memorandum describes further mechanisms whereby the interaction of a virus with the host's immune system may lead to tissue damage. Cell-mediated immunity plays a vital role in promoting recovery from virus infections, but under some circumstances tissue damage may be caused by the reaction of immune cells with viral antigens. When mice are infected with lymphocytic choriomeningitis virus neonatally or as adults while receiving immunosuppressive drugs, widespread invasion of cells is seen but there is little overt disease. If, however, normal adults are infected or if immune cells are transfused into tolerant mice, cell injury and death follow. Viruses have long been suspected of contributing to the pathogenesis of autoimmune diseases. Antibodies directed against normal cell constituents have been reported in several virus infections. Viruses may conceivably unmask or release host antigens, alter host antigens and act as “helper determinants”, or perhaps in other ways provoke immune responses against normal body constituents. The immunopathological manifestations caused by viruses may also be influenced by the host's genetic makeup. Certain observations indicate that, in addition to controlling susceptibility to virus infection, genetic factors partly determine the effectiveness of the immune response. The memorandum calls attention to the possible implications of these concepts and findings for clinical research. Some of the diseases of animals and man that serve as models for studies of virus-associated immunopathology are briefly described. PMID:4539416

  8. Platelets prevent IFN-alpha/beta-induced lethal hemorrhage promoting CTL-dependent clearance of lymphocytic choriomeningitis virus.

    PubMed

    Iannacone, Matteo; Sitia, Giovanni; Isogawa, Masanori; Whitmire, Jason K; Marchese, Patrizia; Chisari, Francis V; Ruggeri, Zaverio M; Guidotti, Luca G

    2008-01-15

    We found that mice infected with different isolates of lymphocytic choriomeningitis virus (LCMV) develop a mild hemorrhagic anemia, which becomes severe and eventually lethal in animals depleted of platelets or lacking integrin beta3. Lethal hemorrhagic anemia is mediated by virus-induced IFN-alpha/beta that causes platelet dysfunction, mucocutaneous blood loss and suppression of erythropoiesis. In addition to the life-threatening hemorrhagic anemia, platelet-depleted mice fail to mount an efficient cytotoxic T lymphocyte (CTL) response and cannot clear LCMV. Transfusion of functional platelets into these animals reduces hemorrhage, prevents death and restores CTL-induced viral clearance in a manner partially dependent on CD40 ligand (CD40L). These results indicate that, upon activation, platelets expressing integrin beta3 and CD40L are required for protecting the host against the induction of an IFN-alpha/beta-dependent lethal hemorrhagic diathesis and for clearing LCMV infection through CTLs.

  9. The implications of immunopathology for parasite evolution.

    PubMed

    Best, Alex; Long, Gráinne; White, Andy; Boots, Mike

    2012-08-22

    By definition, parasites harm their hosts, but in many infections much of the pathology is driven by the host immune response rather than through direct damage inflicted by parasites. While these immunopathological effects are often well studied and understood mechanistically in individual disease interactions, there remains relatively little understanding of their broader impact on the evolution of parasites and their hosts. Here, we theoretically investigate the implications of immunopathology, broadly defined as additional mortality associated with the host's immune response, on parasite evolution. In particular, we examine how immunopathology acting on different epidemiological traits (namely transmission, virulence and recovery) affects the evolution of disease severity. When immunopathology is costly to parasites, such that it reduces their fitness, for example by decreasing transmission, there is always selection for increased disease severity. However, we highlight a number of host-parasite interactions where the parasite may benefit from immunopathology, and highlight scenarios that may lead to the evolution of slower growing parasites and potentially reduced disease severity. Importantly, we find that conclusions on disease severity are highly dependent on how severity is measured. Finally, we discuss the effect of treatments used to combat disease symptoms caused by immunopathology.

  10. Cross-priming of CD8+ T cells stimulated by virus-induced type I interferon.

    PubMed

    Le Bon, Agnes; Etchart, Nathalie; Rossmann, Cornelia; Ashton, Miranda; Hou, Sam; Gewert, Dirk; Borrow, Persephone; Tough, David F

    2003-10-01

    CD8+ T cell responses can be generated against antigens that are not expressed directly within antigen-presenting cells (APCs), through a process known as cross-priming. To initiate cross-priming, APCs must both capture extracellular antigen and receive specific activation signals. We have investigated the nature of APC activation signals associated with virus infection that stimulate cross-priming. We show that infection with lymphocytic choriomeningitis virus induces cross-priming by a mechanism dependent on type I interferon (IFN-alpha/beta). Activation of cross-priming by IFN-alpha/beta was independent of CD4+ T cell help or interaction of CD40 and CD40 ligand, and involved direct stimulation of dendritic cells. These data identify expression of IFN-alpha/beta as a mechanism for the induction of cross-priming during virus infections. PMID:14502286

  11. Lymphocytic choriomeningitis virus-associated meningitis, southern Spain.

    PubMed

    Pérez-Ruiz, Mercedes; Navarro-Marí, José-María; Sánchez-Seco, María-Paz; Gegúndez, María-Isabel; Palacios, Gustavo; Savji, Nazir; Lipkin, W Ian; Fedele, Giovanni; de Ory-Manchón, Fernando

    2012-05-01

    Lymphocytic choriomeningitis virus (LCMV) was detected in 2 patients with acute meningitis in southern Spain within a 3-year period. Although the prevalence of LCMV infection was low (2 [1.3%] of 159 meningitis patients), it represents 2.9% of all pathogens detected. LCMV is a noteworthy agent of neurologic illness in immunocompetent persons.

  12. 21 CFR 866.3360 - Lymphocytic choriomeningitis virus serological reagents.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Lymphocytic choriomeningitis virus serological reagents. 866.3360 Section 866.3360 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological...

  13. 21 CFR 866.3360 - Lymphocytic choriomeningitis virus serological reagents.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Lymphocytic choriomeningitis virus serological reagents. 866.3360 Section 866.3360 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological...

  14. 21 CFR 866.3360 - Lymphocytic choriomeningitis virus serological reagents.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Lymphocytic choriomeningitis virus serological reagents. 866.3360 Section 866.3360 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological...

  15. 21 CFR 866.3360 - Lymphocytic choriomeningitis virus serological reagents.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Lymphocytic choriomeningitis virus serological reagents. 866.3360 Section 866.3360 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological...

  16. 21 CFR 866.3360 - Lymphocytic choriomeningitis virus serological reagents.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Lymphocytic choriomeningitis virus serological reagents. 866.3360 Section 866.3360 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological...

  17. Polygenic mutations in the cytotoxicity pathway increase susceptibility to develop HLH immunopathology in mice.

    PubMed

    Sepulveda, Fernando E; Garrigue, Alexandrine; Maschalidi, Sophia; Garfa-Traore, Meriem; Ménasché, Gaël; Fischer, Alain; de Saint Basile, Geneviève

    2016-04-28

    Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening hyperinflammatory disease. Inherited forms of HLH are caused by biallelic mutations in several effectors of granule-dependent lymphocyte-mediated cytotoxicity. A small proportion of patients with a so-called "secondary" form of HLH, which develops in the aftermath of infection, autoimmunity, or cancer, carry a monoallelic mutation in one or more HLH-associated genes. Although this observation suggests that HLH may have a polygenic mode of inheritance, the latter is very difficult to prove in humans. In order to determine whether the accumulation of partial genetic defects in lymphocyte-mediated cytotoxicity can contribute to the development of HLH, we generated mice that were doubly or triply heterozygous for mutations in HLH-associated genes, those coding for perforin, Rab27a, and syntaxin-11. We found that the accumulation of monoallelic mutations did indeed increase the risk of developing HLH immunopathology after lymphocytic choriomeningitis virus infection. In mechanistic terms, the accumulation of heterozygous mutations in the two degranulation genes Rab27a and syntaxin-11, impaired the dynamics and secretion of cytotoxic granules at the immune synapse of T lymphocytes. In addition, the accumulation of heterozygous mutations within the three genes impaired natural killer lymphocyte cytotoxicity in vivo. The genetic defects can be ranked in terms of the severity of the resulting HLH manifestations. Our results form the basis of a polygenic model of the occurrence of secondary HLH. PMID:26864340

  18. Immunopathology of psoriasis and psoriatic arthritis

    PubMed Central

    Veale, D; Ritchlin, C; FitzGerald, O

    2005-01-01

    Psoriatic arthritis (PsA) is characterised by several unique clinical features that differentiate it from rheumatoid arthritis (RA). Attempts to identify immunopathological mechanisms, some shared with psoriasis, that underlie these differences from RA have been most challenging. Recent research studies, however, highlight novel findings in PsA at the molecular, cellular, and tissue levels that form the basis for a new understanding of this relatively common form of inflammatory arthritis. In particular, the availability of new, biological antitumour necrosis factor α therapies have allowed further insight into the immunopathology of psoriasis and PsA. This brief review focuses on immunohistological studies in psoriatic skin, PsA synovium, and bone to demonstrate how these data advance our knowledge of disease pathogenesis. PMID:15708930

  19. The permeability of the blood-brain barrier in mice suffering from fatal lymphocytic choriomeningitis virus infection.

    PubMed

    Marker, O; Nielsen, M H; Diemer, N H

    1984-01-01

    The ultrastructure and the blood-brain-barrier (BBB) permeability were studied in mice suffering from lymphocytic choriomeningitis (LCM). Brains and meninges from mice suffering from LCM virus-induced lymphocytic choriomeningitis were studied by investigating the BBB function and by electron and light microscopy. The cellular exudate in the leptomeninges was located in the subarachnoid space, in arachnoidea and pia, and it was dominated by proliferated pial cells and mononuclear cells, most of which were lymphocytes, while there were only a few neutrophil granulocytes. Many intravascular lymphocytes were seen adhering to as well as penetrating the vessel walls. Many of these lymphocytes were morphologically compatible with T cells. Lymphocytes and larger mononuclear cells were also accumulated in the choroid plexus, and lymphocytes were present in the ventricular system with a tendency to adhere to ependymal epithelial cells. Inspection of the ultrathin sections incubated for horseradish peroxidase (HRP)-activity revealed that the overwhelming part of the peroxidase activity was localized in the extracellular space of the meningeal vessel walls and especially in the abundant intercellular fluid which, like the inflammatory cells, was found in the subarachnoid space in arachnoidea and in pia. In the neuropil, only very small quantities of reaction product were seen intercellularly in the most superficial layers of the cortex. The tight junctions were always intact, but the possibility of a non-demonstrable opening is discussed. Evaluation of the BBB permeability for 2-amino[1-14C]isobutyric acid (AIB) was made by quantitative autoradiography, and it was demonstrated convincingly that AIB concentrations in the subpial and perichorodial tissues were markedly increased in diseased animals as compared to the controls. Our results seem to contradict previous theories on the cause of death resulting from the LCM disease. The findings presented here do not speak in favor

  20. 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.

  1. Lessons learned and concepts formed from study of the pathogenesis of the two negative-strand viruses lymphocytic choriomeningitis and influenza

    PubMed Central

    Oldstone, Michael B. A.

    2013-01-01

    Viruses have unique lifestyles. To describe the pathogenesis and significance of viral infection in terms of host responses, resultant injury, and therapy, we focused on two RNA viruses: lymphocytic choriomeningitis (LCMV) and influenza (Flu). Many of the currently established concepts and consequences about viruses and immunologic tolerance, virus-induced immunosuppression, virus-induced autoimmunity, immune complex disease, and virus–lymphocyte and virus–dendritic cell interactions evolved through studies of LCMV in its natural murine host. Similarly, the mechanisms, aftermath, and treatment of persistent RNA viruses emerged, in large part, from research on LCMV. Analysis of acute influenza virus infections uncovered the prominent direct role that cytokine storm plays in the pathogenesis, morbidity, and mortality from this disease. Cytokine storm of influenza virus infection is initiated via a pulmonary endothelial cell amplification loop involving IFN-producing cells and virus-infected pulmonary epithelial cells. Importantly, the cytokine storm is chemically treatable with specific agonist therapy directed to the sphingosphine 1 phosphate receptor 1, which is located on pulmonary endothelial cells, pointing to the endothelial cells as the gatekeepers of this hyperaggressive host immune response. PMID:23341590

  2. [Incidence and features of neuroinfections induced by lymphocytic choriomeningitis virus].

    PubMed

    Dekonenko, E P; Tkachenko, E A; Umanskiĭ, K G; Ivanov, A P; Rezapkin, G V

    1986-01-01

    A follow-up examination of blood sera and cerebrospinal fluid was carried out in 413 patients with various neuroinfections and related diseases. The modern immunological methods were employed: the complement fixation test, the fluorescent antibody test as well as immuno-enzymic and radioimmunoassays. It was established that 8.5% of serous meningitides and 12% of encephalitides were induced by lymphocytic choriomeningitis (LCM) virus. The verified diseases were subjected to a clinical analysis. It is emphasized that the immunological examination of the cerebrospinal fluid in patients with LCM infection contributes to a more detailed study of the pathogenesis of the disease.

  3. [Novel immunopathological approaches to pulmonary arterial hypertension].

    PubMed

    Perros, Frédéric; Montani, David; Dorfmüller, Peter; Huertas, Alice; Chaumais, Marie-Camille; Cohen-Kaminsky, Sylvia; Humbert, Marc

    2011-04-01

    Inflammation is important for the initiation and the maintenance of vascular remodeling in the most commun animal models of pulmonary hypertension (PH), and its therapeutical targeting blocks PH development in these models. In human, pulmonary vascular lesions of PH are also the source of an intense chemokine production, linked to inflammatory cell recruitment. However, arteritis is uncommon in PH patients. Of note, current PH treatments have immunomodulatory properties. In addition, some studies have shown a correlation between levels of circulating inflammatory mediators and patients' survival. The study of autoimmunity in the pathophysiology of pulmonary arterial hypertension is becoming an area of intense investigation. New immunopathological approaches to PH should allow the development of innovative treatments for this very severe condition. PMID:21536178

  4. [Immunopathological findings in herpes gestationis (author's transl)].

    PubMed

    Scherer, R; Wolff, H H; Braun-Falco, O

    1977-08-12

    Herpes gestationis occurred in a 26-year-old woman during the last weeks of her second pregnancy. Within 8 days of the delivery the disease had progressed to such an extent that systemic treatment became necessary. Whereas pre-delivery treatment had consisted exclusively of local desinfection, and steroid and antibiotic ointments, treatment after delivery also included systemic use of prednisolone. After treatment for 3 weeks the skin changes had disappeared except for minimal pigmentation. Using immunofluorescent microscopy a complement activation in the dermo-epidermal junction and in adjacent clinically healthy skin could be demonstrated: There were massive linear depositions of C3, C1q and C4. In the basal membrane of the epidermis IgM could be demonstrated as an unusual finding. Further immunopathological features were found in the form of an immune complex vasculitis which could be shown during the active phase of the disease.

  5. Microplaque reduction: new assay for neutralizing antibody to lymphocytic choriomeningitis virus.

    PubMed

    Hotchin, J; Kinch, W

    1975-02-01

    A plaque-reduction neutralization test for lymphocytic choriomeningitis virus was developed; microtiter dilution techniques and assay plates were used for the new test. Plaques develop by day 4 after inoculation of serum and lymphocytic chorio-meningitis virus into 5-mm cups containing agarose suspension of baby hamster kidney cells. The method lends itself well to the titration of neutralizing antibody and gives rapid results with great economy of reagents. When tested with one batch of 55 lymphocytic choriomeningitis virus-positive sera, the plaque reduction test was more senstive for detection of specific antibody than either the immunofluorescence or the complement fixation method.

  6. Inhibition of diacylglycerol kinase α restores restimulation-induced cell death and reduces immunopathology in XLP-1.

    PubMed

    Ruffo, Elisa; Malacarne, Valeria; Larsen, Sasha E; Das, Rupali; Patrussi, Laura; Wülfing, Christoph; Biskup, Christoph; Kapnick, Senta M; Verbist, Katherine; Tedrick, Paige; Schwartzberg, Pamela L; Baldari, Cosima T; Rubio, Ignacio; Nichols, Kim E; Snow, Andrew L; Baldanzi, Gianluca; Graziani, Andrea

    2016-01-13

    X-linked lymphoproliferative disease (XLP-1) is an often-fatal primary immunodeficiency associated with the exuberant expansion of activated CD8(+) T cells after Epstein-Barr virus (EBV) infection. XLP-1 is caused by defects in signaling lymphocytic activation molecule (SLAM)-associated protein (SAP), an adaptor protein that modulates T cell receptor (TCR)-induced signaling. SAP-deficient T cells exhibit impaired TCR restimulation-induced cell death (RICD) and diminished TCR-induced inhibition of diacylglycerol kinase α (DGKα), leading to increased diacylglycerol metabolism and decreased signaling through Ras and PKCθ (protein kinase Cθ). We show that down-regulation of DGKα activity in SAP-deficient T cells restores diacylglycerol signaling at the immune synapse and rescues RICD via induction of the proapoptotic proteins NUR77 and NOR1. Pharmacological inhibition of DGKα prevents the excessive CD8(+) T cell expansion and interferon-γ production that occur in SAP-deficient mice after lymphocytic choriomeningitis virus infection without impairing lytic activity. Collectively, these data highlight DGKα as a viable therapeutic target to reverse the life-threatening EBV-associated immunopathology that occurs in XLP-1 patients.

  7. Morphological comparison of Machupo with lymphocytic choriomeningitis virus: basis for a new taxonomic group.

    PubMed

    Murphy, F A; Webb, P A; Johnson, K M; Whitfield, S G

    1969-10-01

    Striking morphologic similarities between Machupo, Tacaribe, and lymphocytic choriomeningitis viruses were found by thin-section electron microscopy. It is proposed that these viruses be brought together into a single taxonomic group.

  8. Pet Rodents and Fatal Lymphocytic Choriomeningitis in Transplant Patients

    PubMed Central

    Pavlin, Boris I.; Albariño, Cesar G.; Comer, James A.; Erickson, Bobbie R.; Oliver, Jennifer B.; Sealy, Tara K.; Vincent, Martin J.; Nichol, Stuart T.; Paddock, Christopher D.; Tumpey, Abbigail J.; Wagoner, Kent D.; Glauer, R. David; Smith, Kathleen A.; Winpisinger, Kim A.; Parsely, Melody S.; Wyrick, Phil; Hannafin, Christopher H.; Bandy, Utpala; Zaki, Sherif; Rollin, Pierre E.; Ksiazek, Thomas G.

    2007-01-01

    In April 2005, 4 transplant recipients became ill after receiving organs infected with lymphocytic choriomeningitis virus (LCMV); 3 subsequently died. All organs came from a donor who had been exposed to a hamster infected with LCMV. The hamster was traced back through a Rhode Island pet store to a distribution center in Ohio, and more LCMV-infected hamsters were discovered in both. Rodents from the Ohio facility and its parent facility in Arkansas were tested for the same LCMV strain as the 1 involved in the transplant-associated deaths. Phylogenetic analysis of virus sequences linked the rodents from the Ohio facility to the Rhode Island pet store, the index hamster, and the transplant recipients. This report details the animal traceback and the supporting laboratory investigations. PMID:17553250

  9. Cell entry of lymphocytic choriomeningitis virus is restricted in myotubes.

    PubMed

    Iwasaki, Masaharu; Urata, Shuzo; Cho, Yoshitake; Ngo, Nhi; de la Torre, Juan C

    2014-06-01

    In mice persistently infected since birth with the prototypic arenavirus lymphocytic choriomeningitis viurs, viral antigen and RNA are readily detected in most organs and cell types but remarkably absent in skeletal muscle. Here we report that mouse C2C12 myoblasts that are readily infected by LCMV, become highly refractory to LCMV infection upon their differentiation into myotubes. Myotube's resistance to LCMV was not due to an intracellular restriction of virus replication but rather an impaired cell entry mediated by the LCMV surface glycoprotein. Our findings provide an explanation for the observation that in LCMV carrier mice myotubes, which are constantly exposed to blood-containing virus, remain free of viral antigen and RNA despite myotubes express high levels of the LCMV receptor alpha dystroglycan and do not pose an intracellular blockade to LCMV multiplication.

  10. [Epidemiological studies on lymphocytic choriomeningitis virus in Japan].

    PubMed

    Morita, C

    1997-04-01

    Human case of lymphocytic choriomeningitis virus (LCMV) infection was not confirmed virologically or serologically in Japan. Existence of the virus in experimental animals was reported in Japan shortly after first isolation of LCMV in U.S.A. In Japan, antibodies against LCMV and the virus were revealed in international sea ports. Using gene analysis, we found LCMV bearing mice would invade into Japan from South Asian countries where Mus musclus castaneus habitats. The antibodies against LCMV were distributed in the territories of M.m. castaneus and M. m. gasuensis in China. This result suggested that gene analysis will be useful tool for tracing the spread of LCMV into certain areas because of polymorphism of the wild hose mouse genes.

  11. A basic overview of multiple sclerosis immunopathology.

    PubMed

    Grigoriadis, N; van Pesch, V

    2015-10-01

    Multiple sclerosis (MS) is a multi-component disease characterized by inflammation, neurodegeneration and failure of central nervous system (CNS) repair mechanisms. Immune dysregulation appears to originate with dendritic cells (antigen-presenting cells) which have an activated phenotype in individuals with MS. Dendritic cells migrate across the blood-brain barrier and induce differentiation of memory T cells into pro-inflammatory T helper 1 (Th1) and Th17 lymphocytes. In turn, induction of macrophage and microglial activation produces other pro-inflammatory cytokines and oxygen and nitric oxide radicals responsible for the demyelination and axonal loss. Other known mediators of MS pathology include CD8+ T cells and memory B cells within the CNS. Some pathological hallmarks of MS are early axonal degeneration and progressive decline of brain volume in patients with clinically isolated syndromes who progress to clinically definite MS. Many new options to interfere with the course of MS have become available in recent years. To limit inflammatory demyelinating processes and delay disease progression, intervention to control inflammation must begin as early as possible. Each distinct type of immunotherapy (immunomodulation, immunosuppression and immune-selective intervention - blockade type, sequestering type or depleting type) corresponds to a specific underlying immunopathology of MS.

  12. The interferon inducer ampligen [poly(I)-poly(C12U)] markedly protects mice against coxsackie B3 virus-induced myocarditis.

    PubMed

    Padalko, Elizaveta; Nuyens, Dieter; De Palma, Armando; Verbeken, Erik; Aerts, Joeri L; De Clercq, Erik; Carmeliet, Peter; Neyts, Johan

    2004-01-01

    Viral replication, as well as an immunopathological component, is assumed to be involved in coxsackie B virus-induced myocarditis. We evaluated the efficacy of the interferon inducer Ampligen on coxsackie B3 virus-induced myocarditis in C3H/HeNHsd mice. The efficacy of Ampligen was compared with that of the interferon inducer poly(inosinic acid)-poly(cytidylic acid) [poly(IC)], alpha interferon 2b (INTRON A), and pegylated alpha interferon 2b (PEG-INTRON-alpha-2b). Ampligen at 20 mg/kg of body weight/day was able to reduce the severity of virus-induced myocarditis, as assessed by morphometric analysis, by 98% (P = 3.0 x 10(-8)). When poly(IC) was administered at 15 mg/kg/day, it reduced the severity of virus-induced myocarditis by 93% (P = 5.6 x 10(-5)). Alpha interferon 2b (1 x 10(5) U/day) and pegylated alpha interferon 2b (5 x 10(5) U/day) were less effective and reduced the severity of virus-induced myocarditis by 66% (P = 0.0009) and 78% (P = 0.0002), respectively. The observed efficacies of Ampligen and poly(IC) were corroborated by the observation that the drugs also markedly reduced the virus titers in the heart, as detected by (i) quantitative real-time reverse transcription-PCR and (ii) titration for infectious virus content. Whereas the electrocardiograms for untreated mice with myocarditis were severely disturbed, the electrocardiographic parameters were normalized in Ampligen- and poly(IC)-treated mice. Even when start of treatment with Ampligen was delayed until day 2 postinfection, a time at which lesions had already appeared in untreated control animals, a marked protective effect on the development of viral myocarditis (as assessed at day 6 postinfection) was still noted.

  13. [Isolation of lymphocytic choriomeningitis virus from human individuals].

    PubMed

    Saavedra, M C; Ambrosio, A M; Riera, L; Levis, S; Sottosanti, J; Sabattini, M

    2001-01-01

    The activity of lymphocytic choriomeningitis virus (LCMv) in Argentina has been previously reported on the basis of serological evidence in rodents and humans and the isolation of only one strain of LCMv from a Mus domesticus captured in the province of Córdoba. The aim of this paper was to register patients with serological diagnosis of LCM, to isolate and to identify human strains of LCMv in Argentina. During the last 19 years, 15 cases were diagnosed as LCM by immunoflourescent indirect assay (IFI) and enzyme-linked immunosorbent assay (ELISA) but when neutralizing assay (NT) was incorporated, eight cases were classified as confirmed, three as probable and four as negative. The geographic distribution of the cases included three provinces: Córdoba, Buenos Aires and Santa Fe. Viral isolation was attempted in five patients classified as confirmed and only two resulted positive (P5226 and P8573). They were identified as LCMv by IFI and NT. The coexistence of LCMv with other arenaviruses, such as Junin and Oliveros viruses, in the same area, raises the probability of interactions between them, which could modify the virulence and/or pathogenicity for humans associated to genomic changes. Future studies of antigenic, genomic and virulence variability of different Argentine strains of LCMv, as well as the systematic search for human infection, will contribute to define the importance of this viral agent in our country and to implement control measures.

  14. Antiviral Effect of Interferon Lambda Against Lymphocytic Choriomeningitis Virus.

    PubMed

    Lukacikova, Lubomira; Oveckova, Ingrid; Betakova, Tatiana; Laposova, Katarina; Polcicova, Katarina; Pastorekova, Silvia; Pastorek, Jaromir; Tomaskova, Jana

    2015-07-01

    Lambda interferons inhibit replication of many viruses, but their role in the inhibition of lymphocytic choriomeningitis virus (LCMV) infection remains unclear. In this study, we examined the antiviral effects of interferon (IFN)-λ2 and IFN-λ3 against LCMV in A549 cells. We found that IFN-λ2 is a more potent inhibitor of LCMV strain MX compared with IFN-λ3, whereas both cytokines have similar antiviral effects against an immunosuppressive variant of LCMV, clone-13. We also demonstrated that the antiviral activity of IFN-λ2 is more effective if it is delivered early rather than after establishment of a long-term infection, suggesting that virus replication is only partially responsive to the cytokine. In agreement with this observation, we showed that LCMV infection significantly reduces IFNLR1 mRNA expression in infected cells. In addition, LCMV infection, to some extent, compromises the signal transduction pathway of IFN-λ2. This implies that IFN receptors as well as their downstream signaling components could be selectively targeted either directly by LCMV proteins or indirectly by cellular factor(s) that are induced or activated by LCMV infection.

  15. Intestinal microbiota modulates gluten-induced immunopathology in humanized mice.

    PubMed

    Galipeau, Heather J; McCarville, Justin L; Huebener, Sina; Litwin, Owen; Meisel, Marlies; Jabri, Bana; Sanz, Yolanda; Murray, Joseph A; Jordana, Manel; Alaedini, Armin; Chirdo, Fernando G; Verdu, Elena F

    2015-11-01

    Celiac disease (CD) is an immune-mediated enteropathy triggered by gluten in genetically susceptible individuals. The recent increase in CD incidence suggests that additional environmental factors, such as intestinal microbiota alterations, are involved in its pathogenesis. However, there is no direct evidence of modulation of gluten-induced immunopathology by the microbiota. We investigated whether specific microbiota compositions influence immune responses to gluten in mice expressing the human DQ8 gene, which confers moderate CD genetic susceptibility. Germ-free mice, clean specific-pathogen-free (SPF) mice colonized with a microbiota devoid of opportunistic pathogens and Proteobacteria, and conventional SPF mice that harbor a complex microbiota that includes opportunistic pathogens were used. Clean SPF mice had attenuated responses to gluten compared to germ-free and conventional SPF mice. Germ-free mice developed increased intraepithelial lymphocytes, markers of intraepithelial lymphocyte cytotoxicity, gliadin-specific antibodies, and a proinflammatory gliadin-specific T-cell response. Antibiotic treatment, leading to Proteobacteria expansion, further enhanced gluten-induced immunopathology in conventional SPF mice. Protection against gluten-induced immunopathology in clean SPF mice was reversed after supplementation with a member of the Proteobacteria phylum, an enteroadherent Escherichia coli isolated from a CD patient. The intestinal microbiota can both positively and negatively modulate gluten-induced immunopathology in mice. In subjects with moderate genetic susceptibility, intestinal microbiota changes may be a factor that increases CD risk.

  16. Intestinal microbiota modulates gluten-induced immunopathology in humanized mice.

    PubMed

    Galipeau, Heather J; McCarville, Justin L; Huebener, Sina; Litwin, Owen; Meisel, Marlies; Jabri, Bana; Sanz, Yolanda; Murray, Joseph A; Jordana, Manel; Alaedini, Armin; Chirdo, Fernando G; Verdu, Elena F

    2015-11-01

    Celiac disease (CD) is an immune-mediated enteropathy triggered by gluten in genetically susceptible individuals. The recent increase in CD incidence suggests that additional environmental factors, such as intestinal microbiota alterations, are involved in its pathogenesis. However, there is no direct evidence of modulation of gluten-induced immunopathology by the microbiota. We investigated whether specific microbiota compositions influence immune responses to gluten in mice expressing the human DQ8 gene, which confers moderate CD genetic susceptibility. Germ-free mice, clean specific-pathogen-free (SPF) mice colonized with a microbiota devoid of opportunistic pathogens and Proteobacteria, and conventional SPF mice that harbor a complex microbiota that includes opportunistic pathogens were used. Clean SPF mice had attenuated responses to gluten compared to germ-free and conventional SPF mice. Germ-free mice developed increased intraepithelial lymphocytes, markers of intraepithelial lymphocyte cytotoxicity, gliadin-specific antibodies, and a proinflammatory gliadin-specific T-cell response. Antibiotic treatment, leading to Proteobacteria expansion, further enhanced gluten-induced immunopathology in conventional SPF mice. Protection against gluten-induced immunopathology in clean SPF mice was reversed after supplementation with a member of the Proteobacteria phylum, an enteroadherent Escherichia coli isolated from a CD patient. The intestinal microbiota can both positively and negatively modulate gluten-induced immunopathology in mice. In subjects with moderate genetic susceptibility, intestinal microbiota changes may be a factor that increases CD risk. PMID:26456581

  17. Virus-induced congenital malformations in cattle.

    PubMed

    Agerholm, Jørgen S; Hewicker-Trautwein, Marion; Peperkamp, Klaas; Windsor, Peter A

    2015-09-24

    Diagnosing the cause of bovine congenital malformations (BCMs) is challenging for bovine veterinary practitioners and laboratory diagnosticians as many known as well as a large number of not-yet reported syndromes exist. Foetal infection with certain viruses, including bovine virus diarrhea virus (BVDV), Schmallenberg virus (SBV), blue tongue virus (BTV), Akabane virus (AKAV), or Aino virus (AV), is associated with a range of congenital malformations. It is tempting for veterinary practitioners to diagnose such infections based only on the morphology of the defective offspring. However, diagnosing a virus as a cause of BCMs usually requires laboratory examination and even in such cases, interpretation of findings may be challenging due to lack of experience regarding genetic defects causing similar lesions, even in cases where virus or congenital antibodies are present. Intrauterine infection of the foetus during the susceptible periods of development, i.e. around gestation days 60-180, by BVDV, SBV, BTV, AKAV and AV may cause malformations in the central nervous system, especially in the brain. Brain lesions typically consist of hydranencephaly, porencephaly, hydrocephalus and cerebellar hypoplasia, which in case of SBV, AKAV and AV infections may be associated by malformation of the axial and appendicular skeleton, e.g. arthrogryposis multiplex congenita. Doming of the calvarium is present in some, but not all, cases. None of these lesions are pathognomonic so diagnosing a viral cause based on gross lesions is uncertain. Several genetic defects share morphology with virus induced congenital malformations, so expert advice should be sought when BCMs are encountered.

  18. Trace-Forward Investigation of Mice in Response to Lymphocytic Choriomeningitis Virus Outbreak

    PubMed Central

    Knust, Barbara; Petersen, Bret; Gabel, Julie; Manning, Craig; Drenzek, Cherie; Ströher, Ute; Rollin, Pierre E.; Thoroughman, Douglas; Nichol, Stuart T.

    2014-01-01

    During follow-up of a 2012 US outbreak of lymphocytic choriomeningitis virus (LCMV), we conducted a trace-forward investigation. LCMV-infected feeder mice originating from a US rodent breeding facility had been distributed to >500 locations in 21 states. All mice from the facility were euthanized, and no additional persons tested positive for LCMV infection. PMID:24447898

  19. Trifluoperazine inhibits Sendai virus-induced hemolysis.

    PubMed

    MacDonald, R I

    1986-04-14

    Sendai virus-induced hemolysis, a manifestation of virus-red cell fusion, is inhibited by exposure of the virus to 50 microM and higher concentrations of trifluoperazine. Trifluoperazine does not disrupt the virus, since trifluoperazine-treated virus with no hemolytic activity sediments slightly faster than untreated virus on sucrose density gradients and contains viral proteins in proportions characteristic of untreated virus. Trifluoperazine affects the fusion protein to a greater extent than the hemagglutinin, since trifluoperazine-treated virus with no hemolytic activity is as active or nearly as active in agglutinating red cells. The partition coefficient of trifluoperazine between the virus membrane and buffer is lower at 4 degrees C than, but the same at 37 degrees C, as that between the red cell membrane and buffer. Nevertheless, virus-independent red cell lysis and inactivation of virus-mediated hemolysis occur when the red cell and viral membranes, respectively, contain similar concentrations of trifluoperazine. Furthermore, 13-28% more trifluoperazine is necessary to achieve either effect at 4 degrees C or at 25 degrees C than at 37 degrees C. Changes in the surface activity of trifluoperazine do not explain these results, insofar as the critical micellar concentration of (0.75 mM) and maximal reduction in surface tension by (40 dyn/cm) trifluoperazine are the same at 25 degrees C and 37 degrees C. The fluorescence of viral tryptophan decreases by approx. 25% when viral hemolysis is inactivated by trifluoperazine, by trypsin treatment or by heating at 100 degrees C for 5 min.

  20. Virus-induced congenital malformations in cattle.

    PubMed

    Agerholm, Jørgen S; Hewicker-Trautwein, Marion; Peperkamp, Klaas; Windsor, Peter A

    2015-01-01

    Diagnosing the cause of bovine congenital malformations (BCMs) is challenging for bovine veterinary practitioners and laboratory diagnosticians as many known as well as a large number of not-yet reported syndromes exist. Foetal infection with certain viruses, including bovine virus diarrhea virus (BVDV), Schmallenberg virus (SBV), blue tongue virus (BTV), Akabane virus (AKAV), or Aino virus (AV), is associated with a range of congenital malformations. It is tempting for veterinary practitioners to diagnose such infections based only on the morphology of the defective offspring. However, diagnosing a virus as a cause of BCMs usually requires laboratory examination and even in such cases, interpretation of findings may be challenging due to lack of experience regarding genetic defects causing similar lesions, even in cases where virus or congenital antibodies are present. Intrauterine infection of the foetus during the susceptible periods of development, i.e. around gestation days 60-180, by BVDV, SBV, BTV, AKAV and AV may cause malformations in the central nervous system, especially in the brain. Brain lesions typically consist of hydranencephaly, porencephaly, hydrocephalus and cerebellar hypoplasia, which in case of SBV, AKAV and AV infections may be associated by malformation of the axial and appendicular skeleton, e.g. arthrogryposis multiplex congenita. Doming of the calvarium is present in some, but not all, cases. None of these lesions are pathognomonic so diagnosing a viral cause based on gross lesions is uncertain. Several genetic defects share morphology with virus induced congenital malformations, so expert advice should be sought when BCMs are encountered. PMID:26399846

  1. [Titration of antibodies to lymphocytic choriomeningitis virus by the method of indirect immunofluorescence].

    PubMed

    Sheĭnbergas, M M; Vorob'eva, Z N

    1975-01-01

    Antibody to lymphocytic choriomeningitis virus was determined by the indirect immunofluorescence test in immune sera of guinea pigs and immune ascitic fluids of rats and mice. Among 135 patients with aseptic meningitis serum antibody was found in 11 patients in titers of 1 : 64 to 1 : 128 and in the cerebro-spinal fluid of these patients in considerably lower titers. By the indirect immunofluorescence test antibody in maximum titers was found early after the appearance of meningeal symptoms.

  2. Molecular epidemiology of respiratory viruses in virus-induced asthma

    PubMed Central

    Ishioka, Taisei; Noda, Masahiro; Kozawa, Kunihisa; Kimura, Hirokazu

    2013-01-01

    Acute respiratory illness (ARI) due to various viruses is not only the most common cause of upper respiratory infection in humans but is also a major cause of morbidity and mortality, leading to diseases such as bronchiolitis and pneumonia. Previous studies have shown that respiratory syncytial virus (RSV), human rhinovirus (HRV), human metapneumovirus (HMPV), human parainfluenza virus (HPIV), and human enterovirus infections may be associated with virus-induced asthma. For example, it has been suggested that HRV infection is detected in the acute exacerbation of asthma and infection is prolonged. Thus it is believed that the main etiological cause of asthma is ARI viruses. Furthermore, the number of asthma patients in most industrial countries has greatly increased, resulting in a morbidity rate of around 10-15% of the population. However, the relationships between viral infections, host immune response, and host factors in the pathophysiology of asthma remain unclear. To gain a better understanding of the epidemiology of virus-induced asthma, it is important to assess both the characteristics of the viruses and the host defense mechanisms. Molecular epidemiology enables us to understand the pathogenesis of microorganisms by identifying specific pathways, molecules, and genes that influence the risk of developing a disease. However, the epidemiology of various respiratory viruses associated with virus-induced asthma is not fully understood. Therefore, in this article, we review molecular epidemiological studies of RSV, HRV, HPIV, and HMPV infection associated with virus-induced asthma. PMID:24062735

  3. Experimental Models of Microvascular Immunopathology: The Example of Cerebral Malaria

    PubMed Central

    El-Assaad, Fatima; Combes, Valery; Grau, Georges ER

    2015-01-01

    Human cerebral malaria is a severe and often lethal complication of Plasmodium falciparum infection. Complex host and parasite interactions should the precise mechanisms involved in the onset of this neuropathology. Adhesion of parasitised red blood cells and host cells to endothelial cells lead to profound endothelial alterations that trigger immunopathological changes, varying degrees of brain oedema and can compromise cerebral blood flow, cause cranial nerve dysfunction and hypoxia. Study of the cerebral pathology in human patients is limited to clinical and genetic field studies in endemic areas, thus cerebral malaria (CM) research relies heavily on experimental models. The availability of malaria models allows study from the inoculation of Plasmodium to the onset of disease and permit invasive experiments. Here, we discuss some aspects of our current understanding of CM, the experimental models available and some important recent findings extrapolated from these models. PMID:26430675

  4. Isolation and characterization of a new strain of lymphocytic choriomeningitis virus from rodents in southwestern France.

    PubMed

    Yama, Ines N; Cazaux, Benoite; Britton-Davidian, Janice; Moureau, Grégory; Thirion, Laurence; de Lamballerie, Xavier; Dobigny, Gauthier; Charrel, Rémi N

    2012-10-01

    A total of 821 tissue samples from rodents trapped during field campaigns organized in Europe and Africa were screened for the presence of arenaviruses by molecular methods and cell culture inoculation when feasible. Two Mus musculus domesticus trapped in the southwestern part of France were infected with a potentially new strain of lymphocytic choriomeningitis virus (LCMV), here referred to as LCMV strain HP65-2009, which was isolated and genetically characterized by whole genome sequencing. Genetic and phylogenetic analyses comparing LCMV HP65-2009 with 26 other LCMV strains showed that it represents a novel highly-divergent strain within the group of Mus musculus-associated LCMV.

  5. Identification of lymphocytic choriomeningitis mammarenavirus in house mouse (Mus musculus, Rodentia) in French Guiana.

    PubMed

    Lavergne, Anne; de Thoisy, Benoît; Tirera, Sourakhata; Donato, Damien; Bouchier, Christiane; Catzeflis, François; Lacoste, Vincent

    2016-01-01

    Thirty-seven house mice (Mus musculus, Rodentia) caught in different localities in French Guiana were screened to investigate the presence of lymphocytic choriomeningitis mammarenavirus (LCMV). Two animals trapped in an urban area were found positive, hosting a new strain of LCMV, that we tentatively named LCMV "Comou". The complete sequence was determined using a metagenomic approach. Phylogenetic analyses revealed that this strain is related to genetic lineage I composed of strains inducing severe disease in humans. These results emphasize the need for active surveillance in humans as well as in house mouse populations, which is a rather common rodent in French Guianese cities and settlements.

  6. SHP-1-dependent macrophage differentiation exacerbates virus-induced myositis

    PubMed Central

    Watson, Neva B.; Schneider, Karin M.; Massa, Paul T.

    2015-01-01

    Virus-induced myositis is an emerging global affliction that remains poorly characterized with few treatment options. Moreover, muscle-tropic viruses often spread to the central nervous system causing dramatically increased morbidity. Therefore, there is an urgent need to explore genetic factors involved in this class of human disease. This report investigates critical innate immune pathways affecting murine virus-induced myositis. Of particular importance, the key immune regulator SHP-1, which normally suppresses macrophage-mediated inflammation, is a major factor in promoting clinical disease in muscle. We show that Theiler’s murine encephalomyelitis virus infection of skeletal myofibers induces inflammation and subsequent dystrophic calcification with loss of ambulation in wild type mice. Surprisingly, although similar extensive myofiber infection and inflammation is observed in SHP-1-deficient (SHP-1−/−) mice, these mice neither accumulate dead calcified myofibers nor lose ambulation. Macrophages were the predominant effector cells infiltrating WT and SHP-1−/− muscle, and an increased infiltration of immature monocytes/macrophages correlated with absence of clinical disease in SHP-1−/− mice, while mature M1-like macrophages corresponded with increased myofiber degeneration in WT mice. Furthermore, blocking SHP-1 activation in WT macrophages blocked virus-induced myofiber degeneration, and pharmacologic ablation of macrophages inhibited muscle calcification in TMEV-infected WT animals. These data suggest that following TMEV infection of muscle, SHP-1 promotes M1 differentiation of infiltrating macrophages, and these inflammatory macrophages are likely involved in damaging muscle fibers. These findings reveal a pathological role for SHP-1 in promoting inflammatory macrophage differentiation and myofiber damage in virus-infected skeletal muscle, thus identifying SHP-1 and M1 macrophages as essential mediators of virus-induced myopathy. PMID:25681345

  7. Influenza virus induces apoptosis via BAD-mediated mitochondrial dysregulation.

    PubMed

    Tran, Anh T; Cortens, John P; Du, Qiujiang; Wilkins, John A; Coombs, Kevin M

    2013-01-01

    Influenza virus infection results in host cell death and major tissue damage. Specific components of the apoptotic pathway, a signaling cascade that ultimately leads to cell death, are implicated in promoting influenza virus replication. BAD is a cell death regulator that constitutes a critical control point in the intrinsic apoptosis pathway, which occurs through the dysregulation of mitochondrial outer membrane permeabilization and the subsequent activation of downstream apoptogenic factors. Here we report a novel proviral role for the proapoptotic protein BAD in influenza virus replication. We show that influenza virus-induced cytopathology and cell death are considerably inhibited in BAD knockdown cells and that both virus replication and viral protein production are dramatically reduced, which suggests that virus-induced apoptosis is BAD dependent. Our data showed that influenza viruses induced phosphorylation of BAD at residues S112 and S136 in a temporal manner. Viral infection also induced BAD cleavage, late in the viral life cycle, to a truncated form that is reportedly a more potent inducer of apoptosis. We further demonstrate that knockdown of BAD resulted in reduced cytochrome c release and suppression of the intrinsic apoptotic pathway during influenza virus replication, as seen by an inhibition of caspases-3, caspase-7, and procyclic acidic repetitive protein (PARP) cleavage. Our data indicate that influenza viruses carefully modulate the activation of the apoptotic pathway that is dependent on the regulatory function of BAD and that failure of apoptosis activation resulted in unproductive viral replication.

  8. The Role of Myeloid Cell Activation and Arginine Metabolism in the Pathogenesis of Virus-Induced Diseases

    PubMed Central

    Burrack, Kristina S.; Morrison, Thomas E.

    2014-01-01

    When an antiviral immune response is generated, a balance must be reached between two opposing pathways: the production of proinflammatory and cytotoxic effectors that drive a robust antiviral immune response to control the infection and regulators that function to limit or blunt an excessive immune response to minimize immune-mediated pathology and repair tissue damage. Myeloid cells, including monocytes and macrophages, play an important role in this balance, particularly through the activities of the arginine-hydrolyzing enzymes nitric oxide synthase 2 (Nos2; iNOS) and arginase 1 (Arg1). Nitric oxide (NO) production by iNOS is an important proinflammatory mediator, whereas Arg1-expressing macrophages contribute to the resolution of inflammation and wound repair. In the context of viral infections, expression of these enzymes can result in a variety of outcomes for the host. NO has direct antiviral properties against some viruses, whereas during other virus infections NO can mediate immunopathology and/or inhibit the antiviral immune response to promote chronic infection. Arg1 activity not only has important wound healing functions but can also inhibit the antiviral immune response during some viral infections. Thus, depending on the specific virus and the tissue(s) involved, the activity of both of these arginine-hydrolyzing enzymes can either exacerbate or limit the severity of virus-induced disease. In this review, we will discuss a variety of viral infections, including HIV, SARS-CoV, LCMV, HCV, RSV, and others, where myeloid cells influence the control and clearance of the virus from the host, as well as the severity and resolution of tissue damage, via the activities of iNOS and/or Arg1. Clearly, monocyte/macrophage activation and arginine metabolism will continue to be important areas of investigation in the context of viral infections. PMID:25250029

  9. Epidemiology of virus-induced asthma exacerbations: with special reference to the role of human rhinovirus

    PubMed Central

    Saraya, Takeshi; Kurai, Daisuke; Ishii, Haruyuki; Ito, Anri; Sasaki, Yoshiko; Niwa, Shoichi; Kiyota, Naoko; Tsukagoshi, Hiroyuki; Kozawa, Kunihisa; Goto, Hajime; Takizawa, Hajime

    2014-01-01

    Viral respiratory infections may be associated with the virus-induced asthma in adults as well as children. Particularly, human rhinovirus is strongly suggested a major candidate for the associations of the virus-induced asthma. Thus, in this review, we reviewed and focused on the epidemiology, pathophysiology, and treatment of virus-induced asthma with special reference on human rhinovirus. Furthermore, we added our preliminary data regarding the clinical and virological findings in the present review. PMID:24904541

  10. Virus-induced gene silencing using begomovirus satellite molecules.

    PubMed

    Zhou, Xueping; Huang, Changjun

    2012-01-01

    Virus-induced gene silencing (VIGS) has emerged as a powerful method for studying gene function. VIGS is induced by infecting a plant with a plant virus that has had its genome modified to include a sequence from the host gene to be silenced. DNAβ and DNA1 are satellite and single-stranded DNA molecules associated with begomoviruses (family Geminiviridae). We converted DNAβ and DNA1 into gene-silencing vectors. The VIGS vectors can induce silencing efficiently in many solanaceous plants. Here, we describe procedures for the use of these two gene-silencing vectors for VIGS in different hosts. PMID:22678572

  11. Wolbachia and its implications for the immunopathology of filariasis.

    PubMed

    Genchi, Claudio; Kramer, Laura H; Sassera, Davide; Bandi, Claudio

    2012-03-01

    Filarial infections are characterized by immunopathological phenomena, that are responsible for the onset of often dramatic pathological outcomes, such as blindness (Onchocerca volvulus) and elephantiasis (W. bancrofti). In addition, the long-term survival (as long as 10 years) of these parasites in otherwise immunocompetent hosts indicates that these nematodes are capable of manipulating the host immune response. The ground-breaking discovery of the bacterial endosymbiont Wolbachia, which resides in most filarial nematodes causing disease, has led to increasing interest in the role it may play in immuno-modulation, pro-inflammatory pathology and other aspects of filarial infection. Indeed, Wolbachia has been shown to be responsible for exacerbating inflammation (as in river blindness), while at the same time blocking efficient elimination of parasites through the host immune response (Onchocerca ochengi). While studies aimed at identifying Wolbachia as a potential target for anti-filarial therapy are at the forefront of current research, understanding its role in the immunology of filarial infection is a fascinating field that has yet to uncover many secrets. PMID:22214329

  12. Immunopathological Features of Canine Myocarditis Associated with Leishmania infantum Infection.

    PubMed

    Costagliola, Alessandro; Piegari, Giuseppe; Otrocka-Domagala, Iwona; Ciccarelli, Davide; Iovane, Valentina; Oliva, Gaetano; Russo, Valeria; Rinaldi, Laura; Papparella, Serenella; Paciello, Orlando

    2016-01-01

    Myocarditis associated with infectious diseases may occur in dogs, including those caused by the protozoa Neospora caninum, Trypanosoma cruzi, Babesia canis, and Hepatozoon canis. However, although cardiac disease due to Leishmania infection has also been documented, the immunopathological features of myocarditis have not been reported so far. The aim of this study was to examine the types of cellular infiltrates and expression of MHC classes I and II in myocardial samples obtained at necropsy from 15 dogs with an established intravitam diagnosis of visceral leishmaniasis. Pathological features of myocardium were characterized by hyaline degeneration of cardiomyocytes, necrosis, and infiltration of mononuclear inflammatory cells consisting of lymphocytes and macrophages, sometimes with perivascular pattern; fibrosis was also present in various degrees. Immunophenotyping of inflammatory cells was performed by immunohistochemistry on cryostat sections obtained from the heart of the infected dogs. The predominant leukocyte population was CD8+ with a fewer number of CD4+ cells. Many cardiomyocytes expressed MHC classes I and II on the sarcolemma. Leishmania amastigote forms were not detected within macrophages or any other cell of the examined samples. Our study provided evidence that myocarditis in canine visceral leishmaniasis might be related to immunological alterations associated with Leishmania infection. PMID:27413751

  13. The immuno-pathological conversions of canine demodicosis.

    PubMed

    Singh, Shanker K; Dimri, Umesh

    2014-06-16

    Canine demodicosis is a common but exigent noncontagious parasitic dermatosis caused by overpopulation of the host-specific follicular mites of various Demodex species. Receptivity of dogs to demodicosis and progression of the clinical disease are influenced by numerous factors including; genetic defect, alteration of skin's structure and biochemistry, immunological disorders, hormonal status, breed, age, nutritional status, oxidative stress, length of hair coat, stage of oestrus cycle, parturition, endoparasitism and debilitating diseases. Of these, the immune status is thought to be the most significant. Thus, in the present review we intended to edify the immuno-pathological conversions of canine demodicosis. Generalized demodicosis requires a cutaneous environment that is ecologically and immunologically favorable for extreme colonization of demodectic mites. Demodex canis mites can down regulate the CD4+ T cells; possibly by an increased rate of apoptosis or immunological exhaustion of CD4+ T cells. An increased apoptosis of peripheral leukocytes confers progression of the clinical manifestations. Mites induced elevation of TGF-β and inhibition of TNF-α mRNA expression might be a key factor for revealing the difference in the mechanism of onset between localized and generalized demodicosis. Moreover, an elevated serum level of IL-10 could be accountable for the recurrence as well as occurrence of demodicosis in dogs. Over production of reactive oxygen species can corroborate immunological discrepancies in dogs with demodicosis.

  14. Immunopathological Features of Canine Myocarditis Associated with Leishmania infantum Infection

    PubMed Central

    Piegari, Giuseppe; Otrocka-Domagala, Iwona; Ciccarelli, Davide; Iovane, Valentina; Oliva, Gaetano; Russo, Valeria; Rinaldi, Laura; Papparella, Serenella; Paciello, Orlando

    2016-01-01

    Myocarditis associated with infectious diseases may occur in dogs, including those caused by the protozoa Neospora caninum, Trypanosoma cruzi, Babesia canis, and Hepatozoon canis. However, although cardiac disease due to Leishmania infection has also been documented, the immunopathological features of myocarditis have not been reported so far. The aim of this study was to examine the types of cellular infiltrates and expression of MHC classes I and II in myocardial samples obtained at necropsy from 15 dogs with an established intravitam diagnosis of visceral leishmaniasis. Pathological features of myocardium were characterized by hyaline degeneration of cardiomyocytes, necrosis, and infiltration of mononuclear inflammatory cells consisting of lymphocytes and macrophages, sometimes with perivascular pattern; fibrosis was also present in various degrees. Immunophenotyping of inflammatory cells was performed by immunohistochemistry on cryostat sections obtained from the heart of the infected dogs. The predominant leukocyte population was CD8+ with a fewer number of CD4+ cells. Many cardiomyocytes expressed MHC classes I and II on the sarcolemma. Leishmania amastigote forms were not detected within macrophages or any other cell of the examined samples. Our study provided evidence that myocarditis in canine visceral leishmaniasis might be related to immunological alterations associated with Leishmania infection. PMID:27413751

  15. An Ultrasensitive Mechanism Regulates Influenza Virus-Induced Inflammation

    PubMed Central

    Shoemaker, Jason E.; Fukuyama, Satoshi; Eisfeld, Amie J.; Zhao, Dongming; Kawakami, Eiryo; Sakabe, Saori; Maemura, Tadashi; Gorai, Takeo; Katsura, Hiroaki; Muramoto, Yukiko; Watanabe, Shinji; Watanabe, Tokiko; Fuji, Ken; Matsuoka, Yukiko; Kitano, Hiroaki; Kawaoka, Yoshihiro

    2015-01-01

    Influenza viruses present major challenges to public health, evident by the 2009 influenza pandemic. Highly pathogenic influenza virus infections generally coincide with early, high levels of inflammatory cytokines that some studies have suggested may be regulated in a strain-dependent manner. However, a comprehensive characterization of the complex dynamics of the inflammatory response induced by virulent influenza strains is lacking. Here, we applied gene co-expression and nonlinear regression analysis to time-course, microarray data developed from influenza-infected mouse lung to create mathematical models of the host inflammatory response. We found that the dynamics of inflammation-associated gene expression are regulated by an ultrasensitive-like mechanism in which low levels of virus induce minimal gene expression but expression is strongly induced once a threshold virus titer is exceeded. Cytokine assays confirmed that the production of several key inflammatory cytokines, such as interleukin 6 and monocyte chemotactic protein 1, exhibit ultrasensitive behavior. A systematic exploration of the pathways regulating the inflammatory-associated gene response suggests that the molecular origins of this ultrasensitive response mechanism lie within the branch of the Toll-like receptor pathway that regulates STAT1 phosphorylation. This study provides the first evidence of an ultrasensitive mechanism regulating influenza virus-induced inflammation in whole lungs and provides insight into how different virus strains can induce distinct temporal inflammation response profiles. The approach developed here should facilitate the construction of gene regulatory models of other infectious diseases. PMID:26046528

  16. Lymphocytic choriomeningitis virus in employees and mice at multipremises feeder-rodent operation, United States, 2012.

    PubMed

    Knust, Barbara; Ströher, Ute; Edison, Laura; Albariño, César G; Lovejoy, Jodi; Armeanu, Emilian; House, Jennifer; Cory, Denise; Horton, Clayton; Fowler, Kathy L; Austin, Jessica; Poe, John; Humbaugh, Kraig E; Guerrero, Lisa; Campbell, Shelley; Gibbons, Aridth; Reed, Zachary; Cannon, Deborah; Manning, Craig; Petersen, Brett; Metcalf, Douglas; Marsh, Bret; Nichol, Stuart T; Rollin, Pierre E

    2014-02-01

    We investigated the extent of lymphocytic choriomeningitis virus (LCMV) infection in employees and rodents at 3 commercial breeding facilities. Of 97 employees tested, 31 (32%) had IgM and/or IgG to LCMV, and aseptic meningitis was diagnosed in 4 employees. Of 1,820 rodents tested in 1 facility, 382 (21%) mice (Mus musculus) had detectable IgG, and 13 (0.7%) were positive by reverse transcription PCR; LCMV was isolated from 8. Rats (Rattus norvegicus) were not found to be infected. S-segment RNA sequence was similar to strains previously isolated in North America. Contact by wild mice with colony mice was the likely source for LCMV, and shipments of infected mice among facilities spread the infection. The breeding colonies were depopulated to prevent further human infections. Future outbreaks can be prevented with monitoring and management, and employees should be made aware of LCMV risks and prevention.

  17. Lymphocytic Choriomeningitis Virus in Employees and Mice at Multipremises Feeder-Rodent Operation, United States, 2012

    PubMed Central

    Ströher, Ute; Edison, Laura; Albariño, César G.; Lovejoy, Jodi; Armeanu, Emilian; House, Jennifer; Cory, Denise; Horton, Clayton; Fowler, Kathy L.; Austin, Jessica; Poe, John; Humbaugh, Kraig E.; Guerrero, Lisa; Campbell, Shelley; Gibbons, Aridth; Reed, Zachary; Cannon, Deborah; Manning, Craig; Petersen, Brett; Metcalf, Douglas; Marsh, Bret; Nichol, Stuart T.; Rollin, Pierre E.

    2014-01-01

    We investigated the extent of lymphocytic choriomeningitis virus (LCMV) infection in employees and rodents at 3 commercial breeding facilities. Of 97 employees tested, 31 (32%) had IgM and/or IgG to LCMV, and aseptic meningitis was diagnosed in 4 employees. Of 1,820 rodents tested in 1 facility, 382 (21%) mice (Mus musculus) had detectable IgG, and 13 (0.7%) were positive by reverse transcription PCR; LCMV was isolated from 8. Rats (Rattus norvegicus) were not found to be infected. S-segment RNA sequence was similar to strains previously isolated in North America. Contact by wild mice with colony mice was the likely source for LCMV, and shipments of infected mice among facilities spread the infection. The breeding colonies were depopulated to prevent further human infections. Future outbreaks can be prevented with monitoring and management, and employees should be made aware of LCMV risks and prevention. PMID:24447605

  18. Naturally occurring Parelaphostrongylus tenuis-associated choriomeningitis in a guinea pig with neurologic signs.

    PubMed

    Southard, T; Bender, H; Wade, S E; Grunenwald, C; Gerhold, R W

    2013-05-01

    An adult male guinea pig (Cavia porcellus) with a 1-month history of hind limb paresis, torticollis, and seizures was euthanized and submitted for necropsy. Gross examination was unremarkable, but histologic examination revealed multifocal eosinophilic and lymphoplasmacytic choriomeningitis and cross sections of nematode parasites within the leptomeninges of the midbrain and diencephalon. Morphologic features of the nematode were consistent with a metastrongyle, and the parasite was identified as Parelaphostrongylus tenuis by polymerase chain reaction testing and nucleotide sequencing. Further questioning of the owner revealed that the guinea pig was fed grass from a yard often grazed by white-tailed deer (Odocoileus virginianus). To the authors' knowledge, this is the first report of a naturally occurring P. tenuis infection in a guinea pig.

  19. Quantification of lymphocytic choriomeningitis virus with an immunological focus assay in 24- or 96-well plates.

    PubMed

    Battegay, M; Cooper, S; Althage, A; Bänziger, J; Hengartner, H; Zinkernagel, R M

    1991-06-01

    Titers of lymphocytic choriomeningitis virus (LCMV) were determined on adherent fibroblast cell lines in 24- or 96-well plates. After absorption of virus by cells and 48 h incubation under a methylcellulose overlay, cell monolayers were fixed with 4% formaldehyde in phosphate-buffered saline, permeabilized by incubation in 0.5% Triton X-100 in balanced salt solution and then stained with a monoclonal rat anti-LCMV and a peroxidase-labeled second stage antibody. The sensitivity of the assay is within a factor of 2-4 of conventional plaquing methods. The method also detects poorly or non-plaquing LCMV isolates, and therefore drastically reduces the need for titration of LCMV in mice. The method is quicker (2-3 days), as compared to conventional methods (4-6 days) and less expensive in terms of work and materials.

  20. Serological relationship of the Tacaribe complex of viruses to lymphocytic choriomeningitis virus.

    PubMed

    Rowe, W P; Pugh, W E; Webb, P A; Peters, C J

    1970-03-01

    By means of the indirect fluorescent-antibody test, cross serological reactivity was demonstrated between lymphocytic choriomeningitis (LCM) virus and the viruses of the Tacaribe complex. Antisera to all members of the Tacaribe complex reacted with LCM virus; LCM antisera gave significant staining of Amapari virus, but minimal or inconsistent reactions with Tacaribe virus, and no reaction with two other viruses of the Tacaribe complex. A low level cross-reaction was observed in complement fixation tests of Machupo and Pichinde antisera against LCM antigen. Immunization with Tacaribe and Amapari viruses did not protect mice against challenge with LCM virus. Because of the identical appearance of the virions, the sharing of antigens, and the many biological similarities between LCM and the Tacaribe complex viruses, it is proposed that they be considered as constituting a new taxonomic group of viruses.

  1. Lymphocytic choriomeningitis virus in employees and mice at multipremises feeder-rodent operation, United States, 2012.

    PubMed

    Knust, Barbara; Ströher, Ute; Edison, Laura; Albariño, César G; Lovejoy, Jodi; Armeanu, Emilian; House, Jennifer; Cory, Denise; Horton, Clayton; Fowler, Kathy L; Austin, Jessica; Poe, John; Humbaugh, Kraig E; Guerrero, Lisa; Campbell, Shelley; Gibbons, Aridth; Reed, Zachary; Cannon, Deborah; Manning, Craig; Petersen, Brett; Metcalf, Douglas; Marsh, Bret; Nichol, Stuart T; Rollin, Pierre E

    2014-02-01

    We investigated the extent of lymphocytic choriomeningitis virus (LCMV) infection in employees and rodents at 3 commercial breeding facilities. Of 97 employees tested, 31 (32%) had IgM and/or IgG to LCMV, and aseptic meningitis was diagnosed in 4 employees. Of 1,820 rodents tested in 1 facility, 382 (21%) mice (Mus musculus) had detectable IgG, and 13 (0.7%) were positive by reverse transcription PCR; LCMV was isolated from 8. Rats (Rattus norvegicus) were not found to be infected. S-segment RNA sequence was similar to strains previously isolated in North America. Contact by wild mice with colony mice was the likely source for LCMV, and shipments of infected mice among facilities spread the infection. The breeding colonies were depopulated to prevent further human infections. Future outbreaks can be prevented with monitoring and management, and employees should be made aware of LCMV risks and prevention. PMID:24447605

  2. Lymphocytic choriomeningitis virus infection in fetal, newborn, and young adult Syrian hamsters (Mesocricetus auratus).

    PubMed Central

    Parker, J C; Igel, H J; Reynolds, R K; Lewis, A M; Rowe, W P

    1976-01-01

    The pathogenesis of lymphocytic choriomeningitis virus infection in fetal, newborn, and young adult hamsters was studied. Infected newborn hamsters initially developed a persistent viremia and viruria with titers often in excess of 10(4.0) mean infectious doses/0.03 ml of blood or urine. After week 12 two different patterns of infection became evident. Approximately one-half of the hamsters eventually cleared the infection, whereas the others developed a chronic progressive and ultimalely fatal disease characterized by continuous high-titered viremia and viruria and high titers of virus in their tissues. Complement-fixing antibody and, to a lesser degree, virus-neutralizing antibody coexisted with the viremia. Hamsters with persistently high levels of viremia and viruria developed chronic glomerulonephritis and widespread vasculitis, whereas hamsters that cleared their infections did not develop these lesions. Litters of hamsters born to viremic mothers were invariably infected. Litter sizes were small and breeding effectiveness was reduce; however, vertical, congenital infection was successfully passed through three generations. The course of infection in the congenitally infected hamsters was similar to that in newborn infected hamsters, with all animals producing complement-fixing antibody, some animals being capable of clearing the viremia and remaining healthy, and other animals having persistent viremia and fatal disease. Inoculated young adult hamsters did not become diseased, developed viremia and viruria which persisted up to 3 and 6 months, respectively, and developed complement-fixing antibody by 10 days after infection. The prolonged urinary excretion of large amounts of lymphocytic choriomeningitis virus by asymptomatic, chronically infected hamsters is an important public health consideration when dealing with potential human infection. Images PMID:1270139

  3. Quantity and Quality of Inhaled Dose Predicts Immunopathology in Tuberculosis

    PubMed Central

    Fennelly, Kevin P.; Jones-López, Edward C.

    2015-01-01

    Experimental animal models of tuberculosis (TB) have convincingly demonstrated that inhaled dose predicts immunopathology and survival. In contrast, the importance of inhaled dose has generally not been appreciated in TB epidemiology, clinical science, or the practice of TB control. Infectiousness of TB patients has traditionally been assessed using microscopy for acid-fast bacilli in the sputum, which should be considered only a risk factor. We have recently demonstrated that cough aerosol cultures from index cases with pulmonary TB are the best predictors of new infection among household contacts. We suggest that cough aerosols of M. tuberculosis are the best surrogates of inhaled dose, and we hypothesize that the quantity of cough aerosols is associated with TB infection versus disease. Although several factors affect the quality of infectious aerosols, we propose that the particle size distribution of cough aerosols is an important predictor of primary upper airway disease and cervical lymphadenitis and of immune responses in exposed hosts. We hypothesize that large droplet aerosols (>5 μ) containing M. tuberculosis deposit in the upper airway and can induce immune responses without establishing infection. We suggest that this may partially explain the large proportion of humans who never develop TB disease in spite of having immunological evidence of M. tuberculosis infection (e.g., positive tuberculin skin test or interferon gamma release assay). If these hypotheses are proven true, they would alter the current paradigm of latent TB infection and reactivation, further demonstrating the need for better biomarkers or methods of assessing TB infection and the risk of developing disease. PMID:26175730

  4. Clinical, immunopathologic, and therapeutic considerations of inflammatory myopathies.

    PubMed

    Dalakas, M C

    1992-10-01

    The inflammatory myopathies encompass a group of heterogenous muscle diseases which have in common an acquired myopathy with histological signs of endomysial inflammation. We present evidence based on recently emerged clinical, histologic, immunopathologic, demographic and therapeutic observations that these myopathies comprise three major and distinct groups: polymyositis (PM), dermatomyositis (DM), and inclusion-body myositis (IBM). Immune-mediated mechanisms characteristic for each group appear to play a primary role in the pathogenesis of these diseases. In DM there is an intramuscular microangiopathy mediated by the C5b-9 membranolytic attack complex, leading sequentially to loss of capillaries, muscle ischemia, muscle fiber necrosis and perifascicular atrophy. In contrast, in PM and IBM the muscle fiber injury is initiated by sensitized CD8+ cytotoxic T cells that recognize MHC-I restricted muscle antigens, leading to phagocytosis and fiber necrosis. Among the viruses implicated in the cause of inflammatory myopathies, only the retroviruses, HIV, HTLV-1 and simian retroviruses, have been convincingly associated with PM. Retroviruses, therefore, appear to be the leading group of viruses capable of triggering these diseases. The treatment of inflammatory myopathies has been largely empirical. A detailed therapeutic plan based on our experience with a large number of patients is presented. Patients with bona fide PM or DM respond to steroids to some degree and for some period of time. In contrast, patients with IBM do not respond to any therapy and the disease should be suspected when a patient with presumed PM has failed treatment. Methotrexate and cyclophosphamide are disappointing. Cyclosporine and Azathioprine are commonly used but they are of uncertain benefit. Plasmapheresis is ineffective. High-dose intravenous immunoglobulin is a promising new therapeutic modality.

  5. Virus -induced plankton dynamic and sea spray oragnics

    NASA Astrophysics Data System (ADS)

    Facchini, Maria Cristina; O'Dowd, Colin; Danovaro, Roberto

    2015-04-01

    The processes that link phytoplankton biomass and productivity to the organic matter enrichment in sea spray aerosol are far from being understood and modelling predictions remain highly uncertain at the moment. While some studies have asserted that the enrichment of OM in sea spray aerosol is independent on marine productivity, others, on the contrary, have shown significant correlation with phytoplankton biomass and productivity (Chl-a retrieved by satellites). Here we show that viral infection of prokaryotes and phytoplankton, by inducing the release of large quantities of surfaceactive organic matter (cell debris, exudates and other colloidal gel-forming material), in part due to cell lysis and plankton defence reactions, and in part from rapid virus multiplication, triggers the organic matter (OM) enrichment in the sea-spray particles during blooms. We show that virus-induced bloom dynamics may explain the contrasting results present in literature on the link between primary productivity and OM sea spray enrichment.

  6. Virus-induced secondary bacterial infection: a concise review

    PubMed Central

    Hendaus, Mohamed A; Jomha, Fatima A; Alhammadi, Ahmed H

    2015-01-01

    Respiratory diseases are a very common source of morbidity and mortality among children. Health care providers often face a dilemma when encountering a febrile infant or child with respiratory tract infection. The reason expressed by many clinicians is the trouble to confirm whether the fever is caused by a virus or a bacterium. The aim of this review is to update the current evidence on the virus-induced bacterial infection. We present several clinical as well in vitro studies that support the correlation between virus and secondary bacterial infections. In addition, we discuss the pathophysiology and prevention modes of the virus–bacterium coexistence. A search of the PubMed and MEDLINE databases was carried out for published articles covering bacterial infections associated with respiratory viruses. This review should provide clinicians with a comprehensive idea of the range of bacterial and viral coinfections or secondary infections that could present with viral respiratory illness. PMID:26345407

  7. Immunobiology of cytotoxic T-cell escape mutants of lymphocytic choriomeningitis virus.

    PubMed Central

    Moskophidis, D; Zinkernagel, R M

    1995-01-01

    Infection with virus variants exhibiting changes in the peptide sequences defining immunodominant determinants that abolish recognition by antiviral cytotoxic T cells (CTL) presents a considerable challenge to the antiviral T-cell immune system and may enable some viruses to persist in hosts. The potential importance of such variants with respect to mechanisms of viral persistence and disease pathogenesis was assessed by infecting adult mice with variants of lymphocytic choriomeningitis virus (LCMV) strain WE. These variants were selected in vivo or in vitro for resistance to lysis by CD8+ H-2b-restricted antiviral CTL. The majority of anti-LCMV CTL in infected H-2b mice recognize epitopes defined by residues 32 to 42 and 275 to 289 (epitopes 32-42 and 275-289) of the LCMV glycoprotein or 397 to 407 of the viral nucleoprotein. The 8.7 variant exhibits a change in the epitope 32-42 (Val-35-->Leu), and variant CL1.2 exhibits a change in the epitope 275-289 (Asn-280-->Asp) of the wild-type LCMV-WE. The double-mutated 8.7-B23 variant had the variation of 8.7 and an additional change located in the epitope 275-289 (Asn-280-->Ser). The 8.7 variant peptide with unchanged anchor positions bound efficiently to H-2Db and H-2Kb molecules but induced only a very weak CTL response. CTL epitope 275-289 of CL1.2 and 8.7-B23 altered at predicted anchor residues were unable to bind Db molecules and were also not recognized by antiviral CTL. Infection of C57BL/6 mice (H-2b) with the variants exhibiting mutations of one of the CTL epitopes, i.e., 8.7 or CL1.2, induced CTL responses specific for the unmutated epitopes comparable with those induced by infection with WE, and these responses were sufficient to eliminate virus from the host. In contrast, infection with the double-mutated variant 8.7-B23 induced CTL activity that was reduced by a factor of about 50-fold compared with wild-type LCMV. Consequently, high doses (10(7) PFU intravenously) of this virus were eliminated slowly and

  8. Immunopathology and Cytokine Responses in Commercial Broiler Chickens with Gangrenous Dermatitis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Gangrene dermatitis (GD) is an emerging disease of increasing economic importance in poultry that results from infection by Clostridium septicum and C. perfringens (CP) type A. Lack of a reproducible disease model has been a major obstacle in understanding the immunopathology of GD. To gain better u...

  9. TPL-2 Regulates Macrophage Lipid Metabolism and M2 Differentiation to Control TH2-Mediated Immunopathology

    PubMed Central

    Entwistle, Lewis J.; Khoury, Hania; Papoutsopoulou, Stamatia; Mahmood, Radma; Mansour, Nuha R.; Ching-Cheng Huang, Stanley; Pearce, Edward J.; Pedro S. de Carvalho, Luiz; Ley, Steven C.

    2016-01-01

    Persistent TH2 cytokine responses following chronic helminth infections can often lead to the development of tissue pathology and fibrotic scarring. Despite a good understanding of the cellular mechanisms involved in fibrogenesis, there are very few therapeutic options available, highlighting a significant medical need and gap in our understanding of the molecular mechanisms of TH2-mediated immunopathology. In this study, we found that the Map3 kinase, TPL-2 (Map3k8; Cot) regulated TH2-mediated intestinal, hepatic and pulmonary immunopathology following Schistosoma mansoni infection or S. mansoni egg injection. Elevated inflammation, TH2 cell responses and exacerbated fibrosis in Map3k8–/–mice was observed in mice with myeloid cell-specific (LysM) deletion of Map3k8, but not CD4 cell-specific deletion of Map3k8, indicating that TPL-2 regulated myeloid cell function to limit TH2-mediated immunopathology. Transcriptional and metabolic assays of Map3k8–/–M2 macrophages identified that TPL-2 was required for lipolysis, M2 macrophage activation and the expression of a variety of genes involved in immuno-regulatory and pro-fibrotic pathways. Taken together this study identified that TPL-2 regulated TH2-mediated inflammation by supporting lipolysis and M2 macrophage activation, preventing TH2 cell expansion and downstream immunopathology and fibrosis. PMID:27487182

  10. TPL-2 Regulates Macrophage Lipid Metabolism and M2 Differentiation to Control TH2-Mediated Immunopathology.

    PubMed

    Kannan, Yashaswini; Perez-Lloret, Jimena; Li, Yanda; Entwistle, Lewis J; Khoury, Hania; Papoutsopoulou, Stamatia; Mahmood, Radma; Mansour, Nuha R; Ching-Cheng Huang, Stanley; Pearce, Edward J; Pedro S de Carvalho, Luiz; Ley, Steven C; Wilson, Mark S

    2016-08-01

    Persistent TH2 cytokine responses following chronic helminth infections can often lead to the development of tissue pathology and fibrotic scarring. Despite a good understanding of the cellular mechanisms involved in fibrogenesis, there are very few therapeutic options available, highlighting a significant medical need and gap in our understanding of the molecular mechanisms of TH2-mediated immunopathology. In this study, we found that the Map3 kinase, TPL-2 (Map3k8; Cot) regulated TH2-mediated intestinal, hepatic and pulmonary immunopathology following Schistosoma mansoni infection or S. mansoni egg injection. Elevated inflammation, TH2 cell responses and exacerbated fibrosis in Map3k8-/-mice was observed in mice with myeloid cell-specific (LysM) deletion of Map3k8, but not CD4 cell-specific deletion of Map3k8, indicating that TPL-2 regulated myeloid cell function to limit TH2-mediated immunopathology. Transcriptional and metabolic assays of Map3k8-/-M2 macrophages identified that TPL-2 was required for lipolysis, M2 macrophage activation and the expression of a variety of genes involved in immuno-regulatory and pro-fibrotic pathways. Taken together this study identified that TPL-2 regulated TH2-mediated inflammation by supporting lipolysis and M2 macrophage activation, preventing TH2 cell expansion and downstream immunopathology and fibrosis. PMID:27487182

  11. First outbreak of callitrichid hepatitis in Germany: genetic characterization of the causative lymphocytic choriomeningitis virus strains.

    PubMed

    Asper, M; Hofmann, P; Osmann, C; Funk, J; Metzger, C; Bruns, M; Kaup, F J; Schmitz, H; Günther, S

    2001-06-01

    Callitrichid hepatitis (CH) is a highly fatal, rodent-borne zoonosis of New World primates (family Callitrichidae) caused by lymphocytic choriomeningitis virus (LCMV). It is unclear whether virulence in Callitrichidae is associated with specific genetic or phylogenetic markers of the virus as only a partial S RNA sequence of a single CH-associated isolate is known. In a period of 10 months, three pygmy marmosets (Cebuella pygmaea) and one Goeldi's monkey (Callimico goeldii) died from CH in a German zoo. LCMV was most likely transmitted by wild mice. Infection was associated with characteristic histopathological lesions in liver, brain, and lymphoid tissue. Virus sequences from all callitrichids and a captured mouse were > or =99.2% identical. LCMV strains from a pygmy marmoset and the Goeldi's monkey were isolated in cell culture and the 3.4-kb S RNA was completely sequenced. Both strains differed considerably in their genetic and phylogenetic characteristics from known LCMV strains, including the previously described CH-associated strain. These data show that CH is widespread and can be caused by distantly related LCMV strains.

  12. Lymphocytic choriomeningitis virus (LCMV) infection of macaques: a model for Lassa fever

    PubMed Central

    Zapata, Juan C.; Pauza, C. David; Djavani, Mahmoud M.; Rodas, Juan D.; Moshkoff, Dmitry; Bryant, Joseph; Ateh, Eugene; Garcia, Cybele; Lukashevich, Igor S.; Salvato, Maria S.

    2011-01-01

    Arenaviruses such as Lassa fever virus (LASV) and lymphocytic choriomeningitis virus (LCMV) are benign in their natural reservoir hosts, and can occasionally cause severe viral hemorrhagic fever (VHF) in non-human primates and in human beings. LCMV is considerably more benign for human beings than Lassa virus, however certain strains, like the LCMV-WE strain, can cause severe disease when the virus is delivered as a high-dose inoculum. Here we describe a rhesus macaque model for Lassa fever that employs a virulent strain of LCMV. Since LASV must be studied within Biosafety Level-4 (BSL-4) facilities, the LCMV-infected macaque model has the advantage that it can be used at BSL-3. LCMV-induced disease is rarely as severe as other VHF, but it is similar in cases where vascular leakage leads to lethal systemic failure. The LCMV-infected macaque has been valuable for describing the course of disease with differing viral strains, doses and routes of infection. By monitoring system-wide changes in physiology and gene expression in a controlled experimental setting, it is possible to identify events that are pathognomonic for developing VHF and potential treatment targets. PMID:21820469

  13. Replication of lymphocytic choriomeningitis virus is restricted in terminally differentiated neurons.

    PubMed Central

    de la Torre, J C; Rall, G; Oldstone, C; Sanna, P P; Borrow, P; Oldstone, M B

    1993-01-01

    We have investigated the replication of lymphocytic choriomeningitis virus (LCMV) before and after the nerve growth factor (NGF)-induced transdifferentiation of PC12 cells from the chromaffin to the neuron-like phenotype. Untreated and NGF-treated cells were equally susceptible to LCMV infection; however, the viral yield was found to be 1,000-fold lower in NGF-differentiated PC12 cells. The reduced viral yield correlated with restricted LCMV replication and transcription within the infected cell, which was not caused by the lack of cell proliferation in the NGF-treated cells but rather was related to the induction or changes in expression levels of specific gene product(s) associated with the cell commitment to a neuronal phenotype. The return to the chromaffin phenotype after withdrawal of NGF restored normal LCMV yields as well as levels of viral replication and transcription. The finding of reduced viral replication in terminally differentiated neuronal cells has important implications for understanding the mechanism by which neurotropic viruses, such as LCMV, are able to establish a long-term persistent infection in the central nervous system in the absence of severe pathological changes. Images PMID:8230458

  14. Resistance of lymphocytic choriomeningitis virus to alpha/beta interferon and to gamma interferon.

    PubMed Central

    Moskophidis, D; Battegay, M; Bruendler, M A; Laine, E; Gresser, I; Zinkernagel, R M

    1994-01-01

    The susceptibility to alpha/beta interferon (IFN-alpha/beta) or to gamma interferon (IFN-gamma) of various lymphocytic choriomeningitis virus (LCMV) strains was evaluated in C57BL/6 mice and in various cell lines. Anti-IFN-gamma treatment in vivo revealed that the LCMV strains Armstrong, Aggressive, and WE were most susceptible to IFN-gamma whereas Traub, Cl 13-Armstrong, and Docile were resistant. The same pattern of susceptibility to recombinant IFN-gamma was observed in vitro. In vivo treatment with anti-IFN-alpha/beta showed a sizeable increase in replication of Aggressive, Armstrong, and WE; effects were less pronounced for Docile, Cl 13-Armstrong, or Traub. Correspondingly, WE, Armstrong, and Aggressive were all relatively sensitive to purified IFN-alpha/beta in vitro, and Cl 13-Armstrong, Docile, and Traub were more resistant. Overall, there was a good correlation between the capacity of LCMV strains to establish a persistent infection in adult immunocompetent mice and their relative resistance to IFN-gamma and IFN-alpha/beta. PMID:8107255

  15. Occurrence of virus-induced COPD exacerbations during four seasons.

    PubMed

    Djamin, Remco S; Uzun, Sevim; Snelders, Eveline; Kluytmans, Jan J W; Hoogsteden, Henk C; Aerts, Joachim G J V; Van Der Eerden, Menno M

    2015-02-01

    In this study, we investigated the occurrence of viral infections in acute exacerbations of chronic obstructive pulmonary disease (COPD) during four seasons. Viral infections were detected by the use of real-time reverse transcriptase polymerase chain reaction on pharyngeal swabs. During a 12-month period pharyngeal swabs were obtained in 136 exacerbations of 63 patients. In 35 exacerbations (25.7%) a viral infection was detected. Most viral infections occurred in the winter (n = 14, 40.0%), followed by summer (n = 9, 25.7%), autumn (n = 6, 17.1%), and spring (n = 6, 17.1%). Rhinovirus was the most frequently isolated virus (n = 19, 51.4%), followed by respiratory syncytial virus (n = 6, 16.2%), human metapneumovirus (n = 5, 13.5%), influenza A (n = 4, 10.8%), parainfluenza 4 (n = 2, 5.4%), and parainfluenza 3 (n = 1, 2.7%). This study showed that virus-induced COPD exacerbations occur in all four seasons with a peak in the winter months. However, the distribution of rhinovirus infections showed a different pattern, with most infections occurring in July.

  16. Virus-Induced Silencing of a Plant Cellulose Synthase Gene

    PubMed Central

    Burton, Rachel A.; Gibeaut, David M.; Bacic, Antony; Findlay, Kim; Roberts, Keith; Hamilton, Andrew; Baulcombe, David C.; Fincher, Geoffrey B.

    2000-01-01

    Specific cDNA fragments corresponding to putative cellulose synthase genes (CesA) were inserted into potato virus X vectors for functional analysis in Nicotiana benthamiana by using virus-induced gene silencing. Plants infected with one group of cDNAs had much shorter internode lengths, small leaves, and a “dwarf” phenotype. Consistent with a loss of cell wall cellulose, abnormally large and in many cases spherical cells ballooned from the undersurfaces of leaves, particularly in regions adjacent to vascular tissues. Linkage analyses of wall polysaccharides prepared from infected leaves revealed a 25% decrease in cellulose content. Transcript levels for at least one member of the CesA cellulose synthase gene family were lower in infected plants. The decrease in cellulose content in cell walls was offset by an increase in homogalacturonan, in which the degree of esterification of carboxyl groups decreased from ∼50 to ∼33%. The results suggest that feedback loops interconnect the cellular machinery controlling cellulose and pectin biosynthesis. On the basis of the phenotypic features of the infected plants, changes in wall composition, and the reduced abundance of CesA mRNA, we concluded that the cDNA fragments silenced one or more cellulose synthase genes. PMID:10810144

  17. Foxtail Mosaic Virus-Induced Gene Silencing in Monocot Plants.

    PubMed

    Liu, Na; Xie, Ke; Jia, Qi; Zhao, Jinping; Chen, Tianyuan; Li, Huangai; Wei, Xiang; Diao, Xianmin; Hong, Yiguo; Liu, Yule

    2016-07-01

    Virus-induced gene silencing (VIGS) is a powerful technique to study gene function in plants. However, very few VIGS vectors are available for monocot plants. Here we report that Foxtail mosaic virus (FoMV) can be engineered as an effective VIGS system to induce efficient silencing of endogenous genes in monocot plants including barley (Hordeum vulgare L.), wheat (Triticum aestivum) and foxtail millet (Setaria italica). This is evidenced by FoMV-based silencing of phytoene desaturase (PDS) and magnesium chelatase in barley, of PDS and Cloroplastos alterados1 in foxtail millet and wheat, and of an additional gene IspH in foxtail millet. Silencing of these genes resulted in photobleached or chlorosis phenotypes in barley, wheat, and foxtail millet. Furthermore, our FoMV-based gene silencing is the first VIGS system reported for foxtail millet, an important C4 model plant. It may provide an efficient toolbox for high-throughput functional genomics in economically important monocot crops. PMID:27225900

  18. Tom70 Mediates Sendai Virus-Induced Apoptosis on Mitochondria

    PubMed Central

    Wei, Bo; Cui, Ye; Huang, Yuefeng; Liu, Heng; Li, Lin; Li, Mi; Ruan, Kang-Cheng

    2015-01-01

    ABSTRACT Virus infection triggers immediate innate immune responses. Apoptosis represents another effective means to restrict virus invasion, besides robust expression of host cytokines and chemokines. IRF3 was recently demonstrated to be indispensable for Sendai virus (SeV)-induced apoptosis, but the underlying mechanism is not fully understood. Here we report that a dynamic protein complex, Tom70/Hsp90/IRF3/Bax, mediates SeV-induced apoptosis. The cytosolic proapoptotic protein Bax interacts specifically with IRF3 upon virus infection. The mitochondrial outer membrane protein Tom70 recruits IRF3 to mitochondria via Hsp90. Consequently, the relocation of Bax onto mitochondria induces the leakage of cytochrome c into the cytosol and initiates the corresponding apoptosis. Interestingly, IKK-i is essential for this apoptosis, whereas TBK1 is dispensable. Collectively, our study characterizes a novel protein complex that is important for SeV-induced apoptosis. IMPORTANCE Apoptosis is an effective means of sacrificing virus-infected cells and restraining the spread of virus. In this study, we demonstrate that IRF3 associates with Bax upon virus infection. Tom70 recruits this protein complex to the mitochondrial outer membrane through Hsp90, which thus induces the release of cytochrome c into the cytosol, initiating virus-induced apoptosis. Interestingly, IKK-i plays an essential role in this activation. This study uncovers a novel mechanism of SeV-induced apoptosis. PMID:25609812

  19. Virus-induced gene silencing in eggplant (Solanum melongena).

    PubMed

    Liu, Haiping; Fu, Daqi; Zhu, Benzhong; Yan, Huaxue; Shen, Xiaoying; Zuo, Jinhua; Zhu, Yi; Luo, Yunbo

    2012-06-01

    Eggplant (Solanum melongena) is an economically important vegetable requiring investigation into its various genomic functions. The current limitation in the investigation of genomic function in eggplant is the lack of effective tools available for conducting functional assays. Virus-induced gene silencing (VIGS) has played a critical role in the functional genetic analyses. In this paper, TRV-mediated VIGS was successfully elicited in eggplant. We first cloned the CDS sequence of PDS (PHYTOENE DESATURASE) in eggplant and then silenced the PDS gene. Photo-bleaching was shown on the newly-developed leaves four weeks after agroinoculation, indicating that VIGS can be used to silence genes in eggplant. To further illustrate the reliability of VIGS in eggplant, we selected Chl H, Su and CLA1 as reporters to elicit VIGS using the high-pressure spray method. Suppression of Chl H and Su led to yellow leaves, while the depletion of CLA1 resulted in albino. In conclusion, four genes, PDS, Chl H, Su (Sulfur), CLA1, were down-regulated significantly by VIGS, indicating that the VIGS system can be successfully applied in eggplant and is a reliable tool for the study of gene function.

  20. Virus-induced gene silencing in eggplant (Solanum melongena).

    PubMed

    Liu, Haiping; Fu, Daqi; Zhu, Benzhong; Yan, Huaxue; Shen, Xiaoying; Zuo, Jinhua; Zhu, Yi; Luo, Yunbo

    2012-06-01

    Eggplant (Solanum melongena) is an economically important vegetable requiring investigation into its various genomic functions. The current limitation in the investigation of genomic function in eggplant is the lack of effective tools available for conducting functional assays. Virus-induced gene silencing (VIGS) has played a critical role in the functional genetic analyses. In this paper, TRV-mediated VIGS was successfully elicited in eggplant. We first cloned the CDS sequence of PDS (PHYTOENE DESATURASE) in eggplant and then silenced the PDS gene. Photo-bleaching was shown on the newly-developed leaves four weeks after agroinoculation, indicating that VIGS can be used to silence genes in eggplant. To further illustrate the reliability of VIGS in eggplant, we selected Chl H, Su and CLA1 as reporters to elicit VIGS using the high-pressure spray method. Suppression of Chl H and Su led to yellow leaves, while the depletion of CLA1 resulted in albino. In conclusion, four genes, PDS, Chl H, Su (Sulfur), CLA1, were down-regulated significantly by VIGS, indicating that the VIGS system can be successfully applied in eggplant and is a reliable tool for the study of gene function. PMID:22268843

  1. Vaccinia Virus Induces Programmed Necrosis in Ovarian Cancer Cells

    PubMed Central

    Whilding, Lynsey M; Archibald, Kyra M; Kulbe, Hagen; Balkwill, Frances R; Öberg, Daniel; McNeish, Iain A

    2013-01-01

    The mechanisms by which oncolytic vaccinia virus induces tumor cell death are poorly understood. We have evaluated cell death pathways following infection of ovarian cancer cells with both wild-type and thymidine kinase-deleted (dTK) Lister strain vaccinia. We show that death does not rely upon classical apoptosis despite the appearances of some limited apoptotic features, including phosphatidylserine externalization and appearance of sub-G1 DNA populations. Vaccinia infection induces marked lipidation of LC3 proteins, but there is no general activation of the autophagic process and cell death does not rely upon autophagy induction. We show that vaccinia induces necrotic morphology on transmission electron microscopy, accompanied by marked by reductions in intracellular adenosine triphosphate, altered mitochondrial metabolism, and release of high mobility group box 1 (HMGB1) protein. This necrotic cell death appears regulated, as infection induces formation of a receptor interacting protein (RIP1)/caspase-8 complex. In addition, pharmacological inhibition of both RIP1 and substrates downstream of RIP1, including MLKL, significantly attenuate cell death. Blockade of TNF-α, however, does not alter virus efficacy, suggesting that necrosis does not result from autocrine cytokine release. Overall, these results show that, in ovarian cancer cells, vaccinia virus causes necrotic cell death that is mediated through a programmed series of events. PMID:23985697

  2. Efficient Virus-Induced Gene Silencing in Solanum rostratum.

    PubMed

    Meng, Lan-Huan; Wang, Rui-Heng; Zhu, Ben-Zhong; Zhu, Hong-Liang; Luo, Yun-Bo; Fu, Da-Qi

    2016-01-01

    Solanum rostratum is a "super weed" that grows fast, is widespread, and produces the toxin solanine, which is harmful to both humans and other animals. To our knowledge, no study has focused on its molecular biology owing to the lack of available transgenic methods and sequence information for S. rostratum. Virus-induced gene silencing (VIGS) is a powerful tool for the study of gene function in plants; therefore, in the present study, we aimed to establish tobacco rattle virus (TRV)-derived VIGS in S. rostratum. The genes for phytoene desaturase (PDS) and Chlorophyll H subunit (ChlH) of magnesium protoporphyrin chelatase were cloned from S. rostratum and used as reporters of gene silencing. It was shown that high-efficiency VIGS can be achieved in the leaves, flowers, and fruit of S. rostratum. Moreover, based on our comparison of three different types of infection methods, true leaf infection was found to be more efficient than cotyledon and sprout infiltration in long-term VIGS in multiple plant organs. In conclusion, the VIGS technology and tomato genomic sequences can be used in the future to study gene function in S. rostratum.

  3. Efficient Virus-Induced Gene Silencing in Solanum rostratum

    PubMed Central

    Meng, Lan-Huan; Wang, Rui-Heng; Zhu, Ben-Zhong; Zhu, Hong-Liang; Luo, Yun-Bo; Fu, Da-Qi

    2016-01-01

    Solanum rostratum is a “super weed” that grows fast, is widespread, and produces the toxin solanine, which is harmful to both humans and other animals. To our knowledge, no study has focused on its molecular biology owing to the lack of available transgenic methods and sequence information for S. rostratum. Virus-induced gene silencing (VIGS) is a powerful tool for the study of gene function in plants; therefore, in the present study, we aimed to establish tobacco rattle virus (TRV)-derived VIGS in S. rostratum. The genes for phytoene desaturase (PDS) and Chlorophyll H subunit (ChlH) of magnesium protoporphyrin chelatase were cloned from S. rostratum and used as reporters of gene silencing. It was shown that high-efficiency VIGS can be achieved in the leaves, flowers, and fruit of S. rostratum. Moreover, based on our comparison of three different types of infection methods, true leaf infection was found to be more efficient than cotyledon and sprout infiltration in long-term VIGS in multiple plant organs. In conclusion, the VIGS technology and tomato genomic sequences can be used in the future to study gene function in S. rostratum. PMID:27258320

  4. Efficient Virus-Induced Gene Silencing in Solanum rostratum.

    PubMed

    Meng, Lan-Huan; Wang, Rui-Heng; Zhu, Ben-Zhong; Zhu, Hong-Liang; Luo, Yun-Bo; Fu, Da-Qi

    2016-01-01

    Solanum rostratum is a "super weed" that grows fast, is widespread, and produces the toxin solanine, which is harmful to both humans and other animals. To our knowledge, no study has focused on its molecular biology owing to the lack of available transgenic methods and sequence information for S. rostratum. Virus-induced gene silencing (VIGS) is a powerful tool for the study of gene function in plants; therefore, in the present study, we aimed to establish tobacco rattle virus (TRV)-derived VIGS in S. rostratum. The genes for phytoene desaturase (PDS) and Chlorophyll H subunit (ChlH) of magnesium protoporphyrin chelatase were cloned from S. rostratum and used as reporters of gene silencing. It was shown that high-efficiency VIGS can be achieved in the leaves, flowers, and fruit of S. rostratum. Moreover, based on our comparison of three different types of infection methods, true leaf infection was found to be more efficient than cotyledon and sprout infiltration in long-term VIGS in multiple plant organs. In conclusion, the VIGS technology and tomato genomic sequences can be used in the future to study gene function in S. rostratum. PMID:27258320

  5. Dominant inhibitory Ras delays Sindbis virus-induced apoptosis in neuronal cells.

    PubMed Central

    Joe, A K; Ferrari, G; Jiang, H H; Liang, X H; Levine, B

    1996-01-01

    Mature neurons are more resistant than dividing cells or differentiating neurons to Sindbis virus-induced apoptotic death. Therefore, we hypothesized that mitogenic signal transduction pathways may influence susceptibility to Sindbis virus-induced apoptosis. Since Ras, a 21-kDa GTP-binding protein, plays an important role in cellular proliferation and neuronal differentiation, we investigated the effect of an inducible dominant inhibitory Ras on Sindbis virus-induced death of a rat pheochromocytoma cell line, PC12 cells. Dexamethasone induction of dominant inhibitory Ras (Ha Ras(Asn17)) expression in transfected PC12 cell lines (MMTV-M17-21 and GSrasDN6 cells) resulted in a marked delay in Sindbis virus-induced apoptosis, compared with infected, uninduced cells. The delay in death after Sindbis virus infection in induced versus uninduced PC12 cells was not associated with differences in viral titers or viral infectivity. No delay in Sindbis virus-induced apoptosis was observed in Ha Ras(Asn17)-transfected PC12 cells if dexamethasone induction was initiated less than 12 h before Sindbis virus infection or in wild-type PC12 cells infected with a chimeric Sindbis virus construct that expresses Ha Ras(Asn17). The delay in Sindbis virus-induced apoptosis in induced Ha Ras(Asn17)-transfected PC12 cells was associated with a decrease in cellular DNA synthesis as measured by 5'-bromo-2'-deoxyuridine incorporation. Thus, in PC12 cells, inducible dominant inhibitory Ras inhibits cellular proliferation and delays Sindbis virus-induced apoptosis. These findings suggest that a Ras-dependent signaling pathway is a determinant of neuronal susceptibility to Sindbis virus-induced apoptosis. PMID:8892895

  6. Mechanisms of dengue virus-induced bone marrow suppression.

    PubMed

    La Russa, V F; Innis, B L

    1995-03-01

    Infection with many flaviviruses is associated with transient suppression of haematopoiesis. Of the flaviviruses of man, none are more accessible to clinical and laboratory study than dengue. Consequently, the clinical syndrome of dengue-associated bone marrow suppression has been well documented. A review of experimental dengue infections of volunteers and histopathological studies of bone marrow from patients with severe dengue virus infection suggests that marrow suppression evolves rapidly through several phases: (1) onset of marrow suppression within 3-4 days of infection; (2) onset of host inflammatory responses in the marrow and of fever shortly thereafter; (3) occurrence of a neutrophil nadir on the fourth to fifth day after onset of fever; (4) almost simultaneously, immune activation sufficient to neutralize viraemia and accelerate elimination of infected cells; (5) remission of symptoms; and (6) resolution of cytopenias. Clinical observations and experimental data bear on possible mechanisms of dengue virus-mediated marrow suppression. Work from the authors' laboratory in which long-term bone marrow cultures were used to investigate interactions between dengue virus and bone marrow cells (stromal elements and haematopoietic progenitors) is also reviewed. Long-term marrow culture (LTMC) was a useful experimental system. In vitro, early blast cells as well as the more differentiated haematopoietic elements were abortively infected, killed and eliminated by phagocytosis by specialized marrow macrophages called dendritic cells. Moreover, the ARC from stroma rather than haematopoietic precursors were productively infected. When ARC were infected, stroma failed to support haematopoiesis. Cytokine production by virus-infected stromal cells was altered. A hypothesis is proposed to account for dengue virus-induced marrow suppression. Down-regulation of haematopoiesis is probably a protective mechanism of the microenvironment that limits injury to the marrow stem

  7. Evidence of Lymphocytic Choriomeningitis Virus (LCMV) in Domestic Mice in Gabon: Risk of Emergence of LCMV Encephalitis in Central Africa

    PubMed Central

    N′Dilimabaka, Nadine; Berthet, Nicolas; Rougeron, Virginie; Mangombi, Joa Braïthe; Durand, Patrick; Maganga, Gael D.; Bouchier, Christiane; Schneider, Bradley S.; Fair, Joseph; Renaud, François

    2014-01-01

    Lymphocytic choriomeningitis virus (LCMV) can cause acute fatal disease on all continents but was never detected in Africa. We report the first detection of LCMV RNA in a common European house mouse (Mus musculus domesticus) in Africa. Phylogenetic analyses show a close relationship with North American strains. These findings suggest that there is a risk of the appearance of LCMV acute encephalitis cases. This is a perfect example of virus dissemination by its natural host that may have dramatic public health consequences. PMID:25378495

  8. Prevalence of lymphocytic choriomeningitis virus infection in a human population of Argentina.

    PubMed

    Ambrosio, A M; Feuillade, M R; Gamboa, G S; Maiztegui, J I

    1994-03-01

    The activity of lymphocytic choriomeningitis virus (LCMV) in the endemic area of Argentine hemorrhagic fever has been previously reported and represents the first evidence of the coexistence of two arenaviruses pathogenic for humans, Junin and LCMV, in the same geographic area. Data are presented on the prevalence of LCMV human infection in a 10,000-km2 area located in Santa Fe Province, Argentina. Study subjects were males, 15-65 years old, living and/or working in the rural area of 41 localities. One serum sample was obtained from each 7,227 volunteers from a total population of 21,340 individuals with the described features. Antibodies to LCMV were assessed by means of an indirect immunofluorescence assay. These antibodies were found in 172 serum samples, with titers ranging from 1:8 to 1:128 (geometric mean titer = 15.03), and a mean percentage of infection of 2.38%. A significantly different distribution of positive individuals was found between the eastern (1.54%) and western (3.07%) borders of the region studied (P < 0.0003). The higher percentage of infection on the western side was due to the existence of two clusters of counties with a mean percentage of 6.06% that was significantly different from the 1.67% obtained in the rest of the study area (P < 0.0003). These results provide new information on the LCMV activity in Argentina, and update the evidence on the coexistence of two arenaviruses in the same region of Argentina. This circumstance increases the probability of generation of viral reassortants with changes that could determine the need for new therapeutic and/or preventive strategies for arenaviral diseases.

  9. Chemokine gene expression in the brains of mice with lymphocytic choriomeningitis.

    PubMed Central

    Asensio, V C; Campbell, I L

    1997-01-01

    Chemokines are pivotal in the trafficking of leukocytes. In the present study, we examined the expression of multiple chemokine genes during the course of lymphocytic choriomeningitis (LCM) in mice. In noninfected mice, no detectable chemokine gene expression was found in the brain; however, by day 3 postinfection, the induction of a number of chemokine mRNAs was observed as follows (in order from the greatest to the least): cytokine responsive gene-2 or interferon-inducible 10-kDa protein (Crg-2/IP-10), RANTES, monocyte chemotactic protein-1 (MCP-1), macrophage inflammatory protein-1 (MIP-1beta), and MCP-3. At day 6 postinfection, the expression of these chemokine mRNAs was increased, and low expression of lymphotactin, C10, MIP-2, and MIP-1alpha mRNAs was detectable. Transcript for T-cell activation-3 was not detectable in the brain at any time following LCM virus (LCMV) infection. With some exceptions, a pattern of chemokine gene expression similar to that in the brain was observed in the peripheral organs of LCMV-infected mice. Mice that lacked expression of gamma interferon developed LCM and had a qualitatively similar but quantitatively reduced cerebral chemokine gene expression profile. In contrast, little or no chemokine gene expression was detectable in the brains of LCMV-infected athymic mice which did not develop LCM. Expression of Crg-2/IP-10 RNA was localized to predominantly resident cells of the central nervous system (CNS) and overlapped with sites of viral infection and immune cell infiltration. These findings demonstrate the expression of a number of chemokine genes in the brains of mice infected with LCMV. The pattern of chemokine gene expression in LCM may profoundly influence the characteristic phenotype and response of leukocytes in the brain and contribute to the immunopathogenesis of this fatal CNS infection. PMID:9311871

  10. Macrophages in Immunopathology of Atherosclerosis: A Target for Diagnostics and Therapy

    PubMed Central

    Orekhov, Alexander N; Sobenin, Igor A; Gavrilin, Mikhail A; Gratchev, Alexei; Kotyashova, Svetlana Y; Nikiforov, Nikita G; Kzhyshkowska, Julia

    2015-01-01

    Immunopathology plays important roles in the development of different life-threatening diseases, such as atherosclerosis and its consequences (acute myocardial infarction and stroke), cancer, chronic inflammatory diseases. Effective modulation of the immune system may significantly increase the efficacy of prevention and therapy efforts. Currently there are no marketed drugs capable of normalizing immune system function in an intrinsic and comprehensive way. Here, we describe a test system designed for complex analysis of monocyte activity in individuals to diagnose immunopathology and monitor treatment efficacy. This cell-based test system may also be useful for screening compounds with an immune-correcting effects. Both diagnostic and screening systems are based on primary culture of human monocytes and/or monocyte-derived macrophages. This is the first step in creating a method for assessment of macrophage activity, which is required for further development of immune-correcting drugs. The existing preliminary data provide the basis for realization of this idea. PMID:25312739

  11. New insights into the immunopathology and control of dengue virus infection.

    PubMed

    Screaton, Gavin; Mongkolsapaya, Juthathip; Yacoub, Sophie; Roberts, Catherine

    2015-12-01

    Dengue virus poses a major threat to global public health: two-thirds of the world's population is now at risk from infection by this mosquito-borne virus. Dengue virus causes a range of diseases with a small proportion of infected patients developing severe plasma leakage that leads to dengue shock syndrome, organ impairment and bleeding. Infection with one of the four viral serotypes results in the development of homotypic immunity to that serotype. However, subsequent infection with a different serotype is associated with an increased risk of developing severe disease, which has led to the suggestion that severe disease is triggered by immunopathology. This Review outlines recent advances in the understanding of immunopathology, vaccine development and human monoclonal antibodies produced against dengue virus. PMID:26603900

  12. New insights into the immunopathology and control of dengue virus infection.

    PubMed

    Screaton, Gavin; Mongkolsapaya, Juthathip; Yacoub, Sophie; Roberts, Catherine

    2015-12-01

    Dengue virus poses a major threat to global public health: two-thirds of the world's population is now at risk from infection by this mosquito-borne virus. Dengue virus causes a range of diseases with a small proportion of infected patients developing severe plasma leakage that leads to dengue shock syndrome, organ impairment and bleeding. Infection with one of the four viral serotypes results in the development of homotypic immunity to that serotype. However, subsequent infection with a different serotype is associated with an increased risk of developing severe disease, which has led to the suggestion that severe disease is triggered by immunopathology. This Review outlines recent advances in the understanding of immunopathology, vaccine development and human monoclonal antibodies produced against dengue virus.

  13. Baculovirus vectors expressing F proteins in combination with virus-induced signaling adaptor (VISA) molecules confer protection against respiratory syncytial virus infection.

    PubMed

    Zhang, Yuan; Qiao, Lei; Hu, Xiao; Zhao, Kang; Zhang, Yanwen; Chai, Feng; Pan, Zishu

    2016-01-01

    Baculovirus has been exploited for use as a novel vaccine vector. To investigate the feasibility and efficacy of recombinant baculoviruses (rBVs) expressing respiratory syncytial virus (RSV) fusion (F) proteins, four constructs (Bac-tF/64, Bac-CF, Bac-CF/tF64 and Bac-CF/tF64-VISA) were generated. Bac-tF64 displays the F ectodomain (tF) on the envelope of rBVs, whereas Bac-CF expresses full-length F protein in transduced mammalian cells. Bac-CF/tF64 not only displays tF on the envelope but also expresses F in cells. Bac-CF/tF64-VISA comprises Bac-CF/tF64 harboring the virus-induced signaling adaptor (VISA) gene. After administration to BALB/c mice, all four vectors elicited RSV neutralizing antibody (Ab), systemic Ab (IgG, IgG1, and IgG2a), and cytokine responses. Compared with Bac-tF64, mice inoculated with Bac-CF and Bac-CF/tF64 exhibited an increased mixed Th1/Th2 cytokine response, increased ratios of IgG2a/IgG1 antibody responses, and reduced immunopathology upon RSV challenge. Intriguingly, co-expression of VISA reduced Th2 cytokine (IL-4, IL-5, and IL-10) production induced by Bac-CF/tF64, thus relieving lung pathology upon a subsequent RSV challenge. Our results indicated that the Bac-CF/tF64 vector incorporated with the VISA molecule may provide an effective vaccine strategy for protection against RSV.

  14. In vivo selection of lymphocyte-tropic and macrophage-tropic variants of lymphocytic choriomeningitis virus during persistent infection.

    PubMed Central

    King, C C; de Fries, R; Kolhekar, S R; Ahmed, R

    1990-01-01

    This study demonstrates cell-specific selection of viral variants during persistent lymphocytic choriomeningitis virus infection in its natural host. We have analyzed viral isolates obtained from CD4+ T cells and macrophages of congenitally infected carrier mice and found that three types of variants are present in individual carrier mice: (i) macrophage-tropic, (ii) lymphotropic, and (iii) amphotropic. The majority of the isolates were amphotropic and exhibited enhanced growth in both lymphocytes and macrophages. However, some of the lymphocyte-derived isolates grew well in lymphocytes but poorly in macrophages, and a macrophage-derived isolate replicated well in macrophages but not in lymphocytes. In striking contrast, the original wild-type (wt) Armstrong strain of lymphocytic choriomeningitis virus that was used to initiate the chronic infection and from which the variants are derived grew poorly in both lymphocytes and macrophages. These three types of variants also differed from the parental virus in their ability to establish a chronic infection in immunocompetent hosts. Adult mice infected with the wt Armstrong strain cleared the infection within 2 weeks, whereas adult mice infected with the variants harbored virus for several months. These results suggest that the ability of the variants to persist in adult mice is due to enhanced replication in macrophages and/or lymphocytes. This conclusion is further strengthened by the finding that the variants and the parental wt virus grew equally well in mouse fibroblasts and that the observed growth differences were specific for cells of the immune system. Images PMID:1976825

  15. Aggravation of viral hepatitis by platelet-derived serotonin.

    PubMed

    Lang, Philipp A; Contaldo, Claudio; Georgiev, Panco; El-Badry, Ashraf Mohammad; Recher, Mike; Kurrer, Michael; Cervantes-Barragan, Luisa; Ludewig, Burkhard; Calzascia, Thomas; Bolinger, Beatrice; Merkler, Doron; Odermatt, Bernhard; Bader, Michael; Graf, Rolf; Clavien, Pierre-Alain; Hegazy, Ahmed N; Löhning, Max; Harris, Nicola L; Ohashi, Pamela S; Hengartner, Hans; Zinkernagel, Rolf M; Lang, Karl S

    2008-07-01

    More than 500 million people worldwide are persistently infected with hepatitis B virus or hepatitis C virus. Although both viruses are poorly cytopathic, persistence of either virus carries a risk of chronic liver inflammation, potentially resulting in liver steatosis, liver cirrhosis, end-stage liver failure or hepatocellular carcinoma. Virus-specific T cells are a major determinant of the outcome of hepatitis, as they contribute to the early control of chronic hepatitis viruses, but they also mediate immunopathology during persistent virus infection. We have analyzed the role of platelet-derived vasoactive serotonin during virus-induced CD8(+) T cell-dependent immunopathological hepatitis in mice infected with the noncytopathic lymphocytic choriomeningitis virus. After virus infection, platelets were recruited to the liver, and their activation correlated with severely reduced sinusoidal microcirculation, delayed virus elimination and increased immunopathological liver cell damage. Lack of platelet-derived serotonin in serotonin-deficient mice normalized hepatic microcirculatory dysfunction, accelerated virus clearance in the liver and reduced CD8(+) T cell-dependent liver cell damage. In keeping with these observations, serotonin treatment of infected mice delayed entry of activated CD8(+) T cells into the liver, delayed virus control and aggravated immunopathological hepatitis. Thus, vasoactive serotonin supports virus persistence in the liver and aggravates virus-induced immunopathology.

  16. [Neutralization test for lymphocytic choriomeningitis virus for distinguishing between two arenavirus infections in Argentina].

    PubMed

    Ambrosio, A M; Riera, L; Saavedra, M C; Sottosanti, J J

    2001-01-01

    The active coexistence of two pathogenic arenaviruses, Junin (JUNV) and lymphocytic choriomeningitis (LCMV), in the same region of Argentina, has been known since the early 70's, and records of clinical and subclinical human infections by one and/or the other agent have been continuously produced for the last 25 years. Anti-LCMV antibody is currently searched only by indirect immunofluorescence, a test that shows cross reactions among a number of arenaviruses yielding, in the cases of LCMV and JUNV consecutive infections, a concomitant seroconversion for both viruses, as an inconclusive diagnostic result. In contrast, neutralization (NT) tests reveal arenavirus antibodies directed to unique epitopes on these virus envelopes, thus allowing to disclose the sequence in the cases of consecutive infections. In this paper, the characteristics of neutralization (NT) test for LCMV in cell cultures are described, as well as its performance in the field diagnosis of LCMV human infections. The native LCMV strain Cba An 13065 was inoculated on L-929 cell (ATCC CCL 1), and procedures were followed to perform a constant virus-variable serum NT test. Final points of sera titrations were expressed as the maximal serum dilution that yielded 75% of pfu inhibition. This NT test was assayed on paired serum samples of 36 patients with confirmed Argentine hemorrhagic fever (AHF) (a disease caused by JUNV), who had had a known previous contact with LCMV through IFI. The use of this one test led to confusing diagnosis of the disease due to concomitant seroconversion for JUNV and LCMV. By using NT test, it was shown that: some of them were possibly not infected by LCMV, and that 30/36 cases (83.3%) had a pre-existing level of LCMV antibody, with titers in the range of 5 to 640, remaining unchanged 60 days after the clinical AHF. This shows that NT antibodies to LCMV are not influenced by the outcome of the immune response to JUNV, thus confirming the efficiency of NT test as identificator

  17. THE COURSE OF VIRUS-INDUCED RABBIT PAPILLOMAS AS DETERMINED BY VIRUS, CELLS, AND HOST

    PubMed Central

    Kidd, John G.

    1938-01-01

    An experimental analysis of the factors responsible for the observed differences in the course of virus-induced papillomas of the rabbit has shown that some are referable to the virus, others to the cells, and yet others to host influences. The interplay of these factors affords enlightening illustration of the nature of the cell-virus relationship in virus-induced tumors. Retrogression of the rabbit papillomas appears to be consequent on a generalized resistance of host origin, elicited by and directed against the proliferating, virus-infected cells. PMID:19870740

  18. Tbet or Continued RORγt Expression Is Not Required for Th17-Associated Immunopathology

    PubMed Central

    Brucklacher-Waldert, Verena; Ferreira, Cristina; Innocentin, Silvia; Kamdar, Shraddha; Withers, David R.; Kullberg, Marika C.

    2016-01-01

    The discovery of Th17 cell plasticity, in which CD4+ IL-17–producing Th17 cells give rise to IL-17/IFN-γ double-producing cells and Th1-like IFNγ+ ex-Th17 lymphocytes, has raised questions regarding which of these cell types contribute to immunopathology during inflammatory diseases. In this study, we show using Helicobacter hepaticus-induced intestinal inflammation that IL-17ACre– or Rag1Cre-mediated deletion of Tbx21 has no effect on the generation of IL-17/IFN-γ double-producing cells, but leads to a marked absence of Th1-like IFNγ+ ex-Th17 cells. Despite the lack of Th1-like ex-Th17 cells, the degree of H. hepaticus-triggered intestinal inflammation in mice in which Tbx21 was excised in IL-17–producing or Rag1-expressing cells is indistinguishable from that observed in control mice. In stark contrast, using experimental autoimmune encephalomyelitis, we show that IL-17ACre–mediated deletion of Tbx21 prevents the conversion of Th17 cells to IL-17A/IFN-γ double-producing cells as well as Th1-like IFN-γ+ ex-Th17 cells. However, IL-17ACre–mediated deletion of Tbx21 has only limited effects on disease course in this model and is not compensated by Ag-specific Th1 cells. IL-17ACre–mediated deletion of Rorc reveals that RORγt is essential for the maintenance of the Th17 cell lineage, but not immunopathology during experimental autoimmune encephalomyelitis. These results show that neither the single Th17 subset, nor its progeny, is solely responsible for immunopathology or autoimmunity. PMID:27183623

  19. Thymic stromal lymphopoietin as a novel mediator amplifying immunopathology in rheumatic disease.

    PubMed

    Hillen, Maarten R; Radstake, Timothy R D J; Hack, Cornelis E; van Roon, Joel A G

    2015-10-01

    Thymic stromal lymphopoietin (TSLP) is an IL-7-related cytokine that has been studied extensively in atopic diseases and more recently in various rheumatic disorders. It is involved in T cell development in the thymus and promotes homeostatic T cell expansion by classical dendritic cells. However, deregulated TSLP expression in various rheumatic diseases has implicated this cytokine as a strong mediator in immunopathology. Overexpressed TSLP induces strong T cell activation and production of pro-inflammatory cytokines in human cells and animal models for RA, SSc and LN, underscoring the therapeutic potential of targeting the TSLP-TSLP receptor axis.

  20. Immunopathological roles of cytokines, chemokines, signaling molecules, and pattern-recognition receptors in systemic lupus erythematosus.

    PubMed

    Yu, Shui-Lian; Kuan, Woon-Pang; Wong, Chun-Kwok; Li, Edmund K; Tam, Lai-Shan

    2012-01-01

    Systemic lupus erythematosus (SLE) is an autoimmune disease with unknown etiology affecting more than one million individuals each year. It is characterized by B- and T-cell hyperactivity and by defects in the clearance of apoptotic cells and immune complexes. Understanding the complex process involved and the interaction between various cytokines, chemokines, signaling molecules, and pattern-recognition receptors (PRRs) in the immune pathways will provide valuable information on the development of novel therapeutic targets for treating SLE. In this paper, we review the immunopathological roles of novel cytokines, chemokines, signaling molecules, PRRs, and their interactions in immunoregulatory networks and suggest how their disturbances may implicate pathological conditions in SLE.

  1. Thymic stromal lymphopoietin as a novel mediator amplifying immunopathology in rheumatic disease.

    PubMed

    Hillen, Maarten R; Radstake, Timothy R D J; Hack, Cornelis E; van Roon, Joel A G

    2015-10-01

    Thymic stromal lymphopoietin (TSLP) is an IL-7-related cytokine that has been studied extensively in atopic diseases and more recently in various rheumatic disorders. It is involved in T cell development in the thymus and promotes homeostatic T cell expansion by classical dendritic cells. However, deregulated TSLP expression in various rheumatic diseases has implicated this cytokine as a strong mediator in immunopathology. Overexpressed TSLP induces strong T cell activation and production of pro-inflammatory cytokines in human cells and animal models for RA, SSc and LN, underscoring the therapeutic potential of targeting the TSLP-TSLP receptor axis. PMID:26163286

  2. The contribution of the sympathetic nervous system to the immunopathology of experimental pulmonary tuberculosis.

    PubMed

    Barrios-Payán, Jorge; Revuelta, Alberto; Mata-Espinosa, Dulce; Marquina-Castillo, Brenda; Villanueva, Enrique Becerril; Gutiérrez, María Eugenia Hernández; Pérez-Sánchez, Gilberto; Pavón, Lenin; Hernandez-Pando, Rogelio

    2016-09-15

    The role of norepinephrine (NE) in the immunopathology of experimental tuberculosis (TB) was studied by measuring pulmonary NE and determining its cellular sources and targets. Functional studies were performed administrating adrenergic and anti-adrenergic drugs at different TB phases. Results showed high production of NE during early infection by adrenergic nerve terminals and lymphocytes located in the lungs and mediastinal lymph nodes, these cells highly expressed β2 adreno-receptors (β2AR) which by an autocrine mechanism promote Th-1 cell differentiation favoring protection. During advanced infection, the production of NE and β2AR sharply decreased, suggesting that adrenergic activity is less important during late TB. PMID:27609282

  3. Development and application of ELISA for the detection of IgG antibodies to lymphocytic choriomeningitis virus.

    PubMed

    Lapošová, K; Lukáčiková, Ľ; Ovečková, I; Pastoreková, S; Rosocha, J; Kuba, D; Beňa, Ľ; Tomášková, J

    2016-06-01

    Lymphocytic choriomeningitis virus (LCMV) is a neglected human pathogen, which can cause severe illnesses in humans. The most vulnerable are the human foetus and immunosuppressed individuals. Since there is no commercially available enzyme-linked immunosorbent assay (ELISA) for the diagnosis of anti-LCMV antibodies in human sera, we developed a sandwich ELISA method detecting anti-nucleoprotein IgG antibodies, using a specific monoclonal anti-nucleoprotein antibody and cells persistently infected with LCMV strain MX as antigen. In the present study we show standardization of this ELISA protocol, determination of its clinical specificity and sensitivity and its application on 30 clinical samples from multiorgan donors. Comparison of these results to the indirect immunofluorescence antibody test (IFA) demonstrates that ELISA is more sensitive. The developed ELISA assay provides a fast, simple and efficient tool for the clinical detection of anti-nucleoprotein antibodies in human sera. PMID:27265463

  4. Gene expression profiling reveals insight into how distinct viruses induce symptoms

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Plant viruses induce a wide array of disease symptoms and cytopathic effects including alterations of chloroplasts, ribosomes, and cellular architecture. While some of these changes are virus specific, many are common even among diverse viruses, and in most cases, the molecular determinants respons...

  5. TRV Based Virus Induced Gene Silencing in Gladiolus (Gladiolus grandiflorus L.), A Monocotyledonous Ornamental Plant

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Virus-induced gene silencing (VIGS) has not yet successfully been used as a tool for gene functional analysis in non-grass monocotyledonous geophytes. We therefore tested VIGS in gladiolus (Gladiolus grandiflora L) using a Tobacco Rattle Virus (TRV) vector containing a fragment of the gladiolus gene...

  6. Probiotics, prebiotics and immunomodulation of gut mucosal defences: homeostasis and immunopathology.

    PubMed

    Hardy, Holly; Harris, Jennifer; Lyon, Eleanor; Beal, Jane; Foey, Andrew D

    2013-06-01

    Probiotics are beneficial microbes that confer a realistic health benefit on the host, which in combination with prebiotics, (indigestible dietary fibre/carbohydrate), also confer a health benefit on the host via products resulting from anaerobic fermentation. There is a growing body of evidence documenting the immune-modulatory ability of probiotic bacteria, it is therefore reasonable to suggest that this is potentiated via a combination of prebiotics and probiotics as a symbiotic mix. The need for probiotic formulations has been appreciated for the health benefits in "topping up your good bacteria" or indeed in an attempt to normalise the dysbiotic microbiota associated with immunopathology. This review will focus on the immunomodulatory role of probiotics and prebiotics on the cells, molecules and immune responses in the gut mucosae, from epithelial barrier to priming of adaptive responses by antigen presenting cells: immune fate decision-tolerance or activation? Modulation of normal homeostatic mechanisms, coupled with findings from probiotic and prebiotic delivery in pathological studies, will highlight the role for these xenobiotics in dysbiosis associated with immunopathology in the context of inflammatory bowel disease, colorectal cancer and hypersensitivity. PMID:23760057

  7. Monocyte Activation in Immunopathology: Cellular Test for Development of Diagnostics and Therapy

    PubMed Central

    Ivanova, Ekaterina A.; Orekhov, Alexander N.

    2016-01-01

    Several highly prevalent human diseases are associated with immunopathology. Alterations in the immune system are found in such life-threatening disorders as cancer and atherosclerosis. Monocyte activation followed by macrophage polarization is an important step in normal immune response to pathogens and other relevant stimuli. Depending on the nature of the activation signal, macrophages can acquire pro- or anti-inflammatory phenotypes that are characterized by the expression of distinct patterns of secreted cytokines and surface antigens. This process is disturbed in immunopathologies resulting in abnormal monocyte activation and/or bias of macrophage polarization towards one or the other phenotype. Such alterations could be used as important diagnostic markers and also as possible targets for the development of immunomodulating therapy. Recently developed cellular tests are designed to analyze the phenotype and activity of living cells circulating in patient's bloodstream. Monocyte/macrophage activation test is a successful example of cellular test relevant for atherosclerosis and oncopathology. This test demonstrated changes in macrophage activation in subclinical atherosclerosis and breast cancer and could also be used for screening a panel of natural agents with immunomodulatory activity. Further development of cellular tests will allow broadening the scope of their clinical implication. Such tests may become useful tools for drug research and therapy optimization. PMID:26885534

  8. Probiotics, prebiotics and immunomodulation of gut mucosal defences: homeostasis and immunopathology.

    PubMed

    Hardy, Holly; Harris, Jennifer; Lyon, Eleanor; Beal, Jane; Foey, Andrew D

    2013-05-29

    Probiotics are beneficial microbes that confer a realistic health benefit on the host, which in combination with prebiotics, (indigestible dietary fibre/carbohydrate), also confer a health benefit on the host via products resulting from anaerobic fermentation. There is a growing body of evidence documenting the immune-modulatory ability of probiotic bacteria, it is therefore reasonable to suggest that this is potentiated via a combination of prebiotics and probiotics as a symbiotic mix. The need for probiotic formulations has been appreciated for the health benefits in "topping up your good bacteria" or indeed in an attempt to normalise the dysbiotic microbiota associated with immunopathology. This review will focus on the immunomodulatory role of probiotics and prebiotics on the cells, molecules and immune responses in the gut mucosae, from epithelial barrier to priming of adaptive responses by antigen presenting cells: immune fate decision-tolerance or activation? Modulation of normal homeostatic mechanisms, coupled with findings from probiotic and prebiotic delivery in pathological studies, will highlight the role for these xenobiotics in dysbiosis associated with immunopathology in the context of inflammatory bowel disease, colorectal cancer and hypersensitivity.

  9. Distinct surveillance pathway for immunopathology during acute infection via autophagy and SR-BI

    PubMed Central

    Pfeiler, Susanne; Khandagale, Avinash B.; Magenau, Astrid; Nichols, Maryana; Heijnen, Harry F. G.; Rinninger, Franz; Ziegler, Tilman; Seveau, Stephanie; Schubert, Sören; Zahler, Stefan; Verschoor, Admar; Latz, Eicke; Massberg, Steffen; Gaus, Katharina; Engelmann, Bernd

    2016-01-01

    The mechanisms protecting from immunopathology during acute bacterial infections are incompletely known. We found that in response to apoptotic immune cells and live or dead Listeria monocytogenes scavenger receptor BI (SR-BI), an anti-atherogenic lipid exchange mediator, activated internalization mechanisms with characteristics of macropinocytosis and, assisted by Golgi fragmentation, initiated autophagic responses. This was supported by scavenger receptor-induced local increases in membrane cholesterol concentrations which generated lipid domains particularly in cell extensions and the Golgi. SR-BI was a key driver of beclin-1-dependent autophagy during acute bacterial infection of the liver and spleen. Autophagy regulated tissue infiltration of neutrophils, suppressed accumulation of Ly6C+ (inflammatory) macrophages, and prevented hepatocyte necrosis in the core of infectious foci. Perifocal levels of Ly6C+ macrophages and Ly6C− macrophages were unaffected, indicating predominant regulation of the focus core. SR-BI-triggered autophagy promoted co-elimination of apoptotic immune cells and dead bacteria but barely influenced bacterial sequestration and survival or inflammasome activation, thus exclusively counteracting damage inflicted by immune responses. Hence, SR-BI- and autophagy promote a surveillance pathway that partially responds to products of antimicrobial defenses and selectively prevents immunity-induced damage during acute infection. Our findings suggest that control of infection-associated immunopathology can be based on a unified defense operation. PMID:27694929

  10. Host Transcriptional Profiles and Immunopathologic Response following Mycobacterium avium subsp. paratuberculosis Infection in Mice

    PubMed Central

    Shin, Min-Kyoung; Park, Hongtae; Shin, Seung Won; Jung, Myunghwan; Lee, Su-Hyung; Kim, Dae-Yong; Yoo, Han Sang

    2015-01-01

    Paratuberculosis or Johne’s disease is a chronic granulomatous enteropathy in ruminants caused by Mycobacterium avium subsp. paratuberculosis (MAP) infection. In the present study, we examined the host response to MAP infection in spleens of mice in order to investigate the host immunopathology accompanying host-pathogen interaction. Transcriptional profiles of the MAP-infected mice at 3 and 6 weeks p.i. showed severe histopathological changes, whereas those at 12 weeks p.i. displayed reduced lesion severity in the spleen and liver. MAP-infected mice at 3 and 6 weeks p.i. showed up-regulation of interferon-related genes, scavenger receptor, and complement components, suggesting an initial innate immune reaction, such as macrophage activation, bactericidal activity, and macrophage invasion of MAP. Concurrently, MAP-infected mice at 3 and 6 weeks p.i. were also suggested to express M2 macrophage phenotype with up-regulation of Mrc1, and Marco and down-regulation of MHC class II, Ccr7, and Irf5, and canonical pathways related to the T cell response including ICOS-ICOSL signaling in T helper cells, calcium-induced T lymphocyte apoptosis, and CD28 signaling in T helper cell. These results provide information which furthers the understanding of the immunopathologic response to MAP infection in mice, thereby providing insights valuable for research into the pathogenesis for MAP infection. PMID:26439498

  11. IL-23-mediated mononuclear phagocyte crosstalk protects mice from Citrobacter rodentium-induced colon immunopathology.

    PubMed

    Aychek, Tegest; Mildner, Alexander; Yona, Simon; Kim, Ki-Wook; Lampl, Nardy; Reich-Zeliger, Shlomit; Boon, Louis; Yogev, Nir; Waisman, Ari; Cua, Daniel J; Jung, Steffen

    2015-01-01

    Gut homeostasis and mucosal immune defense rely on the differential contributions of dendritic cells (DC) and macrophages. Here we show that colonic CX3CR1(+) mononuclear phagocytes are critical inducers of the innate response to Citrobacter rodentium infection. Specifically, the absence of IL-23 expression in macrophages or CD11b(+) DC results in the impairment of IL-22 production and in acute lethality. Highlighting immunopathology as a death cause, infected animals are rescued by the neutralization of IL-12 or IFNγ. Moreover, mice are also protected when the CD103(+) CD11b(-) DC compartment is rendered deficient for IL-12 production. We show that IL-12 production by colonic CD103(+) CD11b(-) DC is repressed by IL-23. Collectively, in addition to its role in inducing IL-22 production, macrophage-derived or CD103(-) CD11b(+) DC-derived IL-23 is required to negatively control the otherwise deleterious production of IL-12 by CD103(+) CD11b(-) DC. Impairment of this critical mononuclear phagocyte crosstalk results in the generation of IFNγ-producing former TH17 cells and fatal immunopathology.

  12. Differential Inhibition of Macrophage Activation by Lymphocytic Choriomeningitis Virus and Pichinde Virus Is Mediated by the Z Protein N-Terminal Domain

    PubMed Central

    Xing, Junji; Chai, Zheng; Ly, Hinh

    2015-01-01

    Several arenavirus pathogens, such as Lassa and Junin viruses, inhibit macrophage activation, the molecular mechanism of which is unclear. We show that lymphocytic choriomeningitis virus (LCMV) can also inhibit macrophage activation, in contrast to Pichinde and Tacaribe viruses, which are not known to naturally cause human diseases. Using a recombinant Pichinde virus system, we show that the LCMV Z N-terminal domain (NTD) mediates the inhibition of macrophage activation and immune functions. PMID:26423945

  13. Blockade of PD-1 Signaling Enhances Th2 Cell Responses and Aggravates Liver Immunopathology in Mice with Schistosomiasis japonica

    PubMed Central

    Zhou, Sha; Jin, Xin; Li, Yalin; Li, Wei; Chen, Xiaojun; Xu, Lei; Zhu, Jifeng; Xu, Zhipeng; Zhang, Yang; Liu, Feng; Su, Chuan

    2016-01-01

    Background More than 220 million people worldwide are chronically infected with schistosomes, causing severe disease or even death. The major pathological damage occurring in schistosomiasis is attributable to the granulomatous inflammatory response and liver fibrosis induced by schistosome eggs. The inflammatory response is tightly controlled and parallels immunosuppressive regulation, constantly maintaining immune homeostasis and limiting excessive immunopathologic damage in important host organs. It is well known that the activation of programmed death 1 (PD-1) signaling causes a significant suppression of T cell function. However, the roles of PD-1 signaling in modulating CD4+ T cell responses and immunopathology during schistosome infection, have yet to be defined. Methodology/Principal Findings Here, we show that PD-1 is upregulated in CD4+ T cells in Schistosoma japonicum (S. japonicum)-infected patients. We also show the upregulation of PD-1 expression in CD4+ T cells in the spleens, mesenteric lymph nodes, and livers of mice with S. japonicum infection. Finally, we found that the blockade of PD-1 signaling enhanced CD4+ T helper 2 (Th2) cell responses and led to more severe liver immunopathology in mice with S. japonicum infection, without a reduction of egg production or deposition in the host liver. Conclusions/Significance Overall, our study suggests that PD-1 signaling is specifically induced to control Th2-associated inflammatory responses during schistosome infection and is beneficial to the development of PD-1-based control of liver immunopathology. PMID:27792733

  14. Optimization of virus-induced gene silencing in pepper (Capsicum annuum L.).

    PubMed

    Wang, J-E; Li, D-W; Gong, Z-H; Zhang, Y-L

    2013-07-24

    Virus-induced gene silencing is currently a powerful tool for the study of gene function in plants. Here, we optimized the protocol for virus-induced gene silencing, and investigated factors that affect the efficiency of tobacco rattle virus-induced gene silencing in pepper plants. Consequently, an optimal protocol was obtained by the syringe-infiltration method in the leaves of pepper plants. The protocol involves 2-leaf stage plants, preparing the Agrobacterium inoculum at a final OD600 of 1.0 and then growing the inoculated plants at 22°C. Using this protocol, we achieved high efficiency in silencing CaPDS in different cultivars of pepper plants. We further used the CaPOD gene to illustrate the general reliability of this optimized protocol. Viral symptoms were observed on the leaves of inoculated plants of the Early Calwonder cultivar 25 days post-inoculation, indicating that this protocol can also be used to silence other genes in pepper plants. Real-time polymerase chain reaction analyses revealed that the expression levels of CaPDS and CaPOD were dramatically reduced in inoculated leaves compared to control plants. These results demonstrate that the optimized protocol can be applied to functional genomic studies in pepper to investigate genes involved in a wide range of biological processes.

  15. Influenza Virus Induces Inflammatory Response in Mouse Primary Cortical Neurons with Limited Viral Replication

    PubMed Central

    Jiang, Zhiwu; Gu, Liming; Chen, Yanxia

    2016-01-01

    Unlike stereotypical neurotropic viruses, influenza A viruses have been detected in the brain tissues of human and animal models. To investigate the interaction between neurons and influenza A viruses, mouse cortical neurons were isolated, infected with human H1N1 influenza virus, and then examined for the production of various inflammatory molecules involved in immune response. We found that replication of the influenza virus in neurons was limited, although early viral transcription was not affected. Virus-induced neuron viability decreased at 6 h postinfection (p.i.) but increased at 24 h p.i. depending upon the viral strain. Virus-induced apoptosis and cytopathy in primary cortical neurons were not apparent at 24 h p.i. The mRNA levels of inflammatory cytokines, chemokines, and type I interferons were upregulated at 6 h and 24 h p.i. These results indicate that the influenza virus induces inflammatory response in mouse primary cortical neurons with limited viral replication. The cytokines released in viral infection-induced neuroinflammation might play critical roles in influenza encephalopathy, rather than in viral replication-induced cytopathy. PMID:27525278

  16. Influenza Virus Induces Inflammatory Response in Mouse Primary Cortical Neurons with Limited Viral Replication.

    PubMed

    Wang, Gefei; Li, Rui; Jiang, Zhiwu; Gu, Liming; Chen, Yanxia; Dai, Jianping; Li, Kangsheng

    2016-01-01

    Unlike stereotypical neurotropic viruses, influenza A viruses have been detected in the brain tissues of human and animal models. To investigate the interaction between neurons and influenza A viruses, mouse cortical neurons were isolated, infected with human H1N1 influenza virus, and then examined for the production of various inflammatory molecules involved in immune response. We found that replication of the influenza virus in neurons was limited, although early viral transcription was not affected. Virus-induced neuron viability decreased at 6 h postinfection (p.i.) but increased at 24 h p.i. depending upon the viral strain. Virus-induced apoptosis and cytopathy in primary cortical neurons were not apparent at 24 h p.i. The mRNA levels of inflammatory cytokines, chemokines, and type I interferons were upregulated at 6 h and 24 h p.i. These results indicate that the influenza virus induces inflammatory response in mouse primary cortical neurons with limited viral replication. The cytokines released in viral infection-induced neuroinflammation might play critical roles in influenza encephalopathy, rather than in viral replication-induced cytopathy. PMID:27525278

  17. Comparative analysis of radiation- and virus-induced leukemias in BALB/c mice

    SciTech Connect

    Newcomb, E.W.; Binari, R.; Fleissner, E.

    1985-01-15

    Endogenous murine leukemia virus (MuLV) proviral copies were analyzed in thymomas induced in normal BALB/c (Fv-1b) and in Fv-1n congenic mice by X-irradiation. Both strains of mice developed leukemia with similar kinetics, indicating that N-tropism of endogenous MuLV was not a rate-limiting factor in development of disease. Southern blot analysis, using a probe specific for ecotropic virus and for ecotropic-specific sequences retained in pathogenic, env-recombinant viruses, showed that the majority of radiation leukemias lacked newly acquired, clonally integrated, proviruses. This was in contrast to virus-induced leukemias, which routinely exhibited several new proviral integration sites. When an internal proviral DNA restriction fragment was monitored, some radiation leukemias showed evidence of nonclonal infection, accounting for more frequent isolation of infectious virus from such leukemias. Differences in expression of T-cell surface antigens were found in X-ray-induced and virus-induced leukemias. All radiation leukemias were TL positive, whereas virus-induced leukemias were primarily negative for TL. Some differences were also found in Lyt-1 and Lyt-2 expression. The data as a whole suggest that, in the majority of cases, radiation leukemogenesis is not initiated by a viral route--that is, the sort of viral mechanism for which exogenous infection by known pathogenic MuLV is the paradigm.

  18. Absence of missense mutations in activated c-myc genes in avian leukosis virus-induced B-cell lymphomas

    SciTech Connect

    Hahn, M.; Hayward, W.S.

    1988-06-01

    The authors determined the nucleotide sequences of two independent DNA clones which contained the activated c-myc genes from avian leukosis virus-induced B-cell lymphomas. Neither of these c-myce genes contained missense mutations. This strongly supports the notion that the c-myc photo-oncogene in avian leukosis virus-induced B-cell lymphomas can be oncogenically activated by altered expression of the gene without a change in the primary structure of the gene product.

  19. Genomic profiling of human Leishmania braziliensis lesions identifies transcriptional modules associated with cutaneous immunopathology.

    PubMed

    Novais, Fernanda O; Carvalho, Lucas P; Passos, Sara; Roos, David S; Carvalho, Edgar M; Scott, Phillip; Beiting, Daniel P

    2015-01-01

    The host immune response has a critical role not only in protection from human leishmaniasis but also in promoting disease severity. Although candidate gene approaches in mouse models of leishmaniasis have been extremely informative, a global understanding of the immune pathways active in lesions from human patients is lacking. To address this issue, genome-wide transcriptional profiling of Leishmania braziliensis-infected cutaneous lesions and normal skin controls was carried out. A signature of the L. braziliensis skin lesion was defined, which includes over 2,000 differentially regulated genes. Pathway-level analysis of this transcriptional response revealed key biological pathways present in cutaneous lesions, generating a testable 'metapathway' model of immunopathology and providing new insights for treatment of human leishmaniasis.

  20. Development of replication-defective lymphocytic choriomeningitis virus vectors for the induction of potent CD8+ T cell immunity

    PubMed Central

    Flatz, Lukas; Hegazy, Ahmed N; Bergthaler, Andreas; Verschoor, Admar; Claus, Christina; Fernandez, Marylise; Gattinoni, Luca; Johnson, Susan; Kreppel, Florian; Kochanek, Stefan; van den Broek, Maries; Radbruch, Andreas; Lévy, Frédéric; Lambert, Paul-Henri; Siegrist, Claire-Anne; Restifo, Nicholas P; Löhning, Max; Ochsenbein, Adrian F; Nabel, Gary J; Pinschewer, Daniel D

    2011-01-01

    Lymphocytic choriomeningitis virus (LCMV) exhibits natural tropism for dendritic cells and represents the prototypic infection that elicits protective CD8+ T cell (cytotoxic T lymphocyte (CTL)) immunity. Here we have harnessed the immunobiology of this arenavirus for vaccine delivery. By using producer cells constitutively synthesizing the viral glycoprotein (GP), it was possible to replace the gene encoding LCMV GP with vaccine antigens to create replication-defective vaccine vectors. These rLCMV vaccines elicited CTL responses that were equivalent to or greater than those elicited by recombinant adenovirus 5 or recombinant vaccinia virus in their magnitude and cytokine profiles, and they exhibited more effective protection in several models. In contrast to recombinant adenovirus 5, rLCMV failed to elicit vector-specific antibody immunity, which facilitated re-administration of the same vector for booster vaccination. In addition, rLCMV elicited T helper type 1 CD4+ T cell responses and protective neutralizing antibodies to vaccine antigens. These features, together with low seroprevalence in humans, suggest that rLCMV may show utility as a vaccine platform against infectious diseases and cancer. PMID:20139992

  1. Phenotypic and Functional Analysis of Activated Regulatory T Cells Isolated from Chronic Lymphocytic Choriomeningitis Virus-infected Mice.

    PubMed

    Park, Hyo Jin; Oh, Ji Hoon; Ha, Sang-Jun

    2016-01-01

    Regulatory T (Treg) cells, which express Foxp3 as a transcription factor, are subsets of CD4(+) T cells. Treg cells play crucial roles in immune tolerance and homeostasis maintenance by regulating the immune response. The primary role of Treg cells is to suppress the proliferation of effector T (Teff) cells and the production of cytokines such as IFN-γ, TNF-α, and IL-2. It has been demonstrated that Treg cells' ability to inhibit the function of Teff cells is enhanced during persistent pathogen infection and cancer development. To clarify the function of Treg cells under resting or inflamed conditions, a variety of in vitro suppression assays using mouse or human Treg cells have been devised. The main aim of this study is to develop a method to compare the differences in phenotype and suppressive function between resting and activated Treg cells. To isolate activated Treg cells, mice were infected with lymphocytic choriomeningitis virus (LCMV) clone 13 (CL13), a chronic strain of LCMV. Treg cells isolated from the spleen of LCMV CL13-infected mice exhibited both the activated phenotype and enhanced suppressive activity compared with resting Treg cells isolated from naïve mice. Here, we describe the basic protocol for ex vivo phenotype analysis to distinguish activated Treg cells from resting Treg cells. Furthermore, we describe a protocol for the measurement of the suppressive activity of fully activated Treg cells. PMID:27404802

  2. Virus-triggered acquired immunodeficiency by cytotoxic T-cell-dependent destruction of antigen-presenting cells and lymph follicle structure.

    PubMed Central

    Odermatt, B; Eppler, M; Leist, T P; Hengartner, H; Zinkernagel, R M

    1991-01-01

    Virus-induced acquired immune suppression in mice infected with lymphocytic choriomeningitis virus is shown here to be caused by the CD8+-T-cell-dependent elimination of macrophages/antigen-presenting cells. Surprisingly, this is associated with severe destruction of the follicular organization of lymphoid organs, indicating a crucial role for dendritic cells and marginal zone macrophages in maintaining follicular structure. Once established, this immunopathology cannot be readily reversed by the elimination of CD8+ effector cells. Such a T-cell-mediated pathogenesis may play a pivotal role in acquired virus-induced immunosuppression and may represent one strategy by which virus escapes immune surveillance and establishes persistent infections in initially immunocompetent hosts. Images PMID:1910175

  3. Comorbidity of Narcolepsy Type 1 With Autoimmune Diseases and Other Immunopathological Disorders: A Case-Control Study

    PubMed Central

    Martinez-Orozco, Francisco Javier; Vicario, Jose Luis; De Andres, Clara; Fernandez-Arquero, Miguel; Peraita-Adrados, Rosa

    2016-01-01

    Background Several evidences suggest that autoimmune diseases (ADs) tend to co-occur in an individual and within the same family. Narcolepsy type 1 (NT1) is a chronic sleep disorder caused by a selective loss of hypocretin-producing neurons due to a mechanism of neural destruction that indicates an autoimmune pathogenesis, although no evidence is available. We report on the comorbidity of ADs and other immunopathological diseases (including allergy diseases) in narcolepsy. Methods We studied 158 Caucasian NT1 patients (60.7% male; mean age 49.4 ± 19.7 years), in whom the diagnosis was confirmed by polysomnography followed by a multiple sleep latency test, or by hypocretin-1 levels measurements. Results Thirty out of 158 patients (18.99%; 53.3% female; 29 sporadic and one familial cases) had one or more immunopathological diseases associated. A control group of 151 subjects were matched by gender and age with the narcolepsy patients. Results demonstrated that there was a higher frequency of ADs in our series of narcolepsy patients compared to the sample of general population (odds ratio: 3.17; 95% confidence interval: 1.01 - 10.07; P = 0.040). A temporal relationship with the age at onset of the diseases was found. Conclusions Cataplexy was significantly more severe in NT1 patients with immunopathological diseases, and immunopathological diseases are a risk factor for severe forms of cataplexy in our series (odds ratio: 23.6; 95% confidence interval: 5.5 - 100.1). PMID:27298657

  4. EGFR activation suppresses respiratory virus-induced IRF1-dependent CXCL10 production.

    PubMed

    Kalinowski, April; Ueki, Iris; Min-Oo, Gundula; Ballon-Landa, Eric; Knoff, David; Galen, Benjamin; Lanier, Lewis L; Nadel, Jay A; Koff, Jonathan L

    2014-07-15

    Airway epithelial cells are the primary cell type involved in respiratory viral infection. Upon infection, airway epithelium plays a critical role in host defense against viral infection by contributing to innate and adaptive immune responses. Influenza A virus, rhinovirus, and respiratory syncytial virus (RSV) represent a broad range of human viral pathogens that cause viral pneumonia and induce exacerbations of asthma and chronic obstructive pulmonary disease. These respiratory viruses induce airway epithelial production of IL-8, which involves epidermal growth factor receptor (EGFR) activation. EGFR activation involves an integrated signaling pathway that includes NADPH oxidase activation of metalloproteinase, and EGFR proligand release that activates EGFR. Because respiratory viruses have been shown to activate EGFR via this signaling pathway in airway epithelium, we investigated the effect of virus-induced EGFR activation on airway epithelial antiviral responses. CXCL10, a chemokine produced by airway epithelial cells in response to respiratory viral infection, contributes to the recruitment of lymphocytes to target and kill virus-infected cells. While respiratory viruses activate EGFR, the interaction between CXCL10 and EGFR signaling pathways is unclear, and the potential for EGFR signaling to suppress CXCL10 has not been explored. Here, we report that respiratory virus-induced EGFR activation suppresses CXCL10 production. We found that influenza virus-, rhinovirus-, and RSV-induced EGFR activation suppressed IFN regulatory factor (IRF) 1-dependent CXCL10 production. In addition, inhibition of EGFR during viral infection augmented IRF1 and CXCL10. These findings describe a novel mechanism that viruses use to suppress endogenous antiviral defenses, and provide potential targets for future therapies.

  5. Age-related Defects in Ocular and Nasal Mucosal Immune System and the Immunopathology of Dry Eye Disease

    PubMed Central

    Farid, Marjan; Agrawal, Anshu; Fremgen, Daniel; Tao, Jeremiah; Chuyi, He; Nesburn, Anthony B.; BenMohamed, Lbachir

    2014-01-01

    Dry eye disease (DED) is a prevalent public health concern that affects up to 30% of adults and is particularly chronic and severe in the elderly. Two interconnected mechanisms cause DED: (1) an age-related dysfunction of lacrimal and meibomian glands, which leads to decreased tear production and/or an increase in tear evaporation; and (2) an age-related uncontrolled inflammation of the surface of the eye triggered by yet-to-be-determined internal immunopathological mechanisms, independent of tear deficiency and evaporation. In this review we summarize current knowledge on animal models that mimic both the severity and chronicity of inflammatory DED and that have been reliably used to provide insights into the immunopathological mechanisms of DED, and we provide an overview of the opportunities and limitations of the rabbit model in investigating the role of both ocular and nasal mucosal immune systems in the immunopathology of inflammatory DED and in testing novel immunotherapies aimed at delaying or reversing the uncontrolled age-related inflammatory DED. PMID:25535823

  6. Age-related Defects in Ocular and Nasal Mucosal Immune System and the Immunopathology of Dry Eye Disease.

    PubMed

    Farid, Marjan; Agrawal, Anshu; Fremgen, Daniel; Tao, Jeremiah; Chuyi, He; Nesburn, Anthony B; BenMohamed, Lbachir

    2016-06-01

    Dry eye disease (DED) is a prevalent public health concern that affects up to 30% of adults and is particularly chronic and severe in the elderly. Two interconnected mechanisms cause DED: (1) an age-related dysfunction of lacrimal and meibomian glands, which leads to decreased tear production and/or an increase in tear evaporation; and (2) an age-related uncontrolled inflammation of the surface of the eye triggered by yet-to-be-determined internal immunopathological mechanisms, independent of tear deficiency and evaporation. In this review we summarize current knowledge on animal models that mimic both the severity and chronicity of inflammatory DED and that have been reliably used to provide insights into the immunopathological mechanisms of DED, and we provide an overview of the opportunities and limitations of the rabbit model in investigating the role of both ocular and nasal mucosal immune systems in the immunopathology of inflammatory DED and in testing novel immunotherapies aimed at delaying or reversing the uncontrolled age-related inflammatory DED.

  7. [Professor Adam Nowosławski (1925-2012)--founder of the Polish School of Immunopathology].

    PubMed

    Madaliński, Kazimierz

    2012-01-01

    Professor dr med. Adam Nowosławski, has died at age of 87, on February 3, 2012, the founder of the Polish school of immunopathology, member of Polish Academy of Sciences and of Polish Academy of Art and Sciences. Professor was born on April 30, 1925 in Rzeszów (SE Poland). During the Second World War he took part in the anti-nazi resistance movement; he was the soldier of the 'Baszta' regiment of the Home Army. Subsequently, he was imprisoned in the Pawiak and concentration camps: Majdanek and Buchenwald. The medical studies he has completed at Warsaw Medical Academy between 1946-1951. The degree of doctor of medicine Prof. Adam Nowosławski has obtained in 1963, habilitation degree in the field of immunopathology--in 1966; the title of Professor he has obtained in 1980. His scientific achievements consist of 170 publications, including 101 original papers. His publications were quoted in several American books for students and physicians. Topics of his early papers concerned the immunopatogenesis ofPneumocystis carinii--induced pneumonia in premature babies, immunopatogenesis of rheumatoid arthritis, and the origin of rheumatoid factor. The enormous role in the field of hepatology played research on the virus of hepatitis B. These studies dealt with the discovery of HB core antigen which had the cellular localization different from HB surface antigen and with the parameters of the immune response to infection. Papers published on this topic were the mostly quoted in the literature and earned him national awards. The activity of Prof. Adam Nowosławski in the field of HIV/AIDS prevention was honored by the special prize of the Minister of Health. Professor was the honorary member of the two Societies: Polish Society of Pathologists and Polish Society of Hepatology. He was also the member of International Association for the Study of the Liver and International Academy of Pathology. Prof. Adam Nowosławski received the national medals: Polonia Restituta Crosses

  8. MR VIGS: microRNA-based virus-induced gene silencing in plants.

    PubMed

    Chen, Weiwei; Zhang, Qi; Kong, Junhua; Hu, Feng; Li, Bin; Wu, Chaoqun; Qin, Cheng; Zhang, Pengcheng; Shi, Nongnong; Hong, Yiguo

    2015-01-01

    In plants, microRNA (miRNA)-based virus-induced gene silencing, dubbed MR VIGS, is a powerful technique to delineate the biological functions of genes. By targeting to a specific sequence, miRNAs can knock down expression of genes with fewer off-target effects. Here, using a modified Cabbage leaf curling virus (CaLCuV) and Tobacco rattle virus (TRV) as vectors, we describe two virus-based miRNA expression systems to perform MR VIGS for plant functional genomics assays. PMID:25740363

  9. RIG-I Signaling Is Essential for Influenza B Virus-Induced Rapid Interferon Gene Expression

    PubMed Central

    Österlund, Pamela; Westenius, Veera; Latvala, Sinikka; Diamond, Michael S.; Gale, Michael; Julkunen, Ilkka

    2015-01-01

    ABSTRACT Influenza B virus causes annual epidemics and, along with influenza A virus, accounts for substantial disease and economic burden throughout the world. Influenza B virus infects only humans and some marine mammals and is not responsible for pandemics, possibly due to a very low frequency of reassortment and a lower evolutionary rate than that of influenza A virus. Influenza B virus has been less studied than influenza A virus, and thus, a comparison of influenza A and B virus infection mechanisms may provide new insight into virus-host interactions. Here we analyzed the early events in influenza B virus infection and interferon (IFN) gene expression in human monocyte-derived macrophages and dendritic cells. We show that influenza B virus induces IFN regulatory factor 3 (IRF3) activation and IFN-λ1 gene expression with faster kinetics than does influenza A virus, without a requirement for viral protein synthesis or replication. Influenza B virus-induced activation of IRF3 required the fusion of viral and endosomal membranes, and nuclear accumulation of IRF3 and viral NP occurred concurrently. In comparison, immediate early IRF3 activation was not observed in influenza A virus-infected macrophages. Experiments with RIG-I-, MDA5-, and RIG-I/MDA5-deficient mouse fibroblasts showed that RIG-I is the critical pattern recognition receptor needed for the influenza B virus-induced activation of IRF3. Our results show that innate immune mechanisms are activated immediately after influenza B virus entry through the endocytic pathway, whereas influenza A virus avoids early IRF3 activation and IFN gene induction. IMPORTANCE Recently, a great deal of interest has been paid to identifying the ligands for RIG-I under conditions of natural infection, as many previous studies have been based on transfection of cells with different types of viral or synthetic RNA structures. We shed light on this question by analyzing the earliest step in innate immune recognition of

  10. Multiple mechanisms contribute to impairment of type 1 interferon production during chronic lymphocytic choriomeningitis virus infection of mice.

    PubMed

    Lee, Lian Ni; Burke, Shannon; Montoya, Maria; Borrow, Persephone

    2009-06-01

    Type 1 IFNs, innate cytokines with important effector and immunomodulatory properties, are rapidly induced in the acute phase of many virus infections; however, this is generally a transient response that is not sustained during virus persistence. To gain insight into mechanisms that can contribute to down-regulation of type 1 IFN production during virus persistence, we analyzed type 1 IFN production during acute and chronic lymphocytic choriomeningitis virus (LCMV) infection. High-level type 1 IFN production was transiently up-regulated in cells including plasmacytoid and conventional dendritic cells (DCs) following LCMV infection of mice, but LCMV persistence was associated with only low-level type 1 IFN production. Nonetheless, chronically infected mice were able to up-regulate type 1 IFN production in response to TLR3, 7, and 9 ligands, albeit less efficiently than uninfected mice. Splenic DC numbers in mice chronically infected with LCMV were decreased, and the remaining cells exhibited a reduced response to TLR stimulation. LCMV-infected cell lines efficiently up-regulated type 1 IFN production following TLR ligation and infection with a DNA virus, but exhibited a defect in type 1 IFN induction following infection with Sendai, an RNA virus. This block in type 1 IFN production by infected cells, together with abnormalities in DC numbers and functions, likely contribute to the low-level type 1 IFN production in mice chronically infected with LCMV. Impairment of type 1 IFN production may both promote virus persistence and impact on host immunocompetence. Understanding the mechanisms involved may assist in development of strategies for control of virus persistence and superinfection. PMID:19454715

  11. Uncovering subdominant cytotoxic T-lymphocyte responses in lymphocytic choriomeningitis virus-infected BALB/c mice.

    PubMed Central

    van der Most, R G; Concepcion, R J; Oseroff, C; Alexander, J; Southwood, S; Sidney, J; Chesnut, R W; Ahmed, R; Sette, A

    1997-01-01

    The cytotoxic T-lymphocyte response against lymphocytic choriomeningitis virus (LCMV) in BALB/c mice is predominantly directed against a single, Ld-restricted epitope in the viral nucleoprotein (residues 118 to 126). To investigate whether any Kd/Dd-restricted responses were activated but did not expand during the primary response, we used a BALB/c mutant, BALB/c-H-2dm2, which does not express the Ld molecule. Splenocytes from LCMV-infected BALB/c mice were transferred into irradiated BALB/c-H-2dm2 mice and rechallenged with LCMV. Thus, they were exposed to an antigenic stimulus without the involvement of the immunodominant Ld-restricted epitope. In this adoptive transfer model, the donor splenocytes protected the recipient mice against chronic LCMV infection by mounting a potent Kd- and/or Dd-restricted secondary antiviral response. Analysis of a panel of Kd binding LCMV peptides revealed that residues 283 to 291 from the viral glycoprotein (GP(283-291)) comprise a major new epitope in the adoptive transfer model. Because the donor splenocytes were first activated during the primary infection in BALB/c mice, the GP(283-291) epitope is a subdominant epitope in BALB/c mice that becomes dominant after rechallenge in BALB/c-H-2dm2 mice. This study makes two points. First, it shows that subdominant CTL responses can be protective, and second, it provides a general experimental approach for uncovering subdominant CTL responses in vivo. This strategy can be used to identify subdominant T-cell responses in other systems. PMID:9188577

  12. Type I IFN signaling triggers immunopathology in tuberculosis-susceptible mice by modulating lung phagocyte dynamics

    PubMed Central

    Dorhoi, Anca; Yeremeev, Vladimir; Nouailles, Geraldine; Weiner, January; Jörg, Sabine; Heinemann, Ellen; Oberbeck-Müller, Dagmar; Knaul, Julia K; Vogelzang, Alexis; Reece, Stephen T; Hahnke, Karin; Mollenkopf, Hans-Joachim; Brinkmann, Volker; Kaufmann, Stefan H E

    2014-01-01

    General interest in the biological functions of IFN type I in Mycobacterium tuberculosis (Mtb) infection increased after the recent identification of a distinct IFN gene expression signature in tuberculosis (TB) patients. Here, we demonstrate that TB-susceptible mice lacking the receptor for IFN I (IFNAR1) were protected from death upon aerogenic infection with Mtb. Using this experimental model to mimic primary progressive pulmonary TB, we dissected the immune processes affected by IFN I. IFNAR1 signaling did not affect T-cell responses, but markedly altered migration of inflammatory monocytes and neutrophils to the lung. This process was orchestrated by IFNAR1 expressed on both immune and tissue-resident radioresistant cells. IFNAR1-driven TB susceptibility was initiated by augmented Mtb replication and in situ death events, along with CXCL5/CXCL1-driven accumulation of neutrophils in alveoli, followed by the discrete compartmentalization of Mtb in lung phagocytes. Early depletion of neutrophils rescued TB-susceptible mice to levels observed in mice lacking IFNAR1. We conclude that IFN I alters early innate events at the site of Mtb invasion leading to fatal immunopathology. These data furnish a mechanistic explanation for the detrimental role of IFN I in pulmonary TB and form a basis for understanding the complex roles of IFN I in chronic inflammation. PMID:24782112

  13. Chemokine receptor Ccr1 drives neutrophil-mediated kidney immunopathology and mortality in invasive candidiasis.

    PubMed

    Lionakis, Michail S; Fischer, Brett G; Lim, Jean K; Swamydas, Muthulekha; Wan, Wuzhou; Richard Lee, Chyi-Chia; Cohen, Jeffrey I; Scheinberg, Phillip; Gao, Ji-Liang; Murphy, Philip M

    2012-01-01

    Invasive candidiasis is the 4(th) leading cause of nosocomial bloodstream infection in the US with mortality that exceeds 40% despite administration of antifungal therapy; neutropenia is a major risk factor for poor outcome after invasive candidiasis. In a fatal mouse model of invasive candidiasis that mimics human bloodstream-derived invasive candidiasis, the most highly infected organ is the kidney and neutrophils are the major cellular mediators of host defense; however, factors regulating neutrophil recruitment have not been previously defined. Here we show that mice lacking chemokine receptor Ccr1, which is widely expressed on leukocytes, had selectively impaired accumulation of neutrophils in the kidney limited to the late phase of the time course of the model; surprisingly, this was associated with improved renal function and survival without affecting tissue fungal burden. Consistent with this, neutrophils from wild-type mice in blood and kidney switched from Ccr1(lo) to Ccr1(high) at late time-points post-infection, when Ccr1 ligands were produced at high levels in the kidney and were chemotactic for kidney neutrophils ex vivo. Further, when a 1∶1 mixture of Ccr1(+/+) and Ccr1(-/-) donor neutrophils was adoptively transferred intravenously into Candida-infected Ccr1(+/+) recipient mice, neutrophil trafficking into the kidney was significantly skewed toward Ccr1(+/+) cells. Thus, neutrophil Ccr1 amplifies late renal immunopathology and increases mortality in invasive candidiasis by mediating excessive recruitment of neutrophils from the blood to the target organ.

  14. Bench-to-bedside review: Platelets and active immune functions - new clues for immunopathology?

    PubMed

    Garraud, Olivier; Hamzeh-Cognasse, Hind; Pozzetto, Bruno; Cavaillon, Jean-Marc; Cognasse, Fabrice

    2013-08-27

    Platelets display a number of properties besides the crucial function of repairing damaged vascular endothelium and stopping bleeding; these are exploited to benefit patients receiving platelet component transfusions, which might categorize them as innate immune cells. For example, platelets specialize in pro-inflammatory activities, and can secrete a large number of molecules, many of which display biological response modifier functions. Platelets also express receptors for non-self-infectious and possibly non-infectious danger signals, and can engage infectious pathogens by mechanisms barely explained beyond observation. This relationship with infectious pathogens may involve other innate immune cells, especially neutrophils. The sophisticated interplay of platelets with bacteria may culminate in sepsis, a severe pathology characterized by significant reductions in platelet count and platelet dysfunction. How this occurs is still not fully understood. Recent findings from in-depth platelet signaling studies reveal the complexity of platelets and some of the ways they evolve along the immune continuum, from beneficial functions exemplified in endothelium repair to deleterious immunopathology as in systemic inflammatory response syndrome and acute vascular diseases. This review discusses the extended role of platelets as immune cells to emphasize their interactions with infectious pathogens sensed as potentially dangerous.

  15. Acquired cystic disease-associated renal cell carcinoma: further characterization of the morphologic and immunopathologic features.

    PubMed

    Ahn, Soomin; Kwon, Ghee Young; Cho, Yong Mee; Jun, Sun-Young; Choi, Chan; Kim, Hyun-Jung; Park, Yong Wook; Park, Weon Seo; Shim, Jung Won

    2013-12-01

    Acquired cystic disease-associated renal cell carcinoma (ACD-RCC) is a subtype of renal cell carcinoma (RCC) with unique morphologic features found exclusively in the background of end-stage renal disease. We analyzed the clinicopathologic features and immumoreactive profiles of 12 cases of ACD-RCC to further characterize this recently recognized entity. Review of histologic slides was performed in conjunction with immunohistochemical staining directed to the contemporary diagnostic antibodies and the putative target therapy-related markers. Histologically, the tumors showed characteristic inter-or intracellular microlumens and eosinophilic tumor cells. Intratumoral hemosiderin deposition and degenerating foamy tumor cells were consistent findings which were not previously described. Immunohistochemically, all the tumors were positive for alpha-methylacyl-CoA-racemase, CD10, pan-cytokeratin, PTEN (phosphatase and tensin homolog deleted on chromosome 10) and c-met, while negative for carbonic anhydrase-9, CD57, CD68, c-kit, pax-2, platelet-derived growth factor receptor (PDGFR)-α or vascular endothelial growth factor receptor (VEGFR)-2. Heterogenous staining was found for CK7 and kidney-specific cadherin. Positive reaction to c-met suggests its utility as a plausible therapeutic target in ACD-RCC. Thus, we present the unique morphologic and immunopathologic features of ACD-RCC, which may be helpful in both diagnostic and therapeutic aspects. PMID:23471757

  16. Immunity, immunopathology, and human vaccine development against sexually transmitted Chlamydia trachomatis

    PubMed Central

    Rey-Ladino, Jose; Ross, Allen GP; Cripps, Allan W

    2014-01-01

    This review examines the immunity, immunopathology, and contemporary problems of vaccine development against sexually transmitted Chlamydia trachomatis. Despite improved surveillance and treatment initiatives, the incidence of C. trachomatis infection has increased dramatically over the past 30 years in both the developed and developing world. Studies in animal models have shown that protective immunity to C. trachomatis is largely mediated by Th1 T cells producing IFN-γ which is needed to prevent dissemination of infection. Similar protection appears to develop in humans but in contrast to mice, immunity in humans may take years to develop. Animal studies and evidence from human infection indicate that immunity to C. trachomatis is accompanied by significant pathology in the upper genital tract. Although no credible evidence is currently available to indicate that autoimmunity plays a role, nevertheless, this underscores the necessity to design vaccines strictly based on chlamydial-specific antigens and to avoid those displaying even minimal sequence homologies with host molecules. Current advances in C. trachomatis vaccine development as well as alternatives for designing new vaccines for this disease are discussed. A novel approach for chlamydia vaccine development, based on targeting endogenous dendritic cells, is described. PMID:25483666

  17. Establishment of a highly efficient virus-inducible CRISPR/Cas9 system in insect cells.

    PubMed

    Dong, Zhan-Qi; Chen, Ting-Ting; Zhang, Jun; Hu, Nan; Cao, Ming-Ya; Dong, Fei-Fan; Jiang, Ya-Ming; Chen, Peng; Lu, Cheng; Pan, Min-Hui

    2016-06-01

    Although current antiviral strategies can inhibit baculovirus infection and decrease viral DNA replication to a certain extent, novel tools are required for specific and accurate elimination of baculovirus genomes from infected insects. Using the newly developed clustered regularly interspaced short palindromic repeats/associated protein 9 nuclease (CRISPR/Cas9) technology, we disrupted a viral genome in infected insect cells in vitro as a defense against viral infection. We optimized the CRISPR/Cas9 system to edit foreign and viral genome in insect cells. Using Bombyx mori nucleopolyhedrovirus (BmNPV) as a model, we found that the CRISPR/Cas9 system was capable of cleaving the replication key factor ie-1 in BmNPV thus effectively inhibiting virus proliferation. Furthermore, we constructed a virus-inducible CRISPR/Cas9 editing system, which minimized the probability of off-target effects and was rapidly activated after viral infection. This is the first report describing the application of the CRISPR/Cas9 system in insect antiviral research. Establishment of a highly efficient virus-inducible CRISPR/Cas9 system in insect cells provides insights to produce virus-resistant transgenic strains for future. PMID:26979473

  18. Establishment of a highly efficient virus-inducible CRISPR/Cas9 system in insect cells.

    PubMed

    Dong, Zhan-Qi; Chen, Ting-Ting; Zhang, Jun; Hu, Nan; Cao, Ming-Ya; Dong, Fei-Fan; Jiang, Ya-Ming; Chen, Peng; Lu, Cheng; Pan, Min-Hui

    2016-06-01

    Although current antiviral strategies can inhibit baculovirus infection and decrease viral DNA replication to a certain extent, novel tools are required for specific and accurate elimination of baculovirus genomes from infected insects. Using the newly developed clustered regularly interspaced short palindromic repeats/associated protein 9 nuclease (CRISPR/Cas9) technology, we disrupted a viral genome in infected insect cells in vitro as a defense against viral infection. We optimized the CRISPR/Cas9 system to edit foreign and viral genome in insect cells. Using Bombyx mori nucleopolyhedrovirus (BmNPV) as a model, we found that the CRISPR/Cas9 system was capable of cleaving the replication key factor ie-1 in BmNPV thus effectively inhibiting virus proliferation. Furthermore, we constructed a virus-inducible CRISPR/Cas9 editing system, which minimized the probability of off-target effects and was rapidly activated after viral infection. This is the first report describing the application of the CRISPR/Cas9 system in insect antiviral research. Establishment of a highly efficient virus-inducible CRISPR/Cas9 system in insect cells provides insights to produce virus-resistant transgenic strains for future.

  19. A project by the SIDeMaST Immunopathology Group on cutaneous vasculitis.

    PubMed

    Papini, M; Quaglino, P; La Placa, M; Marzano, A V

    2015-04-01

    Vasculitides are a challenge to the clinician, in terms of both diagnosis and therapy. Multiple classification systems have been implemented and the numerous classification schemes reflect the complexity of establishing a simple classification that could be functional for daily care. Although vasculitis classification has become increasingly elaborated, some areas remain ill defined. Some forms of vasculitis are still difficult to assign to a specific disease entity. Generally accepted operational criteria are available for many vasculitides, but for some entities there are no effective criteria. Moreover, diagnostic criteria for vasculitis with sufficient strength and/or confidence that can be universally accepted are not yet available. The need for diagnostic criteria validated and agreed upon is particularly relevant in the context of cutaneous vasculitis. The project of the SIDeMaST Italian Group of Immunopathology on cutaneous vasculitis is a national prospective observational study designed to develop and validate diagnostic criteria and to improve and validate classification criteria for cutaneous small vessel vasculitis also known as leukocytoclastic vasculitis (CLV). Primary objective of the study will also be that of developing the CUtaneous VAsculitis Severity Index (CUVASI). Secondary objectives of the project will be: 1) definition of the etiological agents that are most frequently associated with CLV; 2) search for possible correlations between causative agent and peculiar clinical and/or histopathological aspects; 3) evaluation of immunofluorescence pattern observed in this specific group of primitive cutaneous vasculitis in order to characterize the diagnostic sensitivity and specificity of this technique; 4) identification of a set of clinical investigations and laboratory tests to be performed for a correct CLV assessment. Actually 15 Italian dermatological clinics are contributing to the project and anticipated recruiting >100 patients with CLV

  20. Unique role for ATG5 in neutrophil-mediated immunopathology during M. tuberculosis infection.

    PubMed

    Kimmey, Jacqueline M; Huynh, Jeremy P; Weiss, Leslie A; Park, Sunmin; Kambal, Amal; Debnath, Jayanta; Virgin, Herbert W; Stallings, Christina L

    2015-12-24

    Mycobacterium tuberculosis, a major global health threat, replicates in macrophages in part by inhibiting phagosome-lysosome fusion, until interferon-γ (IFNγ) activates the macrophage to traffic M. tuberculosis to the lysosome. How IFNγ elicits this effect is unknown, but many studies suggest a role for macroautophagy (herein termed autophagy), a process by which cytoplasmic contents are targeted for lysosomal degradation. The involvement of autophagy has been defined based on studies in cultured cells where M. tuberculosis co-localizes with autophagy factors ATG5, ATG12, ATG16L1, p62, NDP52, BECN1 and LC3 (refs 2-6), stimulation of autophagy increases bacterial killing, and inhibition of autophagy increases bacterial survival. Notably, these studies reveal modest (~1.5-3-fold change) effects on M. tuberculosis replication. By contrast, mice lacking ATG5 in monocyte-derived cells and neutrophils (polymorponuclear cells, PMNs) succumb to M. tuberculosis within 30 days, an extremely severe phenotype similar to mice lacking IFNγ signalling. Importantly, ATG5 is the only autophagy factor that has been studied during M. tuberculosis infection in vivo and autophagy-independent functions of ATG5 have been described. For this reason, we used a genetic approach to elucidate the role for multiple autophagy-related genes and the requirement for autophagy in resistance to M. tuberculosis infection in vivo. Here we show that, contrary to expectation, autophagic capacity does not correlate with the outcome of M. tuberculosis infection. Instead, ATG5 plays a unique role in protection against M. tuberculosis by preventing PMN-mediated immunopathology. Furthermore, while Atg5 is dispensable in alveolar macrophages during M. tuberculosis infection, loss of Atg5 in PMNs can sensitize mice to M. tuberculosis. These findings shift our understanding of the role of ATG5 during M. tuberculosis infection, reveal new outcomes of ATG5 activity, and shed light on early events in innate

  1. Unique role for ATG5 in neutrophil-mediated immunopathology during M. tuberculosis infection.

    PubMed

    Kimmey, Jacqueline M; Huynh, Jeremy P; Weiss, Leslie A; Park, Sunmin; Kambal, Amal; Debnath, Jayanta; Virgin, Herbert W; Stallings, Christina L

    2015-12-24

    Mycobacterium tuberculosis, a major global health threat, replicates in macrophages in part by inhibiting phagosome-lysosome fusion, until interferon-γ (IFNγ) activates the macrophage to traffic M. tuberculosis to the lysosome. How IFNγ elicits this effect is unknown, but many studies suggest a role for macroautophagy (herein termed autophagy), a process by which cytoplasmic contents are targeted for lysosomal degradation. The involvement of autophagy has been defined based on studies in cultured cells where M. tuberculosis co-localizes with autophagy factors ATG5, ATG12, ATG16L1, p62, NDP52, BECN1 and LC3 (refs 2-6), stimulation of autophagy increases bacterial killing, and inhibition of autophagy increases bacterial survival. Notably, these studies reveal modest (~1.5-3-fold change) effects on M. tuberculosis replication. By contrast, mice lacking ATG5 in monocyte-derived cells and neutrophils (polymorponuclear cells, PMNs) succumb to M. tuberculosis within 30 days, an extremely severe phenotype similar to mice lacking IFNγ signalling. Importantly, ATG5 is the only autophagy factor that has been studied during M. tuberculosis infection in vivo and autophagy-independent functions of ATG5 have been described. For this reason, we used a genetic approach to elucidate the role for multiple autophagy-related genes and the requirement for autophagy in resistance to M. tuberculosis infection in vivo. Here we show that, contrary to expectation, autophagic capacity does not correlate with the outcome of M. tuberculosis infection. Instead, ATG5 plays a unique role in protection against M. tuberculosis by preventing PMN-mediated immunopathology. Furthermore, while Atg5 is dispensable in alveolar macrophages during M. tuberculosis infection, loss of Atg5 in PMNs can sensitize mice to M. tuberculosis. These findings shift our understanding of the role of ATG5 during M. tuberculosis infection, reveal new outcomes of ATG5 activity, and shed light on early events in innate

  2. Transcriptome analyses and virus induced gene silencing identify genes in the Rpp4-mediated Asian soybean rust resistance pathway

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rpp4 (Resistance to Phakopsora pachyrhizi 4) confers resistance to P. pachyrhizi, the causal agent of Asian soybean rust (ASR). By combining expression profiling and virus induced gene silencing (VIGS), we are developing a genetic framework for Rpp4-mediated resistance. We measured gene expression i...

  3. Virus-induced gene silencing of RPC5-like subunit of RNA polymerase III caused pleiotropic effects in Nicotiana benthamiana

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In eukaryotic cells, RNA polymerase III is highly conserved, contains 17 subunits and transcribes housekeeping genes such as ribosomal 50S rRNA, tRNA and other small RNAs. Functional roles of the RPC5 are poorly characterized in the literature. In this work, we report that virus-induced gene silenci...

  4. Virus-induced gene silencing in diverse maize lines using the Brome Mosaic virus-based silencing vector

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Virus-induced gene silencing (VIGS) is a widely used tool for gene function studies in many plant species, though its use in monocots has been limited. Using a Brome mosaic virus (BMV) vector designed to silence the maize phytoene desaturase gene, a genetically diverse set of maize inbred lines was ...

  5. Virus-induced gene silencing and transient gene expression in soybean using Bean pod mottle virus infectious clones

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Virus-induced gene silencing (VIGS) is a powerful and rapid approach for determining the functions of plant genes. The basis of VIGS is that a viral genome is engineered so that it can carry fragments of plant genes, typically in the 200-300 base pair size range. The recombinant viruses are used to ...

  6. Strategies for altering plant traits using virus-induced gene silencing technologies.

    PubMed

    Lacomme, Christophe

    2015-01-01

    The rapid progress in genome sequencing and transcriptome analysis in model and crop plants has made possible the identification of a vast number of genes potentially associated with economically important complex traits. The ultimate goal is to assign functions to these genes by using forward and reverse genetic screens. Plant viruses have been developed for virus-induced gene silencing (VIGS) to generate rapid gene knockdown phenotypes in numerous plant species. To fulfill its potential for high-throughput phenomics, it is of prime importance to ensure that parameters conditioning the VIGS response, i.e., plant-virus interactions and associated loss-of-function screens, are "fit for purpose" and optimized to unequivocally conclude the role of a gene of interest in relation to a given trait. This chapter will review and discuss the different strategies used for the development of VIGS-based phenomics in model and crop species. PMID:25740354

  7. Influenza A virus-induced polymorphonuclear leukocyte dysfunction in the pathogenesis of experimental pneumococcal otitis media.

    PubMed Central

    Abramson, J S; Giebink, G S; Quie, P G

    1982-01-01

    The role of influenza A virus-induced polymorphonuclear leukocyte and eustachian tube dysfunction in the pathogenesis of acute purulent otitis media was studied in chinchillas. Polymorphonuclear leukocyte function, middle ear pressure, and the incidence of pneumococcal otitis media were observed after intranasal inoculation with influenza A virus, Streptococcus pneumoniae, or both. Results showed that depressed negative middle ear pressure and polymorphonuclear leukocyte chemiluminescence and chemotactic activity occurred after influenza inoculation, but not after inoculation with pneumococcus alone. The greatest incidence of pneumococcal otitis media occurred when the pneumococcus was inoculated just before the time of influenza-induced polymorphonuclear leukocyte dysfunction and negative middle ear pressure. Animals that had unilateral tympanostomy tubes placed before inoculation of influenza with pneumococcus showed no difference in the occurrence of pneumococcal otitis media in ventilated and nonventilated ears, suggesting that polymorphonuclear leukocyte dysfunction contributes more to the pathogenesis of pneumococcal otitis media than does negative middle ear pressure in this animal model. PMID:7076299

  8. Strategies for altering plant traits using virus-induced gene silencing technologies.

    PubMed

    Lacomme, Christophe

    2015-01-01

    The rapid progress in genome sequencing and transcriptome analysis in model and crop plants has made possible the identification of a vast number of genes potentially associated with economically important complex traits. The ultimate goal is to assign functions to these genes by using forward and reverse genetic screens. Plant viruses have been developed for virus-induced gene silencing (VIGS) to generate rapid gene knockdown phenotypes in numerous plant species. To fulfill its potential for high-throughput phenomics, it is of prime importance to ensure that parameters conditioning the VIGS response, i.e., plant-virus interactions and associated loss-of-function screens, are "fit for purpose" and optimized to unequivocally conclude the role of a gene of interest in relation to a given trait. This chapter will review and discuss the different strategies used for the development of VIGS-based phenomics in model and crop species.

  9. Persistent virus-induced gene silencing in asymptomatic accessions of Arabidopsis.

    PubMed

    Flores, Miguel A; Reyes, Maria I; Robertson, Dominique Niki; Kjemtrup, Susanne

    2015-01-01

    Coupled with the advantages afforded by the model plant Arabidopsis, virus-induced gene silencing (VIGS) offers a rapid means to assess gene function. The geminivirus vector based on Cabbage leaf curl virus described here has the benefits of small insert size and persistent silencing of the target gene through the life cycle of the plant. Here, we show that genetic variation in the vast collection of Arabidopsis accessions can be leveraged to ameliorate viral symptomology that accompanies the VIGS procedure. The plasticity of phenotypes under different day lengths or temperature conditions can be exploited to achieve maximum silencing efficacy in either vegetative or inflorescence tissue, according to the question being asked. Protocols and vectors for Agro-infiltration of primary leaves, subapical pricking in older plants, and microprojectile bombardment are described. PMID:25757779

  10. Characterization of the cytotoxin produced by macrophages in response to dengue virus-induced cytotoxic factor.

    PubMed Central

    Gulati, L.; Chaturvedi, U. C.; Mathur, A.

    1983-01-01

    We have observed earlier that dengue type 2 virus-induced cytotoxic factor (CF) induces macrophages to produce a cytotoxin (CF2) which kills mainly the macrophages, some of the T lymphocytes and has no effect on B-lymphocytes of normal mouse spleen. The findings of the present study show that CF2 is heat-labile, trypsin-sensitive and unstable at acid and alkaline pH. It is a low molecular weight product as it is dialysable, non-sedimentable on ultracentrifugation at 103,500 g for 3 h and passes through 0.22 micron Millipore filter. It is adsorbed onto the target normal mouse spleen cells. The properties of CF and CF2 have been compared. PMID:6849814

  11. Novel Strategy To Protect against Influenza Virus-Induced Pneumococcal Disease without Interfering with Commensal Colonization.

    PubMed

    Greene, Christopher J; Marks, Laura R; Hu, John C; Reddinger, Ryan; Mandell, Lorrie; Roche-Hakansson, Hazeline; King-Lyons, Natalie D; Connell, Terry D; Hakansson, Anders P

    2016-06-01

    Streptococcus pneumoniae commonly inhabits the nasopharynx as a member of the commensal biofilm. Infection with respiratory viruses, such as influenza A virus, induces commensal S. pneumoniae to disseminate beyond the nasopharynx and to elicit severe infections of the middle ears, lungs, and blood that are associated with high rates of morbidity and mortality. Current preventive strategies, including the polysaccharide conjugate vaccines, aim to eliminate asymptomatic carriage with vaccine-type pneumococci. However, this has resulted in serotype replacement with, so far, less fit pneumococcal strains, which has changed the nasopharyngeal flora, opening the niche for entry of other virulent pathogens (e.g., Streptococcus pyogenes, Staphylococcus aureus, and potentially Haemophilus influenzae). The long-term effects of these changes are unknown. Here, we present an attractive, alternative preventive approach where we subvert virus-induced pneumococcal disease without interfering with commensal colonization, thus specifically targeting disease-causing organisms. In that regard, pneumococcal surface protein A (PspA), a major surface protein of pneumococci, is a promising vaccine target. Intradermal (i.d.) immunization of mice with recombinant PspA in combination with LT-IIb(T13I), a novel i.d. adjuvant of the type II heat-labile enterotoxin family, elicited strong systemic PspA-specific IgG responses without inducing mucosal anti-PspA IgA responses. This response protected mice from otitis media, pneumonia, and septicemia and averted the cytokine storm associated with septic infection but had no effect on asymptomatic colonization. Our results firmly demonstrated that this immunization strategy against virally induced pneumococcal disease can be conferred without disturbing the desirable preexisting commensal colonization of the nasopharynx. PMID:27001538

  12. Unique role for ATG5 in PMN-mediated immunopathology during M. tuberculosis infection

    PubMed Central

    Kimmey, Jacqueline M.; Huynh, Jeremy P.; Weiss, Leslie A.; Park, Sunmin; Kambal, Amal; Debnath, Jayanta; Virgin, Herbert W.; Stallings, Christina L.

    2015-01-01

    Summary Paragraph Mycobacterium tuberculosis (Mtb), a major global health threat, replicates in macrophages (MΦ) in part by inhibiting phagosome-lysosome fusion, until IFN-γ activates the MΦ to traffic Mtb to the lysosome. How IFN-γ elicits this effect is unknown, but many studies suggest a role for macroautophagy (autophagy herein), a cellular process by which cytoplasmic contents are sequestered into an autophagosome and targeted for lysosomal degradation1. The involvement of autophagy has been defined based on studies in cultured MΦ or dendritic cells (DC) where Mtb colocalizes with autophagy (ATG) factors ATG5, ATG12, ATG16L1, p62, NDP52, Beclin1 and LC32–6, stimulation of autophagy increases bacterial killing6–8, and inhibition of autophagy allows for increased bacterial survival1,2,4,6,7. Notably, these studies reveal modest (e.g. 1.5- to 3-fold change) effects on Mtb replication. In contrast, Atg5fl/fl-LysM-Cre mice lacking ATG5 in monocyte-derived cells and neutrophils (polymorphic mononuclear cells, PMN) succumb to Mtb within 30 days4,9, an extremely severe phenotype similar to mice lacking IFN-γ signaling10,11. Importantly, ATG5 is the only ATG factor that has been studied during Mtb infection in vivo and autophagy-independent functions of ATG5 have been described12–18. For this reason, we used a genetic approach to elucidate the role for multiple ATG genes and the requirement for autophagy in resistance to Mtb infection in vivo. We have discovered that, contrary to expectation, autophagic capacity does not correlate with the outcome of Mtb infection. Instead, ATG5 plays a unique role in protection against Mtb by preventing PMN-mediated immunopathology. Furthermore, while ATG5 is dispensable in alveolar MΦ during Mtb infection, loss of Atg5 in PMN can sensitize mice to Mtb. These findings shift our understanding of the role of ATG5 during Mtb infection, reveal a new outcome of ATG5 activity, and shed light on early events in innate immunity

  13. Does developmental exposure to perflurooctanoic acid (PFOA) induce immunopathologies commonly observed in neurodevelopmental disorders?

    PubMed

    Hu, Qing; Franklin, Jason N; Bryan, Ian; Morris, Erin; Wood, Andrew; DeWitt, Jamie C

    2012-12-01

    Immune comorbidities often are reported in subsets of patients with neurodevelopmental disorders, including autism spectrum disorders and attention-deficit hyperactivity disorder. A common immunopathology is an increase in serum autoantibodies against myelin basic protein (MBP) relative to control patients. Increases in autoantibodies suggest possible deficits in self-tolerance that may contribute to the formation of brain-specific autoantibodies and subsequent effects on the central nervous system (CNS). Oppositely, the formation of neuronal autoantibodies may be a reaction to neuronal injury or damage. Perfluorooctanoic acid (PFOA) is an environmental pollutant that induces multisystem toxicity in rodent models, including immunotoxicity and neurotoxicity. We hypothesized that developmental exposure to PFOA may induce immunotoxicity similar to that observed in subsets of patients with neurodevelopmental disorders. To test this hypothesis, we evaluated subsets of T cells from spleens, serum markers of autoreactivity, and levels of MBP and T cell infiltration in the cerebella of adult offspring exposed to 0.02, 0.2, or 2mg/kg of PFOA given to dams from gestation through lactation. Litter weights of offspring from dams exposed to 2mg/kg of PFOA were reduced by 32.6%, on average, from postnatal day one (PND1) through weaning (PND21). The percentage of splenic CD4+CD25+Foxp3+ T cells in male and female offspring from dams exposed to 2mg/kg of PFOA was reduced by 22% relative to the control percentage. Ex vivo co-cultures of splenic CD4+CD25+ T cells and CD4+CD25- T cells from dosed male offspring produced less IL-10 relative to control cells. Anti-ssDNA, a serum marker of autoreactivity, was decreased by 26%, on average, in female offspring from dams exposed to 0.02 and 2mg/kg PFOA. No other endpoints were statistically different by dose. These data suggest that developmental PFOA exposure may impact T cell responses and may be a possible route to downstream effects on

  14. Immunization with non-replicating E. coli minicells delivering both protein antigen and DNA protects mice from lethal challenge with lymphocytic choriomeningitis virus

    PubMed Central

    Giacalone, Matthew J.; Zapata, Juan C.; Berkley, Neil L.; Sabbadini, Roger A.; Chu, Yen-Lin; Salvato, Maria S.; McGuire, Kathleen L.

    2008-01-01

    In the midst of new investigations into the mechanisms of both delivery and protection of new vaccines and vaccine carriers, it has become clear that immunization with delivery mechanisms that do not involve living, replicating organisms are vastly preferred. In this report, non-replicating bacterial minicells simultaneously co-delivering the nucleoprotein (NP) of lymphocytic choriomeningitis virus (LCMV) and the corresponding DNA vaccine were tested for the ability to generate protective cellular immune responses in mice. It was found that good protection (89%) was achieved after intramuscular administration, moderate protection (31%) was achieved after intranasal administration, and less protection (7%) was achieved following gastric immunization. These results provide a solid foundation on which to pursue the use of bacterial minicells as a non-replicating vaccine delivery platform. PMID:17258845

  15. MicroRNAs in virus-induced tumorigenesis and IFN system.

    PubMed

    Fiorucci, Gianna; Chiantore, Maria Vincenza; Mangino, Giorgio; Romeo, Giovanna

    2015-04-01

    Numerous microRNAs (miRNAs), small non-coding RNAs encoded in the human genome, have been shown to be involved in cancer pathogenesis and progression. There is evidence that some of these miRNAs possess proapoptotic or proliferation promoting roles in the cell by negatively regulating target mRNAs. Oncogenic viruses are able to produce persistent infection, favoring tumor development by deregulating cell proliferation and inhibiting apoptosis. It has been recently suggested that cellular miRNAs may participate in host-virus interactions, influencing viral replication. Many mammalian viruses counteract this cellular antiviral defense by using viral proteins but also by encoding viral miRNAs involved in virus-induced tumorigenesis. Interferons (IFNs) modulate a number of non-coding RNA genes, especially miRNAs, that may be used by mammalian organisms as a mechanism of IFN system to combat viral infection and related diseases. In particular, IFNs might induce specific cellular miRNAs that target viral transcripts thereby using this strategy as part of their effectiveness against invading viruses. Therefore IFNs, interferon stimulated genes and miRNAs could act synergistically as innate response to virus infection to induce a potent non-permissive cellular environment for virus replication and virus-induced cancer. The relevance of this reviewed research topic is clearly related to the observation that although virus infections are responsible of specific tumors, other unidentified genetic alterations are likely involved in the induction of malignant transformation. The identification of such genetic alterations, i.e. miRNA expression in transformed cells, would be of considerable importance for the analysis of the pathogenesis and for the treatment of cancer induced by specific viruses as well as for the advancement of the current knowledge on the molecular mechanisms underlying virus-host interaction. In this respect, we will review also the important, still little

  16. Prevention of Herpes Simplex Virus Induced Stromal Keratitis by a Glycoprotein B-Specific Monoclonal Antibody

    PubMed Central

    Krawczyk, Adalbert; Dirks, Miriam; Kasper, Maren; Buch, Anna; Dittmer, Ulf; Giebel, Bernd; Wildschütz, Lena; Busch, Martin; Goergens, Andre; Schneweis, Karl E.; Eis-Hübinger, Anna M.; Sodeik, Beate; Heiligenhaus, Arnd; Roggendorf, Michael; Bauer, Dirk

    2015-01-01

    The increasing incidence of acyclovir (ACV) and multidrug-resistant strains in patients with corneal HSV-1 infections leading to Herpetic Stromal Keratitis (HSK) is a major health problem in industrialized countries and often results in blindness. To overcome this obstacle, we have previously developed an HSV-gB-specific monoclonal antibody (mAb 2c) that proved to be highly protective in immunodeficient NOD/SCID-mice towards genital infections. In the present study, we examined the effectivity of mAb 2c in preventing the immunopathological disease HSK in the HSK BALB/c mouse model. Therefore, mice were inoculated with HSV-1 strain KOS on the scarified cornea to induce HSK and subsequently either systemically or topically treated with mAb 2c. Systemic treatment was performed by intravenous administration of mAb 2c 24 h prior to infection (pre-exposure prophylaxis) or 24, 40, and 56 hours after infection (post-exposure immunotherapy). Topical treatment was performed by periodical inoculations (5 times per day) of antibody-containing eye drops as control, starting at 24 h post infection. Systemic antibody treatment markedly reduced viral loads at the site of infection and completely protected mice from developing HSK. The administration of the antiviral antibody prior or post infection was equally effective. Topical treatment had no improving effect on the severity of HSK. In conclusion, our data demonstrate that mAb 2c proved to be an excellent drug for the treatment of corneal HSV-infections and for prevention of HSK and blindness. Moreover, the humanized counterpart (mAb hu2c) was equally effective in protecting mice from HSV-induced HSK when compared to the parental mouse antibody. These results warrant the future development of this antibody as a novel approach for the treatment of corneal HSV-infections in humans. PMID:25587898

  17. Patterns of proviral insertion and deletion in avian leukosis virus-induced lymphomas.

    PubMed Central

    Robinson, H L; Gagnon, G C

    1986-01-01

    Sixty-eight lymphomas induced by eight different avian leukosis viruses have been analyzed on Southern blots for virus-induced mutations in the chicken c-myc gene. Sixty-six of the lymphomas exhibited a proviral insertion in c-myc, whereas one exhibited a new transduction of c-myc. Sixty-four of the proviral insertions were in the same transcriptional orientation as c-myc. Two were in the opposite transcriptional orientation. All of the insertions were upstream of the protein-coding sequences of c-myc, with most residing in the first exon or the first intron of c-myc. All of the lymphoma-inducing proviruses had deletions that included either sequences near the 5' long terminal repeat (LTR) or an LTR. The most frequent lymphoma-inducing provirus appeared to have retained both of its LTRs, but had lost sequences near its 5' LTR. The second and third most frequent lymphoma-inducing proviruses consisted of solo LTRs or of proviruses that had lost the 5' LTR as well as some internal sequences. Twenty-four insertions were mapped in c-myc. Each of these mapped to within 150 base pairs of one of the five DNase I-hypersensitive sites that occur in a 3-kilobase region immediately 5' to the protein-coding sequences of c-myc. One lymphoma contained a new c-myc transducing virus. This virus, MYC-3475, caused rapid-onset myelocytomatosis. Images PMID:3001351

  18. A Foxtail mosaic virus Vector for Virus-Induced Gene Silencing in Maize1[OPEN

    PubMed Central

    Mei, Yu; Kernodle, Bliss M.; Hill, John H.

    2016-01-01

    Plant viruses have been widely used as vectors for foreign gene expression and virus-induced gene silencing (VIGS). A limited number of viruses have been developed into viral vectors for the purposes of gene expression or VIGS in monocotyledonous plants, and among these, the tripartite viruses Brome mosaic virus and Cucumber mosaic virus have been shown to induce VIGS in maize (Zea mays). We describe here a new DNA-based VIGS system derived from Foxtail mosaic virus (FoMV), a monopartite virus that is able to establish systemic infection and silencing of endogenous maize genes homologous to gene fragments inserted into the FoMV genome. To demonstrate VIGS applications of this FoMV vector system, four genes, phytoene desaturase (functions in carotenoid biosynthesis), lesion mimic22 (encodes a key enzyme of the porphyrin pathway), iojap (functions in plastid development), and brown midrib3 (caffeic acid O-methyltransferase), were silenced and characterized in the sweet corn line Golden × Bantam. Furthermore, we demonstrate that the FoMV infectious clone establishes systemic infection in maize inbred lines, sorghum (Sorghum bicolor), and green foxtail (Setaria viridis), indicating the potential wide applications of this viral vector system for functional genomics studies in maize and other monocots. PMID:27208311

  19. Protective effects of quercetin during influenza virus-induced oxidative stress.

    PubMed

    Raju, T A; Lakshmi, A N; Anand, T; Rao, L V; Sharma, G

    2000-12-01

    Oxidative stress was found to have a role in many viral diseases including AIDS, hepatitis and influenza. In the present study the pathology of influenza viral infection in the lungs, which may lead to oxidative stress, was investigated and an attempt was made to study the efficacy of anti-oxidants as therapeutic agents. Adult male mice of Swiss albino type were infected with influenza virus (A/Hong Kong/8/68) and studied for the antioxidant status in the lungs by evaluating the lung enzymatic anti-oxidant system including superoxide dismutase and catalase. Superoxide radical generation, which might increase by the activated alveolar macrophages, was estimated by nitroblue-tetrazolium reduction assay. We have also estimated lipid peroxidation levels in lung through thiobarbutiric acid reactive substances assay. We also examined the ability of flavonoid quercetin in protecting from influenza virus-induced oxidative stress. The influenza-infected group showed decreased levels of superoxide dismutase and catalase; however, anti-oxidant supplemented groups showed these activities to be the same as in the control group. The lipid peroxide levels were increased in virus-infected mice. Administration of quercetin lowered the lipid peroxide levels significantly. Formazan positive cells were increased by 80% in the virus-infected group and supplementation with quercetin reduced their number to 44%.

  20. Inflammatory cytokine-mediated evasion of virus-induced tumors from NK cell control

    PubMed Central

    Mishra, Rabinarayan; Polic, Bojan; Welsh, Raymond M.; Szomolanyi-Tsuda, Eva

    2013-01-01

    Infections with DNA tumor viruses, including members of the polyomavirus family, often result in tumor formation in immune-deficient hosts. The complex control involved in antiviral and antitumor immune responses during these infections can be studied in murine polyomavirus (PyV)-infected mice as a model. We found that NK cells efficiently kill cells derived from PyV-induced salivary gland tumors in vitro in an NKG2D (effector cell) -RAE-1 (target cell) - dependent manner, but in T cell-deficient mice NK cells only delay but do not prevent the development of PyV-induced tumors. Here we show that the PyV-induced tumors have infiltrating functional NK cells. The freshly removed tumors, however, lack surface RAE-1 expression, and the tumor tissues produce soluble factors that down-regulate RAE-1. These factors include the pro-inflammatory cytokines IL-1α, IL-1β, IL-33, and TNF. Each of these cytokines down-regulate RAE-1 expression and susceptibility to NK cell mediated cytotoxicity. CD11b+F4/80+ macrophages infiltrating the PyV-induced tumors produce high amounts of IL-1β and TNF. Thus, our data suggest a new mechanism whereby inflammatory cytokines generated in the tumor environment lead to evasion of NK cell-mediated control of virus-induced tumors. PMID:23772039

  1. A Foxtail mosaic virus Vector for Virus-Induced Gene Silencing in Maize.

    PubMed

    Mei, Yu; Zhang, Chunquan; Kernodle, Bliss M; Hill, John H; Whitham, Steven A

    2016-06-01

    Plant viruses have been widely used as vectors for foreign gene expression and virus-induced gene silencing (VIGS). A limited number of viruses have been developed into viral vectors for the purposes of gene expression or VIGS in monocotyledonous plants, and among these, the tripartite viruses Brome mosaic virus and Cucumber mosaic virus have been shown to induce VIGS in maize (Zea mays). We describe here a new DNA-based VIGS system derived from Foxtail mosaic virus (FoMV), a monopartite virus that is able to establish systemic infection and silencing of endogenous maize genes homologous to gene fragments inserted into the FoMV genome. To demonstrate VIGS applications of this FoMV vector system, four genes, phytoene desaturase (functions in carotenoid biosynthesis), lesion mimic22 (encodes a key enzyme of the porphyrin pathway), iojap (functions in plastid development), and brown midrib3 (caffeic acid O-methyltransferase), were silenced and characterized in the sweet corn line Golden × Bantam. Furthermore, we demonstrate that the FoMV infectious clone establishes systemic infection in maize inbred lines, sorghum (Sorghum bicolor), and green foxtail (Setaria viridis), indicating the potential wide applications of this viral vector system for functional genomics studies in maize and other monocots. PMID:27208311

  2. Development of Virus-Induced Gene Expression and Silencing Vector Derived from Grapevine Algerian Latent Virus

    PubMed Central

    Park, Sang-Ho; Choi, Hoseong; Kim, Semin; Cho, Won Kyong; Kim, Kook-Hyung

    2016-01-01

    Grapevine Algerian latent virus (GALV) is a member of the genus Tombusvirus in the Tombusviridae and infects not only woody perennial grapevine plant but also herbaceous Nicotiana benthamiana plant. In this study, we developed GALV-based gene expression and virus-induced gene silencing (VIGS) vectors in N. benthamiana. The GALV coat protein deletion vector, pGMG, was applied to express the reporter gene, green fluorescence protein (GFP), but the expression of GFP was not detected due to the necrotic cell death on the infiltrated leaves. The p19 silencing suppressor of GALV was engineered to inactivate its expression and GFP was successfully expressed with unrelated silencing suppressor, HC-Pro, from soybean mosaic virus. The pGMG vector was used to knock down magnesium chelatase (ChlH) gene in N. benthamaina and the silencing phenotype was clearly observed on systemic leaves. Altogether, the GALV-derived vector is expected to be an attractive tool for useful gene expression and VIGS vectors in grapevine as well as N. benthamiana. PMID:27493613

  3. Common Viral Integration Sites Identified in Avian Leukosis Virus-Induced B-Cell Lymphomas

    PubMed Central

    Justice, James F.; Morgan, Robin W.

    2015-01-01

    ABSTRACT Avian leukosis virus (ALV) induces B-cell lymphoma and other neoplasms in chickens by integrating within or near cancer genes and perturbing their expression. Four genes—MYC, MYB, Mir-155, and TERT—have previously been identified as common integration sites in these virus-induced lymphomas and are thought to play a causal role in tumorigenesis. In this study, we employ high-throughput sequencing to identify additional genes driving tumorigenesis in ALV-induced B-cell lymphomas. In addition to the four genes implicated previously, we identify other genes as common integration sites, including TNFRSF1A, MEF2C, CTDSPL, TAB2, RUNX1, MLL5, CXorf57, and BACH2. We also analyze the genome-wide ALV integration landscape in vivo and find increased frequency of ALV integration near transcriptional start sites and within transcripts. Previous work has shown ALV prefers a weak consensus sequence for integration in cultured human cells. We confirm this consensus sequence for ALV integration in vivo in the chicken genome. PMID:26670384

  4. Disruption of Rpp1-mediated soybean rust immunity by virus-induced gene silencing.

    PubMed

    Cooper, Bret; Campbell, Kimberly B; McMahon, Michael B; Luster, Douglas G

    2013-01-01

    Phakopsora pachyrhizi, a fungus that causes rust disease on soybean, has potential to impart significant yield loss and disrupt food security and animal feed production. Rpp1 is a soybean gene that confers immunity to soybean rust, and it is important to understand how it regulates the soybean defense system and to use this knowledge to protect commercial crops. It was previously discovered that some soybean proteins resembling transcription factors accumulate in the nucleus of Rpp1 soybeans. To determine if they contribute to immunity, Bean pod mottle virus was used to attenuate or silence the expression of their genes. Rpp1 plants subjected to virus-induced gene silencing exhibited reduced amounts of RNA for 5 of the tested genes, and the plants developed rust-like symptoms after subsequent inoculation with fungal spores. Symptoms were associated with the accumulation of rust fungal RNA and protein. Silenced plants also had reduced amounts of RNA for the soybean Myb84 transcription factor and soybean isoflavone O-methyltransferase, both of which are important to phenylpropanoid biosynthesis and lignin formation, crucial components of rust resistance. These results help resolve some of the genes that contribute to Rpp1-mediated immunity and improve upon the knowledge of the soybean defense system. It is possible that these genes could be manipulated to enhance rust resistance in otherwise susceptible soybean cultivars.

  5. A CRISPR-Based Screen Identifies Genes Essential for West-Nile-Virus-Induced Cell Death.

    PubMed

    Ma, Hongming; Dang, Ying; Wu, Yonggan; Jia, Gengxiang; Anaya, Edgar; Zhang, Junli; Abraham, Sojan; Choi, Jang-Gi; Shi, Guojun; Qi, Ling; Manjunath, N; Wu, Haoquan

    2015-07-28

    West Nile virus (WNV) causes an acute neurological infection attended by massive neuronal cell death. However, the mechanism(s) behind the virus-induced cell death is poorly understood. Using a library containing 77,406 sgRNAs targeting 20,121 genes, we performed a genome-wide screen followed by a second screen with a sub-library. Among the genes identified, seven genes, EMC2, EMC3, SEL1L, DERL2, UBE2G2, UBE2J1, and HRD1, stood out as having the strongest phenotype, whose knockout conferred strong protection against WNV-induced cell death with two different WNV strains and in three cell lines. Interestingly, knockout of these genes did not block WNV replication. Thus, these appear to be essential genes that link WNV replication to downstream cell death pathway(s). In addition, the fact that all of these genes belong to the ER-associated protein degradation (ERAD) pathway suggests that this might be the primary driver of WNV-induced cell death.

  6. Development of Virus-Induced Gene Expression and Silencing Vector Derived from Grapevine Algerian Latent Virus.

    PubMed

    Park, Sang-Ho; Choi, Hoseong; Kim, Semin; Cho, Won Kyong; Kim, Kook-Hyung

    2016-08-01

    Grapevine Algerian latent virus (GALV) is a member of the genus Tombusvirus in the Tombusviridae and infects not only woody perennial grapevine plant but also herbaceous Nicotiana benthamiana plant. In this study, we developed GALV-based gene expression and virus-induced gene silencing (VIGS) vectors in N. benthamiana. The GALV coat protein deletion vector, pGMG, was applied to express the reporter gene, green fluorescence protein (GFP), but the expression of GFP was not detected due to the necrotic cell death on the infiltrated leaves. The p19 silencing suppressor of GALV was engineered to inactivate its expression and GFP was successfully expressed with unrelated silencing suppressor, HC-Pro, from soybean mosaic virus. The pGMG vector was used to knock down magnesium chelatase (ChlH) gene in N. benthamaina and the silencing phenotype was clearly observed on systemic leaves. Altogether, the GALV-derived vector is expected to be an attractive tool for useful gene expression and VIGS vectors in grapevine as well as N. benthamiana. PMID:27493613

  7. Applications and advantages of virus-induced gene silencing for gene function studies in plants.

    PubMed

    Burch-Smith, Tessa M; Anderson, Jeffrey C; Martin, Gregory B; Dinesh-Kumar, S P

    2004-09-01

    Virus-induced gene silencing (VIGS) is a recently developed gene transcript suppression technique for characterizing the function of plant genes. The approach involves cloning a short sequence of a targeted plant gene into a viral delivery vector. The vector is used to infect a young plant, and in a few weeks natural defense mechanisms of the plant directed at suppressing virus replication also result in specific degradation of mRNAs from the endogenous plant gene that is targeted for silencing. VIGS is rapid (3-4 weeks from infection to silencing), does not require development of stable transformants, allows characterization of phenotypes that might be lethal in stable lines, and offers the potential to silence either individual or multiple members of a gene family. Here we briefly review the discoveries that led to the development of VIGS and what is known about the experimental requirements for effective silencing. We describe the methodology of VIGS and how it can be optimized and used for both forward and reverse genetics studies. Advantages and disadvantages of VIGS compared with other loss-of-function approaches available for plants are discussed, along with how the limitations of VIGS might be overcome. Examples are reviewed where VIGS has been used to provide important new insights into the roles of specific genes in plant development and plant defense responses. Finally, we examine the future prospects for VIGS as a powerful tool for assessing and characterizing the function of plant genes. PMID:15315635

  8. Delineation of autoantibody repertoire through differential proteogenomics in hepatitis C virus-induced cryoglobulinemia

    PubMed Central

    Ogishi, Masato; Yotsuyanagi, Hiroshi; Moriya, Kyoji; Koike, Kazuhiko

    2016-01-01

    Antibodies cross-reactive to pathogens and autoantigens are considered pivotal in both infection control and accompanying autoimmunity. However, the pathogenic roles of autoantibodies largely remain elusive without a priori knowledge of disease-specific autoantigens. Here, through a novel quantitative proteogenomics approach, we demonstrated a successful identification of immunoglobulin variable heavy chain (VH) sequences highly enriched in pathological immune complex from clinical specimens obtained from a patient with hepatitis C virus-induced cryoglobulinemia (HCV-CG). Reconstructed single-domain antibodies were reactive to both HCV antigens and potentially liver-derived human proteins. Moreover, over the course of antiviral therapy, a substantial “de-evolution” of a distinct sub-repertoire was discovered, to which proteomically identified cryoprecipitation-prone autoantibodies belonged. This sub-repertoire was characterized by IGHJ6*03-derived, long, hydrophobic complementarity determining region (CDR-H3). This study provides a proof-of-concept of de novo mining of autoantibodies and corresponding autoantigen candidates in a disease-specific context in human, thus facilitating future reverse-translational research for the discovery of novel biomarkers and the development of antigen-specific immunotherapy against various autoantibody-related disorders. PMID:27403724

  9. Foxtail Mosaic Virus-Induced Gene Silencing in Monocot Plants1[OPEN

    PubMed Central

    Liu, Na; Xie, Ke; Jia, Qi; Zhao, Jinping; Chen, Tianyuan; Li, Huangai; Wei, Xiang; Diao, Xianmin; Hong, Yiguo

    2016-01-01

    Virus-induced gene silencing (VIGS) is a powerful technique to study gene function in plants. However, very few VIGS vectors are available for monocot plants. Here we report that Foxtail mosaic virus (FoMV) can be engineered as an effective VIGS system to induce efficient silencing of endogenous genes in monocot plants including barley (Hordeum vulgare L.), wheat (Triticum aestivum) and foxtail millet (Setaria italica). This is evidenced by FoMV-based silencing of phytoene desaturase (PDS) and magnesium chelatase in barley, of PDS and Cloroplastos alterados1 in foxtail millet and wheat, and of an additional gene IspH in foxtail millet. Silencing of these genes resulted in photobleached or chlorosis phenotypes in barley, wheat, and foxtail millet. Furthermore, our FoMV-based gene silencing is the first VIGS system reported for foxtail millet, an important C4 model plant. It may provide an efficient toolbox for high-throughput functional genomics in economically important monocot crops. PMID:27225900

  10. Virus-Induced Gene Silencing in Cultivated Cotton (Gossypium spp.) Using Tobacco Rattle Virus.

    PubMed

    Mustafa, Roma; Shafiq, Muhammad; Mansoor, Shahid; Briddon, Rob W; Scheffler, Brian E; Scheffler, Jodi; Amin, Imran

    2016-01-01

    The study described here has optimized the conditions for virus-induced gene silencing (VIGS) in three cultivated cotton species (Gossypium hirsutum, G. arboreum, and G. herbaceum) using a Tobacco rattle virus (TRV) vector. The system was used to silence the homolog of the Arabidopsis thaliana chloroplastos alterados 1 (AtCLA1) gene, involved in chloroplast development, in G. herbaceum, G. arboreum, and six commercial G. hirsutum cultivars. All plants inoculated with the TRV vector to silence CLA1 developed a typical albino phenotype indicative of silencing this gene. Although silencing in G. herbaceum and G. arboreum was complete, silencing efficiency differed for each G. hirsutum cultivar. Reverse transcriptase polymerase chain reaction (PCR) and real-time quantitative PCR showed a reduction in mRNA levels of the CLA1 homolog in all three species, with the highest efficiency (lowest CLA1 mRNA levels) in G. arboreum followed by G. herbaceum and G. hirsutum. The results indicate that TRV is a useful vector for VIGS in Gossypium species. However, selection of host cultivar is important. With the genome sequences of several cotton species recently becoming publicly available, this system has the potential to provide a very powerful tool for the rapid, large-scale reverse-genetic analysis of genes in Gossypium spp.

  11. Gamma interferon is a major mediator of antiviral defense in experimental measles virus-induced encephalitis.

    PubMed Central

    Finke, D; Brinckmann, U G; ter Meulen, V; Liebert, U G

    1995-01-01

    Measles virus infection of the central nervous system in the murine model of experimental measles virus-induced encephalitis is successfully controlled by virus-specific T-helper lymphocytes. T cells from BALB/c mice that are resistant to measles virus encephalitis proliferate well against measles virus in vitro, and bulk cultures recognize viral nucleocapsid and hemagglutinin as well as fusion proteins. The measles virus-specific T cells secrete large amounts of interleukin 2 (IL-2), gamma interferon (IFN-gamma), and tumor necrosis factor alpha (TNF-alpha) but no IL-4, IL-6, or IL-10, and hence the cytokine pattern is consistent with that of subtype 1 T-helper lymphocytes. In contrast, cells obtained from measles virus-infected susceptible C3H mice recognize measles virus proteins only weakly and secrete little IFN-gamma and TNF-alpha. Treatment of infected mice with anti-TNF-alpha antibodies has no effect on survival or virus clearance from the brain. Upon neutralization of IFN-gamma in vivo, the phenotype of measles virus-specific T-helper cells isolatable from BALB/c mice is reversed from subtype 1 to subtype 2-like. Anti-IFN-gamma antibody-treated BALB/c mice are susceptible to measles virus encephalitis, and viral clearance from the central nervous system is impaired. These results indicate that IFN-gamma plays a significant role in the control of measles virus infection of the central nervous system. PMID:7636992

  12. Autophagy Genes Enhance Murine Gammaherpesvirus 68 Reactivation from Latency by Preventing Virus-Induced Systemic Inflammation.

    PubMed

    Park, Sunmin; Buck, Michael D; Desai, Chandni; Zhang, Xin; Loginicheva, Ekaterina; Martinez, Jennifer; Freeman, Michael L; Saitoh, Tatsuya; Akira, Shizuo; Guan, Jun-Lin; He, You-Wen; Blackman, Marcia A; Handley, Scott A; Levine, Beth; Green, Douglas R; Reese, Tiffany A; Artyomov, Maxim N; Virgin, Herbert W

    2016-01-13

    Host genes that regulate systemic inflammation upon chronic viral infection are incompletely understood. Murine gammaherpesvirus 68 (MHV68) infection is characterized by latency in macrophages, and reactivation is inhibited by interferon-γ (IFN-γ). Using a lysozyme-M-cre (LysMcre) expression system, we show that deletion of autophagy-related (Atg) genes Fip200, beclin 1, Atg14, Atg16l1, Atg7, Atg3, and Atg5, in the myeloid compartment, inhibited MHV68 reactivation in macrophages. Atg5 deficiency did not alter reactivation from B cells, and effects on reactivation from macrophages were not explained by alterations in productive viral replication or the establishment of latency. Rather, chronic MHV68 infection triggered increased systemic inflammation, increased T cell production of IFN-γ, and an IFN-γ-induced transcriptional signature in macrophages from Atg gene-deficient mice. The Atg5-related reactivation defect was partially reversed by neutralization of IFN-γ. Thus Atg genes in myeloid cells dampen virus-induced systemic inflammation, creating an environment that fosters efficient MHV68 reactivation from latency. PMID:26764599

  13. The Florey lecture, 1986. Vaccine prevention of virus-induced human cancers.

    PubMed

    Epstein, M A

    1987-03-23

    Carcinogenic viruses have been discovered in numerous animal species over the last 80 years but their role in human cancer has only recently become an important issue. With EB virus involved with endemic Burkitt's lymphoma and undifferentiated nasopharyngeal carcinoma, hepatitis B virus with primary liver cancer, papilloma viruses with carcinoma of the cervix, and T-cell leukaemia virus with adult T leukaemia, 20-25% of all human cancer appears to have a virus component in its causation. By analogy with certain virus-induced animal cancers, vaccine prevention of infection should greatly reduce subsequent tumour development; vaccines against hepatitis B virus are already on trial for this purpose in populations at risk. Experiments are described in which an EB virus subunit vaccine consisting of the virus-determined membrane antigen glycoprotein molecule of molecular mass 340 kDa (MA gp340) has been prepared by two purification methods. Material from one of these has successfully protected cotton-top tamarins against a 100% lymphomagenic dose of challenge virus and investigations are under way to identify an immunogen, based on MA gp340, suitable for use in man. Genetically engineered bacterial, yeast, and mammalian cells expressing the gp340 gene are already available; this gene has also been inserted into vaccinia and varicella virus vectors. Powerful new adjuvants are also considered, together with future strategies for human vaccine studies. PMID:2884667

  14. Regulation of virus-induced inflammatory response by Dunaliella salina alga extract in macrophages.

    PubMed

    Lin, Hui-Wen; Chen, Yi-Chen; Liu, Cheng-Wei; Yang, Deng-Jye; Chen, Shih-Yin; Chang, Tien-Jye; Chang, Yuan-Yen

    2014-09-01

    Previous reports have suggested that many constituents within various algal samples are able to attenuate LPS-induced inflammatory effects. To date no report has been published on the regulation of virus-induced inflammatory response of Dunaliella salina carotenoid extract. In the present study, the anti-inflammatory effect of D. salina carotenoid extract on pseudorabies virus (PRV)-infected RAW 264.7 macrophages was investigated. We evaluated the anti-inflammatory effect of D. salina carotenoid extract on PRV-infected RAW 264.7 cells by measuring cell viability, cytotoxicity, production of inflammatory mediators such as NO, iNOS, COX-2, pro-inflammatory cytokines and anti-virus replication by plaque assay. We found down-regulation of the expression of the iNOS, COX-2 and pro-inflammatory genes IL-1β, IL-6, TNF-α, and MCP-1 in a dose-dependent manner. Although there was no effect on viral replication, there were tendencies toward lower virus titer and tendencies toward higher cell survival. Most importantly, we found that inhibition of TLR9, PI3K and Akt phosphorylation plays a crucial role in the extract-mediated NF-κB regulation by modulating IKK-IκB signaling in PRV-infected RAW264.7 cells. These results indicate that D. salina carotenoid extracts inhibited inflammation by inhibition of NF-κB activation by TLR9 dependent via PI3K/Akt inactivation.

  15. Hemorrhagic fever virus-induced changes in hemostasis and vascular biology.

    PubMed

    Chen, J P; Cosgriff, T M

    2000-07-01

    Viral hemorrhagic fever (VHF) denotes a virus-induced acute febrile, hemorrhagic disease reported from wide areas of the world. Hemorrhagic fever (HF) viruses are encapsulated, single-stranded RNA viruses that are associated with insect or rodent vectors whose interaction with humans defines the mode of disease transmission. There are 14 HF viruses, which belong to four viral families: Arenaviridae, Bunyaviridae, Filoviridae and Flaviviridae. This review presents, in order, the following aspects of VHF: (1) epidemiology, (2) anomalies of platelets and coagulation factors, (3) vasculopathy, (4) animal models of VHFs, (5) pathogenic mechanisms, and (6) treatment and future studies. HF viruses produce the manifestations of VHFs either by direct effects on cellular functions or by activation of immune and inflammatory pathways. In Lassa fever, Rift Valley fever and Crimean-Congo HF, the main feature of fatal illness appears to be impaired/delayed cellular immunity, which leads to unchecked viremia. However, in HF with renal syndrome and dengue HF, the immune response plays an active role in disease pathogenesis. The interplay of hemostasis, immune response, and inflammation is very complex. Molecular biologic techniques and the use of animal models have helped to unravel some of these interactions.

  16. Functional analyses of cellulose synthase genes in flax (Linum usitatissimum) by virus-induced gene silencing.

    PubMed

    Chantreau, Maxime; Chabbert, Brigitte; Billiard, Sylvain; Hawkins, Simon; Neutelings, Godfrey

    2015-12-01

    Flax (Linum usitatissimum) bast fibres are located in the stem cortex where they play an important role in mechanical support. They contain high amounts of cellulose and so are used for linen textiles and in the composite industry. In this study, we screened the annotated flax genome and identified 14 distinct cellulose synthase (CESA) genes using orthologous sequences previously identified. Transcriptomics of 'primary cell wall' and 'secondary cell wall' flax CESA genes showed that some were preferentially expressed in different organs and stem tissues providing clues as to their biological role(s) in planta. The development for the first time in flax of a virus-induced gene silencing (VIGS) approach was used to functionally evaluate the biological role of different CESA genes in stem tissues. Quantification of transcript accumulation showed that in many cases, silencing not only affected targeted CESA clades, but also had an impact on other CESA genes. Whatever the targeted clade, inactivation by VIGS affected plant growth. In contrast, only clade 1- and clade 6-targeted plants showed modifications in outer-stem tissue organization and secondary cell wall formation. In these plants, bast fibre number and structure were severely impacted, suggesting that the targeted genes may play an important role in the establishment of the fibre cell wall. Our results provide new fundamental information about cellulose biosynthesis in flax that should facilitate future plant improvement/engineering.

  17. Toll-Like Receptor 2 Mediates Fatal Immunopathology in Mice During Treatment of Secondary Pneumococcal Pneumonia Following Influenza

    PubMed Central

    Karlström, Åsa; Heston, Sarah M.; Boyd, Kelli L.; Tuomanen, Elaine I.

    2011-01-01

    Host inflammatory responses contribute to the significant immunopathology that occurs during treatment of secondary bacterial pneumonia following influenza. We undertook the present study to determine the mechanisms underlying disparate outcomes in a mouse model with β-lactam and macrolide antibiotics. Lysis of superinfecting bacteria by ampicillin caused an extensive influx of neutrophils into the lungs resulting in a consolidative pneumonia, necrotic lung damage, and significant mortality. This was mediated through Toll-like receptor (TLR) 2 and was independent of TLR4 and the Streptococcus pneumoniae cytotoxin pneumolysin. Treatment with azithromycin prevented neutrophil accumulation and rescued mice from subsequent mortality. This effect was independent of the antibacterial activity of this macrolide since dual therapy with ampicillin and azithromycin against an azithromycin-resistant strain also was able to cure secondary pneumonia. These data suggest that strategies for eliminating bacteria without lysis coupled with immunomodulation of inflammation should be pursued clinically. PMID:21900488

  18. Immune cells and type 1 IFN in urine of SLE patients correlate with immunopathology in the kidney.

    PubMed

    Scott, Eric; Dooley, Mary Anne; Vilen, Barbara J; Clarke, Stephen H

    2016-07-01

    The immunopathological events in the kidneys of lupus nephritis (LN) patients are poorly understood due in part to the difficulty in acquiring serial biopsies and the inherent limitations in their analysis. To identify a means to circumvent these limitations, we investigated whether immune cells of kidney origin are present in patient urine and whether they correlate with kidney pathology. Flow cytometry analysis was performed on peripheral blood and urine cells of 69 SLE patients, of whom 41 were LN patients. In addition, type I IFN (IFNα/β) levels were determined in plasma and urine by bioassay. Approximately 60% of non-LN patients had urine lymphocytes. In these patients, T cells were always present and predominantly CD8(+), while B cells were either absent or a mixture of naïve and memory B cells. In contrast, >90% of LN patients had urine lymphocytes. In half, the B and T cells resembled those in non-LN patient urine; however, in the remaining patients, the B cells were exclusively Ig-secreting plasmablasts or plasma cells (PB/PCs) and the T cells were predominantly CD4(+). In addition, pDCs and IFNα/β frequently accompanied PB/PCs. The majority of patients with urine PB/PCs presented with proliferative nephritis and a significant loss of kidney function, which in some cases had progressed to end stage renal disease (ESRD). In conclusion, urine can provide access to cells of kidney resident populations for phenotypic and functional characterization. Analysis of these cells provides insight into the kidney immunopathology and may serve as biomarkers to identify patients at risk for developing LN and progressing to ESRD. PMID:27102764

  19. Susceptibility to Theiler's virus-induced demyelinating disease correlates with astrocyte class II induction and antigen presentation.

    PubMed Central

    Borrow, P; Nash, A A

    1992-01-01

    Theiler's murine encephalomyelitis virus (TMEV) is a picornavirus which induces a chronic demyelinating disease of the central nervous system (CNS) in certain susceptible mouse strains. Demyelination has been shown to result from immunopathological responses mediated by CD4+, major histocompatibility complex (MHC) class II-restricted T cells. As little or no class II is expressed in the normal mouse CNS, the ability of astrocytes to express these proteins and present antigen to T cells from TMEV-infected mice was investigated here. It is shown that astrocytes are capable of presenting TMEV to virus-specific T cells in vitro, and that this ability is dependent on prior induction of MHC class II by interferon-gamma (IFN-gamma) treatment. Unlike other viruses such as murine hepatitis virus-JHM (a coronavirus) and measles, TMEV is not capable of inducing class II on astrocytes directly. There is a correlation between the ease of class II induction on astrocytes from different mouse strains by IFN-gamma and mouse strain susceptibility to TMEV-induced demyelinating disease. These results suggest that following viral infection and initial T-cell infiltration into the CNS, class II induction on astrocytes is a key step allowing local antigen presentation and amplification of immunopathological responses within the CNS and hence the development of demyelinating disease. PMID:1628891

  20. Susceptibility to Theiler's virus-induced demyelinating disease correlates with astrocyte class II induction and antigen presentation.

    PubMed

    Borrow, P; Nash, A A

    1992-05-01

    Theiler's murine encephalomyelitis virus (TMEV) is a picornavirus which induces a chronic demyelinating disease of the central nervous system (CNS) in certain susceptible mouse strains. Demyelination has been shown to result from immunopathological responses mediated by CD4+, major histocompatibility complex (MHC) class II-restricted T cells. As little or no class II is expressed in the normal mouse CNS, the ability of astrocytes to express these proteins and present antigen to T cells from TMEV-infected mice was investigated here. It is shown that astrocytes are capable of presenting TMEV to virus-specific T cells in vitro, and that this ability is dependent on prior induction of MHC class II by interferon-gamma (IFN-gamma) treatment. Unlike other viruses such as murine hepatitis virus-JHM (a coronavirus) and measles, TMEV is not capable of inducing class II on astrocytes directly. There is a correlation between the ease of class II induction on astrocytes from different mouse strains by IFN-gamma and mouse strain susceptibility to TMEV-induced demyelinating disease. These results suggest that following viral infection and initial T-cell infiltration into the CNS, class II induction on astrocytes is a key step allowing local antigen presentation and amplification of immunopathological responses within the CNS and hence the development of demyelinating disease.

  1. Latitudinal variation in virus-induced mortality of phytoplankton across the North Atlantic Ocean.

    PubMed

    Mojica, Kristina D A; Huisman, Jef; Wilhelm, Steven W; Brussaard, Corina P D

    2016-02-01

    Viral lysis of phytoplankton constrains marine primary production, food web dynamics and biogeochemical cycles in the ocean. Yet, little is known about the biogeographical distribution of viral lysis rates across the global ocean. To address this, we investigated phytoplankton group-specific viral lysis rates along a latitudinal gradient within the North Atlantic Ocean. The data show large-scale distribution patterns of different virus groups across the North Atlantic that are associated with the biogeographical distributions of their potential microbial hosts. Average virus-mediated lysis rates of the picocyanobacteria Prochlorococcus and Synechococcus were lower than those of the picoeukaryotic and nanoeukaryotic phytoplankton (that is, 0.14 per day compared with 0.19 and 0.23 per day, respectively). Total phytoplankton mortality (virus plus grazer-mediated) was comparable to the gross growth rate, demonstrating high turnover rates of phytoplankton populations. Virus-induced mortality was an important loss process at low and mid latitudes, whereas phytoplankton mortality was dominated by microzooplankton grazing at higher latitudes (>56°N). This shift from a viral-lysis-dominated to a grazing-dominated phytoplankton community was associated with a decrease in temperature and salinity, and the decrease in viral lysis rates was also associated with increased vertical mixing at higher latitudes. Ocean-climate models predict that surface warming will lead to an expansion of the stratified and oligotrophic regions of the world's oceans. Our findings suggest that these future shifts in the regional climate of the ocean surface layer are likely to increase the contribution of viral lysis to phytoplankton mortality in the higher-latitude waters of the North Atlantic, which may potentially reduce transfer of matter and energy up the food chain and thus affect the capacity of the northern North Atlantic to act as a long-term sink for CO2. PMID:26262815

  2. Methods for effective real-time RT-PCR analysis of virus-induced gene silencing.

    PubMed

    Rotenberg, Dorith; Thompson, Thea S; German, Thomas L; Willis, David K

    2006-12-01

    We applied real-time RT-PCR to the analysis of Tobacco rattle virus (TRV)-mediated virus-induced gene silencing (VIGS) of the phytoene desaturase (PDS) gene in Nicotiana benthamiana and tomato. Using a combination of direct measurement and mathematical assessment, we evaluated three plant genes, ubiquitin (ubi3), elongation factor-1 alpha (EF-1), and actin, for use as internal reference transcripts and found that EF-1 and ubi3 were least variable under our experimental conditions. Primer sets designed to amplify the 5' or 3' regions of endogenous PDS transcripts in tomato yielded similar reductions in transcript levels indicating a uniform VIGS-mediated degradation of target RNA. By measuring the ratio of the abundance of the PDS insert transcript to the TRV coat protein RNA, we established that the PDS insert within TRV was stable in both hosts. VIGS in N. benthamiana resulted in complete photo-bleaching of all foliar tissue compared to chimeric bleaching in tomato. PDS transcript levels were decreased eleven- and seven-fold in photobleached leaves of N. benthamiana and tomato, respectively, while sampling tomato leaflets on the basis of age rather than visible bleaching resulted in only a 17% reduction in PDS coupled with a large leaf-to-leaf variation. There was a significant inverse relationship (r2=76%, P=0.01) between the relative abundance of CP RNA and the amount of PDS transcript in rTRV::tPDS-infected tomato suggesting that virus spread and accumulation are required precursors for successful VIGS in this host. PMID:16959330

  3. An efficient virus-induced gene silencing vector for maize functional genomics research.

    PubMed

    Wang, Rong; Yang, Xinxin; Wang, Nian; Liu, Xuedong; Nelson, Richard S; Li, Weimin; Fan, Zaifeng; Zhou, Tao

    2016-04-01

    Maize is a major crop whose rich genetic diversity provides an advanced resource for genetic research. However, a tool for rapid transient gene function analysis in maize that may be utilized in most maize cultivars has been lacking, resulting in reliance on time-consuming stable transformation and mutation studies to obtain answers. We developed an efficient virus-induced gene silencing (VIGS) vector for maize based on a naturally maize-infecting cucumber mosaic virus (CMV) strain, ZMBJ-CMV. An infectious clone of ZMBJ-CMV was constructed, and a vascular puncture inoculation method utilizing Agrobacterium was optimized to improve its utility for CMV infection of maize. ZMBJ-CMV was then modified to function as a VIGS vector. The ZMBJ-CMV vector induced mild to moderate symptoms in many maize lines, making it useful for gene function studies in critically important maize cultivars, such as the sequenced reference inbred line B73. Using this CMV VIGS system, expression of two endogenous genes, ZmPDS and ZmIspH, was found to be decreased by 75% and 78%, respectively, compared with non-silenced tissue. Inserts with lengths of 100-300 bp produced the most complete transcriptional and visual silencing phenotypes. Moreover, genes related to autophagy, ZmATG3 and ZmATG8a, were also silenced, and it was found that they function in leaf starch degradation. These results indicate that our ZMBJ-CMV VIGS vector provides a tool for rapid and efficient gene function studies in maize. PMID:26921244

  4. Systematic knockdown of morphine pathway enzymes in opium poppy using virus-induced gene silencing.

    PubMed

    Wijekoon, Champa P; Facchini, Peter J

    2012-03-01

    Opium poppy (Papaver somniferum) remains the sole commercial source for several pharmaceutical alkaloids including the narcotic analgesics codeine and morphine, and the semi-synthetic drugs oxycodone, buprenorphine and naltrexone. Although most of the biosynthetic genes have been identified, the post-transcriptional regulation of the morphinan alkaloid pathway has not been determined. We have used virus-induced gene silencing (VIGS) as a functional genomics tool to investigate the regulation of morphine biosynthesis via a systematic reduction in enzyme levels responsible for the final six steps in the pathway. Specific gene silencing was confirmed at the transcript level by real-time quantitative PCR (polymerase chain reaction), and at the protein level by immunoblot analysis using antibodies raised against salutaridine synthase (SalSyn), salutaridine reductase (SalR), salutaridine 7-O-acetyltransferase (SalAT), thebaine 6-O-demethylase (T6ODM), codeinone reductase (COR), and codeine O-demethylase (CODM). In some cases, silencing a specific biosynthetic gene resulted in a predictable accumulation of the substrate for the corresponding enzyme. Reduced SalSyn, SalR, T6ODM and CODM protein levels correlated with lower morphine levels and a substantial increase in the accumulation of reticuline, salutaridine, thebaine and codeine, respectively. In contrast, the silencing of genes encoding SalAT and COR resulted in the accumulation of salutaridine and reticuline, respectively, which are not the corresponding enzymatic substrates. The silencing of alkaloid biosynthetic genes using VIGS confirms the physiological function of enzymes previously characterized in vitro, provides insight into the biochemical regulation of morphine biosynthesis, and demonstrates the immense potential for metabolic engineering in opium poppy.

  5. Heterologous virus-induced gene silencing as a promising approach in plant functional genomics.

    PubMed

    Hosseini Tafreshi, Seied Ali; Shariati, Mansour; Mofid, Mohammad Reza; Khayam Nekui, Mojtaba; Esmaeili, Abolghasem

    2012-03-01

    VIGS (virus induced gene silencing) is considered as a powerful genomics tool for characterizing the function of genes in a few closely related plant species. The investigations have been carried out mainly in order to test if a pre-existing VIGS vector can serve as an efficient tool for gene silencing in a diverse array of plant species. Another route of investigation has been the constructing of new viral vectors to act in their hosts. Our approach was the creation of a heterologous system in which silencing of endogenous genes was achieved by sequences isolated from evolutionary remote species. In this study, we showed that a TRV-based vector cloned with sequences from a gymnosperm, Taxus baccata L. silenced the endogenous phytoene desaturase in an angiosperm, N. benthamiana. Our results showed that inserts of between 390 and 724 bp isolated from a conserved fragment of the Taxus PDS led to silencing of its homolog in tobacco. The real time analysis indicated that the expression of PDS was reduced 2.1- to 4.0-fold in pTRV-TbPDS infected plants compared with buffer treated plants. Once the best insert is identified and the conditions are optimized for heterologous silencing by pTRV-TbPDS in tobacco, then we can test if TRV can serve as an efficient silencing vector in Taxus. This strategy could also be used to silence a diverse array of genes from a wide range of species which have no VIGS protocol. The results also showed that plants silenced heterologously by the VIGS system a minimally affected with respect to plant growth which may be ideal for studying the genes that their complete loss of function may lead to decrease of plant growth or plant death. PMID:21655951

  6. Latitudinal variation in virus-induced mortality of phytoplankton across the North Atlantic Ocean.

    PubMed

    Mojica, Kristina D A; Huisman, Jef; Wilhelm, Steven W; Brussaard, Corina P D

    2016-02-01

    Viral lysis of phytoplankton constrains marine primary production, food web dynamics and biogeochemical cycles in the ocean. Yet, little is known about the biogeographical distribution of viral lysis rates across the global ocean. To address this, we investigated phytoplankton group-specific viral lysis rates along a latitudinal gradient within the North Atlantic Ocean. The data show large-scale distribution patterns of different virus groups across the North Atlantic that are associated with the biogeographical distributions of their potential microbial hosts. Average virus-mediated lysis rates of the picocyanobacteria Prochlorococcus and Synechococcus were lower than those of the picoeukaryotic and nanoeukaryotic phytoplankton (that is, 0.14 per day compared with 0.19 and 0.23 per day, respectively). Total phytoplankton mortality (virus plus grazer-mediated) was comparable to the gross growth rate, demonstrating high turnover rates of phytoplankton populations. Virus-induced mortality was an important loss process at low and mid latitudes, whereas phytoplankton mortality was dominated by microzooplankton grazing at higher latitudes (>56°N). This shift from a viral-lysis-dominated to a grazing-dominated phytoplankton community was associated with a decrease in temperature and salinity, and the decrease in viral lysis rates was also associated with increased vertical mixing at higher latitudes. Ocean-climate models predict that surface warming will lead to an expansion of the stratified and oligotrophic regions of the world's oceans. Our findings suggest that these future shifts in the regional climate of the ocean surface layer are likely to increase the contribution of viral lysis to phytoplankton mortality in the higher-latitude waters of the North Atlantic, which may potentially reduce transfer of matter and energy up the food chain and thus affect the capacity of the northern North Atlantic to act as a long-term sink for CO2.

  7. Contrasting community versus population-based estimates of grazing and virus-induced mortality of phytoplankton.

    PubMed

    Staniewski, Michael A; Short, Cindy M; Short, Steven M

    2012-07-01

    In this study, grazing and virus-induced mortality of phytoplankton was investigated in a freshwater pond at the University of Toronto Mississauga, Canada, during September 2009. The modified dilution assay, which partitions phytoplankton mortality into virus and grazing-induced fractions, was used along with newly designed, taxon-specific quantitative polymerase chain reaction (qPCR) assays that target psbA gene fragments to estimate growth and mortality rates for both the entire phytoplankton community and four distinct phytoplankton populations. Community mortality was estimated via fluorometric determination of chlorophyll a (Chl a) concentrations, whereas the relative mortality of individual phytoplankton populations was estimated via qPCR. The sources and amounts of mortality for individual phytoplankton populations differed from those of the whole community, as well as from each other. Grazing was found to be the only significant source of mortality for the community (0.32 day(-1)), and the Prymnesiales (1.65 day(-1)) and Chroococcales (2.79 day(-1)) populations studied. On the other hand, the Chlamydomonadales population examined experienced both significant grazing (1.01 day(-1)) and viral lysis (0.96 day(-1)), while the Chlorellales population only experienced significant mortality as a result of viral lysis (1.38 day(-1)). Our results demonstrate that the combination of qPCR and the modified dilution method can be used to estimate both viral lysis and grazing pressure on several individual phytoplankton populations within a community simultaneously. Further, previously noted limitations of the modified dilution method associated with the dilution of specific phytoplankton populations at low abundances can be overcome with the qPCR-based approach. Most importantly, this study demonstrates that when used alone, whole community-based methods of assessing mortality can overlook valuable information about carbon flow in aquatic microbial food webs. PMID

  8. The influence of virus-induced changes in plants on aphid vectors: insights from luteovirus pathosystems.

    PubMed

    Bosque-Pérez, Nilsa A; Eigenbrode, Sanford D

    2011-08-01

    Plant virus infection can alter the suitability of host plants for their aphid vectors. Most reports indicate that virus-infected plants are superior hosts for vectors compared to virus-free plants with respect to vector growth rates, fecundity and longevity. Some aphid vectors respond preferentially to virus-infected plants compared to virus-free ones, while others avoid infected plants that are inferior hosts. Thus, it appears vectors can exploit changes in host plant quality associated with viral infection. Enhanced vector performance and preference for virus-infected plants might also be advantageous for viruses by promoting their spread and possibly enhancing their fitness. Our research has focused on two of the most important luteoviruses that infect wheat (Barley yellow dwarf virus), or potato (Potato leafroll virus), and their respective aphid vectors, the bird-cherry oat aphid, Rhopalosiphum padi, and the green peach aphid, Myzus persicae. The work has demonstrated that virus infection of host plants enhances the life history of vectors. Additionally, it has shown that virus infection alters the concentration and relative composition of volatile organic compounds in host plants, that apterae of each vector species settle preferentially on virus-infected plants, and that such responses are mediated by volatile organic compounds. The findings also indicate that plants respond heterogeneously to viral infection and as a result different plant parts change in attractiveness to vectors during infection and vector responses to virus-infected plants are dynamic. Such dynamic responses could enhance or reduce the probability of virus acquisition by individual aphids searching among plants. Finally, our work indicates that compared to non-viruliferous aphids, viruliferous ones are less or not responsive to virus-induced host plant volatiles. Changes in vector responsiveness to plants after vectors acquire virus could impact virus epidemiology by influencing virus

  9. Tiotropium Attenuates Virus-Induced Pulmonary Inflammation in Cigarette Smoke–Exposed Mice

    PubMed Central

    Bucher, Hannes; Duechs, Matthias J.; Tilp, Cornelia; Jung, Birgit

    2016-01-01

    Viral infections trigger exacerbations in chronic obstructive pulmonary disease (COPD), and tiotropium, a M3 receptor antagonist, reduces exacerbations in patients by unknown mechanisms. In this report, we investigated whether tiotropium has anti-inflammatory effects in mice exposed to cigarette smoke (CS) and infected with influenza virus A/PR/8/34 (H1N1) or respiratory syncytial virus (RSV) and compared these effects with those of steroid fluticasone and PDE4-inhibitor roflumilast. Mice were exposed to CS; infected with H1N1 or RSV; and treated with tiotropium, fluticasone, or roflumilast. The amount of cells and cytokine levels in the airways, lung function, and viral load was determined. NCI-H292 cells were infected with H1N1 or RSV and treated with the drugs. In CS/H1N1-exposed mice, tiotropium reduced neutrophil and macrophage numbers and levels of interleukin-6 (IL-6) and interferon-γ (IFN-γ) in the airways and improved lung function. In contrast, fluticasone increased the loss of body weight; failed to reduce neutrophil or macrophage numbers; increased IL-6, KC, and tumor necrosis factor-α (TNF-α) in the lungs; and worsened lung function. Treatment with roflumilast reduced macrophage numbers, IL-6, and KC in the lungs but had no effect on neutrophil numbers or lung function. In CS/RSV-exposed mice, treatment with tiotropium, but not fluticasone or roflumilast, reduced neutrophil numbers and IL-6 and TNF-α levels in the lungs. Viral load of H1N1 and RSV was significantly elevated in CS/virus-exposed mice and NCI-H292 cells after fluticasone treatment, whereas tiotropium and roflumilast had no effect. In conclusion, tiotropium has anti-inflammatory effects on CS/virus-induced inflammation in mice that are superior to the effects of roflumilast and fluticasone. This finding might help to explain the observed reduction of exacerbation rates in COPD patients. PMID:27016458

  10. Dissection of Tomato Lycopene Biosynthesis through Virus-Induced Gene Silencing1[C][W][OPEN

    PubMed Central

    Fantini, Elio; Falcone, Giulia; Frusciante, Sarah; Giliberto, Leonardo; Giuliano, Giovanni

    2013-01-01

    Lycopene biosynthesis in tomato (Solanum lycopersicum) fruits has been proposed to proceed through a poly-cis pathway catalyzed by phytoene synthase (PSY), two desaturases (phytoene desaturase [PDS] and ζ-carotene desaturase [ZDS]), and two cis-trans isomerases (ζ-carotene isomerase [ZISO] and prolycopene isomerase [CrtISO]). The mechanism of action of these enzymes has been studied in Escherichia coli, but a systematic study of their in vivo function is lacking. We studied the function of nine candidate genes (PSY1, PSY2, PSY3, PDS, ZDS, ZISO, CrtISO, CrtISO-Like1, and CrtISO-Like2) using virus-induced gene silencing (VIGS) coupled to high-resolution liquid chromatography coupled with diode array detector and mass spectrometry, which allowed the identification and quantitation of 45 different carotenoid isomers, including linear xanthophylls. The data confirm the confinement of the VIGS signal to the silenced fruits and the similarity of the phenotypes of PSY1- and CrtISO-silenced fruits with those of the yellow flesh and tangerine mutants. Light was able to restore lycopene biosynthesis in ZISO-silenced fruits. Isomeric composition of fruits silenced at different metabolic steps suggested the existence of three functional units, comprising PSY1, PDS/ZISO, and ZDS/CrtISO, and responsible for the synthesis of 15-cis-phytoene, 9,9’-di-cis-ζ-carotene, and all-trans-lycopene, respectively. Silencing of a desaturase (PDS or ZDS) resulted in the induction of the isomerase in the same functional unit (ZISO or CrtISO, respectively). All-trans-ζ-carotene was detectable in nonsilenced fruits, greatly increased in ZDS-silenced ones, and disappeared in CrtISO-Like1-/CrtISO-Like2-silenced ones, suggesting the existence of a metabolic side branch, comprising this compound and initiated by the latter enzymes. PMID:24014574

  11. Rapid activation of spleen dendritic cell subsets following lymphocytic choriomeningitis virus infection of mice: analysis of the involvement of type 1 IFN.

    PubMed

    Montoya, Maria; Edwards, Matthew J; Reid, Delyth M; Borrow, Persephone

    2005-02-15

    In this study, we report the dynamic changes in activation and functions that occur in spleen dendritic cell (sDC) subsets following infection of mice with a natural murine pathogen, lymphocytic choriomeningitis virus (LCMV). Within 24 h postinfection (pi), sDCs acquired the ability to stimulate naive LCMV-specific CD8+ T cells ex vivo. Conventional (CD11chigh CD8+ and CD4+) sDC subsets rapidly up-regulated expression of costimulatory molecules and began to produce proinflammatory cytokines. Their tendency to undergo apoptosis ex vivo simultaneously increased, and in vivo the number of conventional DCs in the spleen decreased markedly, dropping approximately 2-fold by day 3 pi. Conversely, the number of plasmacytoid (CD11clowB220+) DCs in the spleen increased, so that they constituted almost 40% of sDCs by day 3 pi. Type 1 IFN production was up-regulated in plasmacytoid DCs by 24 h pi. Analysis of DC activation and maturation in mice unable to respond to type 1 IFNs implicated these cytokines in driving infection-associated phenotypic activation of conventional DCs and their enhanced tendency to undergo apoptosis, but also indicated the existence of type 1 IFN-independent pathways for the functional maturation of DCs during LCMV infection. PMID:15699111

  12. Viruses as therapeutic agents. II. Viral reassortants map prevention of insulin-dependent diabetes mellitus to the small RNA of lymphocytic choriomeningitis virus

    PubMed Central

    1990-01-01

    Nonobese diabetic (NOD) mice are the experimental prototype of type 1 insulin-dependent diabetes mellitus (IDDM). These mice develop a characteristic autoimmune lesion in the pancreatic islets of Langerhans, where infiltrating lymphocytes destroy beta cells, resulting in hypoinsulinemia, hyperglycemia, ketoacidosis, and death. This IDDM, which closely resembles that in humans, is prevented by infecting NOD mice with particular strains of lymphocytic choriomeningitis virus (LCMV), including Armstrong 53b, Traub, WE, and Pasteur. In contrast, the LCMV Armstrong 53b variant, Clone 13, fails to abort IDDM. Hence, although Clone 13 establishes a persistent infection that endures throughout the life spans of NOD mice, their hyperglycemia, hypoinsulinemia, and lymphocytic infiltration into the islets of Langerhans still occur. Genetic reassortant viruses generated between the IDDM therapeutic strain of LCMV Pasteur and the nontherapeutic variant, LCMV Clone 13, were used to treat NOD mice. By using such reassortants and both parental strains of virus to infect NOD mice, the prevention of IDDM was mapped to the S RNA segment of LCMV Pasteur. PMID:2191074

  13. Self-Association of Lymphocytic Choriomeningitis Virus Nucleoprotein Is Mediated by Its N-Terminal Region and Is Not Required for Its Anti-Interferon Function

    PubMed Central

    Ortiz-Riaño, Emilio; Cheng, Benson Yee Hin

    2012-01-01

    Arenaviruses have a bisegmented, negative-strand RNA genome. Both the large (L) and small (S) genome segments use an ambisense coding strategy to direct the synthesis of two viral proteins. The L segment encodes the virus polymerase (L protein) and the matrix Z protein, whereas the S segment encodes the nucleoprotein (NP) and the glycoprotein precursor (GPC). NPs are the most abundant viral protein in infected cells and virions and encapsidate genomic RNA species to form an NP-RNA complex that, together with the virus L polymerase, forms the virus ribonucleoprotein (RNP) core capable of directing both replication and transcription of the viral genome. RNP formation predicts a self-association property of NPs. Here we document self-association (homotypic interaction) of the NP of the prototypic arenavirus lymphocytic choriomeningitis virus (LCMV), as well as those of the hemorrhagic fever (HF) arenaviruses Lassa virus (LASV) and Machupo virus (MACV). We also show heterotypic interaction between NPs from both closely (LCMV and LASV) and distantly (LCMV and MACV) genetically related arenaviruses. LCMV NP self-association was dependent on the presence of single-stranded RNA and mediated by an N-terminal region of the NP that did not overlap with the previously described C-terminal NP domain involved in either counteracting the host type I interferon response or interacting with LCMV Z. PMID:22258244

  14. Self-association of lymphocytic choriomeningitis virus nucleoprotein is mediated by its N-terminal region and is not required for its anti-interferon function.

    PubMed

    Ortiz-Riaño, Emilio; Cheng, Benson Yee Hin; de la Torre, Juan C; Martínez-Sobrido, Luis

    2012-03-01

    Arenaviruses have a bisegmented, negative-strand RNA genome. Both the large (L) and small (S) genome segments use an ambisense coding strategy to direct the synthesis of two viral proteins. The L segment encodes the virus polymerase (L protein) and the matrix Z protein, whereas the S segment encodes the nucleoprotein (NP) and the glycoprotein precursor (GPC). NPs are the most abundant viral protein in infected cells and virions and encapsidate genomic RNA species to form an NP-RNA complex that, together with the virus L polymerase, forms the virus ribonucleoprotein (RNP) core capable of directing both replication and transcription of the viral genome. RNP formation predicts a self-association property of NPs. Here we document self-association (homotypic interaction) of the NP of the prototypic arenavirus lymphocytic choriomeningitis virus (LCMV), as well as those of the hemorrhagic fever (HF) arenaviruses Lassa virus (LASV) and Machupo virus (MACV). We also show heterotypic interaction between NPs from both closely (LCMV and LASV) and distantly (LCMV and MACV) genetically related arenaviruses. LCMV NP self-association was dependent on the presence of single-stranded RNA and mediated by an N-terminal region of the NP that did not overlap with the previously described C-terminal NP domain involved in either counteracting the host type I interferon response or interacting with LCMV Z.

  15. Selection of genetic variants of lymphocytic choriomeningitis virus in spleens of persistently infected mice. Role in suppression of cytotoxic T lymphocyte response and viral persistence

    PubMed Central

    1984-01-01

    We studied the mechanism of lymphocytic choriomeningitis virus (LCMV) persistence and the suppression of cytotoxic T lymphocyte (CTL) responses in BALB/c WEHI mice infected at birth with LCMV Armstrong strain. Using adoptive transfer experiments we found that spleen cells from persistently infected (carrier) mice actively suppressed the expected LCMV-specific CTL response of spleen cells from normal adult mice. The suppression was specific for the CTL response and LCMV - specific antibody responses were not affected. Associated with the specific CTL suppression was the establishment of persistent LCMV infection. The transfer of spleen or lymph node cells containing LCMV - specific CTL resulted in virus clearance and prevented establishment of the carrier state. The suppression of LCMV -specific CTL responses by carrier spleen cells is not mediated by a suppressor cell, but is due to the presence of genetic variants of LCMV in spleens of carrier mice. Such virus variants selectively suppress LCMV-specific CTL responses and cause persistent infections in immunocompetent mice. In striking contrast, wild-type LCMV Armstrong, from which these variants were generated, induces a potent CTL response in immunocompetent mice and the LCMV infection is rapidly cleared. Our results show that LCMV variants that emerge during infection in vivo play a crucial role in the suppression of virus-specific CTL responses and in the maintenance of virus persistence. PMID:6332167

  16. Virus-lymphocyte interaction: T cells of the helper subset are infected with lymphocytic choriomeningitis virus during persistent infection in vivo.

    PubMed Central

    Ahmed, R; King, C C; Oldstone, M B

    1987-01-01

    The lifelong persistence of lymphocytic choriomeningitis virus (LCMV) in neonatally or congenitally infected mice is accompanied by a suppression of virus-specific T-cell responses. In this study, we identified the subset of T cells infected with LCMV during persistent infection in vivo. Using specific monoclonal antibodies to separate the different lymphocyte cell populations and employing both an infectious center assay and immunofluorescence to detect the virus, we found that infection is confined primarily to T cells of the helper subset (L3T4+ Lyt2-), with minimal involvement of cytotoxic T cells (Lyt2+ L3T4-) and mature B cells. About 0.54 to 1.1% of L3T4+ T cells were producing the virus, as determined by the infectious center assay. In contrast, 9.1 to 12.2% of these L3T4+ T cells contained viral antigen, as shown by immunofluorescence studies. This finding suggested that, at any given time, a substantial number of infected T cells were not producing infectious virus. This infection of T helper cells may be involved in the suppression of LCMV-specific T-cell responses observed in persistently infected mice. Images PMID:2952807

  17. Weight loss in obese mice persistently infected with lymphocytic choriomeningitis virus is not associated with elevated tumor necrosis factor/cachectin activity in peritoneal macrophages.

    PubMed Central

    Lathey, J. L.; Oldstone, M. B.

    1988-01-01

    C57BL/6 ob/ob (C57 ob/ob) mice infected persistently with lymphocytic choriomeningitis virus (LCMV) show cachexia as judged by a weight loss of greater than 20%. Virus persists in a subset of macrophages. Because a cachexic state occurs in several chronic debilitating diseases of humans, often accompanied by persistent microbial infections with macrophage/monocytic involvement and tumor necrosis factor (TNF) cachectin production, the role of TNF in the weightloss of ob/ob mice infected persistently with LCMV was investigated. TNF mRNA expression was not increased in peritoneal cells from such persistently-infected mice, nor did their serum levels of TNF rise above those in uninfected litter-mates. Furthermore, in vitro LCMV infection of adherent peritoneal cells from these C57 ob/ob mice did not enhance TNF mRNA or protein expression. Therefore, the cachexia-like weight loss observed in C57 ob/ob mice during a persistent LCMV infection is apparently not associated with a measurable increase in TNF. Images Figure 2 Figure 3 Figure 4 PMID:3414785

  18. Measles virus-induced changes in leukocyte function antigen 1 expression and leukocyte aggregation: possible role in measles virus pathogenesis.

    PubMed

    Attibele, N; Wyde, P R; Trial, J; Smole, S C; Smith, C W; Rossen, R D

    1993-02-01

    Measles virus (MV) infection of U937 cell or peripheral blood leukocyte cultures was shown to induce changes in the expression of leukocyte function antigen 1 (LFA-1) and cause marked aggregation of these cells. Addition of selected monoclonal antibodies specific for LFA-1 epitopes that did not neutralize MV in standard neutralization assays were found to block both virus-induced leukocyte aggregation and virus dissemination. These data suggest that MV modulation of LFA-1 expression on leukocytes may be an important step in MV pathogenesis.

  19. Histone deacetylase inhibitors suppress RSV infection and alleviate virus-induced airway inflammation

    PubMed Central

    Feng, Qiuqin; Su, Zhonglan; Song, Shiyu; Xu, Hui; Zhang, Bin; Yi, Long; Tian, Man; Wang, Hongwei

    2016-01-01

    Respiratory syncytial virus (RSV) is the leading cause of lower respiratory tract infections in infants and young children. However, the majority of RSV-infected patients only show mild symptoms. Different severities of infection and responses among the RSV-infected population indicate that epigenetic regulation as well as personal genetic background may affect RSV infectivity. Histone deacetylase (HDAC) is an important epigenetic regulator in lung diseases. The present study aimed to explore the possible connection between HDAC expression and RSV-induced lung inflammation. To address this question, RSV-infected airway epithelial cells (BEAS-2B) were prepared and a mouse model of RSV infection was established, and then treated with various concentrations of HDAC inhibitors (HDACis), namely trichostatin A (TSA) and suberoylanilide hydroxamic acid (SAHA). Viral replication and markers of virus-induced airway inflammation or oxidative stress were assessed. The activation of the nuclear factor-κB (NF-κB), cyclo-oxygenase-2 (COX-2), mitogen-activated protein kinase (MAPK) and signal transducer and activator of transcription 3 (STAT3) signaling pathways was evaluated by western blot analysis. Our results showed that RSV infection in airway epithelial cells (AECs) significantly decreased histone acetylation levels by altering HDAC2 expression. The treatment of RSV-infected AECs with HDACis significantly restricted RSV replication by upregulating the interferon-α (IFN-α) related signaling pathways. The treatment of RSV-infected AECs with HDACis also significantly inhibited RSV-induced pro-inflammatory cytokine release [interleukin (IL)-6 and IL-8] and oxidative stress-related molecule production [malondialdehyde (MDA), and nitrogen monoxide (NO)]. The activation of NF-κB, COX-2, MAPK and Stat3, which orchestrate pro-inflammatory gene expression and oxidative stress injury, was also significantly inhibited. Our in vivo study using a mouse model of RSV infection

  20. Detection of a unique antigen on radiation leukemia virus-induced leukemia B6RV2

    SciTech Connect

    Nakayama, E.; Uenaka, A.; Stockert, E.; Obata, Y.

    1984-11-01

    Radiation leukemia virus-induced leukemia of a male C57BL/6 mouse, B6RV2, is immunogenic to female BALB/c X C57BL/6 F1 mice. In these mice, B6RV2 tumors regressed after initial growth, and after tumor regression the mice were resistant to repeated inocula of up to 10(8) B6RV2 cells. Serum from these mice reacted with B6RV2 in mixed hemadsorption or protein A assays, and absorption analysis indicated that the antigen was restricted to B6RV2; it could not be detected in normal thymocytes or spleen concanavalin A blasts from different inbred strains, nor in 16 C57BL/6 or BALB/c leukemias. Spleen cells from mice in which the tumor had regressed were cytotoxic to B6RV2 after in vitro stimulation with B6RV2, as shown by /sup 51/chromium release assay. This cytotoxicity was eliminated by pretreatment of the cells with anti-Thy-1.2, anti-Lyt-2.2, anti-Lyt-3.2, and complement, indicating that the effector cells were T-cells. The specificity of T-cell killing of B6RV2 was examined by competitive inhibition assays with unlabeled cells; only B6RV2 inhibited killing, while eight other C57BL/6 leukemias did not inhibit. Thus, the antigen on B6RV2 defined serologically and by cytotoxic T-cells is a unique antigen. However, it was not revealed by antibody-blocking test whether the unique determinant defined serologically was related to that recognized by T-cells; B6RV2 antiserum did not block lytic activity in the absence of added complement, irrespective of whether the target cells were untreated or anti-H-2b-treated B6RV2. H-2Kb antisera, but not H-2Db antisera, blocked lysis. This indicated that the H-2Kb molecule was exclusively involved in recognition of B6RV2 by cytotoxic T-cell.

  1. Histone deacetylase inhibitors suppress RSV infection and alleviate virus-induced airway inflammation.

    PubMed

    Feng, Qiuqin; Su, Zhonglan; Song, Shiyu; Χu, Hui; Zhang, Bin; Yi, Long; Tian, Man; Wang, Hongwei

    2016-09-01

    Respiratory syncytial virus (RSV) is the leading cause of lower respiratory tract infections in infants and young children. However, the majority of RSV-infected patients only show mild symptoms. Different severities of infection and responses among the RSV-infected population indicate that epigenetic regulation as well as personal genetic background may affect RSV infectivity. Histone deacetylase (HDAC) is an important epigenetic regulator in lung diseases. The present study aimed to explore the possible connection between HDAC expression and RSV-induced lung inflammation. To address this question, RSV-infected airway epithelial cells (BEAS‑2B) were prepared and a mouse model of RSV infection was established, and then treated with various concentrations of HDAC inhibitors (HDACis), namely trichostatin A (TSA) and suberoylanilide hydroxamic acid (SAHA). Viral replication and markers of virus-induced airway inflammation or oxidative stress were assessed. The activation of the nuclear factor-κB (NF-κB), cyclo-oxygenase-2 (COX-2), mitogen-activated protein kinase (MAPK) and signal transducer and activator of transcription 3 (STAT3) signaling pathways was evaluated by western blot analysis. Our results showed that RSV infection in airway epithelial cells (AECs) significantly decreased histone acetylation levels by altering HDAC2 expression. The treatment of RSV-infected AECs with HDACis significantly restricted RSV replication by upregulating the interferon-α (IFN-α) related signaling pathways. The treatment of RSV-infected AECs with HDACis also significantly inhibited RSV-induced pro-inflammatory cytokine release [interleukin (IL)-6 and IL-8] and oxidative stress-related molecule production [malondialdehyde (MDA), and nitrogen monoxide (NO)]. The activation of NF-κB, COX-2, MAPK and Stat3, which orchestrate pro‑inflammatory gene expression and oxidative stress injury, was also significantly inhibited. Our in vivo study using a mouse model of

  2. Dietary Vitamin D3 Suppresses Pulmonary Immunopathology Associated with Late-Stage Tuberculosis in C3HeB/FeJ Mice.

    PubMed

    Reeme, Allison E; Robinson, Richard T

    2016-02-01

    Tuberculosis (TB) is a significant human disease caused by inhalation of Mycobacterium tuberculosis. Left untreated, TB mortality is associated with a failure to resolve pulmonary immunopathology. There is currently widespread interest in using vitamin D3 (VitD3) as an adjunct therapy for TB because numerous in vitro studies have shown that VitD3 has direct and indirect mycobactericidal activities. However, to date, there have been no in vivo studies addressing whether VitD3 affects experimental TB outcome. In this study, we used C3HeB/FeJ mice to determine whether dietary VitD3 influences the outcome of experimental TB. We observed that although M. tuberculosis burdens did not differ between mice on a VitD3-replete diet (VitD(HI) mice) and mice on a VitD3-deficient diet (VitD(LO) mice), the inflammatory response in VitD(HI) mice was significantly attenuated relative to VitD(LO) controls. Specifically, the expression of multiple inflammatory pathways was reduced in the lungs at later disease stages as were splenocyte IL12/23p40 and IFN-γ levels following ex vivo restimulation. Dietary VitD3 also suppressed the accumulation of T cells in the mediastinal lymph nodes and lung granulomatous regions while concomitantly accelerating the accumulation of F4/80(+) and Ly6C/Ly6G(+) lineages. The altered inflammatory profile of VitD(HI) mice also associated with reductions in pulmonary immunopathology. VitD receptor-deficient (vdr(-/-)) radiation bone marrow chimeras demonstrate that reductions in pulmonary TB immunopathology are dependent on hematopoietic VitD responsiveness. Collectively, our data support a model wherein the in vivo role of VitD3 during TB is not to promote M. tuberculosis killing but rather to function through hematopoietic cells to reduce M. tuberculosis-elicited immunopathology. PMID:26729807

  3. Virus-induced polyclonal B cell activation improves protective CTL memory via retained CD27 expression on memory CTL.

    PubMed

    Matter, Matthias; Mumprecht, Sabine; Pinschewer, Daniel D; Pavelic, Viktor; Yagita, Hideo; Krautwald, Stefan; Borst, Jannie; Ochsenbein, Adrian F

    2005-11-01

    Different viruses elicit distinct phenotypes of memory cytotoxic T lymphocytes (CTL). This is reflected in differential expression of homing receptors and costimulatory molecules like CD27. Memory CTL retained CD27 following lymphocytic choriomeningitis virus (LCMV) infection, but not after immunization with recombinant vaccinia virus or tumor cells expressing LCMV glycoprotein. Stable CD27 expression on memory CTL required ligation by CD70 expressed on polyclonally activated B cells during the contraction phase. The functional consequence of CD27 expressed on virus-specific CTL was analyzed in CD27-deficient mice. LCMV infection of CD27(-/-) mice revealed that primary CTL activation and expansion as well as elimination of the virus were independent of CD27 expression. In contrast, ligation of CD27 on memory CTL upon secondary antigen encounter increased clonal expansion and improved protection against re-infection. This points to novel B cell-CTL interactions during viral infection and to a beneficial role of polyclonal B cell activation that represents a characteristic of murine LCMV, human immunodeficiency virus and human hepatitis B and C virus infection. PMID:16231287

  4. Programmed cell death of T lymphocytes during acute viral infection: a mechanism for virus-induced immune deficiency.

    PubMed Central

    Razvi, E S; Welsh, R M

    1993-01-01

    Acute viral infections induce immune deficiencies, as shown by unresponsiveness to mitogens and unrelated antigens. T lymphocytes isolated from mice acutely infected with lymphocytic choriomeningitis virus (LCMV) were found in this study to undergo activation-induced apoptosis upon signalling through the T-cell receptor (TcR)-CD3 complex. Kinetic studies demonstrated that this sensitivity to apoptosis directly correlated with the induction of immune deficiency, as measured by impaired proliferation in response to anti-CD3 antibody or to concanavalin A. Cell cycling in interleukin-2 (IL-2) alone stimulated proliferation of LCMV-induced T cells without inducing apoptosis, but preculturing of T cells from acutely infected mice in IL-2 accelerated apoptosis upon subsequent TcR-CD3 cross-linking. T lymphocytes isolated from mice after the acute infection were less responsive to IL-2, but those T cells, presumably memory T cells, responding to IL-2 were primed in each case to die a rapid apoptotic death upon TcR-CD3 cross-linking. These results indicate that virus infection-induced unresponsiveness to T-cell mitogens is due to apoptosis of the activated lymphocytes and suggest that the sensitization of memory cells by IL-2 induced during infection will cause them to die upon antigen recognition, thereby impairing specific responses to nonviral antigens. Images PMID:8371341

  5. Susceptibility to Theiler's virus-induced demyelination. Mapping of the gene within the H-2D region.

    PubMed

    Rodriguez, M; Leibowitz, J; David, C S

    1986-03-01

    Demyelination induced by Theiler's virus was examined in mouse strains with congeneic recombinant haplotypes. Light and electron microscopy of spinal cord sections from mice with s, q, v, p, and f H-2D alleles showed perivascular inflammation and primary demyelination. The presence of susceptible haplotypes in the K or I region did not correlate with pathologic abnormalities. The Qa, Tla, PgK, and UpG genes did not appear to be critical in determining susceptibility to disease. However, mutation in the H-2D genes altered the susceptibility to virus-induced demyelination. B10.D2dm1 mice, which have deletions in the 3' end of Dd and the 5' end of Ld, showed prominent demyelination and clinical deficits. In contrast, BALB/c-dm2, which have a deletion of the entire L gene, showed no pathologic changes. Central nervous system virus titers correlated with susceptibility to demyelination; both resistant and susceptible strains had a strong humoral immune response to the virus. The findings in the congeneic recombinant mice and in mice mutant in the H-2D region strongly suggest that at least one of the genes critical for determining virus-induced demyelination maps to the 3' end of the H-2D gene.

  6. Virus-induced tumor inflammation facilitates effective DC cancer immunotherapy in a Treg-dependent manner in mice

    PubMed Central

    Woller, Norman; Knocke, Sarah; Mundt, Bettina; Gürlevik, Engin; Strüver, Nina; Kloos, Arnold; Boozari, Bita; Schache, Peter; Manns, Michael P.; Malek, Nisar P.; Sparwasser, Tim; Zender, Lars; Wirth, Thomas C.; Kubicka, Stefan; Kühnel, Florian

    2011-01-01

    Vaccination using DCs pulsed with tumor lysates or specific tumor-associated peptides has so far yielded limited clinical success for cancer treatment, due mainly to the low immunogenicity of tumor-associated antigens. In this study, we have identified intratumoral virus-induced inflammation as a precondition for effective antitumor DC vaccination in mice. Administration of a tumor-targeted DC vaccine during ongoing virus-induced tumor inflammation, a regimen referred to as oncolysis-assisted DC vaccination (ODC), elicited potent antitumoral CD8+ T cell responses. This potent effect was not replicated by TLR activation outside the context of viral infection. ODC-elicited immune responses mediated marked tumor regression and successful eradication of preestablished lung colonies, an essential prerequisite for potentially treating metastatic cancers. Unexpectedly, depletion of Tregs during ODC did not enhance therapeutic efficacy; rather, it abrogated antitumor cytotoxicity. This phenomenon could be attributed to a compensatory induction of myeloid-derived suppressor cells in Treg-depleted and thus vigorously inflamed tumors, which prevented ODC-mediated immune responses. Consequently, Tregs are not only general suppressors of immune responses, but are essential for the therapeutic success of multimodal and temporally fine-adjusted vaccination strategies. Our results highlight tumor-targeting, replication-competent viruses as attractive tools for eliciting effective antitumor responses upon DC vaccination. PMID:21646722

  7. A conserved virus-induced cytoplasmic TRAMP-like complex recruits the exosome to target viral RNA for degradation.

    PubMed

    Molleston, Jerome M; Sabin, Leah R; Moy, Ryan H; Menghani, Sanjay V; Rausch, Keiko; Gordesky-Gold, Beth; Hopkins, Kaycie C; Zhou, Rui; Jensen, Torben Heick; Wilusz, Jeremy E; Cherry, Sara

    2016-07-15

    RNA degradation is tightly regulated to selectively target aberrant RNAs, including viral RNA, but this regulation is incompletely understood. Through RNAi screening in Drosophila cells, we identified the 3'-to-5' RNA exosome and two components of the exosome cofactor TRAMP (Trf4/5-Air1/2-Mtr4 polyadenylation) complex, dMtr4 and dZcchc7, as antiviral against a panel of RNA viruses. We extended our studies to human orthologs and found that the exosome as well as TRAMP components hMTR4 and hZCCHC7 are antiviral. While hMTR4 and hZCCHC7 are normally nuclear, infection by cytoplasmic RNA viruses induces their export, forming a cytoplasmic complex that specifically recognizes and induces degradation of viral mRNAs. Furthermore, the 3' untranslated region (UTR) of bunyaviral mRNA is sufficient to confer virus-induced exosomal degradation. Altogether, our results reveal that signals from viral infection repurpose TRAMP components to a cytoplasmic surveillance role where they selectively engage viral RNAs for degradation to restrict a broad range of viruses. PMID:27474443

  8. Comparison of rapid immunodiagnosis assay kit with molecular and immunopathological approaches for diagnosis of rabies in cattle

    PubMed Central

    Ahmad, Ajaz; Singh, C. K.

    2016-01-01

    Aim: Presently, diagnosis of rabies is primarily based on, conventional fluorescent antibody technique (FAT), immunopathological and molecular techniques. Recently, rapid immunodiagnostic assay (RIDA) - A monoclonal antibody-based technique has been introduced for rapid diagnosis of rabies. The present investigation is envisaged to study the efficacy of RIDA kit for the diagnosis of rabies in cattle. Materials and Methods: About 11 brain samples from cattle, clinically suspected for rabies, were screened by the FAT, Heminested reverse transcriptase polymerase chain reaction (HnRT-PCR), Immunohistochemistry (IHC), and RIDA. Results: The sensitivity for detection of rabies from brain tissue by RIDA was 85.7% as compared to 100% by IHC as well as HnRT-PCR. The accuracy of detection of rabies by RIDA was 91.6% as compared to 100% that of IHC and HnRT-PCR, whereas specificity of RIDA was 100% like that of the IHC and HnRT-PCR. Conclusion: Despite a comparatively low-sensitivity and accuracy of RIDA, latter can still be useful in screening a large number of field samples promptly. However, it is recommended that negative results with RIDA in cattle need to be authenticated by suitable alternative diagnostic approaches. PMID:27051193

  9. Cell-type deconvolution with immune pathways identifies gene networks of host defense and immunopathology in leprosy

    PubMed Central

    Inkeles, Megan S.; Teles, Rosane M.B.; Pouldar, Delila; Andrade, Priscila R.; Madigan, Cressida A.; Ambrose, Mike; Sarno, Euzenir N.; Rea, Thomas H.; Ochoa, Maria T.; Iruela-Arispe, M. Luisa; Swindell, William R.; Ottenhoff, Tom H.M.; Geluk, Annemieke; Bloom, Barry R.

    2016-01-01

    Transcriptome profiles derived from the site of human disease have led to the identification of genes that contribute to pathogenesis, yet the complex mixture of cell types in these lesions has been an obstacle for defining specific mechanisms. Leprosy provides an outstanding model to study host defense and pathogenesis in a human infectious disease, given its clinical spectrum, which interrelates with the host immunologic and pathologic responses. Here, we investigated gene expression profiles derived from skin lesions for each clinical subtype of leprosy, analyzing gene coexpression modules by cell-type deconvolution. In lesions from tuberculoid leprosy patients, those with the self-limited form of the disease, dendritic cells were linked with MMP12 as part of a tissue remodeling network that contributes to granuloma formation. In lesions from lepromatous leprosy patients, those with disseminated disease, macrophages were linked with a gene network that programs phagocytosis. In erythema nodosum leprosum, neutrophil and endothelial cell gene networks were identified as part of the vasculitis that results in tissue injury. The present integrated computational approach provides a systems approach toward identifying cell-defined functional networks that contribute to host defense and immunopathology at the site of human infectious disease. PMID:27699251

  10. A Numerically Subdominant CD8 T Cell Response to Matrix Protein of Respiratory Syncytial Virus Controls Infection with Limited Immunopathology

    PubMed Central

    Liu, Jie; Haddad, Elias K.; Marceau, Joshua; Morabito, Kaitlyn M.; Rao, Srinivas S.; Filali-Mouhim, Ali; Sekaly, Rafick-Pierre; Graham, Barney S.

    2016-01-01

    CD8 T cells are involved in pathogen clearance and infection-induced pathology in respiratory syncytial virus (RSV) infection. Studying bulk responses masks the contribution of individual CD8 T cell subsets to protective immunity and immunopathology. In particular, the roles of subdominant responses that are potentially beneficial to the host are rarely appreciated when the focus is on magnitude instead of quality of response. Here, by evaluating CD8 T cell responses in CB6F1 hybrid mice, in which multiple epitopes are recognized, we found that a numerically subdominant CD8 T cell response against DbM187 epitope of the virus matrix protein expressed high avidity TCR and enhanced signaling pathways associated with CD8 T cell effector functions. Each DbM187 T effector cell lysed more infected targets on a per cell basis than the numerically dominant KdM282 T cells, and controlled virus replication more efficiently with less pulmonary inflammation and illness than the previously well-characterized KdM282 T cell response. Our data suggest that the clinical outcome of viral infections is determined by the integrated functional properties of a variety of responding CD8 T cells, and that the highest magnitude response may not necessarily be the best in terms of benefit to the host. Understanding how to induce highly efficient and functional T cells would inform strategies for designing vaccines intended to provide T cell-mediated immunity. PMID:26943673

  11. A Numerically Subdominant CD8 T Cell Response to Matrix Protein of Respiratory Syncytial Virus Controls Infection with Limited Immunopathology.

    PubMed

    Liu, Jie; Haddad, Elias K; Marceau, Joshua; Morabito, Kaitlyn M; Rao, Srinivas S; Filali-Mouhim, Ali; Sekaly, Rafick-Pierre; Graham, Barney S

    2016-03-01

    CD8 T cells are involved in pathogen clearance and infection-induced pathology in respiratory syncytial virus (RSV) infection. Studying bulk responses masks the contribution of individual CD8 T cell subsets to protective immunity and immunopathology. In particular, the roles of subdominant responses that are potentially beneficial to the host are rarely appreciated when the focus is on magnitude instead of quality of response. Here, by evaluating CD8 T cell responses in CB6F1 hybrid mice, in which multiple epitopes are recognized, we found that a numerically subdominant CD8 T cell response against DbM187 epitope of the virus matrix protein expressed high avidity TCR and enhanced signaling pathways associated with CD8 T cell effector functions. Each DbM187 T effector cell lysed more infected targets on a per cell basis than the numerically dominant KdM282 T cells, and controlled virus replication more efficiently with less pulmonary inflammation and illness than the previously well-characterized KdM282 T cell response. Our data suggest that the clinical outcome of viral infections is determined by the integrated functional properties of a variety of responding CD8 T cells, and that the highest magnitude response may not necessarily be the best in terms of benefit to the host. Understanding how to induce highly efficient and functional T cells would inform strategies for designing vaccines intended to provide T cell-mediated immunity.

  12. Cell-type deconvolution with immune pathways identifies gene networks of host defense and immunopathology in leprosy

    PubMed Central

    Inkeles, Megan S.; Teles, Rosane M.B.; Pouldar, Delila; Andrade, Priscila R.; Madigan, Cressida A.; Ambrose, Mike; Sarno, Euzenir N.; Rea, Thomas H.; Ochoa, Maria T.; Iruela-Arispe, M. Luisa; Swindell, William R.; Ottenhoff, Tom H.M.; Geluk, Annemieke; Bloom, Barry R.

    2016-01-01

    Transcriptome profiles derived from the site of human disease have led to the identification of genes that contribute to pathogenesis, yet the complex mixture of cell types in these lesions has been an obstacle for defining specific mechanisms. Leprosy provides an outstanding model to study host defense and pathogenesis in a human infectious disease, given its clinical spectrum, which interrelates with the host immunologic and pathologic responses. Here, we investigated gene expression profiles derived from skin lesions for each clinical subtype of leprosy, analyzing gene coexpression modules by cell-type deconvolution. In lesions from tuberculoid leprosy patients, those with the self-limited form of the disease, dendritic cells were linked with MMP12 as part of a tissue remodeling network that contributes to granuloma formation. In lesions from lepromatous leprosy patients, those with disseminated disease, macrophages were linked with a gene network that programs phagocytosis. In erythema nodosum leprosum, neutrophil and endothelial cell gene networks were identified as part of the vasculitis that results in tissue injury. The present integrated computational approach provides a systems approach toward identifying cell-defined functional networks that contribute to host defense and immunopathology at the site of human infectious disease.

  13. The significance of T cells, B cells, antibodies and macrophages against encephalomyocarditis (EMC)-D virus-induced diabetes in mice.

    PubMed

    Kounoue, Etsushi; Izumi, Ken-ichi; Ogawa, Shuichiro; Kondo, Shiori; Katsuta, Hitoshi; Akashi, Tomoyuki; Niho, Yoshiyuki; Harada, Mine; Tamiya, Sadafumi; Kurisaki, Hironori; Nagafuchi, Seiho

    2008-01-01

    In order to clarify the significance of protective mechanisms against encephalomyocarditis (EMC) virus-induced diabetes in mice, we studied the relative importance of T cells, B cells, antibodies and macrophages in the prevention of virus-induced diabetes. Neither T cell-deficient athymic nude mice nor B cell-deficient microMT/microMT mice showed an enhanced clinical course of EMC-D virus-induced diabetes, indicating that neither T cells nor B cells played a major role in the protection against EMC-D-virus-induced diabetes. Transfer of a large amount of antiserum to EMC-D-virus-infected mice protected the development of diabetes only when transferred within 36 h of infection, the timing of which was earlier than that for the production of natural neutralizing antibodied. Since pretreatment of mice with the macrophage-activating immunopotentiator Corynebacterium parvum (CP) completely prevented the development of diabetes, we studied the clinical outcome of EMC-D-virus-infected mice pretreated with CP. Mice treated with CP showed reduced proliferation of EMC-D virus in the affected organs, including the pancreas, while the levels of development of neutralizing antibody and serum interferon were not enhanced compared with the controls. Finally, we studied the macrophages derived from mice pretreated with CP and found that they inhibited the growth of EMC-D virus in vitro more than those derived from non-treated and thioglycolate-treated mice. Taken together, it can be suggested that neither T cells nor B cells, which have to do with adaptive immunity, play a significant role in the pathogenesis of EMC-D-virus-induced diabetes, while innate immunity, which is dependent on activated macrophages, contributes to in vivo resistance against EMC-D-virus-induced diabetes. PMID:18500429

  14. Evaluation of the immunomodulatory and antiviral effects of the cytokine combination IFN-α and IL-7 in the lymphocytic choriomeningitis virus and Friend retrovirus mouse infection models.

    PubMed

    Audigé, Annette; Hofer, Ursula; Dittmer, Ulf; van den Broek, Maries; Speck, Roberto F

    2011-10-01

    Existing therapies for chronic viral infections are still suboptimal or have considerable side effects, so new therapeutic strategies need to be developed. One option is to boost the host's immune response with cytokines. We have recently shown in an acute ex vivo HIV infection model that co-administration of interferon (IFN)-α and interleukin (IL)-7 allows us to combine the potent anti-HIV activity of IFN-α with the beneficial effects of IL-7 on T-cell survival and function. Here we evaluated the effect of combining IFN-α and IL-7 on viral replication in vivo in the chronic lymphocytic choriomeningitis virus (LCMV) and acute Friend retrovirus (FV) infection models. In the chronic LCMV model, cytokine treatment was started during the early replication phase (i.e., on day 7 post-infection [pi]). Under the experimental conditions used, exogenous IFN-α inhibited FV replication, but had no effect on viral replication in the LCMV model. There was no therapeutic benefit of IL-7 either alone or in combination with IFN-α in either of the two infection models. In the LCMV model, dose-dependent effects of the cytokine combination on T-cell phenotype/function were observed. It is possible that these effects would translate into antiviral activity in re-challenged mice. It is also possible that another type of IFN-α/β or induction of endogenous IFN-α/β alone or in combination with IL-7 would have antiviral activity in the LCMV model. Furthermore, we cannot exclude that some effect on viral titers would have been seen at later time points not investigated here (i.e., beyond day 34 pi). Finally, IFN-α/IL-7 may inhibit the replication of other viruses. Thus it might be worth testing these cytokines in other in vivo models of chronic viral infections.

  15. Molecular determinants of macrophage tropism and viral persistence: importance of single amino acid changes in the polymerase and glycoprotein of lymphocytic choriomeningitis virus.

    PubMed Central

    Matloubian, M; Kolhekar, S R; Somasundaram, T; Ahmed, R

    1993-01-01

    This study documents that the immunosuppressive lymphocytic choriomeningitis virus (LCMV) variant, clone 13, shows a specific predilection for enhanced infection of macrophages both in vitro and in vivo and that single amino acid changes in the viral polymerase and glycoprotein are responsible for macrophage tropism. The growth difference seen between variant clone 13 and the parental Armstrong strain was specific for macrophages, since both clone 13 and Armstrong grew equally well in fibroblasts and neither isolate infected lymphocytes efficiently. Complete sequencing of the clone 13 genome, along with genetic analysis, showed that a single amino acid change in the polymerase (K-->Q at position 1079) was the major determinant of virus yield in macrophages. This was proven unequivocally by comparing the sequences of parental and reassortant viruses, which were identical at all loci except for the single mutation in the polymerase gene. This finding was further strengthened by showing that reversion at this site back to lysine (Q-->K) resulted in loss of macrophage tropism. In addition, an independently derived macrophage-tropic variant of LCMV, clone 28b, had a K-->N mutation at the same position. Thus, these results show that substitution of the positively charged amino acid K with a neutral amino acid (either Q or N) at residue 1079 of the polymerase resulted in enhanced viral replication in macrophages. In addition to the polymerase change, a mutation in the glycoprotein was also associated with macrophage tropism. This single amino acid change in the glycoprotein (F-->L at position 260) did not affect virus yield per macrophage but was critical in determining the number of macrophages infected. Our previous studies have shown that the same two mutations in the polymerase and glycoprotein are essential for establishing a chronic infection in adult mice. Since the same mutations confer macrophage tropism and ability to persist in vivo, these studies provide

  16. Genetic analysis of in vivo-selected viral variants causing chronic infection: importance of mutation in the L RNA segment of lymphocytic choriomeningitis virus.

    PubMed Central

    Ahmed, R; Simon, R S; Matloubian, M; Kolhekar, S R; Southern, P J; Freedman, D M

    1988-01-01

    Viral variants with different biological properties are present in the central nervous systems (CNS) and lymphoid tissues of mice persistently infected with lymphocytic choriomeningitis virus (LCMV). Viral isolates from the CNS are similar to the original Armstrong LCMV strain and induce potent virus-specific T-cell responses in adult mice, and the infection is rapidly cleared. In contrast, LCMV isolates derived from spleens of carrier mice cause persistent infections in adult mice. This chronic infection is associated with low levels of antiviral T-cell responses. In this study, we genetically characterized two independently derived spleen variants by making recombinants (reassortants) between the spleen isolates and wild-type (wt) LCMV and showed that the ability to persist in adult mice and the associated suppression of T-cell responses segregates with the large (L) RNA segment. In addition, we analyzed a revertant (isolated from the CNS) derived from one of the spleen variants. By comparing the biological properties of three reassortants that contained the same S segment but had the L segment of either the original wt Armstrong LCMV, the spleen variant derived from it, or the CNS revertant derived from the spleen variant, we were able to show unequivocally that biologically relevant mutations occurred in the L segment not only during generation of the spleen variant from wt LCMV but also in reversion of the spleen variant to the wt phenotype. Thus, our results showed that (i) genetic alterations in the L genomic segment were involved in organ-specific selection of viral variants, and (ii) these mutations profoundly affected the ability of LCMV to cause chronic infections in adult mice. Images PMID:3261347

  17. Heat Shock Protein 60 in Eggs Specifically Induces Tregs and Reduces Liver Immunopathology in Mice with Schistosomiasis Japonica

    PubMed Central

    Zhou, Sha; Jin, Xin; Chen, Xiaojun; Zhu, Jifeng; Xu, Zhipeng; Wang, Xuefeng; Liu, Feng; Hu, Wei; Zhou, Liang; Su, Chuan

    2015-01-01

    Background Parasitic helminths need to suppress the host immune system to establish chronic infections. Paradoxically, immunosuppression induced by the worm also benefits the host by limiting excessive inflammation and tissue damage, which remains the major cause leading to serious morbidity and mortality. Regulatory T cells (Tregs) are key immune regulators of this mutualism. The successive rise in Tregs during schistosome infection plays a critical role in immunoregulation. We and others previously showed that Schistosoma japonicum (S. japonicum) egg antigens (SEA) induce Tregs both in vitro and in vivo. In addition, we identified that SjHSP60 derived from SEA significantly induces Tregs in vivo and in vitro. However, the contribution of SjHSP60 in SEA to Treg induction and the related mechanisms of the Treg induction have not yet been identified. Methodology/Principal Findings In this study, we showed that S. japonicum stress protein HSP60 (SjHSP60) was constitutively and extensively expressed in eggs of S. japonicum. SjHSP60 specially induced Tregs in vivo and in vitro without inducing other CD4+ T sub-populations including Th1, Th2 and Th17 cells. Furthermore, we showed that the SjHSP60-depleted SEA almost lost the ability in vitro and displayed a significant impaired ability to induce Tregs in vivo. Finally, our study illustrated that the mechanisms of SjHSP60-mediated induction of Tregs are through both conversion of CD4+CD25- T cells into CD4+CD25+Foxp3+ Tregs and expansion of preexisting CD4+CD25+Foxp3+ Tregs in a TLR4-dependent manner. Conclusions/Significance Collectively, our findings identify SjHSP60 as a major parasitic contributor of Treg induction in S. japonicum egg antigens, which not only contributes to the better understanding of the mechanism of immunoregulation during helminth infection, but also suggests its potential as a therapeutic target for control of immunopathology, allergic and autoimmune diseases. PMID:26418003

  18. Immune response to acute virus infection in the Syrian hamster. II. Studies on the identity of virus-induced cytotoxic effector cells

    SciTech Connect

    Nelles, M.J.; Duncan, W.R.; Streilein, J.W.

    1981-01-01

    The identity of the effector cell(s) mediating vaccinia virus-induced cytotoxic activity in Syrian hamsters undergoing acute virus infection has been investigated. Two different approaches have been utilized in this regard. Although T cells do not mediate vaccinia virus-induced cytotoxic activity directly, functional T cells were required for the in vivo development of a significant portion of vaccinia virus-induced cytotoxic activity. In addition, incorporation of aggregated gamma-globulins as well as anti-immunoglobulin reagents into the in vitro 51 Cr release assay inhibited a significant proportion of the cytotoxic activity mediated by spleen cells obtained from acutely infected hamsters possessing an intact thymus. Both approaches have yielded information consistent with the idea that a sizable portion of vaccinia virus-induced cytotoxic activity in the Syrian hamster is effected by K cells mediating antibody-dependent cell-mediated cytotoxicity (ADCC). The significance of this observation is discussed with regard to hamster viral immunity in general.

  19. Dimethyl fumarate suppresses Theiler's murine encephalomyelitis virus-induced demyelinating disease by modifying the Nrf2-Keap1 pathway.

    PubMed

    Kobayashi, Kunitoshi; Tomiki, Hiroki; Inaba, Yuji; Ichikawa, Motoki; Kim, Byung S; Koh, Chang-Sung

    2015-07-01

    Dimethyl fumarate (DMF) is a modifier of the nuclear factor (erythroid-derived 2)-2 (Nrf2)-kelch-like ECH-associated protein 1 (Keap1) pathway. DMF treatment in the effector phase significantly suppressed the development of Theiler's murine encephalomyelitis virus-induced demyelinating disease (TMEV-IDD) both clinically and histologically. DMF treatment leads to an enhanced Nrf2 antioxidant response in TMEV-IDD mice. DMF treatment in the effector phase significantly suppressed the level of IL-17A mRNA. DMF is known to inhibit differentiation of T helper 17 (Th17) cells via suppressing NF-κB. Taken together, our data suggest that DMF treatment in the effector phase may suppress TMEV-IDD not only via enhancing the antioxidant response but also via suppressing IL-17A. PMID:25721871

  20. Institutional Animal Care and Use Committee Considerations Regarding the Use of Virus-Induced Carcinogenesis and Oncolytic Viral Models.

    PubMed

    Lewis, Stephanie D; Hickman-Davis, Judy M; Bergdall, Valerie K

    2016-01-01

    The use of virus-induced carcinogenesis and oncologic experimental animal models is essential in understanding the mechanisms of cancer development to advance prevention, diagnosis, and treatment methods. The Institutional Animal Care and Use Committee (IACUC) is responsible for both the complex philosophical and practical considerations associated with animal models of cancer. Animal models of cancer carry their own unique issues that require special consideration from the IACUC. Many of the considerations to be discussed apply to cancer models in general; specific issues related to viral carcinogenesis or oncolytic viruses will be specifically discussed as they arise. Responsible animal use integrates good science, humane care, and regulatory compliance. To meet those standards, the IACUC, in conjunction with the research investigator and attending veterinarian, must address a wide range of issues, including animal model selection, cancer model selection, humane end point considerations, experimental considerations, postapproval monitoring, reporting requirements, and animal management and personnel safety considerations.

  1. Inhibition of megakaryocyte development in the bone marrow underlies dengue virus-induced thrombocytopenia in humanized mice.

    PubMed

    Sridharan, Aishwarya; Chen, Qingfeng; Tang, Kin Fai; Ooi, Eng Eong; Hibberd, Martin L; Chen, Jianzhu

    2013-11-01

    A characteristic clinical feature of dengue virus infection is thrombocytopenia, though its underlying mechanism is not definitively determined. By adoptive transfer of human CD34(+) fetal liver cells into immunodeficient mice, we have constructed humanized mice with significant levels of human platelets, monocytes/macrophages, and hepatocytes. Infection of these mice with both lab-adapted and clinical strains of dengue virus induces characteristic human hematological changes, including transient leukopenia and thrombocytopenia. We show that the specific depletion of human platelets is not mediated by antibodies in the periphery or reduced production of human thrombopoietin in the liver but reduction of human megakaryocytes and megakaryocyte progenitors in the bone marrow of the infected mice. These findings identify inhibition of platelet production in the bone marrow as a key mechanism underlying dengue-induced thrombocytopenia and suggest the utility of the improved humanized mouse model in studying dengue virus infection and pathogenesis in a human cell context.

  2. Expression of human HLA-B27 transgene alters susceptibility to murine Theiler's virus-induced demyelination.

    PubMed

    Rodriguez, M; Nickerson, C; Patick, A K; David, C S

    1991-04-15

    Infection of certain strains of mice with Theiler's murine encephalomyelitis virus results in persistence of virus and an immune-mediated primary demyelination in the central nervous system that resembles multiple sclerosis. Because susceptibility/resistance to demyelination in B10 congeneic mice maps strongly to class I MHC genes (D region) we tested whether expression of a human class I MHC gene (HLA-B27) would alter susceptibility to Theiler's murine encephalomyelitis virus-induced demyelination. Transgenic HLA-B27 mice were found to co-express human and endogenous mouse class I MHC genes by flow microfluorimetry analysis of PBL. In the absence of the human transgene, H-2stf, or v mice but not H-2b mice had chronic demyelination and persistence of virus at 45 days after infection. No difference in degree of demyelination, meningeal inflammation, or virus persistence was seen between transgenic HLA-B27 and nontransgenic littermate mice of H-2f or H-2v haplotype. In contrast, H-2s (HLA-B27+) mice showed a dramatic decrease in extent of demyelination and number of virus-Ag+ cells in the spinal cord compared with H-2s (HLA-B27-) littermate mice. In addition, none of the eight H-2s mice homozygous for HLA-B27 gene had spinal cord lesions even though infectious virus was isolated chronically from their central nervous system. Expression of HLA-B27 transgene did not interfere with the resistance to demyelination normally observed in B10 (H-2b) mice. These experiments demonstrate that expression of a human class I MHC gene can modulate a virus-induced demyelinating disease process in the mouse.

  3. Contribution of virus-induced lysis and protozoan grazing to benthic bacterial mortality estimated simultaneously in microcosms.

    PubMed

    Fischer, Ulrike R; Wieltschnig, Claudia; Kirschner, Alexander K T; Velimirov, Branko

    2006-08-01

    In contrast to the water column, the fate of bacterial production in freshwater sediments is still a matter of debate. Thus, the importance of virus-induced lysis and protozoan grazing of bacteria was investigated for the first time simultaneously in a silty sediment layer of a mesotrophic oxbow lake. Microcosms were installed in the laboratory in order to study the dynamics of these processes over 15 days. All microbial and physicochemical parameters showed acceptable resemblance to field data observed during a concomitant in situ study, and similar conclusions can be drawn with respect to the quantitative impact of viruses and protozoa on the bacterial compartment. Viral decay rates ranged from undetectable to 0.078 h(-1) (average, 0.033 h(-1)), and the control of bacterial production from below the detection limit to 36% (average, 12%). The contribution of virus-induced lysis of bacteria to the dissolved organic matter pool as well as to benthic bacterial nutrition was low. Ingestion rates of protozoan grazers ranged from undetectable to 24.7 bacteria per heterotrophic nanoflagellate (HNF) per hour (average, 4.8 bacteria HNF(-1) h(-1)) and from undetectable to 73.3 bacteria per ciliate per hour (average, 11.2 bacteria ciliate(-1) h(-1)). Heterotrophic nanoflagellate and ciliates together cropped up to 5% (average, 1%) of bacterial production. The viral impact on bacteria prevailed over protozoan grazing by a factor of 2.5-19.9 (average, 9.5). In sum, these factors together removed up to 36% (average, 12%) of bacterial production. The high number of correlations between viral and protozoan parameters is discussed in view of a possible relationship between virus removal and the presence of protozoan grazers. PMID:16872403

  4. Novel Avian Influenza A (H7N9) Virus Induces Impaired Interferon Responses in Human Dendritic Cells

    PubMed Central

    Arilahti, Veera; Mäkelä, Sanna M.; Tynell, Janne; Julkunen, Ilkka; Österlund, Pamela

    2014-01-01

    In March 2013 a new avian influenza A(H7N9) virus emerged in China and infected humans with a case fatality rate of over 30%. Like the highly pathogenic H5N1 virus, H7N9 virus is causing severe respiratory distress syndrome in most patients. Based on genetic analysis this avian influenza A virus shows to some extent adaptation to mammalian host. In the present study, we analyzed the activation of innate immune responses by this novel H7N9 influenza A virus and compared these responses to those induced by the avian H5N1 and seasonal H3N2 viruses in human monocyte-derived dendritic cells (moDCs). We observed that in H7N9 virus-infected cells, interferon (IFN) responses were weak although the virus replicated as well as the H5N1 and H3N2 viruses in moDCs. H7N9 virus-induced expression of pro-inflammatory cytokines remained at a significantly lower level as compared to H5N1 virus-induced “cytokine storm” seen in human moDCs. However, the H7N9 virus was extremely sensitive to the antiviral effects of IFN-α and IFN-β in pretreated cells. Our data indicates that different highly pathogenic avian viruses may show considerable differences in their ability to induce host antiviral responses in human primary cell models such as moDCs. The unexpected appearance of the novel H7N9 virus clearly emphasizes the importance of the global influenza surveillance system. It is, however, equally important to systematically characterize in normal human cells the replication capacity of the new viruses and their ability to induce and respond to natural antiviral substances such as IFNs. PMID:24804732

  5. Incoming Influenza A Virus Evades Early Host Recognition, while Influenza B Virus Induces Interferon Expression Directly upon Entry

    PubMed Central

    Strengell, Mari; Sarin, L. Peter; Poranen, Minna M.; Fagerlund, Riku; Melén, Krister; Julkunen, Ilkka

    2012-01-01

    The activation of the interferon (IFN) system, which is triggered largely by the recognition of viral nucleic acids, is one of the most important host defense reactions against viral infections. Although influenza A and B viruses, which both have segmented negative-strand RNA genomes, share major structural similarities, they have evolutionarily diverged, with total genetic incompatibility. Here we compare antiviral-inducing mechanisms during infections with type A and B influenza viruses in human dendritic cells. We observed that IFN responses are induced significantly faster in cells infected with influenza B virus than in cells infected with type A influenza virus and that the early induction of antiviral gene expression is mediated by the activation of the transcription factor IFN regulatory factor 3 (IRF3). We further demonstrate that influenza A virus infection activates IFN responses only after viral RNA (vRNA) synthesis, whereas influenza B virus induces IFN responses even if its infectivity is destroyed by UV treatment. Thus, initial viral transcription, replication, and viral protein synthesis are dispensable for influenza B virus-induced antiviral responses. Moreover, vRNA molecules from both type A and B viruses are equally potent activators of IFN induction, but incoming influenza B virus structures are recognized directly in the cytosol, while influenza A virus is able to evade early recognition. Collectively, our data provide new evidence of a novel antiviral evasion strategy for influenza A virus without a contribution of the viral NS1 protein, and this opens up new insights into different influenza virus pathogenicities. PMID:22855501

  6. Induction and maintenance of DNA methylation in plant promoter sequences by apple latent spherical virus-induced transcriptional gene silencing.

    PubMed

    Kon, Tatsuya; Yoshikawa, Nobuyuki

    2014-01-01

    Apple latent spherical virus (ALSV) is an efficient virus-induced gene silencing vector in functional genomics analyses of a broad range of plant species. Here, an Agrobacterium-mediated inoculation (agroinoculation) system was developed for the ALSV vector, and virus-induced transcriptional gene silencing (VITGS) is described in plants infected with the ALSV vector. The cDNAs of ALSV RNA1 and RNA2 were inserted between the cauliflower mosaic virus 35S promoter and the NOS-T sequences in a binary vector pCAMBIA1300 to produce pCALSR1 and pCALSR2-XSB or pCALSR2-XSB/MN. When these vector constructs were agroinoculated into Nicotiana benthamiana plants with a construct expressing a viral silencing suppressor, the infection efficiency of the vectors was 100%. A recombinant ALSV vector carrying part of the 35S promoter sequence induced transcriptional gene silencing of the green fluorescent protein gene in a line of N. benthamiana plants, resulting in the disappearance of green fluorescence of infected plants. Bisulfite sequencing showed that cytosine residues at CG and CHG sites of the 35S promoter sequence were highly methylated in the silenced generation zero plants infected with the ALSV carrying the promoter sequence as well as in progeny. The ALSV-mediated VITGS state was inherited by progeny for multiple generations. In addition, induction of VITGS of an endogenous gene (chalcone synthase-A) was demonstrated in petunia plants infected with an ALSV vector carrying the native promoter sequence. These results suggest that ALSV-based vectors can be applied to study DNA methylation in plant genomes, and provide a useful tool for plant breeding via epigenetic modification. PMID:25426109

  7. Incoming influenza A virus evades early host recognition, while influenza B virus induces interferon expression directly upon entry.

    PubMed

    Österlund, Pamela; Strengell, Mari; Sarin, L Peter; Poranen, Minna M; Fagerlund, Riku; Melén, Krister; Julkunen, Ilkka

    2012-10-01

    The activation of the interferon (IFN) system, which is triggered largely by the recognition of viral nucleic acids, is one of the most important host defense reactions against viral infections. Although influenza A and B viruses, which both have segmented negative-strand RNA genomes, share major structural similarities, they have evolutionarily diverged, with total genetic incompatibility. Here we compare antiviral-inducing mechanisms during infections with type A and B influenza viruses in human dendritic cells. We observed that IFN responses are induced significantly faster in cells infected with influenza B virus than in cells infected with type A influenza virus and that the early induction of antiviral gene expression is mediated by the activation of the transcription factor IFN regulatory factor 3 (IRF3). We further demonstrate that influenza A virus infection activates IFN responses only after viral RNA (vRNA) synthesis, whereas influenza B virus induces IFN responses even if its infectivity is destroyed by UV treatment. Thus, initial viral transcription, replication, and viral protein synthesis are dispensable for influenza B virus-induced antiviral responses. Moreover, vRNA molecules from both type A and B viruses are equally potent activators of IFN induction, but incoming influenza B virus structures are recognized directly in the cytosol, while influenza A virus is able to evade early recognition. Collectively, our data provide new evidence of a novel antiviral evasion strategy for influenza A virus without a contribution of the viral NS1 protein, and this opens up new insights into different influenza virus pathogenicities.

  8. Induction and maintenance of DNA methylation in plant promoter sequences by apple latent spherical virus-induced transcriptional gene silencing

    PubMed Central

    Kon, Tatsuya; Yoshikawa, Nobuyuki

    2014-01-01

    Apple latent spherical virus (ALSV) is an efficient virus-induced gene silencing vector in functional genomics analyses of a broad range of plant species. Here, an Agrobacterium-mediated inoculation (agroinoculation) system was developed for the ALSV vector, and virus-induced transcriptional gene silencing (VITGS) is described in plants infected with the ALSV vector. The cDNAs of ALSV RNA1 and RNA2 were inserted between the cauliflower mosaic virus 35S promoter and the NOS-T sequences in a binary vector pCAMBIA1300 to produce pCALSR1 and pCALSR2-XSB or pCALSR2-XSB/MN. When these vector constructs were agroinoculated into Nicotiana benthamiana plants with a construct expressing a viral silencing suppressor, the infection efficiency of the vectors was 100%. A recombinant ALSV vector carrying part of the 35S promoter sequence induced transcriptional gene silencing of the green fluorescent protein gene in a line of N. benthamiana plants, resulting in the disappearance of green fluorescence of infected plants. Bisulfite sequencing showed that cytosine residues at CG and CHG sites of the 35S promoter sequence were highly methylated in the silenced generation zero plants infected with the ALSV carrying the promoter sequence as well as in progeny. The ALSV-mediated VITGS state was inherited by progeny for multiple generations. In addition, induction of VITGS of an endogenous gene (chalcone synthase-A) was demonstrated in petunia plants infected with an ALSV vector carrying the native promoter sequence. These results suggest that ALSV-based vectors can be applied to study DNA methylation in plant genomes, and provide a useful tool for plant breeding via epigenetic modification. PMID:25426109

  9. Antigen-pulsed bone marrow derived and pulmonary dendritic cells promote Th2 cell responses and immunopathology in lungs during the pathogenesis of murine mycoplasma pneumonia1

    PubMed Central

    Dobbs, Nicole A.; Zhou, Xia; Pulse, Mark; Hodge, Lisa M.; Schoeb, Trenton R.; Simecka, Jerry W.

    2014-01-01

    Mycoplasmas are a common cause of pneumonia in humans and animals, and attempts to create vaccines have not only failed to generate protective host responses, but exacerbated the disease. Mycoplasma pulmonis causes a chronic inflammatory lung disease resulting from a persistent infection, similar to other mycoplasma respiratory diseases. Using this model, Th1 subsets promote resistance to mycoplasma disease and infection, while Th2 responses contribute to immunopathology. The purpose of these studies was to evaluate the capacity of cytokine differentiated dendritic cells (DC) populations to influence the generation of protective and/or pathologic immune responses during M. pulmonis respiratory disease in BALB/c mice. We hypothesized that intratracheal inoculation of mycoplasma antigen-pulsed bone marrow derived dendritic cells (BMDC) could result in the generation of protective T cell responses during mycoplasma infection. However, intratracheal inoculation (priming) of mice with antigen-pulsed DCs resulted enhanced pathology in the recipient mice when challenged with mycoplasma. Inoculation of immunodeficient SCID mice with antigen-pulsed DCs demonstrated that this effect was dependent on lymphocyte responses. Similar results were observed when mice were primed with antigen-pulsed pulmonary, but not splenic, DCs. Lymphocytes generated in uninfected mice after the transfer of either antigen-pulsed BMDCs or pulmonary DCs were shown to be IL13+ Th2 cells, known to be associated with immunopathology. Thus, resident pulmonary DC most likely promote the development of immunopathology in mycoplasma disease through the generation of mycoplasma-specific Th2 responses. Vaccination strategies that disrupt or bypass this process could potentially result in a more effective vaccination. PMID:24973442

  10. Quantitative Label-Free Phosphoproteomics Reveals Differentially Regulated Protein Phosphorylation Involved in West Nile Virus-Induced Host Inflammatory Response.

    PubMed

    Zhang, Hao; Sun, Jun; Ye, Jing; Ashraf, Usama; Chen, Zheng; Zhu, Bibo; He, Wen; Xu, Qiuping; Wei, Yanming; Chen, Huanchun; Fu, Zhen F; Liu, Rong; Cao, Shengbo

    2015-12-01

    West Nile virus (WNV) can cause neuro-invasive and febrile illness that may be fatal to humans. The production of inflammatory cytokines is key to mediating WNV-induced immunopathology in the central nervous system. Elucidating the host factors utilized by WNV for productive infection would provide valuable insights into the evasion strategies used by this virus. Although attempts have been made to determine these host factors, proteomic data depicting WNV-host protein interactions are limited. We applied liquid chromatography-tandem mass spectrometry for label-free, quantitative phosphoproteomics to systematically investigate the global phosphorylation events induced by WNV infection. Quantifiable changes to 1,657 phosphoproteins were found; of these, 626 were significantly upregulated and 227 were downregulated at 12 h postinfection. The phosphoproteomic data were subjected to gene ontology enrichment analysis, which returned the inflammation-related spliceosome, ErbB, mitogen-activated protein kinase, nuclear factor kappa B, and mechanistic target of rapamycin signaling pathways. We used short interfering RNAs to decrease the levels of glycogen synthase kinase-3 beta, bifunctional polynucleotide phosphatase/kinase, and retinoblastoma 1 and found that the activity of nuclear factor kappa B (p65) is significantly decreased in WNV-infected U251 cells, which in turn led to markedly reduced inflammatory cytokine production. Our results provide a better understanding of the host response to WNV infection and highlight multiple targets for the development of antiviral and anti-inflammatory therapies.

  11. Prevention of Encephalomyocarditis Virus-Induced Diabetes in Mice by Inhibition of the Tyrosine Kinase Signalling Pathway and Subsequent Suppression of Nitric Oxide Production in Macrophages

    PubMed Central

    Hirasawa, K.; Jun, H. S.; Han, H. S.; Zhang, M. L.; Hollenberg, M. D.; Yoon, J. W.

    1999-01-01

    Macrophages comprise the major population of cells infiltrating pancreatic islets during the early stages of infection in DBA/2 mice by the D variant of encephalomyocarditis virus (EMC-D virus). Inactivation of macrophages prior to viral infection almost completely prevents EMC-D virus-induced diabetes. This investigation was initiated to determine whether a tyrosine kinase signalling pathway might be involved in the activation of macrophages by EMC-D virus infection and whether tyrosine kinase inhibitors might, therefore, abrogate EMC-D virus-induced diabetes in vivo. When isolated macrophages were infected with EMC-D virus, inducible nitric oxide synthase mRNA was expressed and nitric oxide was subsequently produced. Treatment of macrophages with the tyrosine kinase inhibitor tyrphostin AG126, but not tyrphostin AG556, prior to EMC-D virus infection blocked the production of nitric oxide. The infection of macrophages with EMC-D virus also resulted in the activation of the mitogen-activated protein kinases (MAPKs) p42MAPK/ERK2/p44MAPK/ERK1, p38MAPK, and p46/p54JNK. In accord with the greater potency of AG126 than of AG556 in blocking EMC-D virus-mediated macrophage activation, the incidence of diabetes in EMC-D virus-infected mice treated with AG126 (25%) was much lower than that in AG556-treated (75%) or vehicle-treated (88%) control mice. We conclude that EMC-D virus-induced activation of macrophages resulting in macrophage-mediated β-cell destruction can be prevented by the inhibition of a tyrosine kinase signalling pathway involved in macrophage activation. PMID:10482607

  12. Mechanisms for virus-induced liver disease: tumor necrosis factor-mediated pathology independent of natural killer and T cells during murine cytomegalovirus infection.

    PubMed Central

    Orange, J S; Salazar-Mather, T P; Opal, S M; Biron, C A

    1997-01-01

    The contribution of endogenous NK cells and cytokines to virus-induced liver pathology was evaluated during murine cytomegalovirus infections of mice. In immunocompetent C57BL/6 mice, the virus induced a self-limited liver disease characterized by hepatitis, with focal inflammation, and large grossly visible subcapsular necrotic foci. The inflammatory foci were most numerous and contained the greatest number of cells 3 days after infection; they colocalized with areas of viral antigen expression. The largest number of necrotic foci was found 2 days after infection. Overall hepatic damage, assessed as increased expression of liver enzymes in serum, accompanied the development of inflammatory and necrotic foci. Experiments with neutralizing antibodies demonstrated that although virus-induced tumor necrosis factor (TNF) can have antiviral effects, it also mediated significant liver pathology. TNF was required for development of hepatic necrotic foci and increased levels of liver enzymes in serum but not for increased numbers of inflammatory foci. The necrotic foci and liver enzyme indications of pathology occurred independently of NK and T cells, because mice rendered NK-cell deficient by treatment with antibodies, T- and B-cell-deficient Rag-/- mice, and NK- and T-cell-deficient E26 mice all manifested both parameters of disease. Development of necrotic foci and maximally increased levels of liver enzymes in serum also were TNF dependent in NK-cell-deficient mice. Moreover, in the immunodeficient E26 mice, virus-induced liver disease was progressive, with eventual death of the host, and neutralization of TNF significantly increased longevity. These results establish conditions separating hepatitis from significant liver damage and demonstrate a cytokine-mediated component to viral pathogenesis. PMID:9371583

  13. A method of high frequency virus-induced gene silencing in chili pepper (Capsicum annuum L. cv. Bukang).

    PubMed

    Chung, Eunsook; Seong, Eunsoo; Kim, Yeoung-Cheol; Chung, Eun Joo; Oh, Sang-Keun; Lee, Sanghyeob; Park, Jeong Mee; Joung, Young Hee; Choi, Doil

    2004-04-30

    Using a tobacco rattle virus (TRV)-based virus-induced gene silencing (VIGS) system, expression of phytogene desaturase (PDS) and ribulose-1,5-bisphosphate carboxylase small-subuit (rbcS) genes was suppressed in Nicotiana benthamiana and pepper plants (Capsicum annuum L. cv. Bukang). The silenced phenotypes of pale yellow (rbcS), and photobleached leaves (PDS), were invariably obvious 2 weeks after inoculation with the TRV-based vector. In a parallel experiment, the same set of genes was silenced in N. benthamiana and yielded identical phenotypes to pepper 1 week after inoculation. Northern blot analyses showed that the endogenous levels of CarbcS and CaPDS transcripts were dramatically reduced in the silenced leaf tissues. These observations confirm that the silenced phenotype is closely correlated with the pattern of tissue expression. To our knowledge, this is the first high frequency VIGS method in pepper plants. It should provide a tool for large-scale gene silencing studies in pepper functional genomics.

  14. Decreased Diversity of the Oral Microbiota of Patients with Hepatitis B Virus-Induced Chronic Liver Disease: A Pilot Project.

    PubMed

    Ling, Zongxin; Liu, Xia; Cheng, Yiwen; Jiang, Xiawei; Jiang, Haiyin; Wang, Yuezhu; Li, Lanjuan

    2015-11-26

    Increasing evidence suggests that altered gut microbiota is implicated in the pathogenesis of hepatitis B virus-induced chronic liver disease (HBV-CLD). However, the structure and composition of the oral microbiota of patients with HBV-CLD remains unclear. High-throughput pyrosequencing showed that decreased oral bacterial diversity was found in patients with HBV-CLD. The Firmicutes/Bacteroidetes ratio was increased significantly, which indicated that dysbiosis of the oral microbiota participated in the process of HBV-CLD development. However, the changing patterns of the oral microbiota in patients with HBV-induced liver cirrhosis (LC) were almost similar to patients with chronic hepatitis B (CHB). HBV infection resulted in an increase in potential H2S- and CH3SH-producing phylotypes such as Fusobacterium, Filifactor, Eubacterium, Parvimonas and Treponema, which might contribute to the increased oral malodor. These key oral-derived phylotypes might invade into the gut as opportunistic pathogens and contribute to altering the composition of the gut microbiota. This study provided important clues that dysbiosis of the oral microbiota might be involved in the development of HBV-CLD. Greater understanding of the relationships between the dysbiosis of oral microbiota and the development of HBV-CLD might facilitate the development of non-invasive differential diagnostic procedures and targeted treatments of HBV-CLD patients harbouring specific oral phylotypes.

  15. Involvement of the PI3K and ERK signaling pathways in largemouth bass virus-induced apoptosis and viral replication.

    PubMed

    Huang, Xiaohong; Wang, Wei; Huang, Youhua; Xu, Liwen; Qin, Qiwei

    2014-12-01

    Increased reports demonstrated that largemouth Bass, Micropterus salmoides in natural and artificial environments were always suffered from an emerging iridovirus disease, largemouth Bass virus (LMBV). However, the underlying mechanism of LMBV pathogenesis remained largely unknown. Here, we investigated the cell signaling events involved in virus induced cell death and viral replication in vitro. We found that LMBV infection in epithelioma papulosum cyprini (EPC) cells induced typical apoptosis, evidenced by the appearance of apoptotic bodies, cytochrome c release, mitochondrial membrane permeabilization (MMP) destruction and reactive oxygen species (ROS) generation. Two initiators of apoptosis, caspase-8 and caspase-9, and the executioner of apoptosis, caspase-3, were all significantly activated with the infection time, suggested that not only mitochondrion-mediated, but also death receptor-mediated apoptosis were involved in LMBV infection. Reporter gene assay showed that the promoter activity of transcription factors including p53, NF-κB, AP-1 and cAMP response element-binding protein (CREB) were decreased during LMBV infection. After treatment with different signaling pathway inhibitors, virus production were significantly suppressed by the inhibition of phosphatidylinositol 3-kinase (PI3K) pathway and extracellular-signal-regulated kinases (ERK) signaling pathway. Furthermore, LMBV infection induced apoptosis was enhanced by PI3K inhibitor LY294002, but decreased by addition of ERK inhibitor UO126. Therefore, we speculated that apoptosis was sophisticatedly regulated by a series of cell signaling events for efficient virus propagation. Taken together, our results provided new insights into the molecular mechanism of ranavirus infection. PMID:25260912

  16. Virus-induced gene silencing unravels multiple transcription factors involved in floral growth and development in Phalaenopsis orchids

    PubMed Central

    Hsieh, Ming-Hsien; Pan, Zhao-Jun; Lai, Pei-Han; Lu, Hsiang-Chia; Yeh, Hsin-Hung; Hsu, Chia-Chi; Wu, Wan-Lin; Chung, Mei-Chu; Wang, Shyh-Shyan; Chen, Wen-Huei; Chen, Hong-Hwa

    2013-01-01

    Orchidaceae, one of the largest angiosperm families, has significant commercial value. Isolation of genes involved in orchid floral development and morphogenesis, scent production, and colouration will advance knowledge of orchid flower formation and facilitate breeding new varieties to increase the commercial value. With high-throughput virus-induced gene silencing (VIGS), this study identified five transcription factors involved in various aspects of flower morphogenesis in the orchid Phalaenopsis equestris. These genes are PeMADS1, PeMADS7, PeHB, PebHLH, and PeZIP. Silencing PeMADS1 and PebHLH resulted in reduced flower size together with a pelaloid column containing petal-like epidermal cells and alterations of epidermal cell arrangement in lip lateral lobes, respectively. Silencing PeMADS7, PeHB, and PeZIP alone resulted in abortion of the first three fully developed flower buds of an inflorescence, which indicates the roles of the genes in late flower development. Furthermore, double silencing PeMADS1 and PeMADS6, C- and B-class MADS-box genes, respectively, produced a combinatorial phenotype with two genes cloned in separate vectors. Both PeMADS1 and PeMADS6 are required to ensure the normal development of the lip and column as well as the cuticle formation on the floral epidermal cell surface. Thus, VIGS allows for unravelling the interaction between two classes of MADS transcription factors for dictating orchid floral morphogenesis. PMID:23956416

  17. Involvement of the PI3K and ERK signaling pathways in largemouth bass virus-induced apoptosis and viral replication.

    PubMed

    Huang, Xiaohong; Wang, Wei; Huang, Youhua; Xu, Liwen; Qin, Qiwei

    2014-12-01

    Increased reports demonstrated that largemouth Bass, Micropterus salmoides in natural and artificial environments were always suffered from an emerging iridovirus disease, largemouth Bass virus (LMBV). However, the underlying mechanism of LMBV pathogenesis remained largely unknown. Here, we investigated the cell signaling events involved in virus induced cell death and viral replication in vitro. We found that LMBV infection in epithelioma papulosum cyprini (EPC) cells induced typical apoptosis, evidenced by the appearance of apoptotic bodies, cytochrome c release, mitochondrial membrane permeabilization (MMP) destruction and reactive oxygen species (ROS) generation. Two initiators of apoptosis, caspase-8 and caspase-9, and the executioner of apoptosis, caspase-3, were all significantly activated with the infection time, suggested that not only mitochondrion-mediated, but also death receptor-mediated apoptosis were involved in LMBV infection. Reporter gene assay showed that the promoter activity of transcription factors including p53, NF-κB, AP-1 and cAMP response element-binding protein (CREB) were decreased during LMBV infection. After treatment with different signaling pathway inhibitors, virus production were significantly suppressed by the inhibition of phosphatidylinositol 3-kinase (PI3K) pathway and extracellular-signal-regulated kinases (ERK) signaling pathway. Furthermore, LMBV infection induced apoptosis was enhanced by PI3K inhibitor LY294002, but decreased by addition of ERK inhibitor UO126. Therefore, we speculated that apoptosis was sophisticatedly regulated by a series of cell signaling events for efficient virus propagation. Taken together, our results provided new insights into the molecular mechanism of ranavirus infection.

  18. Angiotensin-converting enzyme 2 (ACE2) mediates influenza H7N9 virus-induced acute lung injury.

    PubMed

    Yang, Penghui; Gu, Hongjing; Zhao, Zhongpeng; Wang, Wei; Cao, Bin; Lai, Chengcai; Yang, Xiaolan; Zhang, LiangYan; Duan, Yueqiang; Zhang, Shaogeng; Chen, Weiwen; Zhen, Wenbo; Cai, Maosheng; Penninger, Josef M; Jiang, Chengyu; Wang, Xiliang

    2014-11-13

    Since March 2013, the emergence of an avian-origin influenza A (H7N9) virus has raised concern in China. Although most infections resulted in respiratory illness, some severe cases resulted in acute respiratory distress syndrome (ARDS), which is a severe form of acute lung injury (ALI) that further contributes to morbidity. To date, no effective drugs that improve the clinical outcome of influenza A (H7N9) virus-infected patients have been identified. Angiotensin-converting enzyme (ACE) and ACE2 are involved in several pathologies such as cardiovascular functions, renal disease, and acute lung injury. In the current study, we report that ACE2 could mediate the severe acute lung injury induced by influenza A (H7N9) virus infection in an experimental mouse model. Moreover, ACE2 deficiency worsened the disease pathogenesis markedly, mainly by targeting the angiotensin II type 1 receptor (AT1). The current findings demonstrate that ACE2 plays a critical role in influenza A (H7N9) virus-induced acute lung injury, and suggest that might be a useful potential therapeutic target for future influenza A (H7N9) outbreaks.

  19. Brain Endothelial- and Epithelial-Specific Interferon Receptor Chain 1 Drives Virus-Induced Sickness Behavior and Cognitive Impairment.

    PubMed

    Blank, Thomas; Detje, Claudia N; Spieß, Alena; Hagemeyer, Nora; Brendecke, Stefanie M; Wolfart, Jakob; Staszewski, Ori; Zöller, Tanja; Papageorgiou, Ismini; Schneider, Justus; Paricio-Montesinos, Ricardo; Eisel, Ulrich L M; Manahan-Vaughan, Denise; Jansen, Stephan; Lienenklaus, Stefan; Lu, Bao; Imai, Yumiko; Müller, Marcus; Goelz, Susan E; Baker, Darren P; Schwaninger, Markus; Kann, Oliver; Heikenwalder, Mathias; Kalinke, Ulrich; Prinz, Marco

    2016-04-19

    Sickness behavior and cognitive dysfunction occur frequently by unknown mechanisms in virus-infected individuals with malignancies treated with type I interferons (IFNs) and in patients with autoimmune disorders. We found that during sickness behavior, single-stranded RNA viruses, double-stranded RNA ligands, and IFNs shared pathways involving engagement of melanoma differentiation-associated protein 5 (MDA5), retinoic acid-inducible gene 1 (RIG-I), and mitochondrial antiviral signaling protein (MAVS), and subsequently induced IFN responses specifically in brain endothelia and epithelia of mice. Behavioral alterations were specifically dependent on brain endothelial and epithelial IFN receptor chain 1 (IFNAR). Using gene profiling, we identified that the endothelia-derived chemokine ligand CXCL10 mediated behavioral changes through impairment of synaptic plasticity. These results identified brain endothelial and epithelial cells as natural gatekeepers for virus-induced sickness behavior, demonstrated tissue specific IFNAR engagement, and established the CXCL10-CXCR3 axis as target for the treatment of behavioral changes during virus infection and type I IFN therapy. PMID:27096319

  20. Brain Endothelial- and Epithelial-Specific Interferon Receptor Chain 1 Drives Virus-Induced Sickness Behavior and Cognitive Impairment.

    PubMed

    Blank, Thomas; Detje, Claudia N; Spieß, Alena; Hagemeyer, Nora; Brendecke, Stefanie M; Wolfart, Jakob; Staszewski, Ori; Zöller, Tanja; Papageorgiou, Ismini; Schneider, Justus; Paricio-Montesinos, Ricardo; Eisel, Ulrich L M; Manahan-Vaughan, Denise; Jansen, Stephan; Lienenklaus, Stefan; Lu, Bao; Imai, Yumiko; Müller, Marcus; Goelz, Susan E; Baker, Darren P; Schwaninger, Markus; Kann, Oliver; Heikenwalder, Mathias; Kalinke, Ulrich; Prinz, Marco

    2016-04-19

    Sickness behavior and cognitive dysfunction occur frequently by unknown mechanisms in virus-infected individuals with malignancies treated with type I interferons (IFNs) and in patients with autoimmune disorders. We found that during sickness behavior, single-stranded RNA viruses, double-stranded RNA ligands, and IFNs shared pathways involving engagement of melanoma differentiation-associated protein 5 (MDA5), retinoic acid-inducible gene 1 (RIG-I), and mitochondrial antiviral signaling protein (MAVS), and subsequently induced IFN responses specifically in brain endothelia and epithelia of mice. Behavioral alterations were specifically dependent on brain endothelial and epithelial IFN receptor chain 1 (IFNAR). Using gene profiling, we identified that the endothelia-derived chemokine ligand CXCL10 mediated behavioral changes through impairment of synaptic plasticity. These results identified brain endothelial and epithelial cells as natural gatekeepers for virus-induced sickness behavior, demonstrated tissue specific IFNAR engagement, and established the CXCL10-CXCR3 axis as target for the treatment of behavioral changes during virus infection and type I IFN therapy.

  1. Systemic virus-induced gene silencing allows functional characterization of maize genes during biotrophic interaction with Ustilago maydis.

    PubMed

    van der Linde, Karina; Kastner, Christine; Kumlehn, Jochen; Kahmann, Regine; Doehlemann, Gunther

    2011-01-01

    Infection of maize (Zea mays) plants with the corn smut fungus Ustilago maydis leads to the formation of large tumors on the stem, leaves and inflorescences. In this biotrophic interaction, plant defense responses are actively suppressed by the pathogen, and previous transcriptome analyses of infected maize plants showed massive and stage-specific changes in host gene expression during disease progression. To identify maize genes that are functionally involved in the interaction with U. maydis, we adapted a virus-induced gene silencing (VIGS) system based on the brome mosaic virus (BMV) for maize. Conditions were established that allowed successful U. maydis infection of BMV-preinfected maize plants. This set-up enabled quantification of VIGS and its impact on U. maydis infection using a quantitative real-time PCR (qRT-PCR)-based readout. In proof-of-principle experiments, an U. maydis-induced terpene synthase was shown to negatively regulate disease development while a protein involved in cell death inhibition was required for full virulence of U. maydis. The results suggest that this system is a versatile tool for the rapid identification of maize genes that determine compatibility with U. maydis.

  2. Green tea phenolic epicatechins inhibit hepatitis C virus replication via cycloxygenase-2 and attenuate virus-induced inflammation.

    PubMed

    Lin, Ying-Ting; Wu, Yu-Hsuan; Tseng, Chin-Kai; Lin, Chun-Kuang; Chen, Wei-Chun; Hsu, Yao-Chin; Lee, Jin-Ching

    2013-01-01

    Chronic hepatitis C virus (HCV) infection is the leading risk factor for hepatocellular carcinoma (HCC) and chronic liver disease worldwide. Green tea, in addition to being consumed as a healthy beverage, contains phenolic catechins that have been used as medicinal substances. In the present study, we illustrated that the epicatechin isomers (+)-epicatechin and (-)-epicatechin concentration-dependently inhibited HCV replication at nontoxic concentrations by using in vitro cell-based HCV replicon and JFH-1 infectious systems. In addition to significantly suppressing virus-induced cyclooxygenase-2 (COX-2) expression, our results revealed that the anti-HCV activity of the epicatechin isomers occurred through the down-regulation of COX-2. Furthermore, both the epicatechin isomers additively inhibited HCV replication in combination with either interferon-α or viral enzyme inhibitors [2'-C-methylcytidine (NM-107) or telaprevir]. They also had prominent anti-inflammatory effects by inhibiting the gene expression of tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and inducible nitrite oxide synthase as well as the COX-2 in viral protein-expressing hepatoma Huh-7 cells. Collectively, (+)-epicatechin and (-)-epicatechin may serve as therapeutic supplements for treating HCV-related diseases.

  3. Investigating plasmodesmata genetics with virus-induced gene silencing and an agrobacterium-mediated GFP movement assay.

    PubMed

    Brunkard, Jacob O; Burch-Smith, Tessa M; Runkel, Anne M; Zambryski, Patricia

    2015-01-01

    Plasmodesmata (PD) are channels that connect the cytoplasm of adjacent plant cells, permitting intercellular transport and communication. PD function and formation are essential to plant growth and development, but we still know very little about the genetic pathways regulating PD transport. Here, we present a method for assaying changes in the rate of PD transport following genetic manipulation. Gene expression in leaves is modified by virus-induced gene silencing. Seven to ten days after infection with Tobacco rattle virus carrying a silencing trigger, the gene(s) of interest is silenced in newly arising leaves. In these new leaves, individual cells are then transformed with Agrobacterium to express GFP, and the rate of GFP diffusion via PD is measured. By measuring GFP diffusion both within the epidermis and between the epidermis and mesophyll, the assay can be used to study the effects of silencing a gene(s) on PD transport in general, or transport through secondary PD specifically. Plant biologists working in several fields will find this assay useful, since PD transport impacts plant physiology, development, and defense.

  4. Altered cellular infiltration and cytokine levels during early Mycobacterium tuberculosis sigC mutant infection are associated with late-stage disease attenuation and milder immunopathology in mice

    PubMed Central

    Abdul-Majid, Khairul-Bariah; Ly, Lan H; Converse, Paul J; Geiman, Deborah E; McMurray, David N; Bishai, William R

    2008-01-01

    Background Mouse virulence assessments of certain Mycobacterium tuberculosis mutants have revealed an immunopathology defect in which high tissue CFU counts are observed but the tissue pathology and lethality are reduced. M. tuberculosis mutants which grow and persist in the mouse lungs, but have attenuated disease progression, have the immunopathology (imp) phenotype. The antigenic properties of these strains may alter the progression of disease due to a reduction in host immune cell recruitment to the lungs resulting in disease attenuation and prolonged host survival. Results In this study we focused on the mouse immune response to one such mutant; the M. tuberculosis ΔsigC mutant. Aerosol infection of DBA/2 and SCID mice with the M. tuberculosis ΔsigC mutant, complemented mutant and wild type strain showed proliferation of mutant bacilli in mouse lungs, but with decreased inflammation and mortality in DBA/2 mice. SCID mice shared the same phenotype as the DBA/2 mice in response to the ΔsigC mutant, however, they succumbed to the infection faster. Bronchoalveolar lavage (BAL) fluid analysis revealed elevated numbers of infiltrating neutrophils in the lungs of mice infected with wild type and complemented ΔsigC mutant strains but not in mice infected with the ΔsigC mutant. In addition, DBA/2 mice infected with the ΔsigC mutant had reduced levels of TNF-α, IL-1β, IL-6 and IFN-γ in the lungs. Similarly, there was a reduction in proinflammatory cytokines in the lungs of SCID mice. In contrast to the mouse model, the ΔsigC mutant had reduced initial growth in guinea pig lungs. A possible mechanism of attenuation in the ΔsigC mutant may be a reduction in neutrophilic-influx in the alveolar spaces of the lungs, and decreased proinflammatory cytokine secretion. In contrast to mouse data, the M. tuberculosis ΔsigC mutant proliferates slowly in guinea pig lungs, a setting characterized by caseating necrosis. Conclusion Our observations suggest that the

  5. Revelation of the IFNα, IL-10, IL-8 and IL-1β as promising biomarkers reflecting immuno-pathological mechanisms in porcine Huntington's disease model.

    PubMed

    Valekova, Ivona; Jarkovska, Karla; Kotrcova, Eva; Bucci, John; Ellederova, Zdenka; Juhas, Stefan; Motlik, Jan; Gadher, Suresh Jivan; Kovarova, Hana

    2016-04-15

    Studies on Huntington's disease (HD) demonstrated altered immune response in HD gene carriers. Using multiplexing immunoassay, we simultaneously investigated seven cytokines in secretomes of microglia and blood monocytes, cerebrospinal fluid (CSF) and serum collected from transgenic HD minipigs at pre-symptomatic disease stage. Decline in IFNα and IL-10 was observed in CSF and secretome of microglia whilst elevated IL-8 and IL-1β levels were secreted by microglia. Additionally, IL-8 was increased in serum. The proportion of mutant huntingtin in microglia may have causative impact on cytokine production. IFNα, IL-10, IL-8 and IL-1β represent promising biomarkers reflecting immuno-pathological mechanisms in porcine HD model. PMID:27049565

  6. IRGM3 Contributes to Immunopathology and Is Required for Differentiation of Antigen-Specific Effector CD8+ T Cells in Experimental Cerebral Malaria

    PubMed Central

    Guo, Jintao; McQuillan, James A.; Yau, Belinda; Tullo, Gregory S.; Long, Carole A.; Bertolino, Patrick; Roediger, Ben; Weninger, Wolfgang; Taylor, Gregory A.; Hunt, Nicholas H.; Ball, Helen J.

    2015-01-01

    Gamma interferon (IFN-γ) drives antiparasite responses and immunopathology during infection with Plasmodium species. Immunity-related GTPases (IRGs) are a class of IFN-γ-dependent proteins that are essential for cell autonomous immunity to numerous intracellular pathogens. However, it is currently unknown whether IRGs modulate responses during malaria. We have used the Plasmodium berghei ANKA (PbA) model in which mice develop experimental cerebral malaria (ECM) to study the roles of IRGM1 and IRGM3 in immunopathology. Induction of mRNA for Irgm1 and Irgm3 was found in the brains and spleens of infected mice at times of peak IFN-γ production. Irgm3−/− but not Irgm1−/− mice were completely protected from the development of ECM, and this protection was associated with the decreased induction of inflammatory cytokines, as well as decreased recruitment and activation of CD8+ T cells within the brain. Although antigen-specific proliferation of transferred CD8+ T cells was not diminished compared to that of wild-type recipients following PbA infection, T cells transferred into Irgm3−/− recipients showed a striking impairment of effector differentiation. Decreased induction of several inflammatory cytokines and chemokines (interleukin-6, CCL2, CCL3, and CCL4), as well as enhanced mRNA expression of type-I IFNs, was found in the spleens of Irgm3−/− mice at day 4 postinfection. Together, these data suggest that protection from ECM pathology in Irgm3−/− mice occurs due to impaired generation of CD8+ effector function. This defect is nonintrinsic to CD8+ T cells. Instead, diminished T cell responses most likely result from defective initiation of inflammatory responses in myeloid cells. PMID:25644000

  7. Chikungunya virus induces IPS-1-dependent innate immune activation and protein kinase R-independent translational shutoff.

    PubMed

    White, Laura K; Sali, Tina; Alvarado, David; Gatti, Evelina; Pierre, Philippe; Streblow, Daniel; Defilippis, Victor R

    2011-01-01

    Chikungunya virus (CHIKV) is an arthritogenic mosquito-transmitted alphavirus that is undergoing reemergence in areas around the Indian Ocean. Despite the current and potential danger posed by this virus, we know surprisingly little about the induction and evasion of CHIKV-associated antiviral immune responses. With this in mind we investigated innate immune reactions to CHIKV in human fibroblasts, a demonstrable in vivo target of virus replication and spread. We show that CHIKV infection leads to activation of the transcription factor interferon regulatory factor 3 (IRF3) and subsequent transcription of IRF3-dependent antiviral genes, including beta interferon (IFN-β). IRF3 activation occurs by way of a virus-induced innate immune signaling pathway that includes the adaptor molecule interferon promoter stimulator 1 (IPS-1). Despite strong transcriptional upregulation of these genes, however, translation of the corresponding proteins is not observed. We further demonstrate that translation of cellular (but not viral) genes is blocked during infection and that although CHIKV is found to trigger inactivation of the translational molecule eukaryotic initiation factor subunit 2α by way of the double-stranded RNA sensor protein kinase R, this response is not required for the block to protein synthesis. Furthermore, overall diminution of cellular RNA synthesis is also observed in the presence of CHIKV and transcription of IRF3-dependent antiviral genes appears specifically blocked late in infection. We hypothesize that the observed absence of IFN-β and antiviral proteins during infection results from an evasion mechanism exhibited by CHIKV that is dependent on widespread shutoff of cellular protein synthesis and a targeted block to late synthesis of antiviral mRNA transcripts.

  8. JC virus induces altered patterns of cellular gene expression: Interferon-inducible genes as major transcriptional targets

    SciTech Connect

    Verma, Saguna; Ziegler, Katja; Ananthula, Praveen; Co, Juliene K.G.; Frisque, Richard J.; Yanagihara, Richard; Nerurkar, Vivek R. . E-mail: nerurkar@pbrc.hawaii.edu

    2006-02-20

    Human polyomavirus JC (JCV) infects 80% of the population worldwide. Primary infection, typically occurring during childhood, is asymptomatic in immunocompetent individuals and results in lifelong latency and persistent infection. However, among the severely immunocompromised, JCV may cause a fatal demyelinating disease, progressive multifocal leukoencephalopathy (PML). Virus-host interactions influencing persistence and pathogenicity are not well understood, although significant regulation of JCV activity is thought to occur at the level of transcription. Regulation of the JCV early and late promoters during the lytic cycle is a complex event that requires participation of both viral and cellular factors. We have used cDNA microarray technology to analyze global alterations in gene expression in JCV-permissive primary human fetal glial cells (PHFG). Expression of more than 400 cellular genes was altered, including many that influence cell proliferation, cell communication and interferon (IFN)-mediated host defense responses. Genes in the latter category included signal transducer and activator of transcription 1 (STAT1), interferon stimulating gene 56 (ISG56), myxovirus resistance 1 (MxA), 2'5'-oligoadenylate synthetase (OAS), and cig5. The expression of these genes was further confirmed in JCV-infected PHFG cells and the human glioblastoma cell line U87MG to ensure the specificity of JCV in inducing this strong antiviral response. Results obtained by real-time RT-PCR and Western blot analyses supported the microarray data and provide temporal information related to virus-induced changes in the IFN response pathway. Our data indicate that the induction of an antiviral response may be one of the cellular factors regulating/controlling JCV replication in immunocompetent hosts and therefore constraining the development of PML.

  9. Abrogation of resistance to Theiler's virus-induced demyelination in H-2b mice deficient in beta 2-microglobulin.

    PubMed

    Rodriguez, M; Dunkel, A J; Thiemann, R L; Leibowitz, J; Zijlstra, M; Jaenisch, R

    1993-07-01

    Intracerebral infection of susceptible strains of mice with Theiler's virus, a picornavirus, results in central nervous system demyelination, which is similar to multiple sclerosis. Immunogenetic experiments indicate that the MHC (H-2) and, in particular, the D region that controls class I-restricted immune responses, is an important determinant to development of demyelination. We tested whether disruption of beta 2-microglobulin (beta 2-m) would abrogate resistance to demyelinating disease normally observed in H-2b mice. All (C57BI/6 x 129)F3 mice transgenic for homozygous beta 2-m gene disruption (-/-) developed chronic demyelination after Theiler's murine encephalomyelitis virus infection, whereas none of the infected littermates with normal expression of class I MHC (beta 2-m, +/+) developed demyelination. Demyelinated lesions showed class II MHC expression, macrophages, and TNF but no class I MHC expression or CD8+ T cells. No correlation was observed between development of demyelination and delayed-type hypersensitivity responses to virus Ag. Despite the presence of demyelinating lesions, none of the infected beta 2-m (-/-) mice developed neurologic deficits. Infectious virus and virus Ag persisted in the central nervous systems of infected beta 2-m (-/-) mice but not in beta 2-m (+/+) mice. These experiments support the hypothesis that a class I immune response mediated by CD8+ T cells is important in resistance to Theiler's murine encephalomyelitis virus-induced demyelination. Development of chronic neurologic deficits as observed in immunocompetent susceptible strains of mice may be dependent on the presence of class I MHC and CD8+ T cells.

  10. Anti-apoptotic Bcl-XL but not Mcl-1 contributes to protection against virus-induced apoptosis.

    PubMed

    Ohmer, Michaela; Weber, Arnim; Sutter, Gerd; Ehrhardt, Katrin; Zimmermann, Albert; Häcker, Georg

    2016-08-18

    Infection of mammalian cells with viruses often induces apoptosis. How the recognition of viruses leads to apoptosis of the infected cell and which host cell factors regulate this cell death is incompletely understood. In this study, we focussed on two major anti-apoptotic proteins of the host cell, whose abundance and activity are important for cell survival, the Bcl-2-like proteins Mcl-1 and Bcl-XL. During infection of epithelial cells and fibroblasts with modified vaccinia virus Ankara (MVA), Mcl-1 protein levels dropped but the MVA Bcl-2-like protein F1L could replace Mcl-1 functionally; a similar activity was found in vaccinia virus (VACV)-infected cells. During infection with murine cytomegalovirus (MCMV), Mcl-1-levels were not reduced but a viral Mcl-1-like activity was also generated. Infection of mouse macrophages with any of these viruses, on the other hand, induced apoptosis. Virus-induced macrophage apoptosis was unaltered in the absence of Mcl-1. However, apoptosis was substantially increased in infected Bcl-XL-deficient macrophages or macrophages treated with the Bcl-2/Bcl-XL-inhibitor ABT-737. Genetic loss of Bcl-XL or treatment of macrophages with ABT-737 reduced the generation of infectious VACV. These data show that Mcl-1 is dispensable for the regulation of apoptosis during infection with different large DNA viruses, either because the viruses replace its function (in fibroblasts and epithelial cells) or because the pro-apoptotic activity generated by the infection appears not to be blocked by it (in macrophages). Bcl-XL, on the other hand, can be important to maintain survival of virus-infected cells, and its activity can determine outcome of the infection.

  11. Anti-apoptotic Bcl-XL but not Mcl-1 contributes to protection against virus-induced apoptosis.

    PubMed

    Ohmer, Michaela; Weber, Arnim; Sutter, Gerd; Ehrhardt, Katrin; Zimmermann, Albert; Häcker, Georg

    2016-01-01

    Infection of mammalian cells with viruses often induces apoptosis. How the recognition of viruses leads to apoptosis of the infected cell and which host cell factors regulate this cell death is incompletely understood. In this study, we focussed on two major anti-apoptotic proteins of the host cell, whose abundance and activity are important for cell survival, the Bcl-2-like proteins Mcl-1 and Bcl-XL. During infection of epithelial cells and fibroblasts with modified vaccinia virus Ankara (MVA), Mcl-1 protein levels dropped but the MVA Bcl-2-like protein F1L could replace Mcl-1 functionally; a similar activity was found in vaccinia virus (VACV)-infected cells. During infection with murine cytomegalovirus (MCMV), Mcl-1-levels were not reduced but a viral Mcl-1-like activity was also generated. Infection of mouse macrophages with any of these viruses, on the other hand, induced apoptosis. Virus-induced macrophage apoptosis was unaltered in the absence of Mcl-1. However, apoptosis was substantially increased in infected Bcl-XL-deficient macrophages or macrophages treated with the Bcl-2/Bcl-XL-inhibitor ABT-737. Genetic loss of Bcl-XL or treatment of macrophages with ABT-737 reduced the generation of infectious VACV. These data show that Mcl-1 is dispensable for the regulation of apoptosis during infection with different large DNA viruses, either because the viruses replace its function (in fibroblasts and epithelial cells) or because the pro-apoptotic activity generated by the infection appears not to be blocked by it (in macrophages). Bcl-XL, on the other hand, can be important to maintain survival of virus-infected cells, and its activity can determine outcome of the infection. PMID:27537523

  12. Mouse Norovirus Replication Is Associated with Virus-Induced Vesicle Clusters Originating from Membranes Derived from the Secretory Pathway▿ †

    PubMed Central

    Hyde, Jennifer L.; Sosnovtsev, Stanislav V.; Green, Kim Y.; Wobus, Christiane; Virgin, Herbert W.; Mackenzie, Jason M.

    2009-01-01

    Human noroviruses (family Caliciviridae) are the leading cause of nonbacterial gastroenteritis worldwide. Despite the prevalence of these viruses within the community, the study of human norovirus has largely been hindered due to the inability to cultivate the viruses ex vivo and the lack of a small-animal model. In 2003, the discovery of a novel murine norovirus (MNV-1) and the identification of the tropism of MNV-1 for cells of a mononuclear origin led to the establishment of the first norovirus tissue culture system. Like other positive-sense RNA viruses, MNV-1 replication is associated with host membranes, which undergo significant rearrangement during infection. We characterize here the subcellular localization of the MNV-1 open reading frame 1 proteins and viral double-stranded RNA (dsRNA). Over the course of infection, dsRNA and the MNV-1 RNA-dependent RNA polymerase (NS7) were observed to proliferate from punctate foci located in the perinuclear region. All of the MNV-1 open reading frame 1 proteins were observed to colocalize with dsRNA during the course of infection. The MNV-1 replication complex was immunolocalized to virus-induced vesicle clusters formed in the cytoplasm of infected cells. Both dsRNA and MNV-1 NS7 were observed to localize to the limiting membrane of the individual clusters by cryo-immunoelectron microscopy. We show that the MNV-1 replication complex initially associates with membranes derived from the endoplasmic reticulum, trans-Golgi apparatus, and endosomes. In addition, we show that MNV-1 replication is insensitive to the fungal metabolite brefeldin A and consistently does not appear to recruit coatomer protein complex I (COPI) or COPII component proteins during replication. These data provide preliminary insights into key aspects of replication of MNV-1, which will potentially further our understanding of the pathogenesis of noroviruses and aid in the identification of potential targets for drug development. PMID:19587041

  13. Expression of interleukin 6 receptors and interleukin 6 mRNA by bovine leukaemia virus-induced tumour cells.

    PubMed

    Droogmans, L; Cludts, I; Cleuter, Y; Kerkhofs, P; Adam, E; Willems, L; Kettmann, R; Burny, A

    1994-11-01

    Bovine leukaemia virus (BLV) is the aetiologic agent of bovine leucosis. The virus induces malignancies of the B-cell lineage (leukaemia/lymphoma). The role played by interleukin 6 (IL-6) in the BLV-induced leukemogenesis process was evaluated. Six cell lines derived from BLV-induced tumours were tested for the expression of IL-6 receptors. Two cell lines (LB155 and YR2) display 250-300 receptor per cell (kd = 1.7 10(-10) M and 1.4 10(-10) M, respectively) whereas the other four (LB159, LB167, YR1 and M51) do not display detectable amounts of receptors. Very low (if any) expression of IL-6 receptors has been found in the case of the B lymphocytes of animals in persistent lymphocytosis (PL). Despite the presence of IL-6 receptors on the surface of LB155 and YR2 cells, no influence of exogenous IL-6 on their growth has been observed. Northern analyses indicated the presence of IL-6 transcripts only in the case of mRNA isolated from LB155 cells. Since this cell line also expresses receptors for the cytokine, an autocrine loop may exist in these cells. Experiments in which bovine and bovine epithelial cell lines were transfected with a plasmid containing the bovine IL-6 promoter controlling the expression of the reporter cat gene failed to indicate any influence of the viral transactivator p34tax on the activity of this promoter. We conclude that IL-6 receptors and IL-6 mRNA can be found in some BLV-induced tumours, but this does not correlate with viral expression in BLV-induced leukaemia/lymphoma. PMID:7893972

  14. Identification of Winter-Responsive Proteins in Bread Wheat Using Proteomics Analysis and Virus-Induced Gene Silencing (VIGS).

    PubMed

    Zhang, Ning; Huo, Wang; Zhang, Lingran; Chen, Feng; Cui, Dangqun

    2016-09-01

    Proteomic approaches were applied to identify protein spots involved in cold responses in wheat. By comparing the differentially accumulated proteins from two cultivars (UC1110 and PI 610750) and their derivatives, as well as the F10 recombinant inbred line population differing in cold-tolerance, a total of 20 common protein spots representing 16 unique proteins were successfully identified using 2-DE method. Of these, 14 spots had significantly enhanced abundance in the cold-sensitive parental cultivar UC1110 and its 20 descendant lines when compared with the cold-tolerant parental cultivar PI 610750 and its 20 descendant lines. Six protein spots with reduced abundance were also detected. The identified protein spots are involved in stress/defense, carbohydrate metabolism, protein metabolism, nitrogen metabolism, energy metabolism, and photosynthesis. The 20 differentially expressed protein spots were chosen for quantitative real-time polymerase chain reaction (qRT-PCR) to investigate expression changes at the RNA level. The results indicated that the transcriptional expression patterns of 11 genes were consistent with their protein expression models. Among the three unknown proteins, Spot 20 (PAP6-like) showed high sequence similarities with PAP6. qRT-PCR results implied that cold and salt stresses increased the expression of PAP6-like in wheat leaves. Furthermore, VIGS (virus-induced gene silencing)-treated plants generated for PAP6-like were subjected to freezing stress, these plants had more serious droop and wilt, an increased rate of relative electrolyte leakage, reduced relative water content (RWC) and decreased tocopherol levels when compared with viral control plants. However, the plants that were silenced for the other two unknown proteins had no significant differences in comparison to the BSMV0-inoculated plants under freezing conditions. These results indicate that PAP6-like possibly plays an important role in conferring cold tolerance in wheat. PMID

  15. Virus-induced gene silencing (VIGS) in Cysticapnos vesicaria, a zygomorphic-flowered Papaveraceae (Ranunculales, basal eudicots)

    PubMed Central

    Hidalgo, Oriane; Bartholmes, Conny; Gleissberg, Stefan

    2012-01-01

    Background and Aims Studies of evolutionary diversification in the basal eudicot family Papaveraceae, such as the transition from actinomorphy to zygomorphy, are hampered by the lack of comparative functional studies. So far, gene silencing methods are only available in the actinomorphic species Eschscholzia californica and Papaver somniferum. This study addresses the amenability of Cysticapnos vesicaria, a derived fumitory with zygomorphic flowers, to virus-induced gene silencing (VIGS), and describes vegetative and reproductive traits in this species. Methods VIGS-mediated downregulation of the C. vesicaria PHYTOENE DESATURASE gene (CvPDS) and of the FLORICAULA gene CvFLO was carried out using Agrobacterium tumefaciens transfer of Tobacco rattle virus (TRV)-based vectors. Wild-type and vector-treated plants were characterized using reverse transcription–PCR (RT–PCR), in situ hybridization, and macroscopic and scanning electron microscopic imaging. Key Results Cysticapnos vesicaria germinates rapidly, can be grown at high density, has a short life cycle and is self-compatible. Inoculation of C. vesicaria with a CvPDS-VIGS vector resulted in strong photobleaching of green parts and reduction of endogenous CvPDS transcript levels. Gene silencing persisted during inflorescence development until fruit set. Inoculation of plants with CvFLO-VIGS affected floral phyllotaxis, symmetry and floral organ identities. Conclusions The high penetrance, severity and stability of pTRV-mediated silencing, including the induction of meristem-related phenotypes, make C. vesicaria a very promising new focus species for evolutionary–developmental (evo–devo) studies in the Papaveraceae. This now enables comparative studies of flower symmetry, inflorescence determinacy and other traits that diversified in the Papaveraceae. PMID:22307568

  16. Development of Agrobacterium-Mediated Virus-Induced Gene Silencing and Performance Evaluation of Four Marker Genes in Gossypium barbadense

    PubMed Central

    Pang, Jinhuan; Zhu, Yue; Li, Qing; Liu, Jinzhi; Tian, Yingchuan; Liu, Yule; Wu, Jiahe

    2013-01-01

    Gossypiumbarbadense is a cultivated cotton species and possesses many desirable traits, including high fiber quality and resistance to pathogens, especially Verticilliumdahliae (a devastating pathogen of Gossypium hirsutum, the main cultivated species). These elite traits are difficult to be introduced into G. hirsutum through classical breeding methods. In addition, genetic transformation of G. barbadense has not been successfully performed. It is therefore important to develop methods for evaluating the function and molecular mechanism of genes in G. barbadense. In this study, we had successfully introduced a virus-induced gene silencing (VIGS) system into three cultivars of G. barbadense by inserting marker genes into the tobacco rattle virus (TRV) vector. After we optimized the VIGS conditions, including light intensity, photoperiod, seedling age and Agrobacterium strain, 100% of plants agroinfiltrated with the GaPDS silencing vector showed white colored leaves. Three other marker genes, GaCLA1, GaANS and GaANR, were employed to further test this VIGS system in G. barbadense. The transcript levels of the endogenous genes in the silenced plants were reduced by more than 99% compared to control plants; these plants presented phenotypic symptoms 2 weeks after inoculation. We introduced a fusing sequence fragment of GaPDS and GaANR gene silencing vectors into a single plant, which resulted in both photobleaching and brownish coloration. The extent of silencing in plants agroinfiltrated with fusing two-gene-silencing vector was consistent with plants harboring a single gene silencing vector. The development of this VIGS system should promote analysis of gene function in G. barbadense, and help to contribute desirable traits for breeding of G. barbadense and G. hirsutum. PMID:24023833

  17. Virus induced gene silencing of three putative prolyl 4-hydroxylases enhances plant growth in tomato (Solanum lycopersicum).

    PubMed

    Fragkostefanakis, Sotirios; Sedeek, Khalid E M; Raad, Maya; Zaki, Marwa Samir; Kalaitzis, Panagiotis

    2014-07-01

    Proline hydroxylation is a major posttranslational modification of hydroxyproline-rich glycoproteins (HRGPs) that is catalyzed by prolyl 4-hydroxylases (P4Hs). HRGPs such as arabinogalactan proteins (AGPs) and extensios play significant roles on cell wall structure and function and their implication in cell division and expansion has been reported. We used tobacco rattle virus (TRV)-based virus induced gene silencing to investigate the role of three tomato P4Hs, out of ten present in the tomato genome, in growth and development. Eight-days old tomato seedlings were infected with the appropriate TRV vectors and plants were allowed to grow under standard conditions for 6 weeks. Lower P4H mRNA levels were associated with lower hydroxyproline content in root and shoot tissues indicating successful gene silencing. P4H-silenced plants had longer roots and shoots and larger leaves. The increased leaf area can be attributed to increased cell division as indicated by the higher leaf epidermal cell number in SlP4H1- and SlP4H9-silenced plants. In contrast, SlP4H7-silenced plants had larger leaves due to enhanced cell expansion. Western blot analysis revealed that silencing of SlP4H7 and SlP4H9 was associated with reduced levels of JIM8-bound AGP and JIM11-bound extensin epitopes, while silencing of SlP4H1 reduced only the levels of AGP proteins. Collectively these results show that P4Hs have significant and distinct roles in cell division and expansion of tomato leaves.

  18. Small interfering RNAs targeted to interleukin-4 and respiratory syncytial virus reduce airway inflammation in a mouse model of virus-induced asthma exacerbation.

    PubMed

    Khaitov, Musa R; Shilovskiy, Igor P; Nikonova, Aleksandra A; Shershakova, Nadezda N; Kamyshnikov, Oleg Y; Babakhin, Alexander A; Zverev, Vitaly V; Johnston, Sebastian L; Khaitov, Rakhim M

    2014-07-01

    Asthma exacerbations are caused primarily by viral infections. Antisense and small interfering RNA (siRNA) technologies have gained attention as potential antiasthma and antiviral approaches. In this study we analyzed whether gene silencing of interleukin (IL)-4 expression and respiratory syncytial virus (RSV) replication by RNA interference is able to suppress allergen- and virus-induced responses in a mouse model of virus-induced asthma exacerbation. Knockdown efficacy of IL-4 siRNA molecules was analyzed in the human HEK293T cell line by cotransfection of six different siRNAs with a plasmid carrying mouse IL-4. The most potent siRNA was then used in a mouse model of RSV-induced asthma exacerbation. BALB/c mice were sensitized intraperitoneally with ovalbumin (OVA) and then infected 12 days later intranasally with RSV Long strain (1×10(6) TCID50/mouse), followed 1 day later by intranasal challenge with OVA for 3 days. Mice were pretreated intranasally three times with either siRNA to IL-4 or GFP control, 2 days before, and on the first two OVA challenge days. siRNAs to RSV or rhinovirus control were inoculated intranasally once, 3 hr before RSV infection. Combined anti-IL-4 and anti-RSV siRNAs were able to significantly reduce total cell counts and eosinophilia in bronchoalveolar lavage fluid, development of airway hyperresponsiveness, and airway inflammation and to downregulate IL-4 mRNA expression and RSV viral RNA, but to upregulate IFN-γ levels in lung tissues. We conclude that anti-helper T cells type 2 and antiviral siRNAs may constitute a new therapeutic approach for treatment of virus induced asthma exacerbations.

  19. The SNARE protein Syp71 is essential for turnip mosaic virus infection by mediating fusion of virus-induced vesicles with chloroplasts.

    PubMed

    Wei, Taiyun; Zhang, Changwei; Hou, Xilin; Sanfaçon, Hélène; Wang, Aiming

    2013-01-01

    All positive-strand RNA viruses induce the biogenesis of cytoplasmic membrane-bound virus factories for viral genome multiplication. We have previously demonstrated that upon plant potyvirus infection, the potyviral 6K2 integral membrane protein induces the formation of ER-derived replication vesicles that subsequently target chloroplasts for robust genome replication. Here, we report that following the trafficking of the Turnip mosaic potyvirus (TuMV) 6K2 vesicles to chloroplasts, 6K2 vesicles accumulate at the chloroplasts to form chloroplast-bound elongated tubular structures followed by chloroplast aggregation. A functional actomyosin motility system is required for this process. As vesicle trafficking and fusion in planta are facilitated by a superfamily of proteins known as SNAREs (soluble N-ethylmaleimide-sensitive-factor attachment protein receptors), we screened ER-localized SNARES or SNARE-like proteins for their possible involvement in TuMV infection. We identified Syp71 and Vap27-1 that colocalize with the chloroplast-bound 6K2 complex. Knockdown of their expression using a Tobacco rattle virus (TRV)-based virus-induced gene silencing vector showed that Syp71 but not Vap27-1 is essential for TuMV infection. In Syp71-downregulated plant cells, the formation of 6K2-induced chloroplast-bound elongated tubular structures and chloroplast aggregates is inhibited and virus accumulation is significantly reduced, but the trafficking of the 6K2 vesicles from the ER to chloroplast is not affected. Taken together, these data suggest that Syp71 is a host factor essential for successful virus infection by mediating the fusion of the virus-induced vesicles with chloroplasts during TuMV infection.

  20. Genetic determinants of feline leukemia virus-induced lymphoid tumors: patterns of proviral insertion and gene rearrangement.

    PubMed

    Tsatsanis, C; Fulton, R; Nishigaki, K; Tsujimoto, H; Levy, L; Terry, A; Spandidos, D; Onions, D; Neil, J C

    1994-12-01

    The genetic basis of feline leukemia virus (FeLV)-induced lymphoma was investigated in a series of 63 lymphoid tumors and tumor cell lines of presumptive T-cell origin. These were examined for virus-induced rearrangements of the c-myc, flvi-2 (bmi-1), fit-1, and pim-1 loci, for T-cell receptor (TCR) gene rearrangements, and for the presence of env recombinant FeLV (FeLV-B). The myc locus was most frequently affected in naturally occurring lymphomas (32%; n = 38) either by transduction (21%) or by proviral insertion (11%). Proviral insertions were also common at flvi-2 (24%). The two other loci were occupied in a smaller number of the naturally occurring tumors (fit-1, 8%; pim-1, 5%). Examination of the entire set of tumors showed that significant numbers were affected at two (19%) or three (5%) of the loci. Occupation of the fit-1 locus was observed most frequently in tumors induced by FeLV-myc strains, while flvi-2 insertions occurred with similar frequency in the presence or absence of obvious c-myc activation. These results suggest a hierarchy of mutational events in the genesis of feline T-cell lymphomas by FeLV and implicate insertion at fit-1 as a late progression step. The strongest links observed were with T-cell development, as monitored by rearrangement status of the TCR beta-chain gene, which was positively associated with activation of myc (P < 0.001), and with proviral insertion at flvi-2 (P = 0.02). This analysis also revealed a genetically distinct subset of thymic lymphomas with unrearranged TCR beta-chain genes in which the known target loci were involved very infrequently. The presence of env recombinant FeLV (FeLV-B) showed a negative correlation with proviral insertion at fit-1, possibly due to the rapid onset of these tumors. These results shed further light on the multistep process of FeLV leukemogenesis and the relationships between lymphoid cell maturation and susceptibility to FeLV transformation.

  1. Total Hepatitis B Core Antigen Antibody, a Quantitative Non-Invasive Marker of Hepatitis B Virus Induced Liver Disease.

    PubMed

    Yuan, Quan; Song, Liu-Wei; Cavallone, Daniela; Moriconi, Francesco; Cherubini, Beatrice; Colombatto, Piero; Oliveri, Filippo; Coco, Barbara Agata; Ricco, Gabriele; Bonino, Ferruccio; Shih, James Wai Kuo; Xia, Ning-Shao; Brunetto, Maurizia Rossana

    2015-01-01

    Non invasive immunologic markers of virus-induced liver disease are unmet needs. We tested the clinical significance of quantitative total and IgM-anti-HBc in well characterized chronic-HBsAg-carriers. Sera (212) were obtained from 111 HBsAg-carriers followed-up for 52 months (28-216) during different phases of chronic-HBV-genotype-D-infection: 10 HBeAg-positive, 25 inactive-carriers (HBV-DNA≤2000IU/ml, ALT<30U/L), 66 HBeAg-negative-CHB-patients and 10 with HDV-super-infection. In 35 patients treated with Peg-IFN±nucleos(t)ide-analogues (NUCs) sera were obtained at baseline, end-of-therapy and week-24-off-therapy and in 22 treated with NUCs (for 60 months, 42-134m) at baseline and end-of-follow-up. HBsAg and IgM-anti-HBc were measured by Architect-assays (Abbott, USA); total-anti-HBc by double-antigen-sandwich-immune-assay (Wantai, China); HBV-DNA by COBAS-TaqMan (Roche, Germany). Total-anti-HBc were detectable in all sera with lower levels in HBsAg-carriers without CHB (immune-tolerant, inactive and HDV-superinfected, median 3.26, range 2.26-4.49 Log10 IU/ml) versus untreated-CHB (median 4.68, range 2.76-5.54 Log10 IU/ml), p<0.0001. IgM-anti-HBc positive using the chronic-hepatitis-cut-off" (0.130-S/CO) were positive in 102 of 212 sera (48.1%). Overall total-anti-HBc and IgM-anti-HBc correlated significantly (p<0.001, r=0.417). Total-anti-HBc declined significantly in CHB patients with response to Peg-IFN (p<0.001) and in NUC-treated patients (p<0.001); the lowest levels (median 2.68, range 2.12-3.08 Log10 IU/ml) were found in long-term responders who cleared HBsAg subsequently. During spontaneous and therapy-induced fluctuations of CHB (remissions and reactivations) total- and IgM-anti-HBc correlated with ALT (p<0.001, r=0.351 and p=0.008, r=0.185 respectively). Total-anti-HBc qualifies as a useful marker of HBV-induced-liver-disease that might help to discriminate major phases of chronic HBV infection and to predict sustained response to antivirals.

  2. Total Hepatitis B Core Antigen Antibody, a Quantitative Non-Invasive Marker of Hepatitis B Virus Induced Liver Disease

    PubMed Central

    Cavallone, Daniela; Moriconi, Francesco; Cherubini, Beatrice; Colombatto, Piero; Oliveri, Filippo; Coco, Barbara Agata; Ricco, Gabriele; Bonino, Ferruccio; Shih, James Wai Kuo; Xia, Ning-Shao; Brunetto, Maurizia Rossana

    2015-01-01

    Non invasive immunologic markers of virus-induced liver disease are unmet needs. We tested the clinical significance of quantitative total and IgM-anti-HBc in well characterized chronic-HBsAg-carriers. Sera (212) were obtained from 111 HBsAg-carriers followed-up for 52 months (28-216) during different phases of chronic-HBV-genotype-D-infection: 10 HBeAg-positive, 25 inactive-carriers (HBV-DNA≤2000IU/ml, ALT<30U/L), 66 HBeAg-negative-CHB-patients and 10 with HDV-super-infection. In 35 patients treated with Peg-IFN±nucleos(t)ide-analogues (NUCs) sera were obtained at baseline, end-of-therapy and week-24-off-therapy and in 22 treated with NUCs (for 60 months, 42-134m) at baseline and end-of-follow-up. HBsAg and IgM-anti-HBc were measured by Architect-assays (Abbott, USA); total-anti-HBc by double-antigen-sandwich-immune-assay (Wantai, China); HBV-DNA by COBAS-TaqMan (Roche, Germany). Total-anti-HBc were detectable in all sera with lower levels in HBsAg-carriers without CHB (immune-tolerant, inactive and HDV-superinfected, median 3.26, range 2.26-4.49 Log10 IU/ml) versus untreated-CHB (median 4.68, range 2.76-5.54 Log10 IU/ml), p<0.0001. IgM-anti-HBc positive using the chronic-hepatitis-cut-off" (0.130-S/CO) were positive in 102 of 212 sera (48.1%). Overall total-anti-HBc and IgM-anti-HBc correlated significantly (p<0.001, r=0.417). Total-anti-HBc declined significantly in CHB patients with response to Peg-IFN (p<0.001) and in NUC-treated patients (p<0.001); the lowest levels (median 2.68, range 2.12-3.08 Log10 IU/ml) were found in long-term responders who cleared HBsAg subsequently. During spontaneous and therapy-induced fluctuations of CHB (remissions and reactivations) total- and IgM-anti-HBc correlated with ALT (p<0.001, r=0.351 and p=0.008, r=0.185 respectively). Total-anti-HBc qualifies as a useful marker of HBV-induced-liver-disease that might help to discriminate major phases of chronic HBV infection and to predict sustained response to antivirals. PMID

  3. Identification of Novel Compounds Inhibiting Chikungunya Virus-Induced Cell Death by High Throughput Screening of a Kinase Inhibitor Library

    PubMed Central

    Gomes, Rafael G. B.; da Silva, Camila T.; Taniguchi, Juliana B.; No, Joo Hwan; Lombardot, Benoit; Schwartz, Olivier; Hansen, Michael A. E.; Freitas-Junior, Lucio H.

    2013-01-01

    antiviral activity - inhibition of virus-induced CPE - likely by targeting kinases involved in apoptosis. PMID:24205414

  4. Genetic determinants of feline leukemia virus-induced lymphoid tumors: patterns of proviral insertion and gene rearrangement.

    PubMed

    Tsatsanis, C; Fulton, R; Nishigaki, K; Tsujimoto, H; Levy, L; Terry, A; Spandidos, D; Onions, D; Neil, J C

    1994-12-01

    The genetic basis of feline leukemia virus (FeLV)-induced lymphoma was investigated in a series of 63 lymphoid tumors and tumor cell lines of presumptive T-cell origin. These were examined for virus-induced rearrangements of the c-myc, flvi-2 (bmi-1), fit-1, and pim-1 loci, for T-cell receptor (TCR) gene rearrangements, and for the presence of env recombinant FeLV (FeLV-B). The myc locus was most frequently affected in naturally occurring lymphomas (32%; n = 38) either by transduction (21%) or by proviral insertion (11%). Proviral insertions were also common at flvi-2 (24%). The two other loci were occupied in a smaller number of the naturally occurring tumors (fit-1, 8%; pim-1, 5%). Examination of the entire set of tumors showed that significant numbers were affected at two (19%) or three (5%) of the loci. Occupation of the fit-1 locus was observed most frequently in tumors induced by FeLV-myc strains, while flvi-2 insertions occurred with similar frequency in the presence or absence of obvious c-myc activation. These results suggest a hierarchy of mutational events in the genesis of feline T-cell lymphomas by FeLV and implicate insertion at fit-1 as a late progression step. The strongest links observed were with T-cell development, as monitored by rearrangement status of the TCR beta-chain gene, which was positively associated with activation of myc (P < 0.001), and with proviral insertion at flvi-2 (P = 0.02). This analysis also revealed a genetically distinct subset of thymic lymphomas with unrearranged TCR beta-chain genes in which the known target loci were involved very infrequently. The presence of env recombinant FeLV (FeLV-B) showed a negative correlation with proviral insertion at fit-1, possibly due to the rapid onset of these tumors. These results shed further light on the multistep process of FeLV leukemogenesis and the relationships between lymphoid cell maturation and susceptibility to FeLV transformation. PMID:7966623

  5. Molecular Characterization of Oxysterol Binding to the Epstein-Barr Virus-induced Gene 2 (GPR183)*

    PubMed Central

    Benned-Jensen, Tau; Norn, Christoffer; Laurent, Stephane; Madsen, Christian M.; Larsen, Hjalte M.; Arfelt, Kristine N.; Wolf, Romain M.; Frimurer, Thomas; Sailer, Andreas W.; Rosenkilde, Mette M.

    2012-01-01

    Oxysterols are oxygenated cholesterol derivates that are emerging as a physiologically important group of molecules. Although they regulate a range of cellular processes, only few oxysterol-binding effector proteins have been identified, and the knowledge of their binding mode is limited. Recently, the family of G protein-coupled seven transmembrane-spanning receptors (7TM receptors) was added to this group. Specifically, the Epstein-Barr virus-induced gene 2 (EBI2 or GPR183) was shown to be activated by several oxysterols, most potently by 7α,25-dihydroxycholesterol (7α,25-OHC). Nothing is known about the binding mode, however. Using mutational analysis, we identify here four key residues for 7α,25-OHC binding: Arg-87 in TM-II (position II:20/2.60), Tyr-112 and Tyr-116 (positions III:09/3.33 and III:13/3.37) in TM-III, and Tyr-260 in TM-VI (position VI:16/6.51). Substituting these residues with Ala and/or Phe results in a severe decrease in agonist binding and receptor activation. Docking simulations suggest that Tyr-116 interacts with the 3β-OH group in the agonist, Tyr-260 with the 7α-OH group, and Arg-87, either directly or indirectly, with the 25-OH group, although nearby residues likely also contribute. In addition, Tyr-112 is involved in 7α,25-OHC binding but via hydrophobic interactions. Finally, we show that II:20/2.60 constitutes an important residue for ligand binding in receptors carrying a positively charged residue at this position. This group is dominated by lipid- and nucleotide-activated receptors, here exemplified by the CysLTs, P2Y12, and P2Y14. In conclusion, we present the first molecular characterization of oxysterol binding to a 7TM receptor and identify position II:20/2.60 as a generally important residue for ligand binding in certain 7TM receptors. PMID:22875855

  6. Involvement of fish signal transducer and activator of transcription 3 (STAT3) in SGIV replication and virus induced paraptosis.

    PubMed

    Huang, Xiaohong; Huang, Youhua; Yang, Ying; Wei, Shina; Qin, Qiwei

    2014-12-01

    Signal transducer and activator of transcription 3 (STAT3) is an important transcription factor which plays crucial roles in immune regulation, inflammation, cell proliferation, transformation, and other physiological processes of the organism. In this study, a novel STAT3 gene from orange spotted grouper (Ec-STAT3) was cloned and characterized. Bioinformatic analysis revealed that full-length of Ec-STAT3 was 3105-bp long and contained a 280-bp 5'UTR, a 470-bp 3'UTR, and a 2355-bp open reading frame (ORF) that encoded a 784-amino acid peptide. The deduced protein of Ec-STAT3 showed 98% identity to that of turbot (Scophthalmus maximus). Amino acid alignment showed that Ec-STAT3 contained four conserved domains, including a protein interaction domain, a coiled coil domain, a DNA binding domain, and an SH2 domain. Quantitative real-time PCR analysis showed that the highest expression level was detected in the liver, followed by skin and spleen. After injection with Singapore grouper iridovirus (SGIV), the transcript of Ec-STAT3 in spleen was increased significantly. To further explore the function of Ec-STAT3, we investigated the roles of Ec-STAT3 in SGIV infection in vitro. Immune fluorescence analysis indicated that SGIV infection altered the distribution of phosphorylated Ec-STAT3 in nucleus, and a small part of phosphorylated Ec-STAT3 was associated with virus assembly sites, suggesting that Ec-STAT3 might be important for SGIV infection. Using STAT3 specific inhibitor, S3I-201, we found that inhibition of Ec-STAT3 activation decreased the SGIV replication significantly. Moreover, inhibition of Ec-STAT3 activation obviously altered SGIV infection induced cell cycle arrest and the expression of pro-survival genes, including Bcl-2, Bcl-xL and Bax inhibitor. Together, our results firstly demonstrated the critical roles of fish STAT3 in DNA virus replication and virus induced paraptosis, but also provided new insights into the mechanism of iridovirus pathogenesis.

  7. Asthma "of horses and men"--how can equine heaves help us better understand human asthma immunopathology and its functional consequences?

    PubMed

    Bullone, Michela; Lavoie, Jean-Pierre

    2015-07-01

    Animal models have been studied to unravel etiological, immunopathological, and genetic attributes leading to asthma. However, while experiments in which the disease is artificially induced have helped discovering biological and molecular pathways leading to allergic airway inflammation, their contribution to the understanding of the causality of the disease has been more limited. Horses naturally suffer from an asthma-like condition called "heaves" which presents sticking similarities with human asthma. It is characterized by reversible airway obstruction, airway neutrophilic inflammation, and a predominant Th2 immune response. This model allows one to investigate the role of neutrophils in asthma, which remains contentious, the regulation of chronic neutrophilic inflammation, and their possible implication in pulmonary allergic responses. Furthermore, the pulmonary remodeling features in heaves closely resemble those of human asthma, which makes this model unique to investigate the kinetics, reversibility, as well as the physiological consequences of tissue remodeling. In conclusion, heaves and asthma share common clinical presentation and also important immunological and tissue remodeling features. This makes heaves an ideal model for the discovery of novel pathways implicated in the asthmatic inflammation and associated tissue remodeling.

  8. A new virus-induced gene silencing vector based on Euphorbia mosaic virus-Yucatan peninsula for NPR1 silencing in Nicotiana benthamiana and Capsicum annuum var. Anaheim.

    PubMed

    Villanueva-Alonzo, Hernan J; Us-Camas, Rosa Y; López-Ochoa, Luisa A; Robertson, Dominique; Guerra-Peraza, Orlene; Minero-García, Yereni; Moreno-Valenzuela, Oscar A

    2013-05-01

    Virus-induced gene silencing is based on the sequence-specific degradation of RNA. Here, a gene silencing vector derived from EuMV-YP, named pEuMV-YP:ΔAV1, was used to silence ChlI and NPR1 genes in Nicotiana benthamiana. The silencing of the ChlI transcripts was efficient in the stems, petioles and leaves as reflected in tissue bleaching and reduced transcript levels. The silencing was stable, reaching the flowers and fruits, and was observed throughout the life cycle of the plants. Additionally, the silencing of the NPR1 gene was efficient in both N. benthamiana and Capsicum annuum. After silencing, the plants' viral symptoms increased to levels similar to those seen in wild-type plants. These results suggest that NPR1 plays a role in the compatible interactions of EuMV-YP N. benthamiana and EuMV-C. annum var. anaheim.

  9. Identification of a locus on mouse chromosome 3 involved in differential susceptibility to Theiler's murine encephalomyelitis virus-induced demyelinating disease.

    PubMed Central

    Melvold, R W; Jokinen, D M; Miller, S D; Dal Canto, M C; Lipton, H L

    1990-01-01

    Theiler's virus-induced demyelinating disease results from a chronic infection in the white matter of the central nervous system and provides an excellent model for human multiple sclerosis. Like multiple sclerosis, there are genetic risk factors in disease development, including genes associated with the major histocompatibility complex and with those encoding the beta chain of the T-cell receptor. Comparisons of the susceptible DBA/2 and resistant C57BL/6 strains have indicated an important role for the H-2D locus and for a non-H-2 gene (not involving the beta chain of the T-cell receptor) in differential susceptibility. In the present report, analysis of recombinant-inbred strains (BXD) between the DBA/2 and C57BL/6 strains indicated that this non-H-2 locus is located at the centromeric end of chromosome 3 near (4 +/- 4 centimorgans) the carbonic anhydrase-2 (Car-2) enzyme locus. PMID:2296080

  10. Apple latent spherical virus vectors for reliable and effective virus-induced gene silencing among a broad range of plants including tobacco, tomato, Arabidopsis thaliana, cucurbits, and legumes

    SciTech Connect

    Igarashi, Aki; Yamagata, Kousuke; Sugai, Tomokazu; Takahashi, Yukari; Sugawara, Emiko; Tamura, Akihiro; Yaegashi, Hajime; Yamagishi, Noriko; Takahashi, Tsubasa; Isogai, Masamichi; Takahashi, Hideki; Yoshikawa, Nobuyuki

    2009-04-10

    Apple latent spherical virus (ALSV) vectors were evaluated for virus-induced gene silencing (VIGS) of endogenous genes among a broad range of plant species. ALSV vectors carrying partial sequences of a subunit of magnesium chelatase (SU) and phytoene desaturase (PDS) genes induced highly uniform knockout phenotypes typical of SU and PDS inhibition on model plants such as tobacco and Arabidopsis thaliana, and economically important crops such as tomato, legume, and cucurbit species. The silencing phenotypes persisted throughout plant growth in these plants. In addition, ALSV vectors could be successfully used to silence a meristem gene, proliferating cell nuclear antigen and disease resistant N gene in tobacco and RCY1 gene in A. thaliana. As ALSV infects most host plants symptomlessly and effectively induces stable VIGS for long periods, the ALSV vector is a valuable tool to determine the functions of interested genes among a broad range of plant species.

  11. Virus-Induced Gene Silencing Identifies an Important Role of the TaRSR1 Transcription Factor in Starch Synthesis in Bread Wheat.

    PubMed

    Liu, Guoyu; Wu, Yufang; Xu, Mengjun; Gao, Tian; Wang, Pengfei; Wang, Lina; Guo, Tiancai; Kang, Guozhang

    2016-01-01

    The function of a wheat starch regulator 1 (TaRSR1) in regulating the synthesis of grain storage starch was determined using the barley stripe mosaic virus-virus induced gene-silencing (BSMV-VIGS) method in field experiments. Chlorotic stripes appeared on the wheat spikes infected with barley stripe mosaic virus-virus induced gene-silencing- wheat starch regulator 1 (BSMV-VIGS-TaRSR1) at 15 days after anthesis, at which time the transcription levels of the TaRSR1 gene significantly decreased. Quantitative real-time PCR was also used to measure the transcription levels of 26 starch synthesis-related enzyme genes in the grains of BSMV-VIGS-TaRSR1-silenced wheat plants at 20, 27, and 31 days after anthesis. The results showed that the transcription levels of some starch synthesis-related enzyme genes were markedly induced at different sampling time points: TaSSI, TaSSIV, TaBEIII, TaISA1, TaISA3, TaPHOL, and TaDPE1 genes were induced at each of the three sampling time points and TaAGPS1-b, TaAGPL1, TaAGPL2, TaSSIIb, TaSSIIc, TaSSIIIb, TaBEI, TaBEIIa, TaBEIIb, TaISA2, TaPHOH, and TaDPE2 genes were induced at one sampling time point. Moreover, both the grain starch contents, one thousand kernel weights, grain length and width of BSMV-VIGS-TaRSR1-infected wheat plants significantly increased. These results suggest that TaRSR1 acts as a negative regulator and plays an important role in starch synthesis in wheat grains by temporally regulating the expression of specific starch synthesis-related enzyme genes. PMID:27669224

  12. The presence of tomato leaf curl Kerala virus AC3 protein enhances viral DNA replication and modulates virus induced gene-silencing mechanism in tomato plants

    PubMed Central

    2011-01-01

    Background Geminiviruses encode few viral proteins. Most of the geminiviral proteins are multifunctional and influence various host cellular processes for the successful viral infection. Though few viral proteins like AC1 and AC2 are well characterized for their multiple functions, role of AC3 in the successful viral infection has not been investigated in detail. Results We performed phage display analysis with the purified recombinant AC3 protein with Maltose Binding Protein as fusion tag (MBP-AC3). Putative AC3 interacting peptides identified through phage display were observed to be homologous to peptides of proteins from various metabolisms. We grouped these putative AC3 interacting peptides according to the known metabolic function of the homologous peptide containing proteins. In order to check if AC3 influences any of these particular metabolic pathways, we designed vectors for assaying DNA replication and virus induced gene-silencing of host gene PCNA. Investigation with these vectors indicated that AC3 enhances viral replication in the host plant tomato. In the PCNA gene-silencing experiment, we observed that the presence of functional AC3 ORF strongly manifested the stunted phenotype associated with the virus induced gene-silencing of PCNA in tomato plants. Conclusions Through the phage display analysis proteins from various metabolic pathways were identified as putative AC3 interacting proteins. By utilizing the vectors developed, we could analyze the role of AC3 in viral DNA replication and host gene-silencing. Our studies indicate that AC3 is also a multifunctional protein. PMID:21496351

  13. Virus-Induced Gene Silencing Identifies an Important Role of the TaRSR1 Transcription Factor in Starch Synthesis in Bread Wheat

    PubMed Central

    Liu, Guoyu; Wu, Yufang; Xu, Mengjun; Gao, Tian; Wang, Pengfei; Wang, Lina; Guo, Tiancai; Kang, Guozhang

    2016-01-01

    The function of a wheat starch regulator 1 (TaRSR1) in regulating the synthesis of grain storage starch was determined using the barley stripe mosaic virus—virus induced gene-silencing (BSMV-VIGS) method in field experiments. Chlorotic stripes appeared on the wheat spikes infected with barley stripe mosaic virus-virus induced gene-silencing- wheat starch regulator 1 (BSMV-VIGS-TaRSR1) at 15 days after anthesis, at which time the transcription levels of the TaRSR1 gene significantly decreased. Quantitative real-time PCR was also used to measure the transcription levels of 26 starch synthesis-related enzyme genes in the grains of BSMV-VIGS-TaRSR1-silenced wheat plants at 20, 27, and 31 days after anthesis. The results showed that the transcription levels of some starch synthesis-related enzyme genes were markedly induced at different sampling time points: TaSSI, TaSSIV, TaBEIII, TaISA1, TaISA3, TaPHOL, and TaDPE1 genes were induced at each of the three sampling time points and TaAGPS1-b, TaAGPL1, TaAGPL2, TaSSIIb, TaSSIIc, TaSSIIIb, TaBEI, TaBEIIa, TaBEIIb, TaISA2, TaPHOH, and TaDPE2 genes were induced at one sampling time point. Moreover, both the grain starch contents, one thousand kernel weights, grain length and width of BSMV-VIGS-TaRSR1-infected wheat plants significantly increased. These results suggest that TaRSR1 acts as a negative regulator and plays an important role in starch synthesis in wheat grains by temporally regulating the expression of specific starch synthesis-related enzyme genes. PMID:27669224

  14. Apoptotic suppression by baculovirus P35 involves cleavage by and inhibition of a virus-induced CED-3/ICE-like protease.

    PubMed Central

    Bertin, J; Mendrysa, S M; LaCount, D J; Gaur, S; Krebs, J F; Armstrong, R C; Tomaselli, K J; Friesen, P D

    1996-01-01

    Baculovirus p35 prevents programmed cell death in diverse organisms and encodes a protein inhibitor (P35) of the CED-3/interleukin-1 beta-converting enzyme (ICE)-related proteases. By using site-directed mutagenesis, we have identified P35 domains necessary for suppression of virus-induced apoptosis in insect cells, the context in which P35 evolved. During infection, P35 was cleaved within an essential domain at or near the site DQMD-87G required for cleavage by CED-3/ICE family proteases. Cleavage site substitution of alanine for aspartic acid at position 87 (D87A) of the P1 residue abolished P35 cleavage and antiapoptotic activity. Although the P4 residue substitution D84A also caused loss of apoptotic suppression, it did not eliminate cleavage and suggested that P35 cleavage is not sufficient for antiapoptotic activity. Apoptotic insect cells contained a CED-3/ICE-like activity that cleaved in vitro-translated P35 and was inhibited by recombinant wild-type P35 but not P1- or P4-mutated P35. Thus, baculovirus infection directly or indirectly activates a novel CED-3/ICE-like protease that is inhibited by P35, thereby preventing virus-induced apoptosis. Our findings confirmed the inhibitory activity of P35 towards the CED-3/ICE protease, including recombinant mammalian enzymes, and were consistent with a mechanism involving P35 stoichiometric interaction and cleavage. P35's inhibition of phylogenetically diverse proteases accounts for its general effectiveness as an apoptotic suppressor. PMID:8709252

  15. Helicobacter pylori Induced Gastric Immunopathology Is Associated with Distinct Microbiota Changes in the Large Intestines of Long-Term Infected Mongolian Gerbils

    PubMed Central

    Heimesaat, Markus M.; Fischer, André; Plickert, Rita; Wiedemann, Tobias; Loddenkemper, Christoph; Göbel, Ulf B.

    2014-01-01

    Background Gastrointestinal (GI) inflammation in mice and men are frequently accompanied by distinct changes of the GI microbiota composition at sites of inflammation. Helicobacter (H.) pylori infection results in gastric immunopathology accompanied by colonization of stomachs with bacterial species, which are usually restricted to the lower intestine. Potential microbiota shifts distal to the inflammatory process following long-term H. pylori infection, however, have not been studied so far. Methodology/Principal Findings For the first time, we investigated microbiota changes along the entire GI tract of Mongolian gerbils after 14 months of infection with H. pylori B8 wildtype (WT) or its isogenic ΔcagY mutant (MUT) strain which is defective in the type IV secretion system and thus unable to modulate specific host pathways. Comprehensive cultural analyses revealed that severe gastric diseases such as atrophic pangastritis and precancerous transformations were accompanied by elevated luminal loads of E. coli and enterococci in the caecum and together with Bacteroides/Prevotella spp. in the colon of H. pylori WT, but not MUT infected gerbils as compared to naïve animals. Strikingly, molecular analyses revealed that Akkermansia, an uncultivable species involved in mucus degradation, was exclusively abundant in large intestines of H. pylori WT, but not MUT infected nor naïve gerbils. Conclusion/Significance Taken together, long-term infection of Mongolian gerbils with a H. pylori WT strain displaying an intact type IV secretion system leads to distinct shifts of the microbiota composition in the distal uninflamed, but not proximal inflamed GI tract. Hence, H. pylori induced immunopathogenesis of the stomach, including hypochlorhydria and hypergastrinemia, might trigger large intestinal microbiota changes whereas the exact underlying mechanisms need to be further unraveled. PMID:24941045

  16. T cell-mediated hepatitis in mice infected with lymphocytic choriomeningitis virus. Liver cell destruction by H-2 class I-restricted virus-specific cytotoxic T cells as a physiological correlate of the /sup 51/Cr-release assay

    SciTech Connect

    Zinkernagel, R.M.; Haenseler, E.; Leist, T.; Cerny, A.; Hengartner, H.; Althage, A.

    1986-10-01

    A model for immunologically T cell-mediated hepatitis was established in mice infected with lymphocytic choriomeningitis virus (LCMV). The severity of hepatitis was monitored histologically and by determination of changes in serum levels of the enzymes alanine aminotransferase (ALT), aspartate aminotransferase (AST), glutamate dehydrogenase (GLDH), and alkaline phosphatase (AP). Kinetics of histological disease manifestations, increases of liver enzyme levels in the serum, and cytotoxic T cell activities in livers and spleens all correlated and were dependent upon several parameters: LCMV-isolate; LCMV-WE caused extensive hepatitis, LCMV-Armstrong virtually none. Virus dose. Route of infection; i.v. or i.p. infection caused hepatitis, whereas infection into the footpad did not. The general genetic background of the murine host; of the strains tested, Swiss mice and A-strain mice were more susceptible than C57BL or CBA mice; BALB/c and DBA/2 mice were least susceptible. The degree of immunocompetence of the murine host; T cell deficient nu/nu mice never developed hepatitis, whereas nu/+ or +/+ mice always did. B cell-depleted anti-IgM-treated mice developed immune-mediated hepatitis comparably or even more extensively than control mice. Local cytotoxic T cell activity; mononuclear cells isolated from livers during the period of overt hepatitis were two to five times more active than equal numbers of spleen cells. Adoptive transfer of nylon wool-nonadherent anti-Thy-1.2 and anti-Lyt-2 plus C-sensitive, anti-L3T4 plus C-resistant lymphocytes into irradiated mice preinfected with LCMV-WE caused a rapid time- and dose-dependent linear increase of serum enzyme levels. This increase was caused by adoptive transfer of lymphocytes if immune cell donors and recipient mice shared class I, but not when they shared class II histocompatibility antigens.

  17. The C-Terminal Region of Lymphocytic Choriomeningitis Virus Nucleoprotein Contains Distinct and Segregable Functional Domains Involved in NP-Z Interaction and Counteraction of the Type I Interferon Response▿

    PubMed Central

    Ortiz-Riaño, Emilio; Cheng, Benson Yee Hin; de la Torre, Juan Carlos; Martínez-Sobrido, Luis

    2011-01-01

    Several arenaviruses cause hemorrhagic fever (HF) disease in humans that is associated with high morbidity and significant mortality. Arenavirus nucleoprotein (NP), the most abundant viral protein in infected cells and virions, encapsidates the viral genome RNA, and this NP-RNA complex, together with the viral L polymerase, forms the viral ribonucleoprotein (vRNP) that directs viral RNA replication and gene transcription. Formation of infectious arenavirus progeny requires packaging of vRNPs into budding particles, a process in which arenavirus matrix-like protein (Z) plays a central role. In the present study, we have characterized the NP-Z interaction for the prototypic arenavirus lymphocytic choriomeningitis virus (LCMV). The LCMV NP domain that interacted with Z overlapped with a previously documented C-terminal domain that counteracts the host type I interferon (IFN) response. However, we found that single amino acid mutations that affect the anti-IFN function of LCMV NP did not disrupt the NP-Z interaction, suggesting that within the C-terminal region of NP different amino acid residues critically contribute to these two distinct and segregable NP functions. A similar NP-Z interaction was confirmed for the HF arenavirus Lassa virus (LASV). Notably, LCMV NP interacted similarly with both LCMV Z and LASV Z, while LASV NP interacted only with LASV Z. Our results also suggest the presence of a conserved protein domain within NP but with specific amino acid residues playing key roles in determining the specificity of NP-Z interaction that may influence the viability of reassortant arenaviruses. In addition, this NP-Z interaction represents a potential target for the development of antiviral drugs to combat human-pathogenic arenaviruses. PMID:21976642

  18. Activation of RNase L by Murine Coronavirus in Myeloid Cells Is Dependent on Basal Oas Gene Expression and Independent of Virus-Induced Interferon

    PubMed Central

    Birdwell, L. Dillon; Zalinger, Zachary B.; Li, Yize; Wright, Patrick W.; Elliott, Ruth; Rose, Kristine M.; Silverman, Robert H.

    2016-01-01

    ABSTRACT The oligoadenylate synthetase (OAS)-RNase L pathway is a potent interferon (IFN)-induced antiviral activity. Upon sensing double-stranded RNA, OAS produces 2′,5′-oligoadenylates (2-5A), which activate RNase L. Murine coronavirus (mouse hepatitis virus [MHV]) nonstructural protein 2 (ns2) is a 2′,5′-phosphodiesterase (PDE) that cleaves 2-5A, thereby antagonizing RNase L activation. PDE activity is required for robust replication in myeloid cells, as a mutant of MHV (ns2H126R) encoding an inactive PDE fails to antagonize RNase L activation and replicates poorly in bone marrow-derived macrophages (BMM), while ns2H126R replicates to high titer in several types of nonmyeloid cells, as well as in IFN receptor-deficient (Ifnar1−/−) BMM. We reported previously that myeloid cells express significantly higher basal levels of OAS transcripts than nonmyeloid cells. Here, we investigated the contributions of Oas gene expression, basal IFN signaling, and virus-induced IFN to RNase L activation. Infection with ns2H126R activated RNase L in Ifih1−/− BMM to a similar extent as in wild-type (WT) BMM, despite the lack of IFN induction in the absence of MDA5 expression. However, ns2H126R failed to induce RNase L activation in BMM treated with IFNAR1-blocking antibody, as well as in Ifnar1−/− BMM, both expressing low basal levels of Oas genes. Thus, activation of RNase L does not require virus-induced IFN but rather correlates with adequate levels of basal Oas gene expression, maintained by basal IFN signaling. Finally, overexpression of RNase L is not sufficient to compensate for inadequate basal OAS levels. IMPORTANCE The oligoadenylate synthetase (OAS)-RNase L pathway is a potent antiviral activity. Activation of RNase L during murine coronavirus (mouse hepatitis virus [MHV]) infection of myeloid cells correlates with high basal Oas gene expression and is independent of virus-induced interferon secretion. Thus, our data suggest that cells with high basal

  19. The IL-6 response to Chlamydia from primary reproductive epithelial cells is highly variable and may be involved in differential susceptibility to the immunopathological consequences of chlamydial infection

    PubMed Central

    2013-01-01

    Background Chlamydia trachomatis infection results in reproductive damage in some women. The process and factors involved in this immunopathology are not well understood. This study aimed to investigate the role of primary human cellular responses to chlamydial stress response proteases and chlamydial infection to further identify the immune processes involved in serious disease sequelae. Results Laboratory cell cultures and primary human reproductive epithelial cultures produced IL-6 in response to chlamydial stress response proteases (CtHtrA and CtTsp), UV inactivated Chlamydia, and live Chlamydia. The magnitude of the IL-6 response varied considerably (up to 1000 pg ml-1) across different primary human reproductive cultures. Thus different levels of IL-6 production by reproductive epithelia may be a determinant in disease outcome. Interestingly, co-culture models with either THP-1 cells or autologous primary human PBMC generally resulted in increased levels of IL-6, except in the case of live Chlamydia where the level of IL-6 was decreased compared to the epithelial cell culture only, suggesting this pathway may be able to be modulated by live Chlamydia. PBMC responses to the stress response proteases (CtTsp and CtHtrA) did not significantly vary for the different participant cohorts. Therefore, these proteases may possess conserved innate PAMPs. MAP kinases appeared to be involved in this IL-6 induction from human cells. Finally, we also demonstrated that IL-6 was induced by these proteins and Chlamydia from mouse primary reproductive cell cultures (BALB/C mice) and mouse laboratory cell models. Conclusions We have demonstrated that IL-6 may be a key factor for the chlamydial disease outcome in humans, given that primary human reproductive epithelial cell culture showed considerable variation in IL-6 response to Chlamydia or chlamydial proteins, and that the presence of live Chlamydia (but not UV killed) during co-culture resulted in a reduced IL-6 response

  20. Virus-Induced Gene Silencing Using Tobacco Rattle Virus as a Tool to Study the Interaction between Nicotiana attenuata and Rhizophagus irregularis

    PubMed Central

    Groten, Karin; Pahari, Nabin T.; Xu, Shuqing; Miloradovic van Doorn, Maja; Baldwin, Ian T.

    2015-01-01

    Most land plants live in a symbiotic association with arbuscular mycorrhizal fungi (AMF) that belong to the phylum Glomeromycota. Although a number of plant genes involved in the plant-AMF interactions have been identified by analyzing mutants, the ability to rapidly manipulate gene expression to study the potential functions of new candidate genes remains unrealized. We analyzed changes in gene expression of wild tobacco roots (Nicotiana attenuata) after infection with mycorrhizal fungi (Rhizophagus irregularis) by serial analysis of gene expression (SuperSAGE) combined with next generation sequencing, and established a virus-induced gene-silencing protocol to study the function of candidate genes in the interaction. From 92,434 SuperSAGE Tag sequences, 32,808 (35%) matched with our in-house Nicotiana attenuata transcriptome database and 3,698 (4%) matched to Rhizophagus genes. In total, 11,194 Tags showed a significant change in expression (p<0.05, >2-fold change) after infection. When comparing the functions of highly up-regulated annotated Tags in this study with those of two previous large-scale gene expression studies, 18 gene functions were found to be up-regulated in all three studies mainly playing roles related to phytohormone metabolism, catabolism and defense. To validate the function of identified candidate genes, we used the technique of virus-induced gene silencing (VIGS) to silence the expression of three putative N. attenuata genes: germin-like protein, indole-3-acetic acid-amido synthetase GH3.9 and, as a proof-of-principle, calcium and calmodulin-dependent protein kinase (CCaMK). The silencing of the three plant genes in roots was successful, but only CCaMK silencing had a significant effect on the interaction with R. irregularis. Interestingly, when a highly activated inoculum was used for plant inoculation, the effect of CCaMK silencing on fungal colonization was masked, probably due to trans-complementation. This study demonstrates that large

  1. Virus-Induced Gene Silencing Using Tobacco Rattle Virus as a Tool to Study the Interaction between Nicotiana attenuata and Rhizophagus irregularis.

    PubMed

    Groten, Karin; Pahari, Nabin T; Xu, Shuqing; Miloradovic van Doorn, Maja; Baldwin, Ian T

    2015-01-01

    Most land plants live in a symbiotic association with arbuscular mycorrhizal fungi (AMF) that belong to the phylum Glomeromycota. Although a number of plant genes involved in the plant-AMF interactions have been identified by analyzing mutants, the ability to rapidly manipulate gene expression to study the potential functions of new candidate genes remains unrealized. We analyzed changes in gene expression of wild tobacco roots (Nicotiana attenuata) after infection with mycorrhizal fungi (Rhizophagus irregularis) by serial analysis of gene expression (SuperSAGE) combined with next generation sequencing, and established a virus-induced gene-silencing protocol to study the function of candidate genes in the interaction. From 92,434 SuperSAGE Tag sequences, 32,808 (35%) matched with our in-house Nicotiana attenuata transcriptome database and 3,698 (4%) matched to Rhizophagus genes. In total, 11,194 Tags showed a significant change in expression (p<0.05, >2-fold change) after infection. When comparing the functions of highly up-regulated annotated Tags in this study with those of two previous large-scale gene expression studies, 18 gene functions were found to be up-regulated in all three studies mainly playing roles related to phytohormone metabolism, catabolism and defense. To validate the function of identified candidate genes, we used the technique of virus-induced gene silencing (VIGS) to silence the expression of three putative N. attenuata genes: germin-like protein, indole-3-acetic acid-amido synthetase GH3.9 and, as a proof-of-principle, calcium and calmodulin-dependent protein kinase (CCaMK). The silencing of the three plant genes in roots was successful, but only CCaMK silencing had a significant effect on the interaction with R. irregularis. Interestingly, when a highly activated inoculum was used for plant inoculation, the effect of CCaMK silencing on fungal colonization was masked, probably due to trans-complementation. This study demonstrates that large

  2. Herpes simplex virus 1 glycoprotein M and the membrane-associated protein UL11 are required for virus-induced cell fusion and efficient virus entry.

    PubMed

    Kim, In-Joong; Chouljenko, Vladimir N; Walker, Jason D; Kousoulas, Konstantin G

    2013-07-01

    Herpes simplex virus 1 (HSV-1) facilitates virus entry into cells and cell-to-cell spread by mediating fusion of the viral envelope with cellular membranes and fusion of adjacent cellular membranes. Although virus strains isolated from herpetic lesions cause limited cell fusion in cell culture, clinical herpetic lesions typically contain large syncytia, underscoring the importance of cell-to-cell fusion in virus spread in infected tissues. Certain mutations in glycoprotein B (gB), gK, UL20, and other viral genes drastically enhance virus-induced cell fusion in vitro and in vivo. Recent work has suggested that gB is the sole fusogenic glycoprotein, regulated by interactions with the viral glycoproteins gD, gH/gL, and gK, membrane protein UL20, and cellular receptors. Recombinant viruses were constructed to abolish either gM or UL11 expression in the presence of strong syncytial mutations in either gB or gK. Virus-induced cell fusion caused by deletion of the carboxyl-terminal 28 amino acids of gB or the dominant syncytial mutation in gK (Ala to Val at amino acid 40) was drastically reduced in the absence of gM. Similarly, syncytial mutations in either gB or gK did not cause cell fusion in the absence of UL11. Neither the gM nor UL11 gene deletion substantially affected gB, gC, gD, gE, and gH glycoprotein synthesis and expression on infected cell surfaces. Two-way immunoprecipitation experiments revealed that the membrane protein UL20, which is found as a protein complex with gK, interacted with gM while gM did not interact with other viral glycoproteins. Viruses produced in the absence of gM or UL11 entered into cells more slowly than their parental wild-type virus strain. Collectively, these results indicate that gM and UL11 are required for efficient membrane fusion events during virus entry and virus spread.

  3. Functional study of Capsicum annuum fatty acid desaturase 1 cDNA clone induced by Tobacco mosaic virus via microarray and virus-induced gene silencing.

    PubMed

    Kim, Ki-Jeong; Lim, Jee Hyuck; Lee, Sanghyeob; Kim, Young Jin; Choi, Soo Bok; Lee, Min Kyung; Choi, Doil; Paek, Kyung-Hee

    2007-10-26

    A series of microarray analyses employing the expressed sequence tags (ESTs) of hot pepper was conducted in an effort to elucidate the molecular mechanisms inherent to hypersensitive response (HR) by viral or bacterial pathogens. There were 2535 ESTs exhibiting differential expression (over 2-fold changes) among about 5000 ESTs during viral or bacterial response. Further, via virus-induced gene silencing (VIGS) and TMV-infection studies, we were able to isolate several ESTs, which may be relevant to defense response against TMV. Of these ESTs, Capsicum annuum fatty acid desaturase 1 (CaFAD1) showed the distinct phenotype against TMV infection and thus was subjected to further study. CaFAD1-silenced plants showed weaker resistance against TMV-P0 infection compared to TRV2 control plants. Also the suppression of FAD1 expression caused blocking of cell death induced by Bcl2-associated X (Bax) protein in tobacco plants. Therefore, this report presents that both microarray and VIGS approaches are feasible in hot pepper plants and the TMV-induced CaFAD1 plays a role in HR response.

  4. Development of an Efficient Virus Induced Gene Silencing Strategy in the Non-Model Wild Ginger-Zingiber zerumbet and Investigation of Associated Proteome Changes

    PubMed Central

    Mahadevan, Chidambareswaren; Jaleel, Abdul; Deb, Lokesh; Thomas, George; Sakuntala, Manjula

    2015-01-01

    Zingiber zerumbet (Zingiberaceae) is a wild, tropical medicinal herb that shows a high degree of resistance to diseases affecting cultivated ginger. Barley stripe mosaic virus (BSMV) silencing vectors containing an endogenous phytoene desaturase (PDS) gene fragment were agroinfiltrated into young leaves of Z. zerumbet under controlled growth conditions to effect virus-induced gene silencing (VIGS). Infiltrated leaves as well as newly emerged leaves and tillers showed visual signs of PDS silencing after 30 days. Replication and systemic movement of the viral vectors in silenced plants were confirmed by RT-PCR. Real-time quantitative PCR analysis verified significant down-regulation of PDS transcripts in the silenced tissues. Label-free proteomic analysis was conducted in leaves with established PDS transcript down regulation and buffer-infiltrated (mock) leaves. A total of 474 proteins were obtained, which were up-regulated, down-regulated or modulated de novo during VIGS. Most of these proteins were localized to the chloroplast, as revealed by UniprotKB analysis, and among the up-regulated proteins there were abiotic stress responsive, photosynthetic, metabolic and membrane proteins. Moreover, the demonstration of viral proteins together with host proteins proved successful viral infection. We report for the first time the establishment of a high-throughput gene functional analysis platform using BSMV-mediated VIGS in Z. zerumbet, as well as proteomic changes associated with VIGS. PMID:25918840

  5. Virus-induced gene silencing is a versatile tool for unraveling the functional relevance of multiple abiotic-stress-responsive genes in crop plants

    PubMed Central

    Ramegowda, Venkategowda; Mysore, Kirankumar S.; Senthil-Kumar, Muthappa

    2014-01-01

    Virus-induced gene silencing (VIGS) is an effective tool for gene function analysis in plants. Over the last decade, VIGS has been successfully used as both a forward and reverse genetics technique for gene function analysis in various model plants, as well as crop plants. With the increased identification of differentially expressed genes under various abiotic stresses through high-throughput transcript profiling, the application of VIGS is expected to be important in the future for functional characterization of a large number of genes. In the recent past, VIGS was proven to be an elegant tool for functional characterization of genes associated with abiotic stress responses. In this review, we provide an overview of how VIGS is used in different crop species to characterize genes associated with drought-, salt-, oxidative- and nutrient-deficiency-stresses. We describe the examples from studies where abiotic stress related genes are characterized using VIGS. In addition, we describe the major advantages of VIGS over other currently available functional genomics tools. We also summarize the recent improvements, limitations and future prospects of using VIGS as a tool for studying plant responses to abiotic stresses. PMID:25071806

  6. Virus-induced gene silencing identifies Catharanthus roseus 7-deoxyloganic acid-7-hydroxylase, a step in iridoid and monoterpene indole alkaloid biosynthesis.

    PubMed

    Salim, Vonny; Yu, Fang; Altarejos, Joaquín; De Luca, Vincenzo

    2013-12-01

    Iridoids are a major group of biologically active molecules that are present in thousands of plant species, and one versatile iridoid, secologanin, is a precursor for the assembly of thousands of monoterpenoid indole alkaloids (MIAs) as well as a number of quinoline alkaloids. This study uses bioinformatics to screen large databases of annotated transcripts from various MIA-producing plant species to select candidate genes that may be involved in iridoid biosynthesis. Virus-induced gene silencing of the selected genes combined with metabolite analyses of silenced plants was then used to identify the 7-deoxyloganic acid 7-hydroxylase (CrDL7H) that is involved in the 3rd to last step in secologanin biosynthesis. Silencing of CrDL7H reduced secologanin levels by at least 70%, and increased the levels of 7-deoxyloganic acid to over 4 mg g(-1) fresh leaf weight compared to control plants in which this iridoid is not detected. Functional expression of this CrDL7H in yeast confirmed its biochemical activity, and substrate specificity studies showed its preference for 7-deoxyloganic acid over other closely related substrates. Together, these results suggest that hydroxylation precedes carboxy-O-methylation in the secologanin pathway in Catharanthus roseus.

  7. Optimization of automated segmentation of monkeypox virus-induced lung lesions from normal lung CT images using hard C-means algorithm

    NASA Astrophysics Data System (ADS)

    Castro, Marcelo A.; Thomasson, David; Avila, Nilo A.; Hufton, Jennifer; Senseney, Justin; Johnson, Reed F.; Dyall, Julie

    2013-03-01

    Monkeypox virus is an emerging zoonotic pathogen that results in up to 10% mortality in humans. Knowledge of clinical manifestations and temporal progression of monkeypox disease is limited to data collected from rare outbreaks in remote regions of Central and West Africa. Clinical observations show that monkeypox infection resembles variola infection. Given the limited capability to study monkeypox disease in humans, characterization of the disease in animal models is required. A previous work focused on the identification of inflammatory patterns using PET/CT image modality in two non-human primates previously inoculated with the virus. In this work we extended techniques used in computer-aided detection of lung tumors to identify inflammatory lesions from monkeypox virus infection and their progression using CT images. Accurate estimation of partial volumes of lung lesions via segmentation is difficult because of poor discrimination between blood vessels, diseased regions, and outer structures. We used hard C-means algorithm in conjunction with landmark based registration to estimate the extent of monkeypox virus induced disease before inoculation and after disease progression. Automated estimation is in close agreement with manual segmentation.

  8. Virus-induced silencing of Comt, pAmt and Kas genes results in a reduction of capsaicinoid accumulation in chili pepper fruits.

    PubMed

    del Rosario Abraham-Juárez, Ma; del Carmen Rocha-Granados, Ma; López, Mercedes G; Rivera-Bustamante, Rafael Francisco; Ochoa-Alejo, Neftalí

    2008-02-01

    Capsaicinoids are responsible for the pungent taste of chili pepper fruits of Capsicum species. Capsaicinoids are biosynthesized through both the phenylpropanoid and the branched-fatty acids pathways. Fragments of Comt (encoding a caffeic acid O-methyltransferase), pAmt (a putative aminotransferase), and Kas (a beta-keto-acyl-[acyl-carrier-protein] synthase) genes, that are differentially expressed in placenta tissue of pungent chili pepper, were individually inserted into a Pepper huasteco yellow veins virus (PHYVV)-derived vector to determine, by virus-induced gene silencing, irrespective of whether these genes are involved in the biosynthesis of capsaicinoids. Reduction of the respective mRNA levels as well as the presence of related siRNAs confirmed the silencing of these three genes. Morphological alterations were evident in plants inoculated with PHYVV::Comt and PHYVV::Kas constructs; however, plants inoculated with PHYVV::pAmt showed no evident alterations. On the other hand, fruit setting was normal in all cases. Biochemical analysis of placenta tissues showed that, indeed, independent silencing of all three genes led to a dramatic reduction in capsaicinoid content in the fruits demonstrating the participation of these genes in capsaicinoid biosynthesis. Using this approach it was possible to generate non-pungent chili peppers at high efficiency.

  9. Virus-induced gene silencing reveals control of reactive oxygen species accumulation and salt tolerance in tomato by γ-aminobutyric acid metabolic pathway.

    PubMed

    Bao, Hexigeduleng; Chen, Xianyang; Lv, Sulian; Jiang, Ping; Feng, Juanjuan; Fan, Pengxiang; Nie, Lingling; Li, Yinxin

    2015-03-01

    γ-Aminobutyric acid (GABA) accumulates in many plant species in response to environmental stress. However, the physiological function of GABA or its metabolic pathway (GABA shunt) in plants remains largely unclear. Here, the genes, including glutamate decarboxylases (SlGADs), GABA transaminases (SlGABA-Ts) and succinic semialdehyde dehydrogenase (SlSSADH), controlling three steps of the metabolic pathway of GABA, were studied through virus-induced gene silencing approach in tomato. Silencing of SlGADs (GABA biosynthetic genes) and SlGABA-Ts (GABA catabolic genes) led to increased accumulation of reactive oxygen species (ROS) as well as salt sensitivity under 200 mm NaCl treatment. Targeted quantitative analysis of metabolites revealed that GABA decreased and increased in the SlGADs- and SlGABA-Ts-silenced plants, respectively, whereas succinate (the final product of GABA metabolism) decreased in both silenced plants. Contrarily, SlSSADH-silenced plants, also defective in GABA degradation process, showed dwarf phenotype, curled leaves and enhanced accumulation of ROS in normal conditions, suggesting the involvement of a bypath for succinic semialdehyde catabolism to γ-hydroxybutyrate as reported previously in Arabidopsis, were less sensitive to salt stress. These results suggest that GABA shunt is involved in salt tolerance of tomato, probably by affecting the homeostasis of metabolites such as succinate and γ-hydroxybutyrate and subsequent ROS accumulation under salt stress.

  10. Virus-induced gene silencing of the RPC5-like subunit of RNA polymerase III caused pleiotropic effects in Nicotiana benthamiana

    PubMed Central

    Nemchinov, Lev G.; Boutanaev, Alexander M.; Postnikova, Olga A.

    2016-01-01

    In eukaryotic cells, RNA polymerase III is highly conserved and transcribes housekeeping genes such as ribosomal 5S rRNA, tRNA and other small RNAs. The RPC5-like subunit is one of the 17 subunits forming RNAPIII and its exact functional roles in the transcription are poorly understood. In this work, we report that virus-induced gene silencing of transcripts encoding a putative RPC5-like subunit of the RNA Polymerase III in a model species Nicotiana benthamiana had pleiotropic effects, including but not limited to severe dwarfing appearance, chlorosis, nearly complete reduction of internodes and abnormal leaf shape. Using transcriptomic analysis, we identified genes and pathways affected by RPC5 silencing and thus presumably related to the cellular roles of the subunit as well as to the downstream cascade of reactions in response to partial loss of RNA Polymerase III function. Our results suggest that silencing of the RPC5L in N. benthamiana disrupted not only functions commonly associated with the core RNA Polymerase III transcripts, but also more diverse cellular processes, including responses to stress. We believe this is the first demonstration that activity of the RPC5 subunit is critical for proper functionality of RNA Polymerase III and normal plant development. PMID:27282827

  11. Antibodies to P-selectin glycoprotein ligand-1 block dendritic cell-mediated enterovirus 71 transmission and prevent virus-induced cells death.

    PubMed

    Ren, Xiao-Xin; Li, Chuan; Xiong, Si-Dong; Huang, Zhong; Wang, Jian-Hua; Wang, Hai-Bo

    2015-01-01

    P-selectin glycoprotein ligand-1 (PSGL-1) has been proved to serve as the functional receptor for enterovirus 71 (EV71). We found the abundant expression of PSGL-1 on monocyte-derived dendritic cells (MDDCs). However, we have previously demonstrated that MDDCs did not support efficient replication of EV71. Dendritic cells (DCs) have been described to be subverted by various viruses including EV71 for viral dissemination, we thus explore the potential contribution of PSGL-1 on DC-mediated EV71 transmission. We found that the cell-surface-expressing PSGL-1 on MDDCs mediated EV71 binding, and intriguingly, these loaded-viruses on MDDCs could be transferred to encountered target cells; Prior-treatment with PSGL-1 antibodies or interference with PSGL-1 expression diminished MDDC-mediated EV71 transfer and rescued virus-induced cell death. Our data uncover a novel role of PSGL-1 in DC-mediated EV71 spread, and provide an insight into blocking primary EV71 infection.

  12. pol-miR-731, a teleost miRNA upregulated by megalocytivirus, negatively regulates virus-induced type I interferon response, apoptosis, and cell cycle arrest

    PubMed Central

    Zhang, Bao-cun; Zhou, Ze-jun; Sun, Li

    2016-01-01

    Megalocytivirus is a DNA virus that is highly infectious in a wide variety of marine and freshwater fish, including Japanese flounder (Paralichthys olivaceus), a flatfish that is farmed worldwide. However, the infection mechanism of megalocytivirus remains largely unknown. In this study, we investigated the function of a flounder microRNA, pol-miR-731, in virus-host interaction. We found that pol-miR-731 was induced in expression by megalocytivirus and promoted viral replication at the early infection stage. In vivo and in vitro studies revealed that pol-miR-731 (i) specifically suppresses the expression of interferon regulatory factor 7 (IRF7) and cellular tumor antigen p53 in a manner that depended on the integrity of the pol-miR-731 complementary sequences in the 3′ untranslated regions of IRF7 and p53, (ii) disrupts megalocytivirus-induced Type I interferon response through IRF7, (iii) inhibits megalocytivirus-induced splenocyte apoptosis and cell cycle arrest through p53. Furthermore, overexpression of IRF7 and p53 abolished both the inhibitory effects of pol-miR-731 on these biological processes and its stimulatory effect on viral replication. These results disclosed a novel evasion mechanism of megalocytivirus mediated by a host miRNA. This study also provides the first evidence that a virus-induced host miRNA can facilitate viral infection by simultaneously suppressing several antiviral pathways. PMID:27311682

  13. Activation of the c-H-ras proto-oncogene by retrovirus insertion and chromosomal rearrangement in a Moloney leukemia virus-induced T-cell leukemia.

    PubMed Central

    Ihle, J N; Smith-White, B; Sisson, B; Parker, D; Blair, D G; Schultz, A; Kozak, C; Lunsford, R D; Askew, D; Weinstein, Y

    1989-01-01

    A rearrangement of the c-H-ras locus was detected in a T-cell line (DA-2) established from a Moloney leukemia virus-induced tumor. This rearrangement was associated with the high-level expression of H-ras RNA and the H-ras gene product, p21. DNA from DA-2 cells transformed fibroblasts in DNA transfection experiments, and the transformed fibroblasts contained the rearranged H-ras locus. The rearrangement involved one allele and was present in tissue from the primary tumor from which the cell line was isolated. Cloning and sequencing of the rearranged allele and comparison with the normal allele demonstrated that the rearrangement was complex and probably resulted from the integration of a retrovirus in the H-ras locus between a 5' noncoding exon and the first coding exon and a subsequent homologous recombination between this provirus and another newly acquired provirus also located on chromosome 7. These events resulted in the translocation of the coding exons of the H-ras locus away from the 5' noncoding exon region to a new genomic site on chromosome 7. Sequencing of the coding regions of the gene failed to detect mutations in the 12th, 13th, 59th, or 61st codons. The possible reasons for the complexity of the rearrangement and the significance of the activation of the H-ras locus to T-cell transformation are discussed. Images PMID:2542606

  14. Out-of-Sequence Signal 3 as a Mechanism for Virus-Induced Immune Suppression of CD8 T Cell Responses

    PubMed Central

    Urban, Stina L.; Welsh, Raymond M.

    2014-01-01

    Virus infections are known to induce a transient state of immune suppression often associated with an inhibition of T cell proliferation in response to mitogen or cognate-antigen stimulation. Recently, virus-induced immune suppression has been linked to responses to type 1 interferon (IFN), a signal 3 cytokine that normally can augment the proliferation and differentiation of T cells exposed to antigen (signal 1) and co-stimulation (signal 2). However, pre-exposure of CD8 T cells to IFN-inducers such as viruses or poly(I∶C) prior to antigen signaling is inhibitory, indicating that the timing of IFN exposure is of essence. We show here that CD8 T cells pretreated with poly(I∶C) down-regulated the IFN receptor, up-regulated suppressor of cytokine signaling 1 (SOCS1), and were refractory to IFNβ-induced signal transducers and activators of transcription (STAT) phosphorylation. When exposed to a viral infection, these CD8 T cells behaved more like 2-signal than 3-signal T cells, showing defects in short lived effector cell differentiation, reduced effector function, delayed cell division, and reduced levels of survival proteins. This suggests that IFN-pretreated CD8 T cells are unable to receive the positive effects that type 1 IFN provides as a signal 3 cytokine when delivered later in the signaling process. This desensitization mechanism may partially explain why vaccines function poorly in virus-infected individuals. PMID:25255454

  15. Characterization of the Rana grylio virus 3{beta}-hydroxysteroid dehydrogenase and its novel role in suppressing virus-induced cytopathic effect

    SciTech Connect

    Sun Wei; Huang Youhua; Zhao Zhe; Gui Jianfang; Zhang Qiya . E-mail: zhangqy@ihb.ac.cn

    2006-12-08

    The 3{beta}-hydroxysteroid dehydrogenase (3{beta}-HSD) isoenzymes play a key role in cellular steroid hormone synthesis. Here, a 3{beta}-HSD gene homolog was cloned from Rana grylio virus (RGV), a member of family Iridoviridae. RGV 3{beta}-HSD gene has 1068 bp, encoding a 355 aa predicted protein. Transcription analyses showed that RGV 3{beta}-HSD gene was transcribed immediate-early during infection from an initiation site 19 nucleotides upstream of the translation start site. Confocal microscopy revealed that the 3{beta}-HSD-EGFP fusion protein was exclusively colocalized with the mitochondria marker (pDsRed2-Mito) in EPC cells. Upon morphological observation and MTT assay, it was revealed that overexpression of RGV 3{beta}-HSD in EPC cells could apparently suppress RGV-induced cytopathic effect (CPE). The present studies indicate that the RGV immediate-early 3{beta}-HSD gene encodes a mitochondria-localized protein, which has a novel role in suppressing virus-induced CPE. All these suggest that RGV 3{beta}-HSD might be a protein involved in host-virus interaction.

  16. Epstein-Barr Virus-Induced Gene 3 (EBI3): A Novel Diagnosis Marker in Burkitt Lymphoma and Diffuse Large B-Cell Lymphoma

    PubMed Central

    Bastard, Christian; Picquenot, Jean-Michel; Couturier, Jérôme; Radford-Weiss, Isabelle; Dietrich, Céline; Brousse, Nicole; Vacher-Lavenu, Marie-Cécile; Devergne, Odile

    2011-01-01

    The distinction between Burkitt lymphoma (BL) and diffuse large B-cell lymphoma (DLBCL), two types of mature aggressive B-cell lymphomas that require distinct treatments, can be difficult because of forms showing features intermediate between DLBCL and BL (here called BL/DLBCL). They can be discriminated by the presence of c-myc translocations characteristic of BL. However, these are not exclusive of BL and when present in DLBCL are associated with lower survival. In this study, we show that Epstein-Barr virus-induced gene 3 (EBI3) is differentially expressed among BL and DLBCL. Analysis of gene expression data from 502 cases of aggressive mature B-cell lymphomas available on Gene Expression Omnibus and immunohistochemical analysis of 184 cases of BL, BL/DLBCL or DLBCL, showed that EBI3 was not expressed in EBV-positive or -negative BL cases, whereas it was expressed by over 30% of tumoral cells in nearly 80% of DLBCL cases, independently of their subtypes. In addition, we show that c-myc overexpression represses EBI3 expression, and that DLBCL or BL/DLBCL cases with c-myc translocations have lower expression of EBI3. Thus, EBI3 immunohistochemistry could be useful to discriminate BL from DLBCL, and to identify cases of BL/DLBCL or DLBCL with potential c-myc translocations. PMID:21931777

  17. A new mechanism of vitamin C effects on A/FM/1/47(H1N1) virus-induced pneumonia in restraint-stressed mice.

    PubMed

    Cai, Ying; Li, Yi-Fang; Tang, Lu-Ping; Tsoi, Bun; Chen, Min; Chen, Huan; Chen, Xiao-Mei; Tan, Rui-Rong; Kurihara, Hiroshi; He, Rong-Rong

    2015-01-01

    It is well known that vitamin C could protect against influenza infection, but little is known about the mechanisms. This study aimed to investigate the influence and possible mechanisms of vitamin C on pneumonia induced by influenza virus in stressed mice. Results showed that restraint stress significantly increased the mortality and the severity of pneumonia in mice caused by A/FM/1/47(H1N1) virus infection, which was attenuated by oral administration of vitamin C (125 and 250 mg/kg). Moreover, vitamin C administration significantly decreased expression of susceptibility genes, including mitochondrial antiviral signaling (MAVS) and interferon regulatory factor 3 (IRF3), and increased expression of NF-κB. These work in conjunction to induce type I interferons (IFNs) and elicit innate antiviral response as key factors in RIG-I-mediated signal transduction pathway. The above effects of vitamin C were further found to relate with inhibition of excess CORT synthesis by regulating steroid hydroxylating enzymes in adrenal gland. In conclusion, the protective effects of vitamin C on influenza virus-caused pneumonia might be related to its inhibition of CORT synthesis, which reduces the susceptibility to influenza viral infection in restraint-stressed mice. These findings provide a new mechanism for the effects of vitamin C on influenza virus-induced pneumonia in restraint-stressed mice.

  18. Virus-induced gene silencing is an effective tool for assaying gene function in the basal eudicot species Papaver somniferum (opium poppy).

    PubMed

    Hileman, Lena C; Drea, Sinéad; Martino, Gemma; Litt, Amy; Irish, Vivian F

    2005-10-01

    Virus-induced gene silencing (VIGS) is an attractive method for assaying gene function in species that are resistant to conventional genetic approaches. However, VIGS has been shown to be effective in only a few, closely related plant species. Tobacco rattle virus (TRV), a bipartite RNA virus, has a wide host range and so in principle could serve as an efficient vector for VIGS in a diverse array of plant species. Here we show that a vector based on TRV sequences is effective at silencing the endogenous phytoene desaturase (PapsPDS) gene in Papaver somniferum (opium poppy). We show that this vector does not compromise the growth or reproduction of poppy and the plants did not display viral symptoms. The silencing of PapsPDS resulted in a significant reduction in PapsPDS mRNA and a concomitant photobleached phenotype. The ability to rapidly assay gene function in P. somniferum will be valuable in manipulation of the opiate pathway in this pharmaceutically important species. We suggest that our vacuum infiltration method used to deliver TRV-based vectors into poppy is a promising approach for expanding VIGS to diverse angiosperm species in which traditional delivery methods fail to induce VIGS. Furthermore, these studies demonstrate the utility of TRV-VIGS for probing gene function in a basal eudicot species that is phylogenetically distant from model plant species.

  19. Development of tobacco ringspot virus-based vectors for foreign gene expression and virus-induced gene silencing in a variety of plants.

    PubMed

    Zhao, Fumei; Lim, Seungmo; Igori, Davaajargal; Yoo, Ran Hee; Kwon, Suk-Yoon; Moon, Jae Sun

    2016-05-01

    We report here the development of tobacco ringspot virus (TRSV)-based vectors for the transient expression of foreign genes and for the analysis of endogenous gene function in plants using virus-induced gene silencing. The jellyfish green fluorescent protein (GFP) gene was inserted between the TRSV movement protein (MP) and coat protein (CP) regions, resulting in high in-frame expression of the RNA2-encoded viral polyprotein. GFP was released from the polyprotein via an N-terminal homologous MP-CP cleavage site and a C-terminal foot-and-mouth disease virus (FMDV) 2 A catalytic peptide in Nicotiana benthamiana. The VIGS target gene was introduced in the sense and antisense orientations into a SnaBI site, which was created by mutating the sequence following the CP stop codon. VIGS of phytoene desaturase (PDS) in N. benthamiana, Arabidopsis ecotype Col-0, cucurbits and legumes led to obvious photo-bleaching phenotypes. A significant reduction in PDS mRNA levels in silenced plants was confirmed by semi-quantitative RT-PCR.

  20. Ubiquitin-specific Protease 15 Negatively Regulates Virus-induced Type I Interferon Signaling via Catalytically-dependent and -independent Mechanisms

    PubMed Central

    Zhang, Huan; Wang, Dang; Zhong, Huijuan; Luo, Rui; Shang, Min; Liu, Dezhi; Chen, Huanchun; Fang, Liurong; Xiao, Shaobo

    2015-01-01

    Viral infection triggers a series of signaling cascades, which converge to activate the transcription factors nuclear factor-κB (NF-κB) and interferon regulatory factor 3 (IRF3), thereby inducing the transcription of type I interferons (IFNs). Although not fully characterized, these innate antiviral responses are fine-tuned by dynamic ubiquitination and deubiquitination processes. In this study, we report ubiquitin-specific protease (USP) 15 is involved in regulation of the retinoic acid-inducible gene I (RIG-I)-dependent type I IFN induction pathway. Knockdown of endogenous USP15 augmented cellular antiviral responses. Overexpression of USP15 inhibited the transcription of IFN-β. Further analyses identified histidine 862 as a critical residue for USP15’s catalytic activity. Interestingly, USP15 specifically removed lysine 63-linked polyubiquitin chains from RIG-I among the essential components in RIG-I-like receptor-dependent pathway. In addition, we demonstrated that in contrast to USP15 de-ubiquitinating (DUB) activity, USP15-mediated inhibition of IFN signaling was not abolished by mutations eliminating the catalytic activity, indicating that a fraction of USP15-mediated IFN antagonism was independent of the DUB activity. Catalytically inactive USP15 mutants, as did the wild-type protein, disrupted virus-induced interaction of RIG-I and IFN-β promoter stimulator 1. Taken together, our data demonstrate that USP15 acts as a negative regulator of RIG-I signaling via DUB-dependent and independent mechanisms. PMID:26061460

  1. Utilizing virus-induced gene silencing for the functional characterization of maize genes during infection with the fungal pathogen Ustilago maydis.

    PubMed

    van der Linde, Karina; Doehlemann, Gunther

    2013-01-01

    While in dicotyledonous plants virus-induced gene silencing (VIGS) is well established to study plant-pathogen interaction, in monocots only few examples of efficient VIGS have been reported so far. One of the available systems is based on the brome mosaic virus (BMV) which allows gene silencing in different cereals including barley (Hordeum vulgare), wheat (Triticum aestivum), and maize (Zea mays).Infection of maize plants by the corn smut fungus Ustilago maydis leads to the formation of large tumors on stem, leaves, and inflorescences. During this biotrophic interaction, plant defense responses are actively suppressed by the pathogen, and previous transcriptome analyses of infected maize plants showed comprehensive and stage-specific changes in host gene expression during disease progression.To identify maize genes that are functionally involved in the interaction with U. maydis, we adapted a VIGS system based on the Brome mosaic virus (BMV) to maize at conditions that allow successful U. maydis infection of BMV pre-infected maize plants. This setup enables quantification of VIGS and its impact on U. maydis infection using a quantitative real-time PCR (q(RT)-PCR)-based readout.

  2. Aqueous extract of the edible Gracilaria tenuistipitata inhibits hepatitis C viral replication via cyclooxygenase-2 suppression and reduces virus-induced inflammation.

    PubMed

    Chen, Kuan-Jen; Tseng, Chin-Kai; Chang, Fang-Rong; Yang, Jin-Iong; Yeh, Chi-Chen; Chen, Wei-Chun; Wu, Shou-Fang; Chang, Hsueh-Wei; Lee, Jin-Ching

    2013-01-01

    Hepatitis C virus (HCV) is an important human pathogen leading to hepatocellular carcinoma. Using an in vitro cell-based HCV replicon and JFH-1 infection system, we demonstrated that an aqueous extract of the seaweed Gracilaria tenuistipitata (AEGT) concentration-dependently inhibited HCV replication at nontoxic concentrations. AEGT synergistically enhanced interferon-α (IFN-α) anti-HCV activity in a combination treatment. We found that AEGT also significantly suppressed virus-induced cyclooxygenase-2 (COX-2) expression at promoter transactivation and protein levels. Notably, addition of exogenous COX-2 expression in AEGT-treated HCV replicon cells gradually abolished AEGT anti-HCV activity, suggesting that COX-2 down-regulation was responsible for AEGT antiviral effects. Furthermore, we highlighted the inhibitory effect of AEGT in HCV-induced pro-inflammatory gene expression such as the expression of tumour necrosis factor-α, interleukin-1β, inducible nitrite oxide synthase and COX-2 in a concentration-dependent manner to evaluate the potential therapeutic supplement in the management of patients with chronic HCV infections.

  3. Development of tobacco ringspot virus-based vectors for foreign gene expression and virus-induced gene silencing in a variety of plants.

    PubMed

    Zhao, Fumei; Lim, Seungmo; Igori, Davaajargal; Yoo, Ran Hee; Kwon, Suk-Yoon; Moon, Jae Sun

    2016-05-01

    We report here the development of tobacco ringspot virus (TRSV)-based vectors for the transient expression of foreign genes and for the analysis of endogenous gene function in plants using virus-induced gene silencing. The jellyfish green fluorescent protein (GFP) gene was inserted between the TRSV movement protein (MP) and coat protein (CP) regions, resulting in high in-frame expression of the RNA2-encoded viral polyprotein. GFP was released from the polyprotein via an N-terminal homologous MP-CP cleavage site and a C-terminal foot-and-mouth disease virus (FMDV) 2 A catalytic peptide in Nicotiana benthamiana. The VIGS target gene was introduced in the sense and antisense orientations into a SnaBI site, which was created by mutating the sequence following the CP stop codon. VIGS of phytoene desaturase (PDS) in N. benthamiana, Arabidopsis ecotype Col-0, cucurbits and legumes led to obvious photo-bleaching phenotypes. A significant reduction in PDS mRNA levels in silenced plants was confirmed by semi-quantitative RT-PCR. PMID:26950504

  4. The Role of T Cell Immunoglobulin Mucin Domains 1 and 4 in a Herpes Simplex Virus-Induced Behçet's Disease Mouse Model

    PubMed Central

    Shim, Ju A.

    2013-01-01

    The T cell immunoglobulin mucin (TIM) proteins regulate T cell activation and tolerance. TIM-1 plays an important role in the regulation of immune responses and the development of autoimmune diseases. TIM-4 is a natural ligand of TIM-1, and the interaction of TIM-1 and TIM-4 is involved in the regulation of T helper (Th) cell responses and modulation of the Th1/Th2 cytokine balance. Behçet's disease (BD) is a chronic, multisystemic inflammatory disorder with arthritic, intestinal, mucocutaneous, ocular, vascular, and central nervous system involvement. Tim-1 expression was lower in a herpes simplex virus-induced BD mouse model compared to that in asymptomatic BD normal (BDN) mice. Tim-4 expression was higher in BD mice than that in BDN mice. In this study, we investigated the Tim expression in a BD mouse model with BD-like symptoms. Tim-1 and Tim-4 expression was regulated by an expression vector or siRNA injected into the BD mouse model. The Tim-1 vector injected into BD mice resulted in changes in BD-like symptoms and decreased the severity score. Treatment with Tim-4 siRNA also improved BD-like symptoms and decreased the severity score accompanied by upregulation of regulatory T cells. We showed that regulating Tim-1 or Tim-4 affected BD-like symptoms in mice. PMID:24453431

  5. Singapore grouper iridovirus, a large DNA virus, induces nonapoptotic cell death by a cell type dependent fashion and evokes ERK signaling.

    PubMed

    Huang, Xiaohong; Huang, Youhua; Ouyang, Zhengliang; Xu, Lixiao; Yan, Yang; Cui, Huachun; Han, Xin; Qin, Qiwei

    2011-08-01

    Virus induced cell death, including apoptosis and nonapoptotic cell death, plays a critical role in the pathogenesis of viral diseases. Singapore grouper iridovirus (SGIV), a novel iridovirus of genus Ranavirus, causes high mortality and heavy economic losses in grouper aquaculture. Here, using fluorescence microscopy, electron microscopy and biochemical assays, we found that SGIV infection in host (grouper spleen, EAGS) cells evoked nonapoptotic programmed cell death (PCD), characterized by appearance of cytoplasmic vacuoles and distended endoplasmic reticulum, in the absence of DNA fragmentation, apoptotic bodies and caspase activation. In contrast, SGIV induced typical apoptosis in non-host (fathead minnow, FHM) cells, as evidenced by caspase activation and DNA fragmentation, suggesting that SGIV infection induced nonapoptotic cell death by a cell type dependent fashion. Furthermore, viral replication was essential for SGIV induced nonapoptotic cell death, but not for apoptosis. Notably, the disruption of mitochondrial transmembrane potential (ΔΨm) and externalization of phosphatidylserine (PS) were not detected in EAGS cells but in FHM cells after SGIV infection. Moreover, the extracellular signal-regulated kinase (ERK) signaling was involved in SGIV infection induced nonapoptotic cell death and viral replication. This is a first demonstration of ERK-mediated nonapoptotic cell death induced by a DNA virus. These findings contribute to understanding the mechanisms of iridovirus pathogenesis.

  6. Overexpression of Epstein-Barr virus-induced gene 3 protein (EBI3) in MRL/lpr mice suppresses their lupus nephritis by activating regulatory T cells.

    PubMed

    Shinsuke, Nishimura; Hiroshi, Inoue

    2013-11-01

    To identify the effect of an imbalance of Th1/Th2 cytokines on the development of autoimmune glomerulonephritis (lupus nephritis), we studied the modification of pathological changes in diffuse proliferative glomerulonephritis (DPGN) and membranous glomerulonephritis (MGN) in MRL/lpr mice, which are animal models of systemic lupus erythematosus (SLE). Transgenic MRL/lpr mice (Tg) that overexpressed Epstein--Barr virus-induced gene 3 (EBI3) showed almost normal renal function, which was demonstrated by healing of glomerulonephritis upon renal histology, as compared to the wild-type MRL/lpr (Wt) mice. The levels of anti-dsDNA antibodies and IgE decreased in the Tg mice compared to Wt mice. Quantitative real-time PCR indicated an increase in the mRNA levels of FoxP3, and a decrease in that of IFNγ in the splenocytes of Tg mice as compared to Wt mice. In addition, flow cytometric analysis showed an increase in CD4(+)CD25(+)FoxP3(+)-T cells in the former, as compared to the latter. Our findings suggest that EBI3-overexpression in MRL/lpr mice induces generation of regulatory T cells, which causes suppression of autoimmune and inflammatory reactions by affecting the Th1/Th2 cytokine balance. PMID:23845089

  7. Self-renewal of leukemia stem cells in Friend virus-induced erythroleukemia requires proviral insertional activation of Spi1 and hedgehog signaling but not mutation of p53.

    PubMed

    Hegde, Shailaja; Hankey, Pamela; Paulson, Robert F

    2012-02-01

    Friend virus induces erythroleukemia through a characteristic two-stage progression. The prevailing model proposes that during the initial, polyclonal stage of disease most of the infected cells terminally differentiate, resulting in acute erythrocytosis. In the late stage of disease, a clonal leukemia develops through the acquisition of new mutations--proviral insertional activation of Spi1/Pu.1 and mutation of p53. Previous work from our laboratory demonstrated that Friend virus activates the bone morphogenic protein 4 (BMP4)-dependent stress erythropoiesis pathway, which leads to the rapid expansion of stress erythroid progenitors, which are the targets for Friend virus in the spleen. We recently showed that stress erythroid progenitors have intrinsic self-renewal ability and therefore could function as leukemia stem cells (LSCs) when infected with Friend virus. Here, we show that the two stages of Friend virus-induced disease are caused by infection of distinct stress progenitor populations in the spleen. The development of leukemia relies on the ability of the virus to hijack the intrinsic self-renewal capability of stress erythroid progenitors leading to the generation of LSCs. Two signals are required for the self-renewal of Friend virus LSCs proviral insertional activation of Spi1/Pu.1 and Hedgehog-dependent signaling. Surprisingly, mutation of p53 is not observed in LSCs. These data establish a new model for Friend virus-induced erythroleukemia and demonstrate the utility of Friend virus as a model system to study LSC self-renewal.

  8. Immunopathologic aspects of woodchuck hepatitis.

    PubMed Central

    Frommel, D.; Crevat, D.; Vitvitsky, L.; Pichoud, C.; Hantz, O.; Chevalier, M.; Grimaud, J. A.; Lindberg, J.; Trépo, C. G.

    1984-01-01

    The natural history of infection with woodchuck hepatitis virus (WHV) has been studied in a colony of 38 Marmota monax. Besides serologic assessment for WHV markers, light-microscopic findings of 61 liver biopsies were correlated with the results of immunofluorescence analysis for nucleocapsid (WHcAg) and surface (WHsAg) antigens. Twenty-four chronic WHsAg carriers all featured signs of continuous viral replication. Two major immunomorphologic patterns were observed in their livers: 1) portal hepatitis in which WHcAg accumulated in the cytoplasm and WHsAg was associated with the hepatocyte membrane and 2) periportal hepatitis in which WHcAg shifted toward nuclear localization and WHsAg became mostly intracytoplasmic. Progression from portal to periportal hepatitis, observed in 7 woodchucks, appeared to be induced by a partial recovery of specific immune reactivity to WHV, insufficient, however, to interrupt WHV replication. Deposits of WHsAg and immunoglobulins were present in the kidney and spleen of animals with severe hepatitis. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 PMID:6324594

  9. Immunopathology in Taenia solium neurocysticercosis.

    PubMed

    Fleury, A; Cardenas, G; Adalid-Peralta, L; Fragoso, G; Sciutto, E

    2016-03-01

    Neurocysticercosis is a clinically and radiologically heterogeneous disease, ranging from asymptomatic infection to a severe, potentially fatal clinical picture. The intensity and extension of the parasite-elicited inflammatory reaction is a key factor for such variability. The main features of the inflammatory process found in the brain and in the peripheral blood of neurocysticercosis patients will be discussed in this review, and the factors involved in its modulation will be herein presented. PMID:26667781

  10. Immunopathology of experimental cutaneous leishmaniasis.

    PubMed Central

    Andrade, Z. A.; Reed, S. G.; Roters, S. B.; Sadigursky, M.

    1984-01-01

    Relatively susceptible BALB/c and relatively resistant A/J mice were infected subcutaneously in the right hind footpad with promastigotes of Leishmania mexicana amazonensis. A large localized lesion developed within 2 months after infection in the BALB/c mice, while A/J mice exhibited a small discrete fibrotic nodule. Sequential immunologic and histologic examination demonstrated that BALB/c mice developed a nodular foam-cell type of lesion and progressive depression of a delayed-type hypersensitivity (DTH) response to leishmania antigen, while the A/J mice had a mixed cellular fibrosing and encapsulating reaction and developed and maintained positive DTH responses to leishmania antigen. Anti-leishmania antibody responses were positive at similar levels in both strains. The lesions in BALB/c mice were found in bone marrow, tendon, skin appendages, and regional lymph nodes, with a tendency toward cutaneous metastases. Lesions in A/J mice remained localized. Fibrosis, focal fibrinoid necrosis, and lymphocytic and macrophagic infiltration were the outstanding features. Light and transmission electron microscopic studies indicated that no outstanding destruction of leishmanias seemed to occur within macrophages of either mouse strain. In the more resistant A/J mice, however, parasitized macrophages were frequently necrotic, and degenerating leishmanias were often seen free in the interstitial tissue. These observations help the interpretation of the histologic features, as well as the pathogenesis, of cutaneous and mucocutaneous leishmaniasis in man. Images Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 Figure 11 PMID:6691411

  11. Optimization of a Virus-Induced Gene Silencing System with Soybean yellow common mosaic virus for Gene Function Studies in Soybeans

    PubMed Central

    Kim, Kil Hyun; Lim, Seungmo; Kang, Yang Jae; Yoon, Min Young; Nam, Moon; Jun, Tae Hwan; Seo, Min-Jung; Baek, Seong-Bum; Lee, Jeom-Ho; Moon, Jung-Kyung; Lee, Suk-Ha; Lee, Su-Heon; Lim, Hyoun-Sub; Moon, Jae Sun; Park, Chang-Hwan

    2016-01-01

    Virus-induced gene silencing (VIGS) is an effective tool for the study of soybean gene function. Successful VIGS depends on the interaction between virus spread and plant growth, which can be influenced by environmental conditions. Recently, we developed a new VIGS system derived from the Soybean yellow common mosaic virus (SYCMV). Here, we investigated several environmental and developmental factors to improve the efficiency of a SYCMV-based VIGS system to optimize the functional analysis of the soybean. Following SYCMV: Glycine max-phytoene desaturase (GmPDS) infiltration, we investigated the effect of photoperiod, inoculation time, concentration of Agrobacterium inoculm, and growth temperature on VIGS efficiency. In addition, the relative expression of GmPDS between non-silenced and silenced plants was measured by qRT-PCR. We found that gene silencing efficiency was highest at a photoperiod of 16/8 h (light/dark) at a growth temperature of approximately 27°C following syringe infiltration to unrolled unifoliolate leaves in cotyledon stage with a final SYCMV:GmPDS optimal density (OD)600 of 2.0. Using this optimized protocol, we achieved high efficiency of GmPDS-silencing in various soybean germplasms including cultivated and wild soybeans. We also confirmed that VIGS occurred in the entire plant, including the root, stem, leaves, and flowers, and could transmit GmPDS to other soybean germplasms via mechanical inoculation. This optimized protocol using a SYCMV-based VIGS system in the soybean should provide a fast and effective method to elucidate gene functions and for use in large-scale screening experiments. PMID:27147931

  12. Identification of novel pepper genes involved in Bax- or INF1-mediated cell death responses by high-throughput virus-induced gene silencing.

    PubMed

    Lee, Jeong Hee; Kim, Young Cheol; Choi, Doil; Park, Jeong Mee

    2013-11-19

    Hot pepper is one of the economically important crops in Asia. A large number of gene sequences, including expressed sequence tag (EST) and genomic sequences are publicly available. However, it is still a daunting task to determine gene function due to difficulties in genetic modification of a pepper plants. Here, we show the application of the virus-induced gene silencing (VIGS) repression for the study of 459 pepper ESTs selected as non-host pathogen-induced cell death responsive genes from pepper microarray experiments in Nicotiana benthamiana. Developmental abnormalities in N. benthamiana plants are observed in the 32 (7%) pepper ESTs-silenced plants. Aberrant morphological phenotypes largely comprised of three groups: stunted, abnormal leaf, and dead. In addition, by employing the combination of VIGS and Agrobacterium-mediated transient assays, we identified novel pepper ESTs that involved in Bax or INF1-mediated cell death responses. Silencing of seven pepper ESTs homologs suppressed Bax or INF1-induced cell death, five of which suppressed both cell death responses in N. benthamiana. The genes represented by these five ESTs encode putative proteins with functions in endoplasmic reticulum (ER) stress and lipid signaling. The genes represented by the other two pepper ESTs showing only Bax-mediated cell death inhibition encode a CCCH-type zinc finger protein containing an ankyrin-repeat domain and a probable calcium-binding protein, CML30-like. Taken together, we effectively isolated novel pepper clones that are involved in hypersensitive response (HR)-like cell death using VIGS, and identified silenced clones that have different responses to Bax and INF1 exposure, indicating separate signaling pathways for Bax- and INF1-mediated cell death.

  13. Integrated network analysis reveals a novel role for the cell cycle in 2009 pandemic influenza virus-induced inflammation in macaque lungs

    PubMed Central

    2012-01-01

    Background Annually, influenza A viruses circulate the world causing wide-spread sickness, economic loss, and death. One way to better defend against influenza virus-induced disease may be to develop novel host-based therapies, targeted at mitigating viral pathogenesis through the management of virus-dysregulated host functions. However, mechanisms that govern aberrant host responses to influenza virus infection remain incompletely understood. We previously showed that the pandemic H1N1 virus influenza A/California/04/2009 (H1N1; CA04) has enhanced pathogenicity in the lungs of cynomolgus macaques relative to a seasonal influenza virus isolate (A/Kawasaki/UTK-4/2009 (H1N1; KUTK4)). Results Here, we used microarrays to identify host gene sequences that were highly differentially expressed (DE) in CA04-infected macaque lungs, and we employed a novel strategy – combining functional and pathway enrichment analyses, transcription factor binding site enrichment analysis and protein-protein interaction data – to create a CA04 differentially regulated host response network. This network describes enhanced viral RNA sensing, immune cell signaling and cell cycle arrest in CA04-infected lungs, and highlights a novel, putative role for the MYC-associated zinc finger (MAZ) transcription factor in regulating these processes. Conclusions Our findings suggest that the enhanced pathology is the result of a prolonged immune response, despite successful virus clearance. Most interesting, we identify a mechanism which normally suppresses immune cell signaling and inflammation is ineffective in the pH1N1 virus infection; a dyregulatory event also associated with arthritis. This dysregulation offers several opportunities for developing strain-independent, immunomodulatory therapies to protect against future pandemics. PMID:22937776

  14. Optimization of a Virus-Induced Gene Silencing System with Soybean yellow common mosaic virus for Gene Function Studies in Soybeans.

    PubMed

    Kim, Kil Hyun; Lim, Seungmo; Kang, Yang Jae; Yoon, Min Young; Nam, Moon; Jun, Tae Hwan; Seo, Min-Jung; Baek, Seong-Bum; Lee, Jeom-Ho; Moon, Jung-Kyung; Lee, Suk-Ha; Lee, Su-Heon; Lim, Hyoun-Sub; Moon, Jae Sun; Park, Chang-Hwan

    2016-04-01

    Virus-induced gene silencing (VIGS) is an effective tool for the study of soybean gene function. Successful VIGS depends on the interaction between virus spread and plant growth, which can be influenced by environmental conditions. Recently, we developed a new VIGS system derived from the Soybean yellow common mosaic virus (SYCMV). Here, we investigated several environmental and developmental factors to improve the efficiency of a SYCMV-based VIGS system to optimize the functional analysis of the soybean. Following SYCMV: Glycine max-phytoene desaturase (GmPDS) infiltration, we investigated the effect of photoperiod, inoculation time, concentration of Agrobacterium inoculm, and growth temperature on VIGS efficiency. In addition, the relative expression of GmPDS between non-silenced and silenced plants was measured by qRT-PCR. We found that gene silencing efficiency was highest at a photoperiod of 16/8 h (light/dark) at a growth temperature of approximately 27°C following syringe infiltration to unrolled unifoliolate leaves in cotyledon stage with a final SYCMV:GmPDS optimal density (OD)600 of 2.0. Using this optimized protocol, we achieved high efficiency of GmPDS-silencing in various soybean germplasms including cultivated and wild soybeans. We also confirmed that VIGS occurred in the entire plant, including the root, stem, leaves, and flowers, and could transmit GmPDS to other soybean germplasms via mechanical inoculation. This optimized protocol using a SYCMV-based VIGS system in the soybean should provide a fast and effective method to elucidate gene functions and for use in large-scale screening experiments. PMID:27147931

  15. Molecular cloning and functional characterization of the lycopene ε-cyclase gene via virus-induced gene silencing and its expression pattern in Nicotiana tabacum.

    PubMed

    Shi, Yanmei; Wang, Ran; Luo, Zhaopeng; Jin, Lifeng; Liu, Pingping; Chen, Qiansi; Li, Zefeng; Li, Feng; Wei, Chunyang; Wu, Mingzhu; Wei, Pan; Xie, He; Qu, Lingbo; Lin, Fucheng; Yang, Jun

    2014-01-01

    Lycopene ε-cyclase (ε-LCY) is a key enzyme that catalyzes the synthesis of α-branch carotenoids through the cyclization of lycopene. Two cDNA molecules encoding ε-LCY (designated Ntε-LCY1 and Ntε-LCY2) were cloned from Nicotiana tabacum. Ntε-LCY1 and Ntε-LCY2 are encoded by two distinct genes with different evolutionary origins, one originating from the tobacco progenitor, Nicotiana sylvestris, and the other originating from Nicotiana tomentosiformis. The two coding regions are 97% identical at the nucleotide level and 95% identical at the amino acid level. Transcripts of Ntε-LCY were detectable in both vegetative and reproductive organs, with a relatively higher level of expression in leaves than in other tissues. Subcellular localization experiments using an Ntε-LCY1-GFP fusion protein demonstrated that mature Ntε-LCY1 protein is localized within the chloroplast in Bright Yellow 2 suspension cells. Under low-temperature and low-irradiation stress, Ntε-LCY transcript levels substantially increased relative to control plants. Tobacco rattle virus (TRV)-mediated silencing of ε-LCY in Nicotiana benthamiana resulted in an increase of β-branch carotenoids and a reduction in the levels of α-branch carotenoids. Meanwhile, transcripts of related genes in the carotenoid biosynthetic pathway observably increased, with the exception of β-OHase in the TRV-ε-lcy line. Suppression of ε-LCY expression was also found to alleviate photoinhibition of Potosystem II in virus-induced gene silencing (VIGS) plants under low-temperature and low-irradiation stress. Our results provide insight into the regulatory role of ε-LCY in plant carotenoid biosynthesis and suggest a role for ε-LCY in positively modulating low temperature stress responses.

  16. Virus-induced gene silencing of PEAM4 affects floral morphology by altering the expression pattern of PsSOC1a and PsPVP in pea.

    PubMed

    Chen, Zhe-Hao; Jia, Fei-Fei; Hu, Jiang-Qin; Pang, Ji-Liang; Xu, Lei; Wang, Li-Lin

    2014-01-15

    pea-MADS4 (PEAM4) regulates floral morphology in Pisum sativum L., however, its molecular mechanisms still remain unclear. Virus-induced gene silencing (VIGS) is a recently developed reverse genetic approach that facilities an easier and more rapid study of gene functions. In this study, the PEAM4 gene was effectively silenced by VIGS using a pea early browning virus (PEBV) in wild type pea JI992. The infected plants showed abnormal phenotypes, as the floral organs, especially the sepals and petals changed in both size and shape, which made the corolla less closed. The petals changed in morphology and internal symmetry with, the stamens reduced and carpel dehisced. Larger sepals and longer tendrils with small cauline leaves appeared, with some sepals turning into bracts, and secondary inflorescences with fused floral organs were formed, indicating a flower-to-inflorescence change. The infected plants also displayed a delayed and prolonged flowering time. The PEAM4-VIGS plants with altered floral morphology were similar to the pim (proliferating inflorescence meristem) mutant and also mimicked the phenotypes of ap1 mutants in Arabidopsis. The expression pattern of the homologous genes PsSOC1a and PsSVP, which were involved in flowering time and florescence morphological control downstream of PEAM4, were analyzed by real-time RT-PCR and mRNA in situ hybridization. PsSOC1a and PsSVP were ectopically expressed and enhanced in the floral meristems from PEAM4-silenced plants. Our data suggests that PEAM4 may have a similar molecular mechanism as AtAP1, which inhibits the expression of PsSOC1a and PsSVP in the floral meristem from the early stages of flower development. As such, in this way PEAM4 plays a crucial role in maintaining floral organ identity and flower development in pea.

  17. Proteomic and virus-induced gene silencing (VIGS) Analyses reveal that gossypol, brassinosteroids, and jasmonic acid contribute to the resistance of cotton to Verticillium dahliae.

    PubMed

    Gao, Wei; Long, Lu; Zhu, Long-Fu; Xu, Li; Gao, Wen-Hui; Sun, Long-Qing; Liu, Lin-Lin; Zhang, Xian-Long

    2013-12-01

    Verticillium wilt causes massive annual losses of cotton yield, but the mechanism of cotton resistance to Verticillium dahliae is complex and poorly understood. In this study, a comparative proteomic analysis was performed in resistant cotton (Gossypium barbadense cv7124) on infection with V. dahliae. A total of 188 differentially expressed proteins were identified by mass spectrometry (MALDI-TOF/TOF) analysis and could be classified into 17 biological processes based on Gene Ontology annotation. Most of these proteins were implicated in stimulus response, cellular processes and metabolic processes. Based on the proteomic analysis, several genes involved in secondary metabolism, reactive oxygen burst and phytohormone signaling pathways were identified for further physiological and molecular analysis. The roles of the corresponding genes were further characterized by employing virus-induced gene silencing (VIGS). Based on the results, we suggest that the production of gossypol is sufficient to affect the cotton resistance to V. dahliae. Silencing of GbCAD1, a key enzyme involving in gossypol biosynthesis, compromised cotton resistance to V. dahliae. Reactive oxygen species and salicylic acid signaling may be also implicated as regulators in cotton responsive to V. dahliae according to the analysis of GbSSI2, an important regulator in the crosstalk between salicylic acid and jasmonic acid signal pathways. Moreover, brassinosteroids and jasmonic acid signaling may play essential roles in the cotton disease resistance to V. dahliae. The brassinosteroids signaling was activated in cotton on inoculation with V. dahliae and the disease resistance of cotton was enhanced after exogenous application of brassinolide. Meanwhile, jasmonic acid signaling was also activated in cotton after inoculation with V. dahliae and brassinolide application. These data provide highlights in the molecular basis of cotton resistance to V. dahliae.

  18. Optimization of a Virus-Induced Gene Silencing System with Soybean yellow common mosaic virus for Gene Function Studies in Soybeans.

    PubMed

    Kim, Kil Hyun; Lim, Seungmo; Kang, Yang Jae; Yoon, Min Young; Nam, Moon; Jun, Tae Hwan; Seo, Min-Jung; Baek, Seong-Bum; Lee, Jeom-Ho; Moon, Jung-Kyung; Lee, Suk-Ha; Lee, Su-Heon; Lim, Hyoun-Sub; Moon, Jae Sun; Park, Chang-Hwan

    2016-04-01

    Virus-induced gene silencing (VIGS) is an effective tool for the study of soybean gene function. Successful VIGS depends on the interaction between virus spread and plant growth, which can be influenced by environmental conditions. Recently, we developed a new VIGS system derived from the Soybean yellow common mosaic virus (SYCMV). Here, we investigated several environmental and developmental factors to improve the efficiency of a SYCMV-based VIGS system to optimize the functional analysis of the soybean. Following SYCMV: Glycine max-phytoene desaturase (GmPDS) infiltration, we investigated the effect of photoperiod, inoculation time, concentration of Agrobacterium inoculm, and growth temperature on VIGS efficiency. In addition, the relative expression of GmPDS between non-silenced and silenced plants was measured by qRT-PCR. We found that gene silencing efficiency was highest at a photoperiod of 16/8 h (light/dark) at a growth temperature of approximately 27°C following syringe infiltration to unrolled unifoliolate leaves in cotyledon stage with a final SYCMV:GmPDS optimal density (OD)600 of 2.0. Using this optimized protocol, we achieved high efficiency of GmPDS-silencing in various soybean germplasms including cultivated and wild soybeans. We also confirmed that VIGS occurred in the entire plant, including the root, stem, leaves, and flowers, and could transmit GmPDS to other soybean germplasms via mechanical inoculation. This optimized protocol using a SYCMV-based VIGS system in the soybean should provide a fast and effective method to elucidate gene functions and for use in large-scale screening experiments.

  19. Antibody response is required for protection from Theiler's virus-induced encephalitis in C57BL/6 mice in the absence of CD8{sup +} T cells

    SciTech Connect

    Kang, B.-S.; Palma, Joann P.; Lyman, Michael A.; Dal Canto, Mauro; Kim, Byung S. . E-mail: bskim@northwestern.edu

    2005-09-15

    Intracerebral infection of susceptible mice with Theiler's murine encephalomyelitis virus (TMEV) induces immune-mediated demyelinating disease and this system serves as a relevant infectious model for human multiple sclerosis. It was previously shown that {beta}{sub 2}M-deficient C57BL/6 mice lacking functional CD8{sup +} T cells display increased viral persistence and enhanced susceptibility to TMEV-induced demyelination, and yet the majority of mice are free of clinical signs. To understand the mechanisms involved in this general resistance of C57BL/6 mice in the absence of CTL responses, mice ({mu}MT) deficient in the B-cell compartment lacking membrane IgM molecules were treated with anti-CD8 antibody and then infected with TMEV. Although little difference in the proliferative responses of peripheral T cells to UV-inactivated TMEV and the resistance to demyelinating disease was observed between virus-infected {mu}MT and control B6 mice, the levels of CD4{sup +} T cells were higher in the CNS of {mu}MT mice. However, after treatment with anti-CD8 antibody, 100% of the mice displayed clinical gray matter disease and prolonged viral persistence in {mu}MT mice, while only 10% of B6 mice showed clinical symptoms and very low viral persistence. Transfusion of sera from TMEV-infected B6 mice into anti-CD8 antibody-treated {mu}MT mice partially restored resistance to virus-induced encephalitis. These results indicate that the early anti-viral antibody response is also important in the protection from TMEV-induced encephalitis particularly in the absence of CD8{sup +} T cells.

  20. Virus-induced gene silencing of PEAM4 affects floral morphology by altering the expression pattern of PsSOC1a and PsPVP in pea.

    PubMed

    Chen, Zhe-Hao; Jia, Fei-Fei; Hu, Jiang-Qin; Pang, Ji-Liang; Xu, Lei; Wang, Li-Lin

    2014-01-15

    pea-MADS4 (PEAM4) regulates floral morphology in Pisum sativum L., however, its molecular mechanisms still remain unclear. Virus-induced gene silencing (VIGS) is a recently developed reverse genetic approach that facilities an easier and more rapid study of gene functions. In this study, the PEAM4 gene was effectively silenced by VIGS using a pea early browning virus (PEBV) in wild type pea JI992. The infected plants showed abnormal phenotypes, as the floral organs, especially the sepals and petals changed in both size and shape, which made the corolla less closed. The petals changed in morphology and internal symmetry with, the stamens reduced and carpel dehisced. Larger sepals and longer tendrils with small cauline leaves appeared, with some sepals turning into bracts, and secondary inflorescences with fused floral organs were formed, indicating a flower-to-inflorescence change. The infected plants also displayed a delayed and prolonged flowering time. The PEAM4-VIGS plants with altered floral morphology were similar to the pim (proliferating inflorescence meristem) mutant and also mimicked the phenotypes of ap1 mutants in Arabidopsis. The expression pattern of the homologous genes PsSOC1a and PsSVP, which were involved in flowering time and florescence morphological control downstream of PEAM4, were analyzed by real-time RT-PCR and mRNA in situ hybridization. PsSOC1a and PsSVP were ectopically expressed and enhanced in the floral meristems from PEAM4-silenced plants. Our data suggests that PEAM4 may have a similar molecular mechanism as AtAP1, which inhibits the expression of PsSOC1a and PsSVP in the floral meristem from the early stages of flower development. As such, in this way PEAM4 plays a crucial role in maintaining floral organ identity and flower development in pea. PMID:24331430

  1. Development of a virus-induced gene-silencing system for hexaploid wheat and its use in functional analysis of the Lr21-mediated leaf rust resistance pathway.

    PubMed

    Scofield, Steven R; Huang, Li; Brandt, Amanda S; Gill, Bikram S

    2005-08-01

    Virus-induced gene silencing (VIGS) is an important tool for the analysis of gene function in plants. In VIGS, viruses engineered to carry sequences derived from plant gene transcripts activate the host's sequence-specific RNA degradation system. This mechanism targets the RNAs of the viral genome for degradation, and as the virus contains transcribed plant sequence, homologous host mRNAs are also targeted for destruction. While routinely used in some dicots, no VIGS system was known for monocot plants until the recent report of silencing in barley (Hordeum vulgare) by barley stripe mosaic virus (BSMV). Here, we report development of protocols for use of BSMV to efficiently silence genes in hexaploid wheat (Triticum aestivum). The VIGS system was first optimized in studies silencing phytoene desaturase expression. Next, we used it to assay genes functioning in leaf rust resistance mediated by Lr21, which encodes a nucleotide binding site-leucine-rich repeat class resistance gene product. We demonstrated that infection with BSMV constructs carrying a 150-bp fragment of Lr21 caused conversion of incompatible interactions to compatible, whereas infection with a control construct or one that silences phytoene desaturase had no effect on resistance or susceptibility. Additionally, silencing the RAR1, SGT1, and HSP90 genes, known to be required in many but not all nucleotide binding site-leucine-rich repeat resistance pathways in diverse plant species, resulted in conversion to compatibility, indicating that these genes are essential in Lr21-mediated resistance. These studies indicate that BSMV-VIGS is a powerful tool for dissecting the genetic pathways of disease resistance in hexaploid wheat.

  2. Molecular cloning and functional characterization of the lycopene ε-cyclase gene via virus-induced gene silencing and its expression pattern in Nicotiana tabacum.

    PubMed

    Shi, Yanmei; Wang, Ran; Luo, Zhaopeng; Jin, Lifeng; Liu, Pingping; Chen, Qiansi; Li, Zefeng; Li, Feng; Wei, Chunyang; Wu, Mingzhu; Wei, Pan; Xie, He; Qu, Lingbo; Lin, Fucheng; Yang, Jun

    2014-01-01

    Lycopene ε-cyclase (ε-LCY) is a key enzyme that catalyzes the synthesis of α-branch carotenoids through the cyclization of lycopene. Two cDNA molecules encoding ε-LCY (designated Ntε-LCY1 and Ntε-LCY2) were cloned from Nicotiana tabacum. Ntε-LCY1 and Ntε-LCY2 are encoded by two distinct genes with different evolutionary origins, one originating from the tobacco progenitor, Nicotiana sylvestris, and the other originating from Nicotiana tomentosiformis. The two coding regions are 97% identical at the nucleotide level and 95% identical at the amino acid level. Transcripts of Ntε-LCY were detectable in both vegetative and reproductive organs, with a relatively higher level of expression in leaves than in other tissues. Subcellular localization experiments using an Ntε-LCY1-GFP fusion protein demonstrated that mature Ntε-LCY1 protein is localized within the chloroplast in Bright Yellow 2 suspension cells. Under low-temperature and low-irradiation stress, Ntε-LCY transcript levels substantially increased relative to control plants. Tobacco rattle virus (TRV)-mediated silencing of ε-LCY in Nicotiana benthamiana resulted in an increase of β-branch carotenoids and a reduction in the levels of α-branch carotenoids. Meanwhile, transcripts of related genes in the carotenoid biosynthetic pathway observably increased, with the exception of β-OHase in the TRV-ε-lcy line. Suppression of ε-LCY expression was also found to alleviate photoinhibition of Potosystem II in virus-induced gene silencing (VIGS) plants under low-temperature and low-irradiation stress. Our results provide insight into the regulatory role of ε-LCY in plant carotenoid biosynthesis and suggest a role for ε-LCY in positively modulating low temperature stress responses. PMID:25153631

  3. Tomato Infection by Whitefly-Transmitted Circulative and Non-Circulative Viruses Induce Contrasting Changes in Plant Volatiles and Vector Behaviour.

    PubMed

    Fereres, Alberto; Peñaflor, Maria Fernanda G V; Favaro, Carla F; Azevedo, Kamila E X; Landi, Carolina H; Maluta, Nathalie K P; Bento, José Mauricio S; Lopes, Joao R S

    2016-08-11

    , this type of virus-induced manipulation of vector behaviour was not observed for the semi persistent crinivirus, ToCV, which is not specifically transmitted by B. tabaci and has a much less intimate virus-vector relationship.

  4. Transcriptome Profiling of the Virus-Induced Innate Immune Response in Pteropus vampyrus and Its Attenuation by Nipah Virus Interferon Antagonist Functions

    PubMed Central

    Glennon, Nicole B.; Jabado, Omar; Lo, Michael K.

    2015-01-01

    ABSTRACT Bats are important reservoirs for several viruses, many of which cause lethal infections in humans but have reduced pathogenicity in bats. As the innate immune response is critical for controlling viruses, the nature of this response in bats and how it may differ from that in other mammals are of great interest. Using next-generation transcriptome sequencing (mRNA-seq), we profiled the transcriptional response of Pteropus vampyrus bat kidney (PVK) cells to Newcastle disease virus (NDV), an avian paramyxovirus known to elicit a strong innate immune response in mammalian cells. The Pteropus genus is a known reservoir of Nipah virus (NiV) and Hendra virus (HeV). Analysis of the 200 to 300 regulated genes showed that genes for interferon (IFN) and antiviral pathways are highly upregulated in NDV-infected PVK cells, including genes for beta IFN, RIG-I, MDA5, ISG15, and IRF1. NDV-infected cells also upregulated several genes not previously characterized to be antiviral, such as RND1, SERTAD1, CHAC1, and MORC3. In fact, we show that MORC3 is induced by both IFN and NDV infection in PVK cells but is not induced by either stimulus in human A549 cells. In contrast to NDV infection, HeV and NiV infection of PVK cells failed to induce these innate immune response genes. Likewise, an attenuated response was observed in PVK cells infected with recombinant NDVs expressing the NiV IFN antagonist proteins V and W. This study provides the first global profile of a robust virus-induced innate immune response in bats and indicates that henipavirus IFN antagonist mechanisms are likely active in bat cells. IMPORTANCE Bats are the reservoir host for many highly pathogenic human viruses, including henipaviruses, lyssaviruses, severe acute respiratory syndrome coronavirus, and filoviruses, and many other viruses have also been isolated from bats. Viral infections are reportedly asymptomatic or heavily attenuated in bat populations. Despite their ecological importance to viral

  5. Tomato Infection by Whitefly-Transmitted Circulative and Non-Circulative Viruses Induce Contrasting Changes in Plant Volatiles and Vector Behaviour.

    PubMed

    Fereres, Alberto; Peñaflor, Maria Fernanda G V; Favaro, Carla F; Azevedo, Kamila E X; Landi, Carolina H; Maluta, Nathalie K P; Bento, José Mauricio S; Lopes, Joao R S

    2016-01-01

    , this type of virus-induced manipulation of vector behaviour was not observed for the semi persistent crinivirus, ToCV, which is not specifically transmitted by B. tabaci and has a much less intimate virus-vector relationship. PMID:27529271

  6. Tomato Infection by Whitefly-Transmitted Circulative and Non-Circulative Viruses Induce Contrasting Changes in Plant Volatiles and Vector Behaviour

    PubMed Central

    Fereres, Alberto; Peñaflor, Maria Fernanda G. V.; Favaro, Carla F.; Azevedo, Kamila E. X.; Landi, Carolina H.; Maluta, Nathalie K. P.; Bento, José Mauricio S.; Lopes, Joao R.S.

    2016-01-01

    , this type of virus-induced manipulation of vector behaviour was not observed for the semi persistent crinivirus, ToCV, which is not specifically transmitted by B. tabaci and has a much less intimate virus-vector relationship. PMID:27529271

  7. vig-1, a New Fish Gene Induced by the Rhabdovirus Glycoprotein, Has a Virus-Induced Homologue in Humans and Shares Conserved Motifs with the MoaA Family

    PubMed Central

    Boudinot, Pierre; Massin, Pascale; Blanco, Mar; Riffault, Sabine; Benmansour, Abdenour

    1999-01-01

    We used mRNA differential display methodology to analyze the shift of transcription profile induced by the fish rhabdovirus, viral hemorrhagic septicemia virus (VHSV), in rainbow trout leukocytes. We identified and characterized a new gene which is directly induced by VHSV. This VHSV-induced gene (vig-1) encodes a 348-amino-acid protein. vig-1 is highly expressed during the experimental disease in lymphoid organs of the infected fish. Intramuscular injection of a plasmid vector expressing the viral glycoprotein results in vig-1 expression, showing that the external virus protein is sufficient for the induction. vig-1 expression is also obtained by a rainbow trout interferon-like factor, indicating that vig-1 can be induced through different pathways. Moreover, vig-1 is homologous to a recently described human cytomegalovirus-induced gene. Accordingly, vig-1 activation may represent a new virus-induced activation pathway highly conserved in vertebrates. The deduced amino acid sequence of vig-1 is significantly related to sequences required for the biosynthesis of metal cofactors. This suggests that the function of vig-1 may be involved in the nonspecific virus-induced synthesis of enzymatic cofactors of the nitric oxide pathway. PMID:9971762

  8. A novel p38 mitogen activated protein kinase (MAPK) specific inhibitor suppresses respiratory syncytial virus and influenza A virus replication by inhibiting virus-induced p38 MAPK activation.

    PubMed

    Choi, Myung-Soo; Heo, Jinyuk; Yi, Chae-Min; Ban, Junsu; Lee, Noh-Jin; Lee, Na-Rae; Kim, Sang Won; Kim, Nam-Jung; Inn, Kyung-Soo

    2016-08-26

    Respiratory syncytial virus (RSV) and influenza A virus are leading causes of acute lower respiratory infectious disease. Respiratory diseases caused by RSV and influenza A virus result in serious economic burden and life-threatening disease for immunocompromised people. With the revelation that p38 mitogen-activated protein kinase (MAPK) activity in host cells is crucial for infection and replication of RSV and influenza A virus, inhibition of p38 MAPK activity has been suggested as a potential antiviral therapeutic strategy. However, the low selectivity and high toxicity of the p38 MAPK inhibitors necessitate the development of better inhibitors. Herein, we report the synthesis of a novel p38 MAPK inhibitor, NJK14047, with high kinase selectivity. In this work, it was demonstrated that NJK14047 inhibits RSV- and influenza A-mediated p38 MAPK activation in epithelial cells. Subsequently, NJK14047 treatment resulted in decreased viral replication and viral mRNA synthesis. In addition, secretion of interleukin-6 from infected cells was greatly diminished by NJK14047, suggesting that it can ameliorate immunopathological responses to RSV and influenza A. Collectively, the results suggest that NJK14047 has therapeutic potential to treat respiratory viral infection through the suppression of p38 MAPK activation, which is suggested to be an essential step for respiratory virus infection. PMID:27346133

  9. Inhibition of influenza virus-induced NF-kappaB and Raf/MEK/ERK activation can reduce both virus titers and cytokine expression simultaneously in vitro and in vivo.

    PubMed

    Pinto, Ruth; Herold, Susanne; Cakarova, Lidija; Hoegner, Katrin; Lohmeyer, Jürgen; Planz, Oliver; Pleschka, Stephan

    2011-10-01

    Influenza virus (IV) infection can cause severe pneumonia and death. Therapeutic actions are limited to vaccines and a few anti-viral drugs. These target viral functions thereby selecting resistant variants. During replication IV activates the Raf/MEK/ERK-cascade and the transcription factor NF-kappaB. Both result in virus supportive and anti-viral effects by promoting viral genome transport for virus assembly and by inducing expression of pro-inflammatory host factors. Apart from tissue damage caused by the virus lytic replication, an imbalanced overproduction of anti-viral cytokines can cause severe lung damage as observed in human H5-type IV infections. Recently we showed that inhibition of NF-kappaB activity reduces the virus titer in vitro and in vivo. We have now analyzed whether inhibition of these pathways, allows simultaneous reduction of virus titers and virus-induced cytokines. The results show that inhibition of either pathway indeed leads to decreased virus titers and cytokine expression. This was not only true for infected permanent cells or primary mouse alveolar epithelial cells, but also in infected mice. Hereby we demonstrate for the first time in vitro and in vivo that virus titers and pro-inflammatory cytokine expression can be modulated simultaneously. This could provide a new rationale of future therapeutic strategies to treat IV pneumonia.

  10. Epstein-Barr Virus-Induced Gene 3 (EBI3) Blocking Leads to Induce Antitumor Cytotoxic T Lymphocyte Response and Suppress Tumor Growth in Colorectal Cancer by Bidirectional Reciprocal-Regulation STAT3 Signaling Pathway

    PubMed Central

    Liang, Yanfang; Chen, Qianqian; Du, Wenjing; Chen, Can; Li, Feifei; Yang, Jingying; Peng, Jianyu; Kang, Dongping; Lin, Bihua; Chai, Xingxing; Zhou, Keyuan; Zeng, Jincheng

    2016-01-01

    Epstein-Barr virus-induced gene 3 (EBI3) is a member of the interleukin-12 (IL-12) family structural subunit and can form a heterodimer with IL-27p28 and IL-12p35 subunit to build IL-27 and IL-35, respectively. However, IL-27 stimulates whereas IL-35 inhibits antitumor T cell responses. To date, little is known about the role of EBI3 in tumor microenvironment. In this study, firstly we assessed EBI3, IL-27p28, IL-12p35, gp130, and p-STAT3 expression with clinicopathological parameters of colorectal cancer (CRC) tissues; then we evaluated the antitumor T cell responses and tumor growth with a EBI3 blocking peptide. We found that elevated EBI3 may be associated with IL-12p35, gp130, and p-STAT3 to promote CRC progression. EBI3 blocking peptide promoted antitumor cytotoxic T lymphocyte (CTL) response by inducing Granzyme B, IFN-γ production, and p-STAT3 expression and inhibited CRC cell proliferation and tumor growth to associate with suppressing gp130 and p-STAT3 expression. Taken together, these results suggest that EBI3 may mediate a bidirectional reciprocal-regulation STAT3 signaling pathway to assist the tumor escape immune surveillance in CRC. PMID:27247488

  11. Down-regulation of osmotin (PR5) gene by virus-induced gene silencing (VIGS) leads to susceptibility of resistant Piper colubrinum Link. to the oomycete pathogen Phytophthora capsici Leonian.

    PubMed

    Anu, K; Jessymol, K K; Chidambareswaren, M; Gayathri, G S; Manjula, S

    2015-06-01

    Piper colubrinum Link., a distant relative of Piper nigrum L., is immune to the oomycete pathogen Phytophthora capsici Leonian that causes 'quick wilt' in cultivated black pepper (P. nigrum). The osmotin, PR5 gene homologue, earlier identified from P. colubrinum, showed significant overexpression in response to pathogen and defense signalling molecules. The present study focuses on the functional validation of P. colubrinum osmotin (PcOSM) by virus induced gene silencing (VIGS) using Tobacco Rattle Virus (TRV)-based vector. P. colubrinum plants maintained under controlled growth conditions in a growth chamber were infiltrated with Agrobacterium carrying TRV empty vector (control) and TRV vector carrying PcOSM. Three weeks post infiltration, viral movement was confirmed in newly emerged leaves of infiltrated plants by RT-PCR using TRV RNA1 and TRV RNA2 primers. Semi-quantitative RT-PCR confirmed significant down-regulation of PcOSM gene in TRV-PcOSM infiltrated plant compared with the control plants. The control and silenced plants were challenged with Phytophthora capsici which demonstrated that knock-down of PcOSM in P. colubrinum leads to increased fungal mycelial growth in silenced plants compared to control plants, which was accompanied by decreased accumulation of H2O2 as indicated by 3,3'-diaminobenzidine (DAB) staining. Thus, in this study, we demonstrated that Piper colubrinum osmotin gene is required for resisting P. capsici infection and has possible role in hypersensitive cell death response and oxidative burst signaling during infection. PMID:26155671

  12. Down-regulation of osmotin (PR5) gene by virus-induced gene silencing (VIGS) leads to susceptibility of resistant Piper colubrinum Link. to the oomycete pathogen Phytophthora capsici Leonian.

    PubMed

    Anu, K; Jessymol, K K; Chidambareswaren, M; Gayathri, G S; Manjula, S

    2015-06-01

    Piper colubrinum Link., a distant relative of Piper nigrum L., is immune to the oomycete pathogen Phytophthora capsici Leonian that causes 'quick wilt' in cultivated black pepper (P. nigrum). The osmotin, PR5 gene homologue, earlier identified from P. colubrinum, showed significant overexpression in response to pathogen and defense signalling molecules. The present study focuses on the functional validation of P. colubrinum osmotin (PcOSM) by virus induced gene silencing (VIGS) using Tobacco Rattle Virus (TRV)-based vector. P. colubrinum plants maintained under controlled growth conditions in a growth chamber were infiltrated with Agrobacterium carrying TRV empty vector (control) and TRV vector carrying PcOSM. Three weeks post infiltration, viral movement was confirmed in newly emerged leaves of infiltrated plants by RT-PCR using TRV RNA1 and TRV RNA2 primers. Semi-quantitative RT-PCR confirmed significant down-regulation of PcOSM gene in TRV-PcOSM infiltrated plant compared with the control plants. The control and silenced plants were challenged with Phytophthora capsici which demonstrated that knock-down of PcOSM in P. colubrinum leads to increased fungal mycelial growth in silenced plants compared to control plants, which was accompanied by decreased accumulation of H2O2 as indicated by 3,3'-diaminobenzidine (DAB) staining. Thus, in this study, we demonstrated that Piper colubrinum osmotin gene is required for resisting P. capsici infection and has possible role in hypersensitive cell death response and oxidative burst signaling during infection.

  13. Immunopathological study of parasitic cholangitis in cetaceans.

    PubMed

    Jaber, J R; Zafra, R; Pérez, J; Suárez-Bonnet, A; González, J F; Carrascosa, C; Andrada, M; Arbelo, M; Fernández, A

    2013-10-01

    This paper describes the immunophenotype of cellular inflammatory infiltrates in chronic cholangitis in six common dolphins (Delphinus delphis), four striped dolphins (Stenella coeruleoalba), three Atlantic spotted dolphins (Stenella frontalis) and one pygmy sperm whale (Kogia Breviceps) found stranded along the coasts of the Canary Islands (Spain). A panel of 5 antibodies previously tested in dolphins (anti-CD3, -IgG, -MHC class II, -S100 protein and -lysozyme) were used. The present work also reports cross reactivity with dolphin antigens of two antibodies not used to date in dolphins (anti-mouse iNOS and anti-mouse Foxp3). The most common type of cholangitis found was chronic granulomatous cholangitis, associated with the presence of the parasite Campula spp., or its eggs in bile ducts. The cellular composition of the hepatic inflammatory infiltrate associated to chronic parasitic cholangitis was closely similar to that found in the cortex of control lymph nodes, including the presence of S100(+) and MHC class II(+) dendritic-like cells in lymphoid follicles and interfollicular areas. Only occasional macrophages expressed iNOS, whereas Foxp3(+) lymphocytes were not found in any of the lesions described in the different types of cholangitis. PMID:23809732

  14. [Immunopathology of early abortion: current status].

    PubMed

    Guzmán Sánchez, A; González Moreno, J; Castañeda Arellano, I; Villa Villagrana, F

    1997-06-01

    We reviewed the bibliography concerning the roles involved in the immunological mechanism related to the etiology of miscarriage, pointing out the main theories specially related to the Major Histocompatibility Complex and TLX antigen all together are beginners of the antiidiotype reaction in order to avoid having a miscarriage. It is mentioned that the blocking antibodies, suppressor cells and interleukines arrest the citotoxic immune mechanism against the fetal allograft. The new therapeutic approach is mentioned.

  15. [Immunopathologic implications of cryoglobulins (author's transl)].

    PubMed

    Serrano Martínez, M; Pérez Ortolá, R

    1979-11-25

    Cryoglobulins are proteins which appear in the serum of some patients. Their basic characteristic is their power to precipitate at low temperatures. In this work a review is made of the data presented by several authors in regard to the origin, isolation, classification, and precipitation mechanism, as well as of the factors which influence the cryoprecipitability. We also set out the most probable etiopathogenic theories and the possible clinical findings in those patients who have these proteins altered in their serum. Finally we comment on the treatment with special reference to penicillamine.

  16. Chagas Disease Cardiomyopathy: Immunopathology and Genetics

    PubMed Central

    Chevillard, Christophe

    2014-01-01

    Chagas disease, caused by the protozoan Trypanosoma cruzi, is endemic in Latin America and affects ca. 10 million people worldwide. About 30% of Chagas disease patients develop chronic Chagas disease cardiomyopathy (CCC), a particularly lethal inflammatory cardiomyopathy that occurs decades after the initial infection, while most patients remain asymptomatic. Mortality rate is higher than that of noninflammatory cardiomyopathy. CCC heart lesions present a Th1 T-cell-rich myocarditis, with cardiomyocyte hypertrophy and prominent fibrosis. Data suggest that the myocarditis plays a major pathogenetic role in disease progression. Major unmet goals include the thorough understanding of disease pathogenesis and therapeutic targets and identification of prognostic genetic factors. Chagas disease thus remains a neglected disease, with no vaccines or antiparasitic drugs proven efficient in chronically infected adults, when most patients are diagnosed. Both familial aggregation of CCC cases and the fact that only 30% of infected patients develop CCC suggest there might be a genetic component to disease susceptibility. Moreover, previous case-control studies have identified some genes associated to human susceptibility to CCC. In this paper, we will review the immunopathogenesis and genetics of Chagas disease, highlighting studies that shed light on the differential progression of Chagas disease patients to CCC. PMID:25210230

  17. Immunopathological features of rat Staphylococcus aureus arthritis.

    PubMed Central

    Bremell, T; Lange, S; Holmdahl, R; Rydén, C; Hansson, G K; Tarkowski, A

    1994-01-01

    Staphylococcus aureus is the most common bacterial species found in nongonococcal bacterial arthritis in humans. We present the first description, to our knowledge, of an outbreak of spontaneous staphylococcal arthritis in a rat colony. In a group of 10 rats, 9 displayed arthritis. Clinically, the most obvious findings were arthritis of one or both hindpaws and malaise. Bacteriophage typing showed the common phage type 85 in isolates recovered from the joints, blood, and bedding of rats and from the nose and cheeks of one person from the staff of the animal facility. The S. aureus strain proved to produce staphylococcal enterotoxin A and exhibited strong binding to collagen types I and II and bone sialoprotein, which are potentially important virulence factors. When the recovered S. aureus strain was injected intravenously into healthy rats, severe septic arthritis was induced in almost all of the animals. The arthritic lesions were characterized by infiltration of phagocytic cells and T lymphocytes into the synovium. Many of the synovial cells strongly expressed major histocompatibility complex class II molecules. Increased levels of interleukin 6 in serum as well as a prominent polyclonal B-cell activation were noted throughout the disease course. Pretreatment of S. aureus-injected rats in vivo with an antibody to the alpha beta T-cell receptor significantly decreased the severity of the arthritis. Our results indicate that alpha beta + T lymphocytes contribute to an erosive and persistent course of S. aureus arthritis. Images PMID:8188356

  18. Primary Sjogren syndrome: clinical and immunopathologic features.

    PubMed

    Fox, R I; Howell, F V; Bone, R C; Michelson, P

    1984-11-01

    Primary Sjogren syndrome is an autoimmune condition in which dry eyes (keratoconjunctivitis sicca) and dry mouth (xerostomia) result from lymphocytic infiltration of lacrimal and salivary glands. Clinical and laboratory features of 60 primary Sjogren syndrome patients seen at our clinic during the past three years are presented. These patients illustrate the wide spectrum of extraglandular features that may occur as a result of lymphoid infiltration of lung, kidney, skin, stomach, liver, and muscle. They further emphasize the difficulty in classifying a patient as primary or secondary Sjogren syndrome (ie, sicca symptoms associated with systemic lupus erythematosus, rheumatoid arthritis, or scleroderma), particularly early in the disease course. As an initial step in understanding the pathogenesis, the lymphocytes that infiltrate the salivary glands and lymph nodes were characterized by using monoclonal antibodies that recognize distinct lymphocyte subsets and by using in vitro functional assays. These studies have demonstrated that affected tissues have infiltrates of T cells with helper/inducer activity and with a high frequency of "activation antigens." The immunohistologic techniques are useful in differentiating "benign" and "pseudolymphoma" lesions (both due predominantly to T cells) from non-Hodgkin lymphoma (usually due to B-cell infiltrates). Although there is no "cure" for primary Sjogren syndrome patient's symptoms may be significantly improved by measures aimed at prevention of ocular and dental complications and by the recognition of extraglandular features that may be amenable to specific treatment.

  19. Effects of provirus integration in the Tpl-1/Ets-1 locus in Moloney murine leukemia virus-induced rat T-cell lymphomas: levels of expression, polyadenylation, transcriptional initiation, and differential splicing of the Ets-1 mRNA.

    PubMed Central

    Bellacosa, A; Datta, K; Bear, S E; Patriotis, C; Lazo, P A; Copeland, N G; Jenkins, N A; Tsichlis, P N

    1994-01-01

    The Tpl-1 locus was defined as a genomic DNA region which is targeted by provirus insertion during progression of Moloney murine leukemia virus-induced rat T-cell lymphomas. Using a panel of 156 (Mus musculus x Mus spretus) x Mus musculus interspecific backcross mice, we mapped Tpl-1 to mouse chromosome 9 at a distance of 1.2 +/- 0.9 centimorgans from the Ets-1 proto-oncogene (S.E. Bear, A. Bellacosa, P.A. Lazo, N.A. Jenkins, N.G. Copeland, C. Hanson, G. Levan, and P.N. Tsichlis, Proc. Natl. Acad. Sci. USA 86:7495-7499, 1989). In this report, we present evidence that all the known Tpl-1 provirus insertions occurred immediately 5' of the first exon of Ets-1 (exon A) and that the earlier detected distance between Tpl-1 and Ets-1 was due to the high frequency of meiotic recombination in the region between the site of provirus integration and exon III. Northern (RNA) blot analysis of polyadenylated RNA from normal adult rat tissues and Moloney murine leukemia virus-induced T-cell lymphomas and hybridization to a Tpl-1/Ets-1 probe derived from the 5' end of the gene revealed two lymphoid cell-specific RNA transcripts, of 5.5 and 2.2 kb. Sequence analysis of a near-full-length (4,991-bp) cDNA clone of the 5.5-kb RNA revealed a 441-amino-acid open reading frame encoding a protein identical to the human and mouse Ets-1 proteins with the exception of five and nine species-specific conservative amino acid differences, respectively. The steady-state level of the Tpl-1/Ets-1 RNA and of the Ets-1 protein was modestly elevated in tumors carrying a provirus in the Tpl-1 locus. The relative ratio of the two Ets-1 transcripts, which were shown to arise by differential polyadenylation, was not affected by provirus insertion. Moreover, the major site of transcriptional initiation, which was localized by primer extension 250 bp upstream of the 5' end of the Ets-1 cDNA clone, was shown to be identical in normal cells and tumors carrying a provirus in the Tpl-1 locus. Finally, the

  20. Down-regulation of flavonoid 3'-hydroxylase gene expression by virus-induced gene silencing in soybean reveals the presence of a threshold mRNA level associated with pigmentation in pubescence.

    PubMed

    Nagamatsu, Atsushi; Masuta, Chikara; Matsuura, Hideyuki; Kitamura, Keisuke; Abe, Jun; Kanazawa, Akira

    2009-01-01

    Changes in flavonoid content are often manifested as altered pigmentation in plant tissues. Two loci have been identified as controlling pigmentation in soybean pubescence. Of these, the T locus appears to encode flavonoid 3'-hydroxylase (F3'H) protein: the T and t alleles are associated with tawny and gray colors, respectively, in pubescence. We previously down-regulated F3'H gene expression by virus-induced gene silencing (VIGS) in soybean. Despite this successful VIGS, the tawny pubescence pigmentation proved to be unchanged in greenhouse-grown plants. We hypothesized that the reduced mRNA level of the F3'H gene resulting from VIGS remained high enough to induce pigmentation. To verify this hypothesis, in the present study, we performed F3'H VIGS on plants grown under controlled conditions, in which the steady-state mRNA level of the F3'H gene was reduced to approximately 5% of that of greenhouse-grown plants. This VIGS treatment resulted in the loss of tawny pigmentation in pubescence, suggesting that the sf3'h1 gene is involved in the control of pigmentation in pubescence. We detected a marked decrease in target mRNA, an accumulation of short interfering RNAs (siRNAs), and a decrease in quercetin content relative to kaempferol in leaf tissues, indicating that sequence-specific mRNA degradation of the F3'H gene was induced. These results suggest that leaf tissues have a threshold mRNA level of the F3'H gene, which is associated with the occurrence of tawny pigmentation in pubescence. The estimated threshold mRNA level for pigmentation in pubescence was approximately 3% of the steady-state mRNA level of the F3'H gene in greenhouse-grown plants.

  1. Pandemic H1N1 2009 Influenza A Virus Induces Weak Cytokine Responses in Human Macrophages and Dendritic Cells and Is Highly Sensitive to the Antiviral Actions of Interferons ▿

    PubMed Central

    Österlund, Pamela; Pirhonen, Jaana; Ikonen, Niina; Rönkkö, Esa; Strengell, Mari; Mäkelä, Sanna M.; Broman, Mia; Hamming, Ole J.; Hartmann, Rune; Ziegler, Thedi; Julkunen, Ilkka

    2010-01-01

    In less than 3 months after the first cases of swine origin 2009 influenza A (H1N1) virus infections were reported from Mexico, WHO declared a pandemic. The pandemic virus is antigenically distinct from seasonal influenza viruses, and the majority of human population lacks immunity against this virus. We have studied the activation of innate immune responses in pandemic virus-infected human monocyte-derived dendritic cells (DC) and macrophages. Pandemic A/Finland/553/2009 virus, representing a typical North American/European lineage virus, replicated very well in these cells. The pandemic virus, as well as the seasonal A/Brisbane/59/07 (H1N1) and A/New Caledonia/20/99 (H1N1) viruses, induced type I (alpha/beta interferon [IFN-α/β]) and type III (IFN-λ1 to -λ3) IFN, CXCL10, and tumor necrosis factor alpha (TNF-α) gene expression weakly in DCs. Mouse-adapted A/WSN/33 (H1N1) and human A/Udorn/72 (H3N2) viruses, instead, induced efficiently the expression of antiviral and proinflammatory genes. Both IFN-α and IFN-β inhibited the replication of the pandemic (H1N1) virus. The potential of IFN-λ3 to inhibit viral replication was lower than that of type I IFNs. However, the pandemic virus was more sensitive to the antiviral IFN-λ3 than the seasonal A/Brisbane/59/07 (H1N1) virus. The present study demonstrates that the novel pandemic (H1N1) influenza A virus can readily replicate in human primary DCs and macrophages and efficiently avoid the activation of innate antiviral responses. It is, however, highly sensitive to the antiviral actions of IFNs, which may provide us an additional means to treat severe cases of infection especially if significant drug resistance emerges. PMID:19939920

  2. Coupling Virus-Induced Gene Silencing to Exogenous Green Fluorescence Protein Expression Provides a Highly Efficient System for Functional Genomics in Arabidopsis and across All Stages of Tomato Fruit Development1[C][W

    PubMed Central

    Quadrana, Leandro; Rodriguez, Maria Cecilia; López, Mariana; Bermúdez, Luisa; Nunes-Nesi, Adriano; Fernie, Alisdair R.; Descalzo, Adriana; Asis, Ramón; Rossi, Magdalena; Asurmendi, Sebastian; Carrari, Fernando

    2011-01-01

    Since the advent of the postgenomic era, efforts have focused on the development of rapid strategies for annotating plant genes of unknown function. Given its simplicity and rapidity, virus-induced gene silencing (VIGS) has become one of the preeminent approaches for functional analyses. However, several problems remain intrinsic to the use of such a strategy in the study of both metabolic and developmental processes. The most prominent of these is the commonly observed phenomenon of “sectoring” the tissue regions that are not effectively targeted by VIGS. To better discriminate these sectors, an effective marker system displaying minimal secondary effects is a prerequisite. Utilizing a VIGS system based on the tobacco rattle virus vector, we here studied the effect of silencing the endogenous phytoene desaturase gene (pds) and the expression and subsequent silencing of the exogenous green fluorescence protein (gfp) on the metabolism of Arabidopsis (Arabidopsis thaliana) leaves and tomato (Solanum lycopersicum) fruits. In leaves, we observed dramatic effects on primary carbon and pigment metabolism associated with the photobleached phenotype following the silencing of the endogenous pds gene. However, relatively few pleiotropic effects on carbon metabolism were observed in tomato fruits when pds expression was inhibited. VIGS coupled to gfp constitutive expression revealed no significant metabolic alterations after triggering of silencing in Arabidopsis leaves and a mild effect in mature green tomato fruits. By contrast, a wider impact on metabolism was observed in ripe fruits. Silencing experiments with an endogenous target gene of interest clearly demonstrated the feasibility of cosilencing in this system; however, carefully constructed control experiments are a prerequisite to prevent erroneous interpretation. PMID:21531899

  3. Deletion of fucose residues in plant N-glycans by repression of the GDP-mannose 4,6-dehydratase gene using virus-induced gene silencing and RNA interference.

    PubMed

    Matsuo, Kouki; Matsumura, Takeshi

    2011-02-01

    Production of pharmaceutical glycoproteins in plants has many advantages in terms of safety and reduced costs. However, plant-produced glycoproteins have N-glycans with plant-specific sugar residues (core β-1,2-xylose and α-1,3-fucose) and a Lewis a (Le(a) ) epitope, i.e., Galβ(1-3)[Fucα(1-4)]GlcNAc. Because these sugar residues and glycan structures seemed to be immunogenic, several attempts have been made to delete them by repressing their respective glycosyltransferase genes. However, until date, such deletions have not been successful in completely eliminating the fucose residues. In this study, we simultaneously reduced the plant-specific core α-1,3-fucose and α-1,4-fucose residues in the Le(a) epitopes by repressing the Guanosine 5'-diphosphate (GDP)-D-mannose 4,6-dehydratase (GMD) gene, which is associated with GDP-L-fucose biosynthesis, in Nicotiana benthamiana plants. Repression of GMD was achieved using virus-induced gene silencing (VIGS) and RNA interference (RNAi). The proportion of fucose-free N-glycans found in total soluble protein from GMD gene-repressed plants increased by 80% and 95% following VIGS and RNAi, respectively, compared to wild-type plants. A small amount of putative galactose substitution in N-glycans from the NbGMD gene-repressed plants was observed, similar to what has been previously reported GMD-knockout Arabidopsis mutant. On the other hand, the recombinant mouse granulocyte-macrophage colony-stimulating factor (GM-CSF) with fucose-deleted N-glycans was successfully produced in NbGMD-RNAi transgenic N. benthamiana plants. Thus, repression of the GMD gene is thus very useful for deleting immunogenic total fucose residues and facilitating the production of pharmaceutical glycoproteins in plants.

  4. Epstein-Barr virus-induced gene 3 suppresses T helper type 1, type 17 and type 2 immune responses after Trypanosoma cruzi infection and inhibits parasite replication by interfering with alternative macrophage activation.

    PubMed

    Böhme, Julia; Roßnagel, Caroline; Jacobs, Thomas; Behrends, Jochen; Hölscher, Christoph; Erdmann, Hanna

    2016-03-01

    The Epstein-Barr virus-induced gene 3 (EBI3) is a member of the interleukin-12 (IL)-12) family structurally related to the subunit p40 of IL-12 and forms a heterodimer either with the p28 subunit to build IL-27 or with p35 to form IL-35. Interleukin-27 is secreted by antigen-presenting cells whereas IL-35 appears to be produced mainly by regulatory T cells and regulatory B cells but both cytokines negatively regulate inflammatory immune responses. We here analysed the function of EBI3 during infection with the intracellular parasite Trypanosoma cruzi. Compared with C57BL/6 wild-type mice, EBI3-deficient (EBI3(-/-) ) mice showed a higher parasitaemia associated with an increased mortality rate. The EBI3(-/-) mice displayed an elevated inflammatory immune response with an increased production of T helper type 1 (Th1-), Th2- and Th17-derived cytokines. The increased Th2 immune response appears to have over-ridden the otherwise protective Th1 and Th17 immune responses by the induction of arginase-1-expressing alternatively activated macrophages in these mice. Hence, neutralization of IL-4 and arginase-1 activity partially restored protective immune responses in EBI3(-/-) mice. So far, our results demonstrate that EBI3 is an essential general regulator of inflammatory immune responses in experimental Chagas disease and is required for control of T. cruzi infection by inhibiting Th2-dependent alternative macrophage activation. Further studies are needed to dissect the underlying mechanisms and clarify whether EBI3 association with IL-27 or/and IL-35 accounts for its anti-inflammatory character in parasitic disease.

  5. Virus-Induced Gene Silencing-Based Functional Analyses Revealed the Involvement of Several Putative Trehalose-6-Phosphate Synthase/Phosphatase Genes in Disease Resistance against Botrytis cinerea and Pseudomonas syringae pv. tomato DC3000 in Tomato

    PubMed Central

    Zhang, Huijuan; Hong, Yongbo; Huang, Lei; Liu, Shixia; Tian, Limei; Dai, Yi; Cao, Zhongye; Huang, Lihong; Li, Dayong; Song, Fengming

    2016-01-01

    Trehalose and its metabolism have been demonstrated to play important roles in control of plant growth, development, and stress responses. However, direct genetic evidence supporting the functions of trehalose and its metabolism in defense response against pathogens is lacking. In the present study, genome-wide characterization of putative trehalose-related genes identified 11 SlTPSs for trehalose-6-phosphate synthase, 8 SlTPPs for trehalose-6-phosphate phosphatase and one SlTRE1 for trehalase in tomato genome. Nine SlTPSs, 4 SlTPPs, and SlTRE1 were selected for functional analyses to explore their involvement in tomato disease resistance. Some selected SlTPSs, SlTPPs, and SlTRE1 responded with distinct expression induction patterns to Botrytis cinerea and Pseudomonas syringae pv. tomato (Pst) DC3000 as well as to defense signaling hormones (e.g., salicylic acid, jasmonic acid, and a precursor of ethylene). Virus-induced gene silencing-mediated silencing of SlTPS3, SlTPS4, or SlTPS7 led to deregulation of ROS accumulation and attenuated the expression of defense-related genes upon pathogen infection and thus deteriorated the resistance against B. cinerea or Pst DC3000. By contrast, silencing of SlTPS5 or SlTPP2 led to an increased expression of the defense-related genes upon pathogen infection and conferred an increased resistance against Pst DC3000. Silencing of SlTPS3, SlTPS4, SlTPS5, SlTPS7, or SlTPP2 affected trehalose level in tomato plants with or without infection of B. cinerea or Pst DC3000. These results demonstrate that SlTPS3, SlTPS4, SlTPS5, SlTPS7, and SlTPP2 play roles in resistance against B. cinerea and Pst DC3000, implying the importance of trehalose and tis metabolism in regulation of defense response against pathogens in tomato. PMID:27540389

  6. Virus-Induced Gene Silencing-Based Functional Analyses Revealed the Involvement of Several Putative Trehalose-6-Phosphate Synthase/Phosphatase Genes in Disease Resistance against Botrytis cinerea and Pseudomonas syringae pv. tomato DC3000 in Tomato.

    PubMed

    Zhang, Huijuan; Hong, Yongbo; Huang, Lei; Liu, Shixia; Tian, Limei; Dai, Yi; Cao, Zhongye; Huang, Lihong; Li, Dayong; Song, Fengming

    2016-01-01

    Trehalose and its metabolism have been demonstrated to play important roles in control of plant growth, development, and stress responses. However, direct genetic evidence supporting the functions of trehalose and its metabolism in defense response against pathogens is lacking. In the present study, genome-wide characterization of putative trehalose-related genes identified 11 SlTPSs for trehalose-6-phosphate synthase, 8 SlTPPs for trehalose-6-phosphate phosphatase and one SlTRE1 for trehalase in tomato genome. Nine SlTPSs, 4 SlTPPs, and SlTRE1 were selected for functional analyses to explore their involvement in tomato disease resistance. Some selected SlTPSs, SlTPPs, and SlTRE1 responded with distinct expression induction patterns to Botrytis cinerea and Pseudomonas syringae pv. tomato (Pst) DC3000 as well as to defense signaling hormones (e.g., salicylic acid, jasmonic acid, and a precursor of ethylene). Virus-induced gene silencing-mediated silencing of SlTPS3, SlTPS4, or SlTPS7 led to deregulation of ROS accumulation and attenuated the expression of defense-related genes upon pathogen infection and thus deteriorated the resistance against B. cinerea or Pst DC3000. By contrast, silencing of SlTPS5 or SlTPP2 led to an increased expression of the defense-related genes upon pathogen infection and conferred an increased resistance against Pst DC3000. Silencing of SlTPS3, SlTPS4, SlTPS5, SlTPS7, or SlTPP2 affected trehalose level in tomato plants with or without infection of B. cinerea or Pst DC3000. These results demonstrate that SlTPS3, SlTPS4, SlTPS5, SlTPS7, and SlTPP2 play roles in resistance against B. cinerea and Pst DC3000, implying the importance of trehalose and tis metabolism in regulation of defense response against pathogens in tomato. PMID:27540389

  7. Hepatitis C virus-induced hepatocellular carcinoma

    PubMed Central

    Goossens, Nicolas

    2015-01-01

    Hepatitis C virus (HCV) is a leading etiology of hepatocellular carcinoma (HCC). The interaction of HCV with its human host is complex and multilayered; stemming in part from the fact that HCV is a RNA virus with no ability to integrate in the host's genome. Direct and indirect mechanisms of HCV-induced HCC include activation of multiple host pathways such as liver fibrogenic pathways, cellular and survival pathways, interaction with the immune and metabolic systems. Host factors also play a major role in HCV-induced HCC as evidenced by genomic studies identifying polymorphisms in immune, metabolic, and growth signaling systems associated with increased risk of HCC. Despite highly effective direct-acting antiviral agents, the morbidity and incidence of liver-related complications of HCV, including HCC, is likely to persist in the near future. Clinical markers to selectively identify HCV subjects at higher risk of developing HCC have been reported however they require further validation, especially in subjects who have experienced sustained virological response. Molecular biomarkers allowing further refinement of HCC risk are starting to be implemented in clinical platforms, allowing objective stratification of risk and leading to individualized therapy and surveillance for HCV individuals. Another role for molecular biomarker-based stratification could be enrichment of HCC chemoprevention clinical trials leading to smaller sample size, shorter trial duration, and reduced costs. PMID:26157746

  8. Human immunodeficiency virus induced oral candidiasis.

    PubMed

    Warrier, S Aravind; Sathasivasubramanian, S

    2015-08-01

    Human immunodeficiency virus (HIV) infection is a worldwide health problem, which affects in both developing and developed countries. The oral lesions caused due to this disease can drastically change the life of the patient, in terms of quality. We can also know the progression of the disease and also the important immune status of the patient. Lots of information on HIV is known in the developed countries and very less reports are available in the developing countries. The morbidity of HIV disease is due to its association with opportunistic fungal infection and the most common among them is oral candidiasis. Here, we present a case report on an apparently healthy male patient of 39 years, who had oral candidiasis and was one of the indicators for HIV infection.

  9. Virus induced gene silencing in Lolium temulentum

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Lolium temulentum L. is valuable as a model species for studying abiotic stress in closely related forage and turf grasses, many of which are polyploid outcrossing species. As with most monocot species, Agrobacterium-mediated transformation of L. temulentum is still challenging, time consuming and n...

  10. Amphotropic murine leukemia viruses induce spongiform encephalomyelopathy.

    PubMed

    Münk, C; Löhler, J; Prassolov, V; Just, U; Stockschläder, M; Stocking, C

    1997-05-27

    Recombinants of amphotropic murine leukemia virus (A-MuLV) have found widespread use in retroviral vector systems due to their ability to efficiently and stably infect cells of several different species, including human. Previous work has shown that replication-competent recombinants containing the amphotropic env gene, encoding the major SU envelope glycoprotein that determines host tropism, induce lymphomas in vivo. We show here that these viruses also induce a spongiform encephalomyelopathy in mice inoculated perinatally. This fatal central nervous system disease is characterized by noninflammatory spongiform lesions of nerve and glial cells and their processes, and is associated with moderate astro- and microgliosis. The first clinical symptoms are ataxia, tremor, and spasticity, progressing to complete tetraparesis and incontinence, and finally death of the animal. Sequences within the amphotropic env gene are necessary for disease induction. Coinfection of A-MuLV recombinants with nonneuropathogenic ecotropic or polytropic MuLV drastically increases the incidence, degree, and distribution of the neurodegenerative disorder. The consequence of these results in view of the use of A-MuLV recombinants in the clinic is discussed.

  11. [Behavior of Argentine lymphocytic choriomeningitis virus strains in rodents].

    PubMed

    Saavedra, María del Cármen; Ambrosio, Ana M; Riera, Laura; Sabattini, Marta S

    2007-01-01

    The activity of LCM virus was first reported in Argentina at the beginning of the seventies and only five strains have been isolated from rodents Mus domesticus and two from humans. The objective of this paper was to find differential biological characteristics of Argentine strains of LCM virus comparing them in relation to the historical strains WE and Armstrong. Regarding the results obtained in tissue culture, when L 929 cells were used, plaque forming units (PFU) were obtained with human and mouse strains, whilst on Vero cells only human strains developed PFU. Differentials characteristics of historical and Argentine strain's plates were not found, neither differences related to the strain's origin. Neither historical nor Argentine strains were lethal to new-born mice giving a persistent infection, that was demonstrated when we inoculated new-born mouse by intracranial route with different strains of LCM virus and virus was isolated from brains harvested at different days post inoculation. The only exception was Cba An 13065 strain that exhibited virulence in new-born mice, only with 0.026 PFU was obtained 1 DL50. All the strains resulted lethal to adult mice. The mouse strains were more virulent than human strains, being Cba An 13065 the most virulent. These results demonstrate a different behavior in tissue culture between human and mouse strains and allow the identification of virulence markers by intracranial inoculation into new-born or adult mice.

  12. 9 CFR 113.42 - Detection of lymphocytic choriomeningitis contamination.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... of at least 10 mice obtained from a source free of LCM shall be injected in the footpad of a hindfoot with 0.02 ml of the material being tested and observed each day for 21 days. (b) If any of the...

  13. Generation of Lymphocytic Choriomeningitis Virus Based Vaccine Vectors.

    PubMed

    Ring, Sandra; Flatz, Lukas

    2016-01-01

    Vaccination with a recombinant LCMV based vector expressing tumor-associated or viral antigens is a safe and versatile method to induce an immune response against tumors or viral infections. Here, we describe the generation of recombinant LCMV vectors in which the gene encoding the viral LCMV-GP was substituted with a gene of interest (vaccine antigen). This renders the vaccine vector propagation-incompetent while it preserves the property of eliciting a strong cytotoxic T cell response. PMID:27076310

  14. 9 CFR 113.42 - Detection of lymphocytic choriomeningitis contamination.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... of at least 10 mice obtained from a source free of LCM shall be injected in the footpad of a hindfoot with 0.02 ml of the material being tested and observed each day for 21 days. (b) If any of the...

  15. 9 CFR 113.42 - Detection of lymphocytic choriomeningitis contamination.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... of at least 10 mice obtained from a source free of LCM shall be injected in the footpad of a hindfoot with 0.02 ml of the material being tested and observed each day for 21 days. (b) If any of the...

  16. 9 CFR 113.42 - Detection of lymphocytic choriomeningitis contamination.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... of at least 10 mice obtained from a source free of LCM shall be injected in the footpad of a hindfoot with 0.02 ml of the material being tested and observed each day for 21 days. (b) If any of the...

  17. 9 CFR 113.42 - Detection of lymphocytic choriomeningitis contamination.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... of at least 10 mice obtained from a source free of LCM shall be injected in the footpad of a hindfoot with 0.02 ml of the material being tested and observed each day for 21 days. (b) If any of the...

  18. Epidemiological and immunopathological studies on Porcine parvovirus infection in Punjab

    PubMed Central

    Kaur, Amninder; Mahajan, V.; Leishangthem, G. D.; Singh, N. D.; Bhat, Payal; Banga, H. S.; Filia, G.

    2016-01-01

    Aim: The aim of this study was to get the first-hand knowledge about the seroprevalence of Porcine parvovirus (PPV) in Punjab and a diagnosis of PPV from abortion cases of swine using gross, histopathological, and immunohistopathological techniques to observe the tissue tropism of the virus strain. Materials and Methods: Tissue samples from the reproductive tract of pig (n=32), placental tissue (n=10), and aborted fetuses (n=18) were collected from Postmortem Hall of the Department of Veterinary Pathology, GADVASU, field outbreaks and from butcher houses in and around Ludhiana. These samples were processed for histopathological and immunohistochemical (IHC) studies. For seroprevalence study, 90 serum samples of different sex and age were collected from 15 swine farms of Punjab and were subjected to indirect enzyme linked immunosorbent assay using commercial kit. Results: Overall, seroprevalence of PPV was found to be 41.1%. Sex and age related difference in the prevalence was noted. In abortion cases grossly congested and emphysematous lungs, congested internal organs with fluid in abdominal cavity and congestion in brain, changes were noted in fetuses, while diffuse hemorrhages and edema was observed in placental tissue. Histopathologically, the most frequent fetal lesions in aborted fetuses were noted in lungs, liver, and brain. IHC staining revealed PPV antigens in sections of heart, liver, lung, spleen, brain, lymph node of fetuses, placenta, and uterus of sow. Gross, histopathological, and IHC examination of the samples confirmed 5 fetus, 2 placenta and 3 female reproductive samples positive for parvovirus infection. Conclusions: Seroprevalence results may serve as a support either in prevention or control of the disease. IHC is the sensitive technique for diagnosis of PPV associated with the reproductive tract of swine and was found to supplement the gross and histopathological alterations, respectively, associated with the disease. PMID:27651669

  19. Immunopathological analysis of Erdheim-Chester disease with massive ascites.

    PubMed

    Ota, Muneo; Sakamoto, Mayuko; Sato, Kojiro; Yoshida, Yoshihiro; Funakubo Asanuma, Yu; Akiyama, Yuji; Yamakawa, Mitsunori; Mimura, Toshihide

    2012-01-01

    We treated a 77-year-old woman with pleural and pericardial effusion and ascites. Initially, collagen vascular disease was suspected due to the presence of anti-centromere antibodies and suspected complication of pulmonary arterial hypertension. However, soft-tissue abnormalities surrounding the bilateral kidneys detected on computed tomography (CT) and symmetrical lesions of the long bones detected on bone scintigraphy made us consider a diagnosis of Erdheim-Chester disease (ECD), which is a rare form of histiocytosis. We immunochemically analyzed the cells derived from the ascites in detail and confirmed the diagnosis. Immunocytochemical analyses may therefore help to achieve a better understanding of the pathogenesis of this rare disease. PMID:23037484

  20. Dirofilaria immitis. 5. Immunopathology of filarial nephropathy in dogs.

    PubMed Central

    Abramowsky, C. R.; Powers, K. G.; Aikawa, M.; Swinehart, G.

    1981-01-01

    Fourteen beagles infected with larvae (microfilariae) of Dirofilaria immitis, were randomly selected from another study in which the toxic effects of subfilaricidal doses of diethylcarbamazine were being evaluated. This group of 14 dogs, together with 4 uninfected control animals, were variably sacrificed between 14 and 25 months after larval inoculations, and the ensuing renal lesions were studied by light and ultrastructural microscopy and by immunofluorescence and antibody elution techniques. On the basis of these studies, two groups of animals were distinguished. The first group was characterized by a striking pattern of linear fluorescence and fine ultrastructural dense deposits along the glomerular basement membrane, poor antibody response, and an inability to clear microfilariae from the tissues and circulation. The second group, with a nonlinear pattern of fluorescence, was characterized by a strong immune response, efficient elimination of microfilariae, and immunofluorescence and ultrastructural evidence of predominantly mesangiopathic immune complex renal disease. In both groups, elution studies demonstrated tissue deposits of antiworm antibodies, suggesting a filaria-antibody immune-complex nephropathy. No evidence was found for the presence of anti-basement-membrane antibodies. On the basis of a previous experimental model, it is postulated that in the first group of animals with linear fluorescence, the observed lesions may represent a natural form of an immunopathogenic mechanism of glomerular damage in which filarial antigen becomes uniformly localized in the glomerulus and elicits an autologous antibody response. The possible role of the drug diethylcarbamazine in inducing this mechanism of immune injury is discussed. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 Figure 11 Figure 12 PMID:7020425

  1. Immunopathology of Japanese macaque encephalomyelitis is similar to multiple sclerosis.

    PubMed

    Blair, Tiffany C; Manoharan, Minsha; Rawlings-Rhea, Stephanie D; Tagge, Ian; Kohama, Steven G; Hollister-Smith, Julie; Ferguson, Betsy; Woltjer, Randall L; Frederick, Meredith C; Pollaro, James; Rooney, William D; Sherman, Larry S; Bourdette, Dennis N; Wong, Scott W

    2016-02-15

    Japanese macaque encephalomyelitis (JME) is an inflammatory demyelinating disease that occurs spontaneously in a colony of Japanese macaques (JM) at the Oregon National Primate Research Center. Animals with JME display clinical signs resembling multiple sclerosis (MS), and magnetic resonance imaging reveals multiple T2-weighted hyperintensities and gadolinium-enhancing lesions in the central nervous system (CNS). Here we undertook studies to determine if JME possesses features of an immune-mediated disease in the CNS. Comparable to MS, the CNS of animals with JME contain active lesions positive for IL-17, CD4+ T cells with Th1 and Th17 phenotypes, CD8+ T cells, and positive CSF findings.

  2. Saikosaponin A inhibits influenza A virus replication and lung immunopathology

    PubMed Central

    Zhao, Yaqin; Ling, Fangfang; Xiao, Kun; Li, Qian; Li, Bin; Lu, Chunni; Qi, Wenbao; Zeng, Zhenling; Liao, Ming; Liu, Yahong; Chen, Weisan

    2015-01-01

    Fatal influenza outcomes result from a combination of rapid virus replication and collateral lung tissue damage caused by exaggerated pro-inflammatory host immune cell responses. There are few therapeutic agents that target both biological processes for the attenuation of influenza-induced lung pathology. We show that Saikosaponin A, a bioactive triterpene saponin with previouslyestablished anti-inflammatory effects, demonstrates both in vitro and in vivo anti-viral activity against influenza A virus infections. Saikosaponin A attenuated the replication of three different influenza A virus strains, including a highly pathogenic H5N1 strain, in human alveolar epithelial A549 cells. This anti-viral activity occurred through both downregulation of NF-κB signaling and caspase 3-dependent virus ribonucleoprotein nuclear export as demonstrated by NF-κB subunit p65 and influenza virus nucleoprotein nuclear translocation studies in influenza virus infected A549 cells. Critically, Saikosaponin A also attenuated viral replication, aberrant pro-inflammatory cytokine production and lung histopathology in the widely established H1N1 PR8 model of influenza A virus lethality in C57BL/6 mice. Flow cytometry studies of mouse bronchoalveolar lavage cells revealed that SSa exerted immunomodulatory effects through a selective attenuation of lung neutrophil and monocyte recruitment during the early peak of the innate immune response to PR8 infection. Altogether, our results indicate that Saikosaponin A possesses novel therapeutic potential for the treatment of pathological influenza virus infections. PMID:26637810

  3. Saikosaponin A inhibits influenza A virus replication and lung immunopathology.

    PubMed

    Chen, Jianxin; Duan, Mubing; Zhao, Yaqin; Ling, Fangfang; Xiao, Kun; Li, Qian; Li, Bin; Lu, Chunni; Qi, Wenbao; Zeng, Zhenling; Liao, Ming; Liu, Yahong; Chen, Weisan

    2015-12-15

    Fatal influenza outcomes result from a combination of rapid virus replication and collateral lung tissue damage caused by exaggerated pro-inflammatory host immune cell responses. There are few therapeutic agents that target both biological processes for the attenuation of influenza-induced lung pathology. We show that Saikosaponin A, a bioactive triterpene saponin with previouslyestablished anti-inflammatory effects, demonstrates both in vitro and in vivo anti-viral activity against influenza A virus infections. Saikosaponin A attenuated the replication of three different influenza A virus strains, including a highly pathogenic H5N1 strain, in human alveolar epithelial A549 cells. This anti-viral activity occurred through both downregulation of NF-κB signaling and caspase 3-dependent virus ribonucleoprotein nuclear export as demonstrated by NF-κB subunit p65 and influenza virus nucleoprotein nuclear translocation studies in influenza virus infected A549 cells. Critically, Saikosaponin A also attenuated viral replication, aberrant pro-inflammatory cytokine production and lung histopathology in the widely established H1N1 PR8 model of influenza A virus lethality in C57BL/6 mice. Flow cytometry studies of mouse bronchoalveolar lavage cells revealed that SSa exerted immunomodulatory effects through a selective attenuation of lung neutrophil and monocyte recruitment during the early peak of the innate immune response to PR8 infection. Altogether, our results indicate that Saikosaponin A possesses novel therapeutic potential for the treatment of pathological influenza virus infections.

  4. Pattern recognition receptors in innate immunity, host defense, and immunopathology.

    PubMed

    Suresh, Rahul; Mosser, David M

    2013-12-01

    Infection by pathogenic microbes initiates a set of complex interactions between the pathogen and the host mediated by pattern recognition receptors. Innate immune responses play direct roles in host defense during the early stages of infection, and they also exert a profound influence on the generation of the adaptive immune responses that ensue. An improved understanding of the pattern recognition receptors that mediate innate responses and their downstream effects after receptor ligation has the potential to lead to new ways to improve vaccines and prevent autoimmunity. This review focuses on the control of innate immune activation and the role that innate immune receptors play in helping to maintain tissue homeostasis.

  5. Role of platelet adhesion in homeostasis and immunopathology.

    PubMed Central

    Männel, D N; Grau, G E

    1997-01-01

    Various molecules expressed on the surface of platelets have been shown to mediate the protective or deleterious role of these cells in immuno-inflammatory mechanisms. Increasing evidence points to the involvement of the cell adhesion molecules, gpIIb-IIIa, P-selectin, CD31, LFA-1, and CD36 in the interaction between platelets and endothelial cells as well as other cell types. The possible role of these molecules in the ability of platelets to support endothelium and to protect against tumour necrosis factor mediated cytolysis or parasitic invasion are reviewed. The involvement of platelets as effectors of tissue damage in cerebral malaria, lipopolysaccharide induced pathology, and pulmonary fibrosis is also discussed. This has then been extended to include the intercellular mechanisms underpinning their pathogenic role in metastasis, transplant rejection, stroke, brain hypoxia, and related conditions. A better understanding of the complex regulation and hierarchical organisation of these various platelet adhesion molecules may prove useful in the development of new approaches to the treatment of such diseases. Images PMID:9350300

  6. Tracking the immunopathological response to Pseudomonas aeruginosa during respiratory infections

    PubMed Central

    Cigana, Cristina; Lorè, Nicola Ivan; Riva, Camilla; De Fino, Ida; Spagnuolo, Lorenza; Sipione, Barbara; Rossi, Giacomo; Nonis, Alessandro; Cabrini, Giulio; Bragonzi, Alessandra

    2016-01-01

    Repeated cycles of infections, caused mainly by Pseudomonas aeruginosa, combined with a robust host immune response and tissue injury, determine the course and outcome of cystic fibrosis (CF) lung disease. As the disease progresses, P. aeruginosa adapts to the host modifying dramatically its phenotype; however, it remains unclear whether and how bacterial adaptive variants and their persistence influence the pathogenesis and disease development. Using in vitro and murine models of infection, we showed that P. aeruginosa CF-adaptive variants shaped the innate immune response favoring their persistence. Next, we refined a murine model of chronic pneumonia extending P. aeruginosa infection up to three months. In this model, including CFTR-deficient mice, we unveil that the P. aeruginosa persistence lead to CF hallmarks of airway remodelling and fibrosis, including epithelial hyperplasia and structure degeneration, goblet cell metaplasia, collagen deposition, elastin degradation and several additional markers of tissue damage. This murine model of P. aeruginosa chronic infection, reproducing CF lung pathology, will be instrumental to identify novel molecular targets and test newly tailored molecules inhibiting chronic inflammation and tissue damage processes in pre-clinical studies. PMID:26883959

  7. Epidemiological and immunopathological studies on Porcine parvovirus infection in Punjab

    PubMed Central

    Kaur, Amninder; Mahajan, V.; Leishangthem, G. D.; Singh, N. D.; Bhat, Payal; Banga, H. S.; Filia, G.

    2016-01-01

    Aim: The aim of this study was to get the first-hand knowledge about the seroprevalence of Porcine parvovirus (PPV) in Punjab and a diagnosis of PPV from abortion cases of swine using gross, histopathological, and immunohistopathological techniques to observe the tissue tropism of the virus strain. Materials and Methods: Tissue samples from the reproductive tract of pig (n=32), placental tissue (n=10), and aborted fetuses (n=18) were collected from Postmortem Hall of the Department of Veterinary Pathology, GADVASU, field outbreaks and from butcher houses in and around Ludhiana. These samples were processed for histopathological and immunohistochemical (IHC) studies. For seroprevalence study, 90 serum samples of different sex and age were collected from 15 swine farms of Punjab and were subjected to indirect enzyme linked immunosorbent assay using commercial kit. Results: Overall, seroprevalence of PPV was found to be 41.1%. Sex and age related difference in the prevalence was noted. In abortion cases grossly congested and emphysematous lungs, congested internal organs with fluid in abdominal cavity and congestion in brain, changes were noted in fetuses, while diffuse hemorrhages and edema was observed in placental tissue. Histopathologically, the most frequent fetal lesions in aborted fetuses were noted in lungs, liver, and brain. IHC staining revealed PPV antigens in sections of heart, liver, lung, spleen, brain, lymph node of fetuses, placenta, and uterus of sow. Gross, histopathological, and IHC examination of the samples confirmed 5 fetus, 2 placenta and 3 female reproductive samples positive for parvovirus infection. Conclusions: Seroprevalence results may serve as a support either in prevention or control of the disease. IHC is the sensitive technique for diagnosis of PPV associated with the reproductive tract of swine and was found to supplement the gross and histopathological alterations, respectively, associated with the disease.

  8. Clinical immunology and immunopathology of the canine and feline intestine.

    PubMed

    Allenspach, Karin

    2011-03-01

    The mucosal immune system is at the forefront of defense against invading pathogens, but at the same time, it must maintain tolerance toward commensals and food antigens in the intestinal lumen. The interplay between the innate immune response and commensal microorganisms is essential to maintaining this balance. Great progress has been made in identifying some of the genetic predispositions underlying inflammatory bowel disease in certain breeds, such as the German shepherd dog. Several immunologic markers are discussed with respect to their clinical usefulness in the diagnosis and management of inflammatory bowel disease.

  9. Pattern Recognition Receptors in Innate Immunity, Host Defense, and Immunopathology

    ERIC Educational Resources Information Center

    Suresh, Rahul; Mosser, David M.

    2013-01-01

    Infection by pathogenic microbes initiates a set of complex interactions between the pathogen and the host mediated by pattern recognition receptors. Innate immune responses play direct roles in host defense during the early stages of infection, and they also exert a profound influence on the generation of the adaptive immune responses that ensue.…

  10. Renal histology and immunopathology in distal renal tubular acidosis.

    PubMed

    Feest, T G; Lockwood, C M; Morley, A R; Uff, J S

    1978-11-01

    Renal biospy studies are reported from 10 patients with distal renal tubular acidosis (DRTA). On the biopsies from 6 patients who had associated immunological abnormalities immunofluorescent studies for immunoglobulins, complement, and fibrin were performed. Interstitial cellular infiltration and fibrosis were common findings in patients with and without immunological abnormalities, and were usually associated with nephrocalcinosis and/or recurrent urinary infection. No immune deposits were demonstrated in association with the renal tubules. This study shows that DRTA in immunologically abnormal patients is not caused by tubular deposition of antibody or immune complexes. The possibility of cell mediated immune damage is discussed.

  11. Immunopathological study of neuropeptide expression in human salivary gland neoplasms.

    PubMed

    Hayashi, Y; Deguchi, H; Nakahata, A; Kurashima, C; Hirokawa, K

    1990-01-01

    The immunoreactivity of anti-neuron-specific enolase (NSE) and anti-Leu-7 on formalin-fixed sections of human salivary gland neoplasms was determined by the avidin-biotin-peroxidase complex method. In addition, neuropeptides, such as vasoactive intestinal polypeptide, somatostatin, and substance P, in human salivary gland neoplasms were expressed, whereas other polypeptides, including glucagon, cholecystokinin, leu-enkephalin and calcitonin, were absent. When 182 paraffin-embedded examples of human salivary gland tumors, including 112 benign and 70 malignant neoplasms, were examined immunohistochemically, positive immunoreactivity was observed in: 51 cases with NSE (59%) and 46 cases with Leu-7 (54%) of 86 pleomorphic adenomas; 11 cases with Leu-7 (61%) of 18 Warthin's tumors; 7 cases with Leu-7 (58%) of 12 acinic cell carcinomas; 5 cases with NSE (31%) of 16 adenoid cystic carcinomas; 5 cases with NSE (42%) and 4 cases with Leu-7 (33%) of 12 adenocarcinomas; 4 cases with NSE (25%) and 6 cases with Leu-7 (38%) of 16 undifferentiated carcinomas. The other tumors, such as oxyphilic adenomas, basal cell adenomas, epidermoid carcinomas, and mucoepidermoid carcinomas, were nonreactive. Neuropeptides were observed in the neoplastic epithelial cells of certain tumors such as Warthin's tumors, acinic cell carcinomas, adenocarcinomas and undifferentiated carcinomas. These findings suggest the possibility that cells of neuroendocrine origin, present in certain neoplastic salivary gland epithelia may play a significant role in the histogenesis of human salivary gland neoplasms.

  12. Uncovering the mysteries of hantavirus infections.

    PubMed

    Vaheri, Antti; Strandin, Tomas; Hepojoki, Jussi; Sironen, Tarja; Henttonen, Heikki; Mäkelä, Satu; Mustonen, Jukka

    2013-08-01

    Hantaviruses are negative-sense single-stranded RNA viruses that infect many species of rodents, shrews, moles and bats. Infection in these reservoir hosts is almost asymptomatic, but some rodent-borne hantaviruses also infect humans, causing either haemorrhagic fever with renal syndrome (HFRS) or hantavirus cardiopulmonary syndrome (HCPS). In this Review, we discuss the basic molecular properties and cell biology of hantaviruses and offer an overview of virus-induced pathology, in particular vascular leakage and immunopathology.

  13. Uncovering the mysteries of hantavirus infections.

    PubMed

    Vaheri, Antti; Strandin, Tomas; Hepojoki, Jussi; Sironen, Tarja; Henttonen, Heikki; Mäkelä, Satu; Mustonen, Jukka

    2013-08-01

    Hantaviruses are negative-sense single-stranded RNA viruses that infect many species of rodents, shrews, moles and bats. Infection in these reservoir hosts is almost asymptomatic, but some rodent-borne hantaviruses also infect humans, causing either haemorrhagic fever with renal syndrome (HFRS) or hantavirus cardiopulmonary syndrome (HCPS). In this Review, we discuss the basic molecular properties and cell biology of hantaviruses and offer an overview of virus-induced pathology, in particular vascular leakage and immunopathology. PMID:24020072

  14. Aquatic viruses induce host cell death pathways and its application.

    PubMed

    Reshi, Latif; Wu, Jen-Leih; Wang, Hao-Ven; Hong, Jiann-Ruey

    2016-01-01

    Virus infections of mammalian and animal cells consist of a series of events. As intracellular parasites, viruses rely on the use of host cellular machinery. Through the use of cell culture and molecular approaches over the past decade, our knowledge of the biology of aquatic viruses has grown exponentially. The increase in aquaculture operations worldwide has provided new approaches for the transmission of aquatic viruses that include RNA and DNA viruses. Therefore, the struggle between the virus and the host for control of the cell's death machinery is crucial for survival. Viruses are obligatory intracellular parasites and, as such, must modulate apoptotic pathways to control the lifespan of their host to complete their replication cycle. This paper updates the discussion on the detailed mechanisms of action that various aquatic viruses use to induce cell death pathways in the host, such as Bad-mediated, mitochondria-mediated, ROS-mediated and Fas-mediated cell death circuits. Understanding how viruses exploit the apoptotic pathways of their hosts may provide great opportunities for the development of future potential therapeutic strategies and pathogenic insights into different aquatic viral diseases.

  15. Mechanism of Theiler's virus-induced demyelination in nude mice.

    PubMed

    Rosenthal, A; Fujinami, R S; Lampert, P W

    1986-05-01

    In its natural murine host, infection with Theiler's murine encephalomyelitis virus (TMEV) produces a chronic, progressive demyelinating disease. To help elucidate the role of host immune mechanisms involved in demyelination, we studied TMEV infection in Nude mice. These animals demonstrated rising titers of infectious virus within the central nervous system and failed to produce anti-TMEV antibody. Neurologic signs including the development of severe hind limb paralysis were evident approximately 2 weeks postinfection with most animals succumbing within the first month. Immunoperoxidase studies demonstrated viral antigen in the cytoplasm of neurons and glial cells for the entire period of observation. Plaques of demyelination associated with scanty inflammatory infiltrates were present in the spinal cord by 14 days postinfection. Electron microscopic studies of the involved white matter revealed numerous degenerating glial cells, many of which contained paracrystalline arrays of picornavirus within their cytoplasm. Some of the infected glial cells were identified as oligodendrocytes by demonstrating their myelin-plasma membrane connections. The studies indicate that in Nude mice TMEV causes a lytic infection of oligodendrocytes producing demyelination independent of the T lymphocyte immune system.

  16. Theiler's virus-induced central nervous system disease in mice.

    PubMed

    Lipton, H L; Canto, M C

    1976-01-01

    Theiler's viruses, which are common enteric pathogenes of mice, produce an unusual buphasic disease in the natural host following IC inoculation. There is an early phase of virus growth in CNS gray matter resulting in motor neuron degeneration and microglial proliferation. Since the spinal cord is the principal site of involvement, infected animals develop flaccid limb paralysis (early disease). Immunosuppression of the host during the early phase of infection augments virus growth and pathological lesions in gray matter, suggesting that TV causes a cytocidal infection of neurons. More importantly, surviving mice have persistent infection and pathological change limited to the spinal cord. There is marked mononuclear cell infiltration in the leptomeninges and white matter and concomitant primary demyelination. These changes are associated with a distinctive late-developing neurological disorder characterized by general inactivity, slowed movement, poor righting ability, and stimulus-sensitive extensor spasms. It appears that there are differences in host susceptibility to the development of late disease with the SJL/J inbred strain of mouse regularly showing the most severe clinical manifestations. Both humoral and cell-mediated immunity to TV antigen are delayed, reaching a maximum after 2 months; hence, this temporal sequence of the immune response is atypical of acute virus infections. Certain features of the late disease process favor an immune-mediated mechanism for demyelination, and this possibility is currently under investigation. The cells chronically supporting virus replication and the mechanisms of persistent infection remain to be elucidated.

  17. Influenza A virus--induced acute otitis media.

    PubMed

    Buchman, C A; Doyle, W J; Skoner, D P; Post, J C; Alper, C M; Seroky, J T; Anderson, K; Preston, R A; Hayden, F G; Fireman, P

    1995-11-01

    To better understand the significance of viral upper respiratory tract infections in the pathogenesis of acute otitis media (OM), 27 adults underwent intranasal inoculation with influenza A virus. Monitoring consisted of antibody titer determination, tympanometry, and otoscopy. Microbiologic analysis consisted of cultures and polymerase chain reaction (PCR)-based detection for influenza A virus, Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis. All subjects became infected with the challenge virus. By day 4, 16 (59%) developed middle ear pressures of -100 mm H2O or below and 4 (25%) of them developed OM. One subject (4%) developed purulent OM requiring myringotomy for pain relief. Middle ear effusion cultures were negative. PCR analysis of that subject's middle ear effusion and nasal washes were positive for influenza A virus and S. pneumoniae. These findings support a causal role for viral upper respiratory tract infections in the pathogenesis of OM, possibly mediated by middle ear underpressures and viral and bacterial middle ear infection.

  18. Lethal Mutagenesis of Hepatitis C Virus Induced by Favipiravir

    PubMed Central

    de Ávila, Ana I.; Gallego, Isabel; Soria, Maria Eugenia; Gregori, Josep; Quer, Josep; Esteban, Juan Ignacio; Rice, Charles M.; Domingo, Esteban; Perales, Celia

    2016-01-01

    Lethal mutagenesis is an antiviral approach that consists in extinguishing a virus by an excess of mutations acquired during replication in the presence of a mutagen. Here we show that favipiravir (T-705) is a potent mutagenic agent for hepatitis C virus (HCV) during its replication in human hepatoma cells. T-705 leads to an excess of G → A and C → U transitions in the mutant spectrum of preextinction HCV populations. Infectivity decreased significantly in the presence of concentrations of T-705 which are 2- to 8-fold lower than its cytotoxic concentration 50 (CC50). Passaging the virus five times in the presence of 400 μM T-705 resulted in virus extinction. Since T-705 has undergone advanced clinical trials for approval for human use, the results open a new approach based on lethal mutagenesis to treat hepatitis C virus infections. If proven effective for HCV in vivo, this new anti-HCV agent may be useful in patient groups that fail current therapeutic regimens. PMID:27755573

  19. Epstein-barr virus induced cellular changes in nasal mucosa

    PubMed Central

    Gelardi, Matteo; Tomaiuolo, Marilena; Cassano, Michele; Besozzi, Gaspare; Fiorella, Maria Luisa; Calvario, Agata; Castellano, Maria Antonia; Cassano, Pasquale

    2006-01-01

    A 21-year-old man presented with nasal obstruction of the right nasal fossa of 1 year duration. Nasal endoscopy revealed in the right inferior turbinate head a rounded neoplasm about 1 cm in diameter. Cytologic study of a nasal scraping specimen disclosed numerous clusters containing columnar cells with cytomegaly, prominent multinucleation, markedly sparse shortened cilia; the cytoplasm contained an acidophil area and a small round area that stained poorly; cells with a large intracytoplasmic vacuole that was acidophil and PAS+. Serology tests using the nested polymer chain reaction (PCR) technique on serum, nasal and pharyngeal smears revealed an Epstein-Barr virus (EBV) infection that was confirmed at electron microscopy. The clinical and cytological features resolved 19 months after the initial evaluation. Conclusion The authors advise carrying out clinical (endoscopy, serology, etc.) evaluation of all endonasal neoplasms and to routinely perform cytological study on nasal scraping specimens. When samples test positive for EBV, nasal and nasopharyngeal endoscopy should be performed regularly to detect possible evidence for nasopharyngeal carcinoma (NPC). PMID:16451721

  20. Merkel Cell Carcinoma: A Virus-Induced Human Cancer

    PubMed Central

    Chang, Yuan; Moore, Patrick S.

    2013-01-01

    Merkel cell polyomavirus (MCV) is the first polyomavirus directly linked to human cancer, and its recent discovery helps to explain many of the enigmatic features of Merkel cell carcinoma (MCC). MCV is clonally integrated into MCC tumor cells, which then require continued MCV oncoprotein expression to survive. The integrated viral genomes have a tumor-specific pattern of tumor antigen gene mutation that incapacitates viral DNA replication. This human cancer virus provides a new model in which a common, mostly harmless member of the human viral flora can initiate cancer if it acquires a precise set of mutations in a host with specific susceptibility factors, such as age and immune suppression. Identification of this tumor virus has led to new opportunities for early diagnosis and targeted treatment of MCC. PMID:21942528

  1. Calorimetric detection of influenza virus induced membrane fusion.

    PubMed

    Nebel, S; Bartoldus, I; Stegmann, T

    1995-05-01

    Membrane fusion induced by the hemagglutinin glycoprotein of influenza virus has been extensively characterized, but the mechanism whereby the protein achieves the merger of the viral and target membrane lipids remains enigmatic. Various lipid intermediate structures have been proposed, and the energies required for their formation predicted. Here, we have analyzed the enthalpies of fusion of influenza with liposomes by titration calorimetry. If a small sample of virus in a weak neutral pH buffer was added to an excess of liposomes at low pH, a two-component reaction was seen, composed of an exothermic reaction and a slower endothermic reaction. The exothermic reaction was the result of acid-base reactions between the neutral pH virus sample and low pH buffer and low-pH-induced changes in the virus. The endothermic reaction was not observed in the absence of liposomes and much reduced if acid-inactivated virus, which had lost its fusion but not its binding activity, was added to liposomes. The endothermic reaction was more temperature dependent than the exothermic reaction; its pH dependence corresponded with that of fusion and its enthalpy was higher if fusion was more extensive. These data indicate that most of the endothermic reaction was due to membrane fusion. The experimentally determined enthalpy of fusion, 0.6-0.7 kcal per mol of viral phospholipids, is much higher than expected on the basis of current theories about the formation of lipid intermediates during membrane fusion.

  2. [Virus-induced anorectal diseases. Condylomata acuminata and herpes simplex].

    PubMed

    Wienert, V

    2004-03-01

    Genital warts (condylomata acuminata) are very common sexually transmitted infections which may be present in perianal, anal and rarely rectal sites. Their incidence in the population is about 0.1%. As a rule, the diagnosis is simple and can be made by inspection; some variants pose a diagnostic challenge. The therapy is not uniform; it must be adjusted to the clinical manifestations and can be conservative or operative. Herpes simplex infections are also common; they too may be transferred by sexual intercourse and then commonly appear in the perianal skin and the rectal mucosa. While the clinical diagnosis is often difficult, the treatment is simple and effective.

  3. Microglia retard dengue virus-induced acute viral encephalitis

    PubMed Central

    Tsai, Tsung-Ting; Chen, Chia-Ling; Lin, Yee-Shin; Chang, Chih-Peng; Tsai, Cheng-Chieh; Cheng, Yi-Lin; Huang, Chao-Ching; Ho, Chien-Jung; Lee, Yi-Chao; Lin, Liang-Tzung; Jhan, Ming-Kai; Lin, Chiou-Feng

    2016-01-01

    Patients with dengue virus (DENV) infection may also present acute viral encephalitis through an unknown mechanism. Here, we report that encephalitic DENV-infected mice exhibited progressive hunchback posture, limbic seizures, limbic weakness, paralysis, and lethality 7 days post-infection. These symptoms were accompanied by CNS inflammation, neurotoxicity, and blood-brain barrier destruction. Microglial cells surrounding the blood vessels and injured hippocampus regions were activated by DENV infection. Pharmacologically depleting microglia unexpectedly increased viral replication, neuropathy, and mortality in DENV-infected mice. In microglia-depleted mice, the DENV infection-mediated expression of antiviral cytokines and the infiltration of CD8-positive cytotoxic T lymphocytes (CTLs) was abolished. DENV infection prompted the antigen-presenting cell-like differentiation of microglia, which in turn stimulated CTL proliferation and activation. These results suggest that microglial cells play a key role in facilitating antiviral immune responses against DENV infection and acute viral encephalitis. PMID:27279150

  4. Histopathology of spontaneous regression in virus-induced murine leukemia.

    PubMed Central

    Russo, I.; Russo, J.; Baldwin, J.; Rich, M. A.

    1976-01-01

    The histopathology of the spontaneous regression of murine leukemia induced by a particular strain of Friend leukemia virus was studied in Swiss ICR/Ha mice. Animals inoculated with the regressing strain of Friend virus exhibited an initial pathologic response identical to that induced by conventional strains of Friend virus. Unlike the fatal leukemia produced by conventional Friend virus, the pathology of the disease induced by the regressing strain of Friend virus appeared to be self-limiting. The histopathology of the two diseases is compared in this report. Images Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 Figure 11 Figure 12 Figure 13 Figure 1 Figure 2 Figure 3 Figure 4 PMID:970443

  5. A Case of Chikungunya Virus Induced Arthralgia Responsive to Colchicine.

    PubMed

    Redel, Henry

    2016-04-01

    Chikungunya virus is an emerging infectious disease that has started circulating throughout the Americas and Caribbean. It can lead to persistent arthralgia lasting months to years. Treatment has been symptomatic with nonsteroidal anti-inflammatory medications. This case report describes a trial of colchicine for chikungunya arthralgia in 1 patient. PMID:27419183

  6. Amphotropic murine leukemia viruses induce spongiform encephalomyelopathy

    PubMed Central

    Münk, Carsten; Löhler, Jürgen; Prassolov, Vladimir; Just, Ursula; Stockschläder, Marcus; Stocking, Carol

    1997-01-01

    Recombinants of amphotropic murine leukemia virus (A-MuLV) have found widespread use in retroviral vector systems due to their ability to efficiently and stably infect cells of several different species, including human. Previous work has shown that replication-competent recombinants containing the amphotropic env gene, encoding the major SU envelope glycoprotein that determines host tropism, induce lymphomas in vivo. We show here that these viruses also induce a spongiform encephalomyelopathy in mice inoculated perinatally. This fatal central nervous system disease is characterized by noninflammatory spongiform lesions of nerve and glial cells and their processes, and is associated with moderate astro- and microgliosis. The first clinical symptoms are ataxia, tremor, and spasticity, progressing to complete tetraparesis and incontinence, and finally death of the animal. Sequences within the amphotropic env gene are necessary for disease induction. Coinfection of A-MuLV recombinants with nonneuropathogenic ecotropic or polytropic MuLV drastically increases the incidence, degree, and distribution of the neurodegenerative disorder. The consequence of these results in view of the use of A-MuLV recombinants in the clinic is discussed. PMID:9159161

  7. Influenza virus induces bacterial and nonbacterial otitis media.

    PubMed

    Short, Kirsty R; Diavatopoulos, Dimitri A; Thornton, Ruth; Pedersen, John; Strugnell, Richard A; Wise, Andrew K; Reading, Patrick C; Wijburg, Odilia L

    2011-12-15

    Otitis media (OM) is one of the most common childhood diseases. OM can arise when a viral infection enables bacteria to disseminate from the nasopharynx to the middle ear. Here, we provide the first infant murine model for disease. Mice coinfected with Streptococcus pneumoniae and influenza virus had high bacterial load in the middle ear, middle ear inflammation, and hearing loss. In contrast, mice colonized with S. pneumoniae alone had significantly less bacteria in the ear, minimal hearing loss, and no inflammation. Of interest, infection with influenza virus alone also caused some middle ear inflammation and hearing loss. Overall, this study provides a clinically relevant and easily accessible animal model to study the pathogenesis and prevention of OM. Moreover, we provide, to our knowledge, the first evidence that influenza virus alone causes middle ear inflammation in infant mice. This inflammation may then play an important role in the development of bacterial OM.

  8. Molecular mechanism of hepatitis B virus-induced hepatocarcinogenesis

    PubMed Central

    Tarocchi, Mirko; Polvani, Simone; Marroncini, Giada; Galli, Andrea

    2014-01-01

    Hepatitis B virus (HBV) infection is a global public health problem with approximately 2 billion people that have been exposed to the virus. HBV is a member of a family of small, enveloped DNA viruses called hepadnaviruses, and has a preferential tropism for hepatocytes of mammals and birds. Epidemiological studies have proved a strong correlation between chronic hepatitis B virus infection and the development of hepatocellular carcinoma (HCC). HCC is the fifth most common malignancy with about 700000 new cases each year, and more than 50% of them arise in HBV carriers. A large number of studies describe the way in which HBV can contribute to HCC development. Multiple mechanisms have been proposed, including the accumulation of genetic damage due to immune-mediated hepatic inflammation and the induction of oxidative stress. There is evidence of the direct effects of the viral proteins HBx and HBs on the cell biology. Integration of HBV-DNA into the human genome is considered an early event in the carcinogenic process and can induce, through insertional mutagenesis, the alteration of gene expression and chromosomal instability. HBV has also epigenetic effects through the modification of the genomic methylation status. Furthermore, the virus plays an important role in the regulation of microRNA expression. This review will summarize the many mechanisms involved in HBV-related liver carcinogenesis. PMID:25206269

  9. Active immunization by a dengue virus-induced cytokine.

    PubMed Central

    Chaturvedi, U C; Mukerjee, R; Dhawan, R

    1994-01-01

    Dengue type 2 virus (DV)-induced cytotoxic factor (CF) is capable of reproducing various pathological lesions in mice that are seen in human dengue. The present study was undertaken to investigate the protective effect of active immunization of mice with CF. Mice were immunized with 5 microgram of CF and prevention of CF-induced increase in capillary permeability and damage to the blood-brain barrier were studied at weekly intervals, up to 48 weeks, by challenging with 3 microgram of CF. Maximum protection against increase in capillary permeability and damage to the blood-brain barrier was observed in week 4 after immunization. A breakthrough in the protection occurred with higher doses of CF in a dose-dependent manner. Challenge with a lethal intracerebral (i.c.) dose of DV showed significantly prolonged mean survival time and delayed onset of symptoms of sickness in the immunized mice compared with the normal mice, but the titre of the virus in the brain was similar in the two groups. On i.p. challenge with the virus the protection against damage to the blood-brain barrier was 86 +/- 7% at week 4 and 17 +/- 4% at week 26 after immunization. Sera obtained from the immunized mice showed the presence of CF-specific antibodies by ELISA, Western blot, and by neutralization of the cytotoxic activity of CF in vitro. The present study describes successful prevention of a cytokine-induced pathology by specific active immunization. PMID:8187327

  10. Microglia retard dengue virus-induced acute viral encephalitis.

    PubMed

    Tsai, Tsung-Ting; Chen, Chia-Ling; Lin, Yee-Shin; Chang, Chih-Peng; Tsai, Cheng-Chieh; Cheng, Yi-Lin; Huang, Chao-Ching; Ho, Chien-Jung; Lee, Yi-Chao; Lin, Liang-Tzung; Jhan, Ming-Kai; Lin, Chiou-Feng

    2016-01-01

    Patients with dengue virus (DENV) infection may also present acute viral encephalitis through an unknown mechanism. Here, we report that encephalitic DENV-infected mice exhibited progressive hunchback posture, limbic seizures, limbic weakness, paralysis, and lethality 7 days post-infection. These symptoms were accompanied by CNS inflammation, neurotoxicity, and blood-brain barrier destruction. Microglial cells surrounding the blood vessels and injured hippocampus regions were activated by DENV infection. Pharmacologically depleting microglia unexpectedly increased viral replication, neuropathy, and mortality in DENV-infected mice. In microglia-depleted mice, the DENV infection-mediated expression of antiviral cytokines and the infiltration of CD8-positive cytotoxic T lymphocytes (CTLs) was abolished. DENV infection prompted the antigen-presenting cell-like differentiation of microglia, which in turn stimulated CTL proliferation and activation. These results suggest that microglial cells play a key role in facilitating antiviral immune responses against DENV infection and acute viral encephalitis. PMID:27279150

  11. GMCSF-armed vaccinia virus induces an antitumor immune response.

    PubMed

    Parviainen, Suvi; Ahonen, Marko; Diaconu, Iulia; Kipar, Anja; Siurala, Mikko; Vähä-Koskela, Markus; Kanerva, Anna; Cerullo, Vincenzo; Hemminki, Akseli

    2015-03-01

    Oncolytic Western Reserve strain vaccinia virus selective for epidermal growth factor receptor pathway mutations and tumor-associated hypermetabolism was armed with human granulocyte-macrophage colony-stimulating factor (GMCSF) and a tdTomato fluorophore. As the assessment of immunological responses to human transgenes is challenging in the most commonly used animal models, we used immunocompetent Syrian golden hamsters, known to be sensitive to human GMCSF and semipermissive to vaccinia virus. Efficacy was initially tested in vitro on various human and hamster cell lines and oncolytic potency of transgene-carrying viruses was similar to unarmed virus. The hGMCSF-encoding virus was able to completely eradicate subcutaneous pancreatic tumors in hamsters, and to fully protect the animals from subsequent rechallenge with the same tumor. Induction of specific antitumor immunity was also shown by ex vivo co-culture experiments with hamster splenocytes. In addition, histological examination revealed increased infiltration of neutrophils and macrophages in GMCSF-virus-treated tumors. These findings help clarify the mechanism of action of GMCSF-armed vaccinia viruses undergoing clinical trials.

  12. Notes from the Field: Lymphocytic Choriomeningitis Virus Meningoencephalitis from a Household Rodent Infestation - Minnesota, 2015.

    PubMed

    Talley, Pamela; Holzbauer, Stacy; Smith, Kirk; Pomputius, William

    2016-03-11

    On April 20, 2015, a female aged 15 years sought care at her pediatrician's office after 5 days of fever, myalgia, left parietal headache, and photophobia. A rapid influenza assay was negative, and erythrocyte sedimentation rate and total white blood cell count were normal. She improved with symptomatic care at home, but returned to her pediatrician's office on April 28, reporting recurrence of her headache and photophobia and new onset of a stiff neck. She was admitted to the hospital, where she was febrile to 102.9°F (39.4°C) and had meningismus. Computed tomography scan of her head was normal, and a cerebrospinal fluid (CSF) analysis showed a markedly elevated white blood cell count with 68% lymphocytes, low glucose, and a negative Gram stain. She was treated empirically for both bacterial and herpes simplex virus meningitis. The patient's hospital course was notable for hypotension (blood pressure 81/50), irritability, and pancreatitis with a peak lipase of 8,627 U/L. CSF cultures yielded no growth, and CSF polymerase chain reaction (PCR) testing for herpes simplex virus was negative. Nucleic acid amplification testing, acid-fast bacilli stain, and acid-fast bacilli cultures of CSF were negative for Mycobacterium tuberculosis. Results of investigations for human immunodeficiency virus, syphilis, Lyme disease, human herpesvirus 6 and 7, and species of Babesia, Toxoplasma, Histoplasma, Cryptococcus, Blastomyces, and Brucella were negative. She recovered and was discharged on hospital day 11 with no apparent sequelae. PMID:26963688

  13. Notes from the Field: Lymphocytic Choriomeningitis Virus Meningoencephalitis from a Household Rodent Infestation - Minnesota, 2015.

    PubMed

    Talley, Pamela; Holzbauer, Stacy; Smith, Kirk; Pomputius, William

    2016-03-11

    On April 20, 2015, a female aged 15 years sought care at her pediatrician's office after 5 days of fever, myalgia, left parietal headache, and photophobia. A rapid influenza assay was negative, and erythrocyte sedimentation rate and total white blood cell count were normal. She improved with symptomatic care at home, but returned to her pediatrician's office on April 28, reporting recurrence of her headache and photophobia and new onset of a stiff neck. She was admitted to the hospital, where she was febrile to 102.9°F (39.4°C) and had meningismus. Computed tomography scan of her head was normal, and a cerebrospinal fluid (CSF) analysis showed a markedly elevated white blood cell count with 68% lymphocytes, low glucose, and a negative Gram stain. She was treated empirically for both bacterial and herpes simplex virus meningitis. The patient's hospital course was notable for hypotension (blood pressure 81/50), irritability, and pancreatitis with a peak lipase of 8,627 U/L. CSF cultures yielded no growth, and CSF polymerase chain reaction (PCR) testing for herpes simplex virus was negative. Nucleic acid amplification testing, acid-fast bacilli stain, and acid-fast bacilli cultures of CSF were negative for Mycobacterium tuberculosis. Results of investigations for human immunodeficiency virus, syphilis, Lyme disease, human herpesvirus 6 and 7, and species of Babesia, Toxoplasma, Histoplasma, Cryptococcus, Blastomyces, and Brucella were negative. She recovered and was discharged on hospital day 11 with no apparent sequelae.

  14. Modeling the Lymphocytic Choriomeningitis Virus: Insights into understanding its epidemiology in the wild

    NASA Astrophysics Data System (ADS)

    Contreras, Christy; McKay, John; Blattman, Joseph; Holechek, Susan

    2015-03-01

    The lymphocytic choriomenigitis virus (LCMV) is a rodent-spread virus commonly recognized as causing neurological disease that exhibits asymptomatic pathology. The virus is a pathogen normally carried among rodents that can be transmitted to humans by direct or indirect contact with the virus in excretions and secretions from rodents and can cause aseptic meningitis and other conditions in humans. We consider an epidemiological system within rodent populations modeled by a system of ordinary differential equations that captures the dynamics of the diseases transmission and present our findings. The asymptotic nature of the pathogen plays a large role in its spread within a given population, which has motivated us to expand upon an existing SIRC model (Holechek et al in preparation) that accounts for susceptible-, infected-, recovered-, and carrier-mice on the basis of their gender. We are interested in observing and determining the conditions under which the carrier population will reach a disease free equilibrium, and we focus our investigation on the sensitivity of our model to gender, pregnancy related infection, and reproduction rate conditions.

  15. TNFRs and Control of Chronic LCMV Infection: Implications for Therapy.

    PubMed

    Clouthier, Derek L; Watts, Tania H

    2015-11-01

    The control of persistent viral infections requires the immune system to limit the spread of the virus while avoiding immunopathology. Recent studies have revealed that members of the tumor necrosis factor receptor (TNFR) superfamily play unique and pivotal roles in control of chronic lymphocytic choriomeningitis virus (LCMV) infection and in some settings can tip the balance between immune control and immune pathology. We review these findings and discuss how our understanding of the role of TNFRs in the immune response to chronic LCMV infection may shed light on what happens during HIV infection in humans. We discuss preclinical models of TNF/TNFR family-targeted immunotherapy of chronic LCMV infection and evaluate which TNFRs present the most promising targets for immune intervention. PMID:26481667

  16. Exogenous avian leukosis virus-induced activation of the ERK/AP1 pathway is required for virus replication and correlates with virus-induced tumorigenesis

    PubMed Central

    Dai, Manman; Feng, Min; Ye, Yu; Wu, Xiaochan; Liu, Di; Liao, Ming; Cao, Weisheng

    2016-01-01

    A proteomics approach was used to reveal the up-regulated proteins involved in the targeted mitogen-activated protein kinase (MAPK) signal transduction pathway in DF-1 cells after ALV subgroup J (ALV-J) infection. Next, we found that ALV-J CHN06 strain infection of DF-1 cells correlated with extracellular signal-regulated kinase 2 (ERK2) activation, which was mainly induced within 15 min, a very early stage of infection, and at a late infection stage, from 108 h to 132 h post-infection. Infection with other ALV subgroup (A/B) strains also triggered ERK/MAPK activation. Moreover, when activating ERK2, ALV subgroups A, B and J simultaneously induced the phosphorylation of c-Jun, an AP1 family member and p38 activation but had no obvious effect on JNK activation at either 15 min or 120 h. Interestingly, only PD98059 inhibited the ALV-induced c-Jun phosphorylation while SP600125 or SB203580 had no influence on c-Jun activation. Furthermore, the viral gp85 and gag proteins were found to contribute to ERK2/AP1 activation. Additionally, the specific ERK inhibitor, PD980509, significantly suppressed ALV replication, as evidenced by extremely low levels of ALV promoter activity and ALV-J protein expression. In vivo analysis of ERK2 activation in tumor cells derived from ALV-J-infected chicken demonstrated a strong correlation between ERK/MAPK activation and virus-associated tumorigenesis. PMID:26754177

  17. Immunopathology of glomerulonephritis associated with chronic woodchuck hepatitis virus infection in woodchucks (Marmota monax).

    PubMed Central

    Peters, D. N.; Steinberg, H.; Anderson, W. I.; Hornbuckle, W. E.; Cote, P. J.; Gerin, J. L.; Lewis, R. M.; Tennant, B. C.

    1992-01-01

    Retrospective analysis of necropsy findings of 705 woodchucks was performed to determine the prevalence and morphology of immune-mediated glomerulonephritis, its relationship to woodchuck hepatitis virus (WHV) infection, and the presence of major WHV antigens. Twenty-six woodchucks had glomerular lesions. Renal tissue of the 26 animals was evaluated histologically and immunohistochemically for immune-mediated glomerulonephritis. Of these 26 animals, immune-mediated glomerulonephritis was diagnosed in six, all of which were chronic WHV carriers. Membranous glomerulonephritis was identified in three animals, two of which also had mesangial proliferation. Host immunoglobulin was present within the mesangium and along capillary loops in all three. Woodchuck hepatitis virus core antigen (WHcAg) was present along capillary loops of two of these animals, one membranous and one mixed, and in the mesangium of all three. Woodchuck hepatitis virus surface antigen (WHsAg) deposition was similar to WHcAg deposition but was only present along capillaries in those animals with mixed nephritis. The remaining three animals had mesangial proliferation. WHsAg and host immunoglobulin deposition were predominately mesangial; WHcAg was not detected. Transmission electron microscopy showed thickening of the capillary loop basement membranes and subepithelial electron-dense deposits in animal one, and deposits in the mesangium in animal six. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 PMID:1632459

  18. Immunopathological assessments of human Blastocystis spp. in experimentally infected immunocompetent and immunosuppresed mice.

    PubMed

    Abdel-Hafeez, Ekhlas H; Ahmad, Azza K; Abdelgelil, Noha H; Abdellatif, Manal Z M; Kamal, Amany M; Hassanin, Kamel M A; Abdel-Razik, Abdel-Razik H; Abdel-Raheem, Ehab M

    2016-05-01

    Blastocystis spp., one of the most common parasites colonizing the human intestine, is an extracellular, luminal protozoan with controversial pathogenesis. The host's immune response against Blastocystis spp. infection has also not been defined yet. Therefore, this research aimed to assess the potential pathogenicity of this parasite and its ability to modulate the immune response in experimental infected immunocompetent and immunosuppresed mice. These results demonstrated that the infected immunosuppressed mice were more affected than infected immunocompetent mice. Histopathological examination of the small intestine in the infected immunosuppressed mice showed that Blastocystis spp. infiltrated all the layers. Moreover, the epithelia showed exfoliation and inflammatory cell infiltration in submucosa compared to that of the infected immunocompetent mice. As well, examination of the large intestine of the infected immunosuppressed group showed severe goblet cell hyperplasia. Blastocystis spp. infiltrated all the large intestine layers compared to that of the infected immunocompetent group. Furthermore, there was a significant upregulation of the expression of proinflammatory cytokines: interleukin 12 (IL-12) and tumor necrosis factor alpha (TNF-α) in the infected immunosuppressed mice compared to that of the infected immunocompetent ones (p ≤ 0.004 and p ≤ 0.002, respectively). However, the expression of anti-inflammatory cytokines (IL-4 and IL-10) was significantly downregulated in the infected immunosuppressed group compared to that of the infected immunocompetent group one at 10 days postinfection (p ≤ 0.002 and p ≤ 0.001, respectively). The results of this study revealed that Blastocystis spp. affected the production of pro- and anti-inflammatory cytokines in both groups of mice compared to healthy normal (naive) group. Additionally, these data showed that there was a significant upregulation (p ≤ 0.005) of the locally synthesized antibody: secretary IgA (sIgA) in the gut of the infected immunocompetent mice when compared to that of the infected immunosuppressed ones. PMID:26860840

  19. Inflammation and Cell Death in Age-Related Macular Degeneration: An Immunopathological and Ultrastructural Model.

    PubMed

    Ardeljan, Christopher P; Ardeljan, Daniel; Abu-Asab, Mones; Chan, Chi-Chao

    2014-01-01

    The etiology of Age-related Macular Degeneration (AMD) remains elusive despite the characterization of many factors contributing to the disease in its late-stage phenotypes. AMD features an immune system in flux, as shown by changes in macrophage polarization with age, expression of cytokines and complement, microglial accumulation with age, etc. These point to an allostatic overload, possibly due to a breakdown in self vs. non-self when endogenous compounds and structures acquire the appearance of non-self over time. The result is inflammation and inflammation-mediated cell death. While it is clear that these processes ultimately result in degeneration of retinal pigment epithelium and photoreceptor, the prevalent type of cell death contributing to the various phenotypes is unknown. Both molecular studies as well as ultrastructural pathology suggest pyroptosis, and perhaps necroptosis, are the predominant mechanisms of cell death at play, with only minimal evidence for apoptosis. Herein, we attempt to reconcile those factors identified by experimental AMD models and integrate these data with pathology observed under the electron microscope-particularly observations of mitochondrial dysfunction, DNA leakage, autophagy, and cell death. PMID:25580276

  20. Clinical and Immunopathologic Profile of Mexican Patients with IgG4 Autoimmune Pancreatitis

    PubMed Central

    Bourlon, María T.; Bourlon, Christianne; Atisha-Fregoso, Yemil; Chable-Montero, Fredy; Teliz, Marco A.; Angeles-Angeles, Arturo; Carrillo-Maravilla, Eduardo; Llorente, Luis; Uscanga, Luis F.

    2012-01-01

    Autoimmune pancreatitis is part of the spectrum of IgG4-associated diseases. Its diagnostic criteria and histological subtypes have been formally proposed recently and although based on current data it has been suggested that there are differences in clinical presentation among populations, more research is needed to properly establish if this heterogeneity exists. In this paper, we describe 15 cases of autoimmune pancreatitis diagnosed at a Mexican centre of reference, all of them associated to the lymphoplasmocytic sclerosing pancreatitis variant. The mean age at the onset of symptoms was 47.5 ± 14.4 years, and 53% of patients were male. The main manifestations were weight loss (87%), obstructive jaundice (53%), and acute (27%) and chronic (27%) pancreatitis. Only 20% of patients had high IgG4 serum levels at the time of diagnosis. All patients receiving prednisone responded favourably, both in their pancreatic and extrapancreatic manifestations. Clinical manifestations of Mexican patients showed certain differences with respect to those usually reported. PMID:22666608

  1. Role of cysteine and glutathione in signal transduction, immunopathology and cachexia.

    PubMed

    Dröge, W; Hack, V; Breitkreutz, R; Holm, E; Shubinsky, G; Schmid, E; Galter, D

    1998-01-01

    Abnormally low plasma cystine levels have been found in the late asymptomatic stage of HIV infection and several other diseases associated with progressive loss of skeletal muscle mass. The phenomenon is commonly associated with a low NK cell activity, skeletal muscle wasting or muscle fatigue and increased rates of urea production. In its extreme form, the negative nitrogen balance leads to overt cachexia and is associated with severe debilitation and psychological stress. The low NK cell activity is in most cases not life-threatening but may be disasterous in HIV infection, because it may compromise the initially stable balance between immune system and virus and trigger disease progression. This review summarizes briefly (i) the role of cysteine in the physiological regulation of body cell mass and the development of skeletal muscle wasting, and (ii) the role of glutathione in the immune system.

  2. Immunopathologic effects of scorpion venom on hepato-renal tissues: Involvement of lipid derived inflammatory mediators.

    PubMed

    Lamraoui, Amal; Adi-Bessalem, Sonia; Laraba-Djebari, Fatima

    2015-10-01

    Scorpion venoms are known to cause different inflammatory disorders through complex mechanisms in various tissues. In the study here, the involvement of phospholipase A2 (PLA2) and cyclo-oxygenase (COX)-derived metabolites in hepatic and renal inflammation responses were examined. Mice were envenomed with Androctonus australis hector scorpion venom in the absence or presence of inhibitors that can interfere with lipid inflammatory mediator synthesis, i.e., dexamethasone (PLA2 inhibitor), indomethacin (non-selective COX-1/COX-2 inhibitor), or celecoxib (selective COX-2 inhibitor). The inflammatory response was assessed by evaluating vascular permeability changes, inflammatory cell infiltration, oxidative/nitrosative stress marker levels, and by histologic and functional analyses of the liver and kidney. Results revealed that the venom alone induced an inflammatory response in this tissues marked by increased microvascular permeability and inflammatory cell infiltration, increases in levels of nitric oxide and lipid peroxidation, and decreases in antioxidant defense. Moreover, significant alterations in the histological architecture of these organs were associated with increased serum levels of some metabolic enzymes, as well as urea and uric acid. Pre-treatment of mice with dexamethasone led to significant decreases of the inflammatory disorders in the hepatic parenchyma; celecoxib pre-treatment seemed to be more effective against renal inflammation. Indomethacin pre-treatment only slightly reduced the inflammatory disorders in the tissues. These results suggest that the induced inflammation response in liver was mediated mainly by PLA2 activation, while the renal inflammatory process was mediated by prostaglandin formation by COX-2. These findings provide additional insight toward the understanding of activated pathways and related mechanisms involved in scorpion envenoming syndrome.

  3. Serology of Lupus Erythematosus: Correlation between Immunopathological Features and Clinical Aspects

    PubMed Central

    Cozzani, Emanuele; Drosera, Massimo; Parodi, Aurora

    2014-01-01

    Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by the aberrant production of a broad and heterogenous group of autoantibodies. Even though the presence of autoantibodies in SLE has been known, for more than 60 years, still nowadays a great effort is being made to understand the pathogenetic, diagnostic, and prognostic meaning of such autoantibodies. Antibodies to ds-DNA are useful for the diagnosis of SLE, to monitor the disease activity, and correlate with renal and central nervous involvements. Anti-Sm antibodies are highly specific for SLE. Anti-nucleosome antibodies are an excellent marker for SLE and good predictors of flares in quiescent lupus. Anti-histone antibodies characterize drug-induced lupus, while anti-SSA/Ro and anti-SSB/La antibodies are associated with neonatal lupus erythematosus and photosensitivity. Anti-ribosomal P antibodies play a role in neuropsychiatric lupus, but their association with clinical manifestations is still unclear. Anti-phospholipid antibodies are associated with the anti-phospholipid syndrome, cerebral vascular disease, and neuropsychiatric lupus. Anti-C1q antibodies amplify glomerular injury, and the elevation of their titers may predict renal flares. Anti-RNP antibodies are a marker of Sharp's syndrome but can be found in SLE as well. Anti-PCNA antibodies are present in 5–10% of SLE patients especially those with arthritis and hypocomplementemia. PMID:24649358

  4. [Congenital components of immunity: Toll-like receptors in the normal state and in immunopathology].

    PubMed

    Koval'chuk, L V; Khoreva, M V; Varivoda, A S

    2005-01-01

    This review deals with rapidly accumulating information on a highly important components of the congenital immune system: Toll-like receptors playing a leading role in the recognition of microbial patterns. The data on the main structural and functional features of Toll-like receptors and their distribution in the body are summarized. The main signal paths are characterized and the key molecules which take part in the transduction are pointed out. Special attention is paid to the activating action of lipopolysaccharides through TLR4. Pathological processes developing as the result of damages in the structure and function of Toll-like receptors in humans and experimental animals are determined.

  5. [Autoimmune diseases of the peripheral cornea. Immunopathology, clinical aspects and therapy].

    PubMed

    Pleyer, U; Bergmann, L; Krause, A; Hartmann, C

    1996-02-01

    Noninfectious ulceration of the peripheral cornea remains a major diagnostic and therapeutic challenge. The pathogenesis in most of these disorders is unclear, however, on the basis of systemic connective tissue diseases, autoimmune mechanisms are most likely involved. The peripheral cornea has distinct morphological and immunological characteristics that predispose for inflammatory reactions. Major differences exist regarding humoral and cellular components of the immune system. In the peripheral cornea there is more high-molecular IgM and initial complement component C1 than in the central cornea and may predispose for immune complex formation. The close contact to the conjunctival vasculature provides the basis necessary to generate an immune response. Langerhans cells and macrophages as important antigen presenting and processing cells are present in higher number in the peripheral cornea. Autoimmune diseases that affect the peripheral cornea include collagen vascular diseases and Mooren's ulcer. Although this association is obvious in advanced rheumatoid arthritis more subtle forms of polyarteritis nodosa or systemic lupus erythematosus require careful medical evaluation and workup. Ocular manifestations may present as the initial clinical signs and require careful workup in these potentially lethal disorders.

  6. MicroRNAs in the Host-Apicomplexan Parasites Interactions: A Review of Immunopathological Aspects

    PubMed Central

    Judice, Carla C.; Bourgard, Catarina; Kayano, Ana C. A. V.; Albrecht, Letusa; Costa, Fabio T. M.

    2016-01-01

    MicroRNAs (miRNAs), a class of small non-coding regulatory RNAs, have been detected in a variety of organisms ranging from ancient unicellular eukaryotes to mammals. They have been associated with numerous molecular mechanisms involving developmental, physiological and pathological changes of cells and tissues. Despite the fact that miRNA-silencing mechanisms appear to be absent in some Apicomplexan species, an increasing number of studies have reported a role for miRNAs in host-parasite interactions. Host miRNA expression can change following parasite infection and the consequences can lead, for instance, to parasite clearance. In this context, the immune system signaling appears to have a crucial role. PMID:26870701

  7. Modulatory activity of Lactobacillus rhamnosus OLL2838 in a mouse model of intestinal immunopathology.

    PubMed

    Ogita, Tasuku; Bergamo, Paolo; Maurano, Francesco; D'Arienzo, Rossana; Mazzarella, Giuseppe; Bozzella, Giuseppina; Luongo, Diomira; Sashihara, Toshihiro; Suzuki, Takuya; Tanabe, Soichi; Rossi, Mauro

    2015-06-01

    Gut microbiota and probiotic strains play an important role in oral tolerance by modulating regulatory and effector cell components of the immune system. We have previously described the ability of Lactobacilli to influence both the innate and adaptive immunity to wheat gluten, a food antigen, in mouse. In this study, we further explored the immunomodulatory mechanisms elicited in this model by testing three specific probiotic strains, namely L. rhamnosus OLL2838, B. infantis ATCC15697 and S. thermophilus Sfi39. In vitro analysis showed the all tested strains induced maturation of bone marrow derived dendritic cells (DCs). However, only L. rhamnosus induced appreciable levels of IL-10 and nitric oxide productions, whereas S. thermophilus essentially elicited IL-12 and TNF-α. The anti-inflammatory ability of OLL2838 was then tested in vivo by adopting mice that develop a gluten-specific enteropathy. This model is characterized by villus blunting, crypt hyperplasia, high levels of intestinal IFN-γ, increased cell apoptosis in lamina propria, and reduced intestinal total glutathione (GSHtot) and glutathione S-transferase (GST) activity. We found that, following administration of OLL2838, GSHtot and GST activity were enhanced, whereas caspase-3 activity was reduced. On the contrary, this probiotic strain failed in recovering the normal histology and further increased intestinal IFN-γ. Confocal microscopy revealed the inability of the probiotic strain to appropriately interact with enterocytes of the small intestine and with Peyer's patches in treated mice. In conclusion, these data highlighted the potential of L. rhamnosus OLL2838 to recover specific toxicity parameters induced by gluten in enteropathic mice through mechanisms that involve induction of low levels of reactive oxygen species (ROS). PMID:25623030

  8. Immunopathology of mouse hepatitis virus type 3mii. effect of immunosuppression in resistant mice.

    PubMed

    Dupuy, J M; Levey-Leblond, E; Le Prevost, C

    1975-01-01

    Normal adult A strain mice are resistant to MHV-3 infection. A strain mice immunosuppressed by 600 rads of x-irradiation or by anti-lymphocyte serum treatment became susceptible to the virus and died with specific lesions of the liver and high virus titers. However, mice immunized with MHV-3 before sublethal x-iraddiation resisted a second injection of virus. Resistant adult (A times C3H) F-1 hybrids undergoing graft-vs-host (GVH) reaction became highly susceptible to MHV-3 injected 8 days after parental cell injection. Virus titer 3 days after injection was 2 logs higher in mice undergoing GVH than in controls. However F-1 hybrid mice resisted virus challenge when the first injection of virus was given 2 weeks before GVH induction. In addition, thymectomy also modified the behavior of resistant animals toward virus infection. It appears, therefore, that cell-mediated immune functions play an important role in resistance of mice to MHV-3.

  9. Immunopathology of RSV infection: prospects for developing vaccines without this complication.

    PubMed

    van Drunen Littel-van den Hurk, S; Mapletoft, J W; Arsic, N; Kovacs-Nolan, J

    2007-01-01

    Respiratory syncytial virus is the most important cause of lower respiratory tract infection in infants and young children. RSV clinical disease varies from rhinitis and otitis media to bronchiolitis and pneumonia. An increased incidence of asthma later in life has been associated with the more severe lower respiratory tract infections. Despite its importance as a pathogen, there is no licensed vaccine against RSV. This is due to a number of factors complicating the development of an effective and safe vaccine. The immunity to natural RSV infection is incomplete as re-infections occur in all age groups, which makes it challenging to design a protective vaccine. Second, the primary target population is the newborn infant, which has a relatively immature immune system and maternal antibodies that can interfere with vaccination. Finally, some vaccines have resulted in a predisposition for exacerbated pulmonary disease in infants, which was attributed to an imbalanced Th2-biased immune response, although the exact cause has not been elucidated. This makes it difficult to proceed with vaccine testing in infants. It is likely that an effective and safe vaccine needs to elicit a balanced immune response, including RSV-specific neutralising antibodies, CD8 T-cells, Th1/Th2 CD4 T-cells and preferably secretory IgA. Subunit vaccines formulated with appropriate adjuvants may be adequate for previously exposed individuals. However, intranasally delivered genetically engineered attenuated or vectored vaccines are currently most promising for newborns, as they are expected to induce a balanced immune response similar to that elicited to natural infection and not be subject to interference from maternal antibodies. Maternal vaccination may be the optimal strategy to protect the very young infants. PMID:17004293

  10. The immunopathology of herpes gestationis. Immunofluorescence studies and characterization of "HG factor".

    PubMed Central

    Jordon, R E; Heine, K G; Tappeiner, G; Bushkell, L L; Provost, T T

    1976-01-01

    Nine skin biopsies from seven herpes gestationis patients were studied by immunofluorescence (IF) techniques. Basement membrane zone (BMZ) deposition of C3 and properdin was present in all nine skin specimens, while IgG deposition was apparent in only one. With in vitro C3 IF staining, positive BMZ staining (HG factor activity) was noted with all seven of our patients' serum samples tested. By standard indirect IF staining, however, only one of these serum samples contained BMZ antibodies of the IgG type. Two cord serum samples, tested by these same methods, yielded positive in vitro C3 staining (HG factor activity) but negative indirect IF staining (IgG). HG factor activity was found to be stable at 56 degrees C for 30 min and in two of three specimens at 56 degrees C for 1 h. Treatment of the complement source (normal human serum) used in the in vitro C3 staining assay with Mg2-EGTA or use of C2-deficient serum as the complement source inhibited HG factor activity. HG factor blocked the specific staining of the BMZ of normal human skin by labeled bullous pemphigoid antibodies. By sucrose density gradient ultracentrifugation and gel chromatography (Sephadex G-200), HG factor activity eluted with IgG-containing fractions. The highly purified IgG fraction of two herpes gestationis sera was also positive for HG factor activity. Our studies suggest that HG factor is an IgG antibody that may not be demonstrable by conventional IF methods, but which activates the classical complement pathway. Images PMID:58871

  11. Virus diseases of the salmonidae in the western United States. III. Immunopathological aspects

    USGS Publications Warehouse

    Klontz, George W.; Yasutake, William T.; Parisot, T.J.

    1965-01-01

    The immune response among fish, from a phylogenetic standpoint, presents a progressive pattern of increasing development. The cyclostomes have been shown to have only feeble immunologic responsiveness. One of their number, the hagfish, appeared to be totally lacking in the ability to actively acquire antibodies.Among the elasmobranchs, the sharks have received the most study immunologically. This group demonstrated a variable response to antigenic stimulationOf the teleosts, the salmonids and the cyprinids have been the more frequent recipients of experimentally introduced antigens. These fishes, as well as other species of teleosts, are quite active and quite consistent in their response to various antigens.

  12. A novel immunopathological association of IgG4-RD and vasculitis with Hashimoto's thyroiditis

    PubMed Central

    Minamino, Hiroto; Ariyasu, Hiroyuki; Furuta, Hiroto; Nishi, Masahiro; Yoshimasu, Takashi; Nishikawa, Akinori; Nakanishi, Masanori; Tsuchihashi, Shigeki; Kojima, Fumiyoshi; Murata, Shin-ichi; Inoue, Gen; Akamizu, Takashi

    2016-01-01

    Summary A 73-year-old man with Hashimoto's thyroiditis (HT) suffered from purpura on the lower legs. He was diagnosed with IgG4-related disease (IgG4-RD) with serum IgG4 elevation and dacryo-sialadenitis confirmed histologically. Serum Th2 and Treg cytokines, interleukin 7 (IL7), IL8 and Th2 chemokine levels were elevated, while skewed Th1 balance was seen in fluorescence-activated cell sorting (FACS). Therefore, preferential Th1 balance in HT appeared to be followed by IgG4-RD characterized with Th2 and Treg polarization. The commencement of steroid therapy dramatically exacerbated clinical manifestations including IgG4-RD-associated HT. The measurement of cytokine and chemokine levels as well as FACS analysis in the development of IgG4-RD seemed to be beneficial. In conclusion, an innovative association of HT, IgG4-RD and vasculitis was observed. This report also offers novel diagnostic and therapeutic approaches for IgG4-RD. Learning points Recently, a subtype of HT has been considered to be a thyroid manifestation of IgG4-RD, although the etiology of IgG4-RD is not established yet. Immunologically a close association between HT and vasculitis was reported. Leukocytoclastic vasculitis is a rare skin presentation of IgG4-RD. In the current case, during the course of HT, IgG4-RD and leukocytoclastic vasculitis occurred; thus, innate immunity and acquired immunity seem to be involved in the development of IgG4-RD. The measurement of cytokine and chemokines appeared to be beneficial in the development of IgG4-RD. Remarkably, effectiveness of steroid therapy for HT suggested presence of IgG4-RD-associated HT. Therefore, this report highlights the pathogenesis of IgG4-RD and proposes novel therapeutic mechanisms. Clinicians should pay attention to the development of IgG4-RD and vasculitis during long course of HT. PMID:26966543

  13. Pulmonary eosinophils and their role in immunopathologic responses to formalin-inactivated pneumonia virus of mice

    PubMed Central

    Percopo, Caroline M.; Qiu, Zhijun; Phipps, Simon; Foster, Paul S.; Domachowske, Joseph B.; Rosenberg, Helene F.

    2009-01-01

    Enhanced disease is the term used to describe the aberrant Th2 skewed responses to naturally-acquired human respiratory syncytial virus (hRSV) infection observed in individuals vaccinated with formalin-inactivated viral antigens. Here we explore this paradigm with pneumonia virus of mice (PVM), a pathogen that faithfully reproduces features of severe hRSV infection in a rodent host. We demonstrate that PVM infection in mice vaccinated with formalin-inactivated antigens from PVM-infected cells (PVM Ags) yields Th2-skewed hypersensitivity, analogous to that observed in response to hRSV. Specifically, we detect elevated levels of IL-4, IL-5, IL-13, and eosinophils in bronchoalveolar lavage (BAL) fluid of PVM-infected mice that were vaccinated with PVM Ags, but not among mice vaccinated with formalin-inactivated antigens from uninfected cells (Ctrl Ags). Interestingly, infection in PVM Ag-vaccinated mice was associated with a ~10-fold reduction in lung virus titer and protection against weight loss when compared to infected mice vaccinated with Ctrl Ags, despite the absence of serum neutralizing antibodies. Given recent findings documenting a role for eosinophils in promoting clearance of hRSV in vivo, we explored the role of eosinophils in altering the pathogenesis of disease with eosinophil-deficient mice. We found that eosinophil deficiency had no impact on virus titer in PVM Ags-vaccinated mice, nor on weight loss or levels of CCL11 (eotaxin-1), interferon-γ, interleukin (IL)-5, or IL-13 in BAL fluid. However, levels of both IL-4 and CCL3 (macrophage inflammatory protein-1α) in BAL fluid were markedly diminished in PVM Ag-vaccinated, PVM-infected eosinophil-deficient mice when compared to wild type controls (246 words). PMID:19542471

  14. Dual roles of endogenous and exogenous galectin-1 in the control of testicular immunopathology

    PubMed Central

    Pérez, Cecilia V.; Gómez, Leticia G.; Gualdoni, Gisela S.; Lustig, Livia; Rabinovich, Gabriel A.; Guazzone, Vanesa A.

    2015-01-01

    Galectin-1 (Gal-1), a proto-type member of galectin family, is highly expressed in immune privileged sites, including the testis. However, in spite of considerable progress the relevance of endogenous and exogenous Gal-1 in testis pathophysiology have not yet been explored. Here we evaluated the in vivo roles of Gal-1 in experimental autoimmune orchitis (EAO), a well-established model of autoimmune testicular inflammation associated with subfertility and infertility. A significant reduction in the incidence and severity of EAO was observed in mice genetically deficient in Gal-1 (Lgals1−/−) versus wild-type (WT) mice. Testicular histopathology revealed the presence of multifocal testicular damage in WT mice characterized by an interstitial mononuclear cell infiltrate and different degrees of germ cell sloughing of seminiferous tubules. TUNEL assay and assessment of active caspase-3 expression, revealed the prevalence of apoptotic spermatocytes mainly localized in the adluminal compartment of seminiferous tubules in EAO mice. A significant increased number of TUNEL-positive germ cells was detected in EAO testis from WT compared with Lgals1−/− mice. In contrast, exogenous administration of recombinant Gal-1 to WT mice undergoing EAO attenuated the severity of the disease. Our results unveil a dual role of endogenous versus exogenous Gal-1 in the control of autoimmune testis inflammation. PMID:26223819

  15. A model for cardiopathy induced by Trypanosoma brucei brucei in mice. A histologic and immunopathologic study.

    PubMed Central

    Poltera, A. A.; Hochmann, A.; Lambert, P. H.

    1980-01-01

    The successful induction of pancarditis in mice by the use of Trypanosoma brucei brucei is reported. The sequential analysis of whole-organ sections demonstrated the presence of trypanosomes in the cardiac structures from the fourth week after infection. Parasites predominated on the endocardial and epicardial side but were also present in the valves, the conducting system, and the lymphatic system draining the heart, the latter being particularly evident in late infection. At the time of parasite invasion, deposits of IgM and IgG and of complement (C3) appeared in the tissues. Also at this time parasitemia reached a plateau, and the circulating specific antitrypanosomal antibodies, the serum Ig and C3, as well as the Clq activity, reached pathologic levels. Cellular response followed parasite invasion and appeared to be similar to that described in human African trypanosomiasis. In late infection, the draining lymph nodes showed a marked histiocytic proliferation, and the vessels became convoluted and distended. The suggested pathogenic mechanisms involve immunologic and mechanical factors. It is possible that the immunologic process prepares for a simultaneous or subsequent parasite invasion of the tissues with an associated inflammatory response. The partial obstruction of the lymphatic cardiac draining system probably accounts at least in part for the peculiar distribution of the parasite-induced lesions. A therapeutic trial was unsuccessful, but the persistence of trypanosomes in the tissues when circulating parasites were no longer detectable may account for relapses. Images Figure 3 Figure 4 Figure 5 Figure 1 Figure 6 Figure 2 PMID:6990771

  16. MicroRNAs in the Host-Apicomplexan Parasites Interactions: A Review of Immunopathological Aspects.

    PubMed

    Judice, Carla C; Bourgard, Catarina; Kayano, Ana C A V; Albrecht, Letusa; Costa, Fabio T M

    2016-01-01

    MicroRNAs (miRNAs), a class of small non-coding regulatory RNAs, have been detected in a variety of organisms ranging from ancient unicellular eukaryotes to mammals. They have been associated with numerous molecular mechanisms involving developmental, physiological and pathological changes of cells and tissues. Despite the fact that miRNA-silencing mechanisms appear to be absent in some Apicomplexan species, an increasing number of studies have reported a role for miRNAs in host-parasite interactions. Host miRNA expression can change following parasite infection and the consequences can lead, for instance, to parasite clearance. In this context, the immune system signaling appears to have a crucial role.

  17. Inclusion body myositis: from immunopathology and degenerative mechanisms to treatment perspectives.

    PubMed

    Schmidt, Jens; Dalakas, Marinos C

    2013-11-01

    Inclusion body myositis is the most common inflammatory myopathy above the age of 50. It becomes clinically apparent around the fourth decade and leads to a slowly, but relentlessly progressive decline in muscular wasting and weakness. The pathology consists of a complex network of inflammatory and degenerative mechanisms, which lead to an attack of muscle fibers by auto-reactive T cells and possibly antibodies. At the same time, various aberrant proteins accumulate within the muscle fibers, including β-amyloid, tau and α-synuclein. Several key components of proinflammatory cell stress mechanisms such as nitric oxide production and macroautophagic processing contribute to the muscle fiber damage. So far, none of the anti-inflammatory or immunomodulatory treatment efforts have been able to halt the disease progression and help the patients. In this summary, the current concept of the complex disease pathology of IBM is reviewed with a focus on recent findings as well as future treatment perspectives.

  18. Clinical benefits and immunopathological correlates of intravenous immune globulin in the treatment of inflammatory myopathies.

    PubMed

    Dalakas, M C

    1996-05-01

    High-dose intravenous immune globulin (IVIG) is emerging as a promising therapy for patients with inflammatory myopathies who have become unresponsive to, or cannot tolerate, conventional therapies. In a double-blind, placebo-controlled study, using objective criteria for improvement, IVIG demonstrated moderate to dramatic improvement in 75% of the patients with dermatomyositis. Preliminary results from a controlled study in inclusion-body myositis show that IVIG may also exert a mild benefit, but only in a small number of patients and in certain muscle groups. In some patients with polymyositis, IVIG is reported to be of benefit but controlled studies have not yet been completed. Immunocytochemical, immunological and in vitro studies on the patients' repeated muscle biopsies and follow-up sera showed that IVIG exerts its action in inflammatory myopathies by: (i) inhibiting myotoxic cytokines, such as TNF-alpha and IL-1; (ii) blockade of Fc receptors on endomysial macrophages interfering with Fc receptor-mediated phagocytosis; and (iii) inhibiting the uptake of C3 and intercepting the formation and deposition of membranolytic attack complex on the endomysial capillaries.

  19. Teriflunomide attenuates immunopathological changes in the dark agouti rat model of experimental autoimmune encephalomyelitis.

    PubMed

    Ringheim, Garth E; Lee, Lan; Laws-Ricker, Lynn; Delohery, Tomas; Liu, Li; Zhang, Donghui; Colletti, Nicholas; Soos, Timothy J; Schroeder, Kendra; Fanelli, Barbara; Tian, Nian; Arendt, Christopher W; Iglesias-Bregna, Deborah; Petty, Margaret; Ji, Zhongqi; Qian, George; Gaur, Rajula; Weinstock, Daniel; Cavallo, Jean; Telsinskas, Juventas; McMonagle-Strucko, Kathleen

    2013-01-01

    Teriflunomide is an oral disease-modifying therapy recently approved in several locations for relapsing-remitting multiple sclerosis. To gain insight into the effects of teriflunomide, immunocyte population changes were measured during progression of experimental autoimmune encephalomyelitis in Dark Agouti rats. Treatment with teriflunomide attenuated levels of spinal cord-infiltrating T cells, natural killer cells, macrophages, and neutrophils. Teriflunomide also mitigated the disease-induced changes in immune cell populations in the blood and spleen suggesting an inhibitory effect on pathogenic immune responses. PMID:24198809

  20. Platelets promote liver immunopathology contributing to hepatitis B virus-mediated hepatocarcinogenesis.

    PubMed

    Sitia, Giovanni

    2014-06-01

    Chronic hepatitis B virus (HBV) infection is a major risk factor for the development of hepatocellular carcinoma (HCC). Among the pathogenetic factors triggered by HBV, virus-specific CD8(+) T cells play and important role in disease pathogenesis by promoting necroinflammatory liver damage. Accordingly, amelioration of immune-mediated chronic liver injury may prevent HCC. Platelets facilitate this process by sustaining the hepatic accumulation of virus-specific CD8(+) T cells and subsequently other virus nonspecific inflammatory cells that contribute to liver disease. Importantly, a recent study shows that the long-term use of clinically relevant doses of the anti-platelet drugs aspirin and clopidogrel, administered after the onset of liver disease, in an HBV transgenic mouse model of immune-mediated chronic hepatitis and HCC, can prevent hepatocarcinogenesis improving overall survival. Platelets therefore, act as key players in the pathogenesis of HBV-associated liver cancer supporting the notion that immune-mediated necroinflammatory liver disease is sufficient to trigger HCC and that interference with platelet activation may have clinical implications for HCC prevention.

  1. Immunoactivation induced by chronic viral infection inhibits viral replication and drives immunosuppression through sustained IFN-I responses.

    PubMed

    Honke, Nadine; Shaabani, Namir; Merches, Katja; Gassa, Asmae; Kraft, Anke; Ehrhardt, Katrin; Häussinger, Dieter; Löhning, Max; Dittmer, Ulf; Hengel, Hartmut; Recher, Mike; Lang, Philipp A; Lang, Karl S

    2016-02-01

    Acute or chronic viral infections can lead to generalized immunosuppression. Several mechanisms, such as immunopathology of CD8(+) T cells, inhibitory receptors, or regulatory T (Treg) cells, contribute to immune dysfunction. Moreover, patients with chronic viral infections usually do not respond to vaccination, a finding that has not been previously explained. Recently, we reported that CD169(+) macrophages enforce viral replication, which is essential for guaranteeing antigen synthesis and efficient adaptive immune responses. In the present study, we used a chronic lymphocytic choriomeningitis virus infection mouse model to determine whether this mechanism is affected by chronic viral infection, which may impair the activation of adaptive immunity. We found that enforced viral replication of a superinfecting virus is completely blunted in chronically infected mice. This absence of enforced viral replication in CD169(+) macrophages is not explained by CD8(+) T-cell-mediated immunopathology but rather by prolonged IFN-I responses. Consequently, the absence of viral replication impairs both antigen production and the adaptive immune response against the superinfecting virus. These findings indicate that chronic infection leads to sustained IFN-I action, which is responsible for the absence of an antiviral immune response against a secondary viral infection. PMID:26507703

  2. Immunoactivation induced by chronic viral infection inhibits viral replication and drives immunosuppression through sustained IFN‐I responses

    PubMed Central

    Honke, Nadine; Shaabani, Namir; Merches, Katja; Gassa, Asmae; Kraft, Anke; Ehrhardt, Katrin; Häussinger, Dieter; Löhning, Max; Dittmer, Ulf; Hengel, Hartmut; Recher, Mike; Lang, Philipp A.

    2015-01-01

    Acute or chronic viral infections can lead to generalized immunosuppression. Several mechanisms, such as immunopathology of CD8+ T cells, inhibitory receptors, or regulatory T (Treg) cells, contribute to immune dysfunction. Moreover, patients with chronic viral infections usually do not respond to vaccination, a finding that has not been previously explained. Recently, we reported that CD169+ macrophages enforce viral replication, which is essential for guaranteeing antigen synthesis and efficient adaptive immune responses. In the present study, we used a chronic lymphocytic choriomeningitis virus infection mouse model to determine whether this mechanism is affected by chronic viral infection, which may impair the activation of adaptive immunity. We found that enforced viral replication of a superinfecting virus is completely blunted in chronically infected mice. This absence of enforced viral replication in CD169+ macrophages is not explained by CD8+ T‐cell‐mediated immunopathology but rather by prolonged IFN‐I responses. Consequently, the absence of viral replication impairs both antigen production and the adaptive immune response against the superinfecting virus. These findings indicate that chronic infection leads to sustained IFN‐I action, which is responsible for the absence of an antiviral immune response against a secondary viral infection. PMID:26507703

  3. Immunological tolerance to lymphocytic choriomeningitis virus in neonatally infected virus carrier mice: evidence supporting a clonal inactivation mechanism.

    PubMed Central

    Cihak, J; Lehmann-Grube, F

    1978-01-01

    Previous studies have shown that no cell-mediated immunity against LCM virus-infected cells can be detected in neonatally established LCM virus carrier mice suggesting that they are immunologically tolerant to virally-altered cell membrane antigens. In this communication experiments are described aimed at analyzing the mechanism. Virus-specific cell-mediated immunity was assessed by 51Cr release and target cell reduction assays. Attempts to demonstrate cells in spleens of CBA/J carrier mice able to suppress in syngeneic recipients the induction or the effector phase of the cytotoxic T-cell response against LCM virus-infected cells were unsuccessful. Also, no factors were detected in CBA/J and C57BL/6J carrier mice, either spleen cell-associated or free in the circulation, which would block the activity of cytotoxic T-lymphocytes against LCM virus-infected syngeneic target cells. The results indicate that inability of LCM virus carrier mice to act immunologically against virus-infected target cells is due to deletion or irreversible inactivation of T lymphocytes carrying receptors for virally altered cell membrane antigens. PMID:304840

  4. Rapid and massive virus-specific plasmablast responses during acute dengue virus infection in humans.

    PubMed

    Wrammert, Jens; Onlamoon, Nattawat; Akondy, Rama S; Perng, Guey C; Polsrila, Korakot; Chandele, Anmol; Kwissa, Marcin; Pulendran, Bali; Wilson, Patrick C; Wittawatmongkol, Orasri; Yoksan, Sutee; Angkasekwinai, Nasikarn; Pattanapanyasat, Kovit; Chokephaibulkit, Kulkanya; Ahmed, Rafi

    2012-03-01

    Humoral immune responses are thought to play a major role in dengue virus-induced immunopathology; however, little is known about the plasmablasts producing these antibodies during an ongoing infection. Herein we present an analysis of plasmablast responses in patients with acute dengue virus infection. We found very potent plasmablast responses that often increased more than 1,000-fold over the baseline levels in healthy volunteers. In many patients, these responses made up as much 30% of the peripheral lymphocyte population. These responses were largely dengue virus specific and almost entirely made up of IgG-secreting cells, and plasmablasts reached very high numbers at a time after fever onset that generally coincided with the window where the most serious dengue virus-induced pathology is observed. The presence of these large, rapid, and virus-specific plasmablast responses raises the question as to whether these cells might have a role in dengue immunopathology during the ongoing infection. These findings clearly illustrate the need for a detailed understanding of the repertoire and specificity of the antibodies that these plasmablasts produce.

  5. Hepatitis C virus induced insulin resistance impairs response to anti viral therapy

    PubMed Central

    El-Zayadi, Abdel-Rahman; Anis, Mahmoud

    2012-01-01

    Hepatitis C virus (HCV) infection is an important risk factor for insulin resistance (IR). The latter is the pathogenic foundation underlying metabolic syndrome, steatosis and cirrhosis, and possibly hepatocellular carcinoma (HCC). The interplay between genetic and environmental risk factors ultimately leads to the development of IR. Obesity is considered a major risk factor, with dysregulation of levels of secreted adipokines from distended adipose tissue playing a major role in IR. HCV-induced IR may be due to the HCV core protein inducing proteasomal degradation of insulin receptor substrates 1 and 2, blocking intracellular insulin signaling. The latter is mediated by increased levels of both tumour necrosis factor-α (TNF-α) and suppressor of cytokine signaling 3 (SOC-3). IR, through different mechanisms, plays a role in the development of steatosis and its progression to steatohepatitis, cirrhosis and even HCC. In addition, IR has a role in impairing TNF signaling cascade, which in turn blocks STAT-1 translocation and interferon stimulated genes production avoiding the antiviral effect of interferon. PMID:22294824

  6. Co-expression analysis of differentially expressed genes in hepatitis C virus-induced hepatocellular carcinoma.

    PubMed

    Song, Qingfeng; Zhao, Chang; Ou, Shengqiu; Meng, Zhibin; Kang, Ping; Fan, Liwei; Qi, Feng; Ma, Yilong

    2015-01-01

    The aim of the current study was to investigate the molecular mechanisms underlying hepatitis C virus (HCV)-induced hepatocellular carcinoma (HCC) using the expression profiles of HCV-infected Huh7 cells at different time points. The differentially expressed genes (DEGs) were identified with the Samr package in R software once the data were normalized. Functional and pathway enrichment analysis of the identified DEGs was also performed. Subsequently, MCODE in Cytoscape software was applied to conduct module analysis of the constructed co-expression networks. A total of 1,100 DEGs were identified between the HCV-infected and control samples at 12, 18, 24 and 48 h post-infection. DEGs at 24 and 48 h were involved in the same signaling pathways and biological processes, including sterol biosynthetic processes and tRNA amino-acylation. There were 22 time series genes which were clustered into 3 expression patterns, and the demarcation point of the 2 expression patterns that 401 overlapping DEGs at 24 and 48 h clustered into was 24 h post-infection. tRNA synthesis-related biological processes emerged at 24 and 48 h. Replication and assembly of HCV in HCV-infected Huh7 cells occurred mainly at 24 h post-infection. In view of this, the screened time series genes have the potential to become candidate target molecules for monitoring, diagnosing and treating HCV-induced HCC. PMID:25339452

  7. Theiler's murine encephalomyelitis virus induces tumour necrosis factor-alpha in murine astrocyte cell cultures.

    PubMed Central

    Sierra, A; Rubio, N

    1993-01-01

    Cytokines have been postulated to exert an important modulatory and recruiting role in demyelination induced by Theiler's murine encephalomyelitis virus (TMEV) in SJL/J mice. Using a cytolytic bioassay and ELISA, we have detected and quantified a cytokine, tumour necrosis factor-alpha (TNF-alpha), in supernatants from astrocyte cultures infected in vitro with TMEV. TNF was detected only after TMEV-specific infection of astrocyte cultures (approximately 200-400 U/ml). In vitro TNF synthesis appeared in a dose- and time-dependent manner and was produced by both SJL/J (a strain susceptible to TMEV-induced demyelination) and BALB/c (a resistant strain) astrocytes. The precise nature of TNF activity was further assessed by fast protein liquid chromatography (FPLC) and antibody neutralization. These results indicate an active role for astrocytes as accessory immune cells in our experimental model for multiple sclerosis. PMID:8478023

  8. Immunosuppression promotes CNS remyelination in chronic virus-induced demyelinating disease.

    PubMed

    Rodriguez, M; Lindsley, M D

    1992-02-01

    Immunosuppression using cyclophosphamide or anti-T cell monoclonal antibodies (mAbs) directed at CD4 or CD8 promoted remyelination of CNS axons in the spinal cords of mice infected chronically with Theiler's virus. Treatment with a mAb directed at class II major histocompatibility gene products did not increase the extent of CNS remyelination. Following immunosuppressive treatment, quantitative morphometry revealed a five- to sevenfold increase in new myelin synthesis. Proliferating nervous system cells were identified at the edges of remyelinated lesions by their incorporation of [3H]thymidine. CNS remyelination occurred in mice depleted of selected subsets of T lymphocytes despite the local persistence of viral antigen. These findings indicate that CNS remyelination occurs as a normal consequence of primary myelin injury, but factors associated with immune T cells somehow impair remyelination. Interference with the function of immune T cells enhances CNS remyelination by oligodendrocytes. Similar depletion of immune T cells may allow for enhanced remyelination in the CNS of patients with chronic multiple sclerosis.

  9. Human isolates of dengue type 1 virus induce apoptosis in mouse neuroblastoma cells.

    PubMed Central

    Desprès, P; Flamand, M; Ceccaldi, P E; Deubel, V

    1996-01-01

    Human isolates of dengue (DEN) type 1 viruses FGA/89 and BR/90 differ in their membrane fusion properties in mosquito cell lines (P. Desprès et al., Virology 196:209-216, 1993). FGA/89 and BR/90 were assayed for their neurovirulence in newborn mice, and neurons were the major target cells for both DEN-1 virus strains within the central nervous system. To study the susceptibility of neurons to DEN virus infection, DEN virus replication was analyzed in the murine neuroblastoma cell line Neuro 2a. Infection of Neuro 2a cells with FGA/89 or BR/90 induced apoptotic DNA degradation after 25 h of infection. Studies of DEN protein synthesis revealed that accumulation of viral proteins leads to apoptotic cell death. The apoptotic process progressed more rapidly following BR/90 infection than it did after FGA/89 infection. The higher cytotoxicity of BR/90 for Neuro 2a cells was linked to an incomplete maturation of the envelope proteins, resulting in abortive virus assembly. Accumulation of viral proteins in the endoplasmic reticulum may induce stress and thereby activate the apoptotic pathway in mouse neuroblastoma cells. PMID:8648748

  10. Cyclophilin A as a New Therapeutic Target for Hepatitis C Virus-induced Hepatocellular Carcinoma

    PubMed Central

    2013-01-01

    Hepatocellular carcinoma (HCC) related to hepatitis B virus (HBV) and hepatitis C virus (HCV) infections is thought to account for more than 80% of primary liver cancers. Both HBV and HCV can establish chronic liver inflammatory infections, altering hepatocyte and liver physiology with potential liver disease progression and HCC development. Cyclophilin A (CypA) has been identified as an essential host factor for the HCV replication by physically interacting with the HCV non structural protein NS5A that in turn interacts with RNA-dependent RNA polymerase NS5B. CypA, a cytosolic binding protein of the immunosuppressive drug cyclosporine A, is overexpressed in many cancer types and often associated with malignant transformation. Therefore, CypA can be a good target for molecular cancer therapy. Because of antiviral activity, the CypA inhibitors have been tested for the treatment of chronic hepatitis C. Nonimmunosuppressive Cyp inhibitors such as NIM811, SCY-635, and Alisporivir have attracted more interests for appropriating CypA for antiviral chemotherapeutic target on HCV infection. This review describes CypA inhibitors as a potential HCC treatment tool that is contrived by their obstructing chronic HCV infection and summarizes roles of CypA in cancer development. PMID:24227937

  11. Influence of the murine MHC (H-2) on Friend leukemia virus-induced immunosuppression

    PubMed Central

    1986-01-01

    Friend murine leukemia virus complex (FV)-induced immunosuppression was studied by assaying splenic anti-SRBC PFC responses and plasma antibody titers in mice at various times after FV inoculation. Genes located within the H-2 complex were found to influence resistance to FV-induced immunosuppression. Near normal responses were observed in mice having the H-2a/b or H-2b/b genotype, whereas mice having the H-2a/a genotype were suppressed. This H-2 effect was observed not only in mice having heterozygous C57BL/10 X A background genes, including Rfv-3r/s, but also was apparent in mice having homozygous A-strain background genes, including Rfv-3s/s. Therefore, the Rfv-3 gene did not appear to convey resistance to FV-induced immunosuppression. The suppression in susceptible H-2a/a mice was characterized by a partial suppression of the IgM response and a profound suppression of both the primary and secondary IgG responses. Neither splenomegaly nor viremia alone appeared to be sufficient for the induction or maintenance of the immunosuppression. The mechanism of suppression was unclear, but both B lymphocyte and T lymphocyte functions appeared to be altered. PMID:3456010

  12. Primary polyoma virus-induced murine thymic epithelial tumors. A tumor model of thymus physiology.

    PubMed Central

    Hoot, G. P.; Kettman, J. R.

    1989-01-01

    Thymic tumors were induced in C3'/Bittner mice by neonatal inoculation with polyoma virus. The objective of this study was to identify the phenotypes of the cells within the tumors and to attempt to determine the origin of the neoplastic cell population(s). At the ultrastructural level, the neoplastic cells resembled normal thymic epithelium with tonofilaments and desmosomes. Immunoperoxidase staining demonstrated the presence of cytokeratin, Iak, -beta 2-microglobulin, -asialo-GM1, the thymic cortical epithelial marker ER-TR4, and the medullary epithelial marker ER-TR5. Islands of normal cortical thymocytes supported by residual normal cortical epithelium and acid phosphatase-positive cortical macrophages were interspersed in the tumors. Residual islands of normal medullary architecture with nonspecific esterase-positive IDCs were rarely identified in tumors. Most lymphocytes in the tumors were normal immature cortical thymocytes with the phenotype Tdt+, PNA+, Thy 1.2bright, Ly-1dull, H-2Kkdull, ThB+, J11d+, and Lyt-2+L3T4+. Lymphocytes in the tumors were steroid-sensitive like normal thymocytes. The proportions of Lyt-2+L3T4- and Lyt-2-L3T4+ cells were generally larger in the tumors than in normal thymus and reflected the higher frequency of lymphocytes in the tumors capable of proliferating in vitro in response to Con A plus IL-2. The data were consistent with the hypothesis that the neoplasia originates from thymic epithelium that is interspersed with normal, developing thymic lymphocytes. Images Figure 4 p[688]-a Figure 1 Figure 2 Figure 3 p687-a Figure 7 PMID:2552813

  13. Utilizing the virus-induced blocking of apoptosis in an easy baculovirus titration method.

    PubMed

    Niarchos, Athanasios; Lagoumintzis, George; Poulas, Konstantinos

    2015-01-01

    Baculovirus-mediated protein expression is a robust experimental technique for producing recombinant higher-eukaryotic proteins because it combines high yields with considerable post-translational modification capabilities. In this expression system, the determination of the titer of recombinant baculovirus stocks is important to achieve the correct multiplicity of infection for effective amplification of the virus and high expression of the target protein. To overcome the drawbacks of existing titration methods (e.g., plaque assay, real-time PCR), we present a simple and reliable assay that uses the ability of baculoviruses to block apoptosis in their host cells to accurately titrate virus samples. Briefly, after incubation with serial dilutions of baculovirus samples, Sf9 cells were UV irradiated and, after apoptosis induction, they were viewed via microscopy; the presence of cluster(s) of infected cells as islets indicated blocked apoptosis. Subsequently, baculovirus titers were calculated through the determination of the 50% endpoint dilution. The method is simple, inexpensive, and does not require unique laboratory equipment, consumables or expertise; moreover, it is versatile enough to be adapted for the titration of every virus species that can block apoptosis in any culturable host cells which undergo apoptosis under specific conditions.

  14. Murine viral hepatitis involves NK cell depletion associated with virus-induced apoptosis

    PubMed Central

    LEHOUX, M; JACQUES, A; LUSIGNAN, S; LAMONTAGNE, L

    2004-01-01

    Mouse hepatitis virus type 3 (MHV3), a coronavirus, is an excellent animal model for the study of immunological disorders related to acute and chronic hepatitis. In this study, we have verified if the fulminant hepatitis induced by MHV3 could be related to an impairment of innate immunity. Groups of three C57BL/6 mice were infected with the pathogenic L2-MHV3 or attenuated YAC-MHV3 viruses, and the natural killer (NK) cell populations from liver, spleen and bone marrow were analysed. The percentage of intrahepatic NK1·1+T cell receptor (TCR)− cells did not increase while NK1·1+TCRinter cells decreased in both L2-MHV3- and YAC-MHV3-infected mice. Concurrently, splenic and myeloid NK1·1+ cells decreased in L2-MHV3-infected mice. However, the cytotoxic activity of NK cells increased in liver and decreased in bone marrow from pathogenic L2-MHV3-infected mice while no modification was detected in YAC-MHV3-infected mice. Flow cytometric analysis revealed that both normal and larger splenic or myeloid NK cells decreased more in pathogenic L2-MHV3-infected mice than in attenuated YAC-MHV3-infected mice. In vitro viral infections of interleukin (IL)-15-stimulated lymphoid cells from liver and bone marrow revealed that L2-MHV3 induced higher decreases in cell viability of NK1·1+ cells than the YAC-MHV3 variant. The NK cell decreases were due to the viral permissivity leading to cytopathic effects characterized by cell rounding, syncytia formation and apoptosis. Larger NK+ syncytia were observed in L2-MHV3-infected cells than in YAC-MHV3-infected cells. These results suggest that NK cell production is impaired by viral infection favouring fulminant hepatitis. PMID:15196242

  15. Neutrophil Extracellular Traps Enhance Early Inflammatory Response in Sendai Virus-Induced Asthma Phenotype.

    PubMed

    Akk, Antonina; Springer, Luke E; Pham, Christine T N

    2016-01-01

    Paramyxoviral infection in childhood has been linked to a significant increased rate of asthma development. In mice, paramyxoviral infection with the mouse parainfluenza virus type I, Sendai virus (Sev), causes a limited bronchiolitis followed by persistent asthma traits. We have previously shown that the absence of cysteine protease dipeptidyl peptidase I (DPPI) dampened the acute lung inflammatory response and the subsequent asthma phenotype induced by Sev. Adoptive transfer of wild-type neutrophils into DPPI-deficient mice restored leukocyte influx, the acute cytokine response, and the subsequent mucous cell metaplasia that accompanied Sev-induced asthma phenotype. However, the exact mechanism by which DPPI-sufficient neutrophils promote asthma development following Sev infection is still unknown. We hypothesize that neutrophils recruited to the alveolar space following Sev infection elaborate neutrophil extracellular traps (NETs) that propagate the inflammatory cascade, culminating in the eventual asthma phenotype. Indeed, we found that Sev infection was associated with NET formation in the lung and release of cell-free DNA complexed to myeloperoxidase in the alveolar space and plasma that peaked on day 2 post infection. Absence of DPPI significantly attenuated Sev-induced NET formation in vivo and in vitro. Furthermore, concomitant administration of DNase 1, which dismantled NETs, or inhibition of peptidylarginine deiminase 4 (PAD4), an essential mediator of NET formation, suppressed the early inflammatory responses to Sev infection. Lastly, NETs primed bone marrow-derived cells to release cytokines that can amplify the inflammatory cascade. PMID:27617014

  16. Multiple transport systems mediate virus-induced acquired resistance to oxidative stress

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In this paper, we report the phenomenon of acquired cross-tolerance to oxidative (UV-C and H2O2) stress in Nicotiana benthamiana plants infected with Potato virus X (PVX) and investigate the functional expression of transport systems in mediating this phenomenon. By combining multiple approaches, we...

  17. Endomembrane Ca2+ -ATPases play significant role in virus-induced adaptation to oxidative stress

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In our recently published paper (Plant Cell Environ 34: 406-417) we have reported a phenomenon of Potato Virus X (PVX) - induced cross tolerance to oxidative stress in Nicotiana benthamiana plants and showed a critical role of plasma membrane Ca2+/H+ exchangers in this process. The current study fol...

  18. Marek’s disease virus induced transient atrophy of cecal tonsils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Although bursal and thymic atrophy associated with Marek’s disease (MD) is well established and characterized, the effect of Marek's disease virus (MDV) infection on lymphoid aggregates within the gut-associated lymphoid tissue (GALT) is not known. The cecal tonsils (CT) are the two largest lympho...

  19. Galectin-3 is upregulated in activated glia during Junin virus-induced murine encephalitis.

    PubMed

    Jaquenod De Giusti, Carolina; Alberdi, Lucrecia; Frik, Jesica; Ferrer, María F; Scharrig, Emilia; Schattner, Mirta; Gomez, Ricardo M

    2011-09-01

    Argentine haemorrhagic fever (AHF) is a systemic febrile syndrome characterized by several haematological and neurological alterations caused by Junín virus (JUNV), a member of the Arenaviridae family. Newborn mice are highly susceptible to JUNV and the course of infection has been associated with the viral strain used. Galectin-3 (Gal-3) is an animal lectin that has been proposed to play an important role in some central nervous system (CNS) diseases. In this study, we analysed Gal-3 expression at the transcriptional and translational expression levels during JUNV-induced CNS disease. We found that Candid 1 strain induced, with relatively low mortality, a subacute/chronic CNS disease with significant glia activation and upregulation of Gal-3 in microglia cells as well as in reactive astrocytes that correlated with viral levels. Our results suggest an important role for Gal-3 in viral-induced CNS disease.

  20. Disruption of Rpp1-mediated soybean rust resistance by virus-induced gene silencing

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soybean rust is a fungus that causes disease on soybeans. The discovery of soybean genes and proteins that are important for disease resistance to soybean rust may help improve soybean cultivars through breeding or transgenic technology. Proteins previously discovered in the cell nucleus of soybea...

  1. Titration of adenovirus by counting cells containing virus-induced inclusion bodies.

    PubMed

    Weber, J

    1972-05-01

    A new method for the titration of adenovirus types 2 and 12 based on the enumeration of viral inclusions in infected cells was devised and evaluated. The technique gave virus titers comparable to those obtained by the plaque assay procedure.

  2. [Reverse plaque formation by hog cholera virus inducing interference with VSV (author's transl)].

    PubMed

    Laude, H

    1978-01-01

    Infection of PK15 cells with various strains of Hog Cholera (HCV, togaviridae) induces a transient refractory state to VSV. The reverse plaque procedure is convenient for HCV titration of virulent, "chronic" and attenuated strains.

  3. Well-tolerated Spirulina extract inhibits influenza virus replication and reduces virus-induced mortality

    PubMed Central

    Chen, Yi-Hsiang; Chang, Gi-Kung; Kuo, Shu-Ming; Huang, Sheng-Yu; Hu, I-Chen; Lo, Yu-Lun; Shih, Shin-Ru

    2016-01-01

    Influenza is one of the most common human respiratory diseases, and represents a serious public health concern. However, the high mutability of influenza viruses has hampered vaccine development, and resistant strains to existing anti-viral drugs have also emerged. Novel anti-influenza therapies are urgently needed, and in this study, we describe the anti-viral properties of a Spirulina (Arthrospira platensis) cold water extract. Anti-viral effects have previously been reported for extracts and specific substances derived from Spirulina, and here we show that this Spirulina cold water extract has low cellular toxicity, and is well-tolerated in animal models at one dose as high as 5,000 mg/kg, or 3,000 mg/kg/day for 14 successive days. Anti-flu efficacy studies revealed that the Spirulina extract inhibited viral plaque formation in a broad range of influenza viruses, including oseltamivir-resistant strains. Spirulina extract was found to act at an early stage of infection to reduce virus yields in cells and improve survival in influenza-infected mice, with inhibition of influenza hemagglutination identified as one of the mechanisms involved. Together, these results suggest that the cold water extract of Spirulina might serve as a safe and effective therapeutic agent to manage influenza outbreaks, and further clinical investigation may be warranted. PMID:27067133

  4. Transcriptome Analysis of Capsicum Chlorosis Virus-Induced Hypersensitive Resistance Response in Bell Capsicum

    PubMed Central

    Widana Gamage, Shirani M. K.; McGrath, Desmond J.; Persley, Denis M.

    2016-01-01

    Background Capsicum chlorosis virus (CaCV) is an emerging pathogen of capsicum, tomato and peanut crops in Australia and South-East Asia. Commercial capsicum cultivars with CaCV resistance are not yet available, but CaCV resistance identified in Capsicum chinense is being introgressed into commercial Bell capsicum. However, our knowledge of the molecular mechanisms leading to the resistance response to CaCV infection is limited. Therefore, transcriptome and expression profiling data provide an important resource to better understand CaCV resistance mechanisms. Methodology/Principal Findings We assembled capsicum transcriptomes and analysed gene expression using Illumina HiSeq platform combined with a tag-based digital gene expression system. Total RNA extracted from CaCV/mock inoculated CaCV resistant (R) and susceptible (S) capsicum at the time point when R line showed a strong hypersensitive response to CaCV infection was used in transcriptome assembly. Gene expression profiles of R and S capsicum in CaCV- and buffer-inoculated conditions were compared. None of the genes were differentially expressed (DE) between R and S cultivars when mock-inoculated, while 2484 genes were DE when inoculated with CaCV. Functional classification revealed that the most highly up-regulated DE genes in R capsicum included pathogenesis-related genes, cell death-associated genes, genes associated with hormone-mediated signalling pathways and genes encoding enzymes involved in synthesis of defense-related secondary metabolites. We selected 15 genes to confirm DE expression levels by real-time quantitative PCR. Conclusion/Significance DE transcript profiling data provided comprehensive gene expression information to gain an understanding of the underlying CaCV resistance mechanisms. Further, we identified candidate CaCV resistance genes in the CaCV-resistant C. annuum x C. chinense breeding line. This knowledge will be useful in future for fine mapping of the CaCV resistance locus and potential genetic engineering of resistance into CaCV-susceptible crops. PMID:27398596

  5. Vaccinia virus-induced smallpox postvaccinal encephalitis in case of blood-brain barrier damage.

    PubMed

    Garcel, Aude; Fauquette, William; Dehouck, Marie-Pierre; Crance, Jean-Marc; Favier, Anne-Laure

    2012-02-01

    Smallpox vaccination is the only currently effective mean to combat the threat of variola virus used as a bioterrorism agent, although it is responsible for a rare but serious complication, the postvaccinal encephalitis (PVE). Development of safer vaccines therefore is a high priority as the PVE physiopathology is not well understood to date. If vaccinia virus (VACV) is responsible for PVE by central nervous system (CNS) dissemination, trans-migration of the VACV across the blood-brain barrier (BBB) would be supposed to be essential. Given the complexity of the pathogenesis of vaccinia neurovirulence, an in vitro BBB model was used to explore the mechanism of VACV to induce BBB permeability. Two VACV strains were studied, the neurovirulent Western Reserve strain (VACV-WR) and the vaccine reference Lister strain (VACV-List). A mouse model was also developed to study the ability of these two viral strains to propagate in the brain from the blood compartment, their neurovirulence and their neuropathogenesis. In vitro, the loss of permeability resulted from the tight-junctions disruption was induced by virus replication. The ability of VACV to release infectious particles at the abluminal side suggests the capacity of both VACV strains to migrate across the BBB from the blood to the CNS. In vivo, the virus replication in mice CNS was strain-dependent. The VACV-WR laboratory strain proved to be neuroinvasive and neurovirulent, whereas the VACV-List strain is safe in physiological conditions. Mice PVE was observed only with VACV-WR in the co-infection model, when BBB opening was obtained by lipopolysaccharide (LPS) treatment. This study suggests that VACV is able to cross the BBB but encephalitis occurs only in the presence of a co-infection by bacteria. So, a model of co-infection, mimicked by LPS treatment, could have important implication towards the assessment of neurovirulence of new vaccines.

  6. Marek’s disease virus induces transient atrophy of cecal tonsils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Marek’s disease (MD) is a lymphoproliferative disease of domestic chickens caused by an immunosupperessive alpha herpesvirus, Marek’s disease virus (MDV). Clinical signs of MD include bursal/thymic atrophy and neurological disorders. The cecal tonsils (CT) are the largest lymphoid aggregates of avia...

  7. Hepatitis C virus induces a mutator phenotype: enhanced mutations of immunoglobulin and protooncogenes.

    PubMed

    Machida, Keigo; Cheng, Kevin T-N; Sung, Vicky M-H; Shimodaira, Shigetaka; Lindsay, Karen L; Levine, Alexandra M; Lai, Ming-Yang; Lai, Michael M C

    2004-03-23

    Hepatitis C virus (HCV) is a nonretroviral oncogenic RNA virus, which is frequently associated with hepatocellular carcinoma (HCC) and B cell lymphoma. We demonstrated here that acute and chronic HCV infection caused a 5- to 10-fold increase in mutation frequency in Ig heavy chain, BCL-6, p53, and beta-catenin genes of in vitro HCV-infected B cell lines and HCV-associated peripheral blood mononuclear cells, lymphomas, and HCCs. The nucleotide-substitution pattern of p53 and beta-catenin was different from that of Ig heavy chain in HCV-infected cells, suggesting two different mechanisms of mutation. In addition, the mutated protooncogenes were amplified in HCV-associated lymphomas and HCCs, but not in lymphomas of nonviral origin or HBV-associated HCC. HCV induced error-prone DNA polymerase zeta, polymerase iota, and activation-induced cytidine deaminase, which together, contributed to the enhancement of mutation frequency, as demonstrated by the RNA interference experiments. These results indicate that HCV induces a mutator phenotype and may transform cells by a hit-and-run mechanism. This finding provides a mechanism of oncogenesis for an RNA virus.

  8. A complement-microglial axis drives synapse loss during virus-induced memory impairment.

    PubMed

    Vasek, Michael J; Garber, Charise; Dorsey, Denise; Durrant, Douglas M; Bollman, Bryan; Soung, Allison; Yu, Jinsheng; Perez-Torres, Carlos; Frouin, Arnaud; Wilton, Daniel K; Funk, Kristen; DeMasters, Bette K; Jiang, Xiaoping; Bowen, James R; Mennerick, Steven; Robinson, John K; Garbow, Joel R; Tyler, Kenneth L; Suthar, Mehul S; Schmidt, Robert E; Stevens, Beth; Klein, Robyn S

    2016-06-23

    Over 50% of patients who survive neuroinvasive infection with West Nile virus (WNV) exhibit chronic cognitive sequelae. Although thousands of cases of WNV-mediated memory dysfunction accrue annually, the mechanisms responsible for these impairments are unknown. The classical complement cascade, a key component of innate immune pathogen defence, mediates synaptic pruning by microglia during early postnatal development. Here we show that viral infection of adult hippocampal neurons induces complement-mediated elimination of presynaptic terminals in a murine WNV neuroinvasive disease model. Inoculation of WNV-NS5-E218A, a WNV with a mutant NS5(E218A) protein leads to survival rates and cognitive dysfunction that mirror human WNV neuroinvasive disease. WNV-NS5-E218A-recovered mice (recovery defined as survival after acute infection) display impaired spatial learning and persistence of phagocytic microglia without loss of hippocampal neurons or volume. Hippocampi from WNV-NS5-E218A-recovered mice with poor spatial learning show increased expression of genes that drive synaptic remodelling by microglia via complement. C1QA was upregulated and localized to microglia, infected neurons and presynaptic terminals during WNV neuroinvasive disease. Murine and human WNV neuroinvasive disease post-mortem samples exhibit loss of hippocampal CA3 presynaptic terminals, and murine studies revealed microglial engulfment of presynaptic terminals during acute infection and after recovery. Mice with fewer microglia (Il34(-/-) mice with a deficiency in IL-34 production) or deficiency in complement C3 or C3a receptor were protected from WNV-induced synaptic terminal loss. Our study provides a new murine model of WNV-induced spatial memory impairment, and identifies a potential mechanism underlying neurocognitive impairment in patients recovering from WNV neuroinvasive disease. PMID:27337340

  9. Well-tolerated Spirulina extract inhibits influenza virus replication and reduces virus-induced mortality.

    PubMed

    Chen, Yi-Hsiang; Chang, Gi-Kung; Kuo, Shu-Ming; Huang, Sheng-Yu; Hu, I-Chen; Lo, Yu-Lun; Shih, Shin-Ru

    2016-01-01

    Influenza is one of the most common human respiratory diseases, and represents a serious public health concern. However, the high mutability of influenza viruses has hampered vaccine development, and resistant strains to existing anti-viral drugs have also emerged. Novel anti-influenza therapies are urgently needed, and in this study, we describe the anti-viral properties of a Spirulina (Arthrospira platensis) cold water extract. Anti-viral effects have previously been reported for extracts and specific substances derived from Spirulina, and here we show that this Spirulina cold water extract has low cellular toxicity, and is well-tolerated in animal models at one dose as high as 5,000 mg/kg, or 3,000 mg/kg/day for 14 successive days. Anti-flu efficacy studies revealed that the Spirulina extract inhibited viral plaque formation in a broad range of influenza viruses, including oseltamivir-resistant strains. Spirulina extract was found to act at an early stage of infection to reduce virus yields in cells and improve survival in influenza-infected mice, with inhibition of influenza hemagglutination identified as one of the mechanisms involved. Together, these results suggest that the cold water extract of Spirulina might serve as a safe and effective therapeutic agent to manage influenza outbreaks, and further clinical investigation may be warranted. PMID:27067133

  10. Deficient IFN Signaling by Myeloid Cells Leads to MAVS-Dependent Virus-Induced Sepsis

    PubMed Central

    Pinto, Amelia K.; Ramos, Hilario J.; Wu, Xiaobo; Shrestha, Bimmi; Gorman, Matthew; Kim, Kristin Y.; Suthar, Mehul S.; Atkinson, John P.; Gale Jr, Michael; Diamond, Michael S.

    2014-01-01

    The type I interferon (IFN) signaling response limits infection of many RNA and DNA viruses. To define key cell types that require type I IFN signaling to orchestrate immunity against West Nile virus (WNV), we infected mice with conditional deletions of the type I IFN receptor (IFNAR) gene. Deletion of the Ifnar gene in subsets of myeloid cells resulted in uncontrolled WNV replication, vasoactive cytokine production, sepsis, organ damage, and death that were remarkably similar to infection of Ifnar−/− mice completely lacking type I IFN signaling. In Mavs−/−×Ifnar−/− myeloid cells and mice lacking both Ifnar and the RIG-I-like receptor adaptor gene Mavs, cytokine production was muted despite high levels of WNV infection. Thus, in myeloid cells, viral infection triggers signaling through MAVS to induce proinflammatory cytokines that can result in sepsis and organ damage. Viral pathogenesis was caused in part by massive complement activation, as liver damage was minimized in animals lacking complement components C3 or factor B or treated with neutralizing anti-C5 antibodies. Disease in Ifnar−/− and CD11c Cre+Ifnarf/f mice also was facilitated by the proinflammatory cytokine TNF-α, as blocking antibodies diminished complement activation and prolonged survival without altering viral burden. Collectively, our findings establish the dominant role of type I IFN signaling in myeloid cells in restricting virus infection and controlling pathological inflammation and tissue injury. PMID:24743949

  11. Neutrophil Extracellular Traps Enhance Early Inflammatory Response in Sendai Virus-Induced Asthma Phenotype

    PubMed Central

    Akk, Antonina; Springer, Luke E.; Pham, Christine T. N.

    2016-01-01

    Paramyxoviral infection in childhood has been linked to a significant increased rate of asthma development. In mice, paramyxoviral infection with the mouse parainfluenza virus type I, Sendai virus (Sev), causes a limited bronchiolitis followed by persistent asthma traits. We have previously shown that the absence of cysteine protease dipeptidyl peptidase I (DPPI) dampened the acute lung inflammatory response and the subsequent asthma phenotype induced by Sev. Adoptive transfer of wild-type neutrophils into DPPI-deficient mice restored leukocyte influx, the acute cytokine response, and the subsequent mucous cell metaplasia that accompanied Sev-induced asthma phenotype. However, the exact mechanism by which DPPI-sufficient neutrophils promote asthma development following Sev infection is still unknown. We hypothesize that neutrophils recruited to the alveolar space following Sev infection elaborate neutrophil extracellular traps (NETs) that propagate the inflammatory cascade, culminating in the eventual asthma phenotype. Indeed, we found that Sev infection was associated with NET formation in the lung and release of cell-free DNA complexed to myeloperoxidase in the alveolar space and plasma that peaked on day 2 post infection. Absence of DPPI significantly attenuated Sev-induced NET formation in vivo and in vitro. Furthermore, concomitant administration of DNase 1, which dismantled NETs, or inhibition of peptidylarginine deiminase 4 (PAD4), an essential mediator of NET formation, suppressed the early inflammatory responses to Sev infection. Lastly, NETs primed bone marrow-derived cells to release cytokines that can amplify the inflammatory cascade.

  12. Mumps Virus Induces Protein-Kinase-R-Dependent Stress Granules, Partly Suppressing Type III Interferon Production

    PubMed Central

    Hashimoto, Shin; Yamamoto, Soh; Ogasawara, Noriko; Sato, Toyotaka; Yamamoto, Keisuke; Katoh, Hiroshi; Kubota, Toru; Shiraishi, Tsukasa; Kojima, Takashi; Himi, Tetsuo; Tsutsumi, Hiroyuki; Yokota, Shin-ichi

    2016-01-01

    Stress granules (SGs) are cytoplasmic granular aggregations that are induced by cellular stress, including viral infection. SGs have opposing antiviral and proviral roles, which depend on virus species. The exact function of SGs during viral infection is not fully understood. Here, we showed that mumps virus (MuV) induced SGs depending on activation of protein kinase R (PKR). MuV infection strongly induced interferon (IFN)-λ1, 2 and 3, and IFN-β through activation of IFN regulatory factor 3 (IRF3) via retinoic acid inducible gene-I (RIG-I) and the mitochondrial antiviral signaling (MAVS) pathway. MuV-induced IFNs were strongly upregulated in PKR-knockdown cells. MuV-induced SG formation was suppressed by knockdown of PKR and SG marker proteins, Ras-GTPase-activating protein SH3-domain-binding protein 1 and T-cell-restricted intracellular antigen-1, and significantly increased the levels of MuV-induced IFN-λ1. However, viral titer was not altered by suppression of SG formation. PKR was required for induction of SGs by MuV infection and regulated type III IFN (IFN-λ1) mRNA stability. MuV-induced SGs partly suppressed type III IFN production by MuV; however, the limited suppression was not sufficient to inhibit MuV replication in cell culture. Our results provide insight into the relationship between SGs and IFN production induced by MuV infection. PMID:27560627

  13. Sirtuin 1 Regulates Dendritic Cell Activation and Autophagy during Respiratory Syncytial Virus-Induced Immune Responses.

    PubMed

    Owczarczyk, Anna B; Schaller, Matthew A; Reed, Michelle; Rasky, Andrew J; Lombard, David B; Lukacs, Nicholas W

    2015-08-15

    Respiratory syncytial virus (RSV) is the major cause of lower respiratory tract infection in children worldwide. Sirtuin 1 (SIRT1), an NAD(+)-dependent deacetylase, has been associated with the induction of autophagy and the regulation of inflammatory mediators. We found that Sirt1 was upregulated in mouse lung after RSV infection. Infected animals that received EX-527, a selective SIRT1 inhibitor, displayed exacerbated lung pathology, with increased mucus production, elevated viral load, and enhanced Th2 cytokine production. Gene expression analysis of isolated cell populations revealed that Sirt1 was most highly upregulated in RSV-treated dendritic cells (DCs). Upon RSV infection, EX-527-treated DCs, Sirt1 small interfering RNA-treated DCs, or DCs from conditional knockout (Sirt1(f/f)-CD11c-Cre(+)) mice showed downregulated inflammatory cytokine gene expression and attenuated autophagy. Finally, RSV infection of Sirt1(f/f)-CD11c-Cre(+) mice resulted in altered lung and lymph node cytokine responses, leading to exacerbated pathology. These data indicate that SIRT1 promotes DC activation associated with autophagy-mediated processes during RSV infection, thereby directing efficient antiviral immune responses. PMID:26157176

  14. Varicella-zoster virus induces the formation of dynamic nuclear capsid aggregates

    SciTech Connect

    Lebrun, Marielle; Thelen, Nicolas; Thiry, Marc; Riva, Laura; Ote, Isabelle; Condé, Claude; Vandevenne, Patricia; Di Valentin, Emmanuel; Bontems, Sébastien; Sadzot-Delvaux, Catherine

    2014-04-15

    The first step of herpesviruses virion assembly occurs in the nucleus. However, the exact site where nucleocapsids are assembled, where the genome and the inner tegument are acquired, remains controversial. We created a recombinant VZV expressing ORF23 (homologous to HSV-1 VP26) fused to the eGFP and dually fluorescent viruses with a tegument protein additionally fused to a red tag (ORF9, ORF21 and ORF22 corresponding to HSV-1 UL49, UL37 and UL36). We identified nuclear dense structures containing the major capsid protein, the scaffold protein and maturing protease, as well as ORF21 and ORF22. Correlative microscopy demonstrated that the structures correspond to capsid aggregates and time-lapse video imaging showed that they appear prior to the accumulation of cytoplasmic capsids, presumably undergoing the secondary egress, and are highly dynamic. Our observations suggest that these structures might represent a nuclear area important for capsid assembly and/or maturation before the budding at the inner nuclear membrane. - Highlights: • We created a recombinant VZV expressing the small capsid protein fused to the eGFP. • We identified nuclear dense structures containing capsid and procapsid proteins. • Correlative microscopy showed that the structures correspond to capsid aggregates. • Procapsids and partial capsids are found within the aggregates of WT and eGFP-23 VZV. • FRAP and FLIP experiments demonstrated that they are dynamic structures.

  15. A generic screening platform for inhibitors of virus induced cell fusion using cellular electrical impedance

    PubMed Central

    Watterson, Daniel; Robinson, Jodie; Chappell, Keith J.; Butler, Mark S.; Edwards, David J.; Fry, Scott R.; Bermingham, Imogen M.; Cooper, Matthew A.; Young, Paul R.

    2016-01-01

    Fusion of the viral envelope with host cell membranes is an essential step in the life cycle of all enveloped viruses. Despite such a clear target for antiviral drug development, few anti-fusion drugs have progressed to market. One significant hurdle is the absence of a generic, high-throughput, reproducible fusion assay. Here we report that real time, label-free measurement of cellular electrical impedance can quantify cell-cell fusion mediated by either individually expressed recombinant viral fusion proteins, or native virus infection. We validated this approach for all three classes of viral fusion and demonstrated utility in quantifying fusion inhibition using antibodies and small molecule inhibitors specific for dengue virus and respiratory syncytial virus. PMID:26976324

  16. Neutral Sphingomyelinase in Physiological and Measles Virus Induced T Cell Suppression

    PubMed Central

    Collenburg, Lena; Grassmé, Heike; Schneider-Schaulies, Sibylle

    2014-01-01

    T cell paralysis is a main feature of measles virus (MV) induced immunosuppression. MV contact mediated activation of sphingomyelinases was found to contribute to MV interference with T cell actin reorganization. The role of these enzymes in MV-induced inhibition of T cell activation remained equally undefined as their general role in regulating immune synapse (IS) activity which relies on spatiotemporal membrane patterning. Our study for the first time reveals that transient activation of the neutral sphingomyelinase 2 (NSM2) occurs in physiological co-stimulation of primary T cells where ceramide accumulation is confined to the lamellum (where also NSM2 can be detected) and excluded from IS areas of high actin turnover. Genetic ablation of the enzyme is associated with T cell hyper-responsiveness as revealed by actin dynamics, tyrosine phosphorylation, Ca2+-mobilization and expansion indicating that NSM2 acts to suppress overshooting T cell responses. In line with its suppressive activity, exaggerated, prolonged NSM2 activation as occurring in co-stimulated T cells following MV exposure was associated with aberrant compartmentalization of ceramides, loss of spreading responses, interference with accumulation of tyrosine phosphorylated protein species and expansion. Altogether, this study for the first time reveals a role of NSM2 in physiological T cell stimulation which is dampening and can be abused by a virus, which promotes enhanced and prolonged NSM2 activation to cause pathological T cell suppression. PMID:25521388

  17. Inhibition of respiratory syncytial virus replication and virus-induced p38 kinase activity by berberine.

    PubMed

    Shin, Han-Bo; Choi, Myung-Soo; Yi, Chae-Min; Lee, Jun; Kim, Nam-Jung; Inn, Kyung-Soo

    2015-07-01

    Respiratory syncytial virus (RSV) causes severe lower respiratory tract infection and poses a major public health threat worldwide. No effective vaccines or therapeutics are currently available; berberine, an isoquinoline alkaloid from various medicinal plants, has been shown to exert antiviral and several other biological effects. Recent studies have shown that p38 mitogen-activated protein kinase (MAPK) activity is implicated in infection by and replication of viruses such as RSV and the influenza virus. Because berberine has previously been implicated in modulating the activity of p38 MAPK, its effects on RSV infection and RSV-mediated p38 MAPK activation were examined. Replication of RSV in epithelial cells was significantly reduced by treatment with berberine. Berberine treatment caused decrease in viral protein and mRNA syntheses. Similar to previously reported findings, RSV infection caused phosphorylation of p38 MAPK at a very early time point of infection, and phosphorylation was dramatically reduced by berberine treatment. In addition, production of interleukin-6 mRNA upon RSV infection was significantly suppressed by treatment with berberine, suggesting the anti-inflammatory role of berberine during RSV infection. Taken together, we showed that berberine, a natural compound already proven to be safe for human consumption, suppresses the replication of RSV. In addition, the current study suggests that inhibition of RSV-mediated early p38 MAPK activation, which has been implicated as an early step in viral infection, as a potential molecular mechanism.

  18. Association of human immunodeficiency virus-induced immunosuppression with human papillomavirus infection and cervical intraepithelial neoplasia.

    PubMed

    Henry, M J; Stanley, M W; Cruikshank, S; Carson, L

    1989-02-01

    Human papillomavirus infection plays an important causal role in cervical intraepithelial neoplasia and carcinoma. The rate of infection with human papillomavirus as well as the incidence of cervical intraepithelial neoplasia and carcinoma are increased in immunosuppressed patients. We report a possible association between infection with human immunodeficiency virus and cervical intraepithelial neoplasia with human papillomavirus infection.

  19. Human monoclonal antibodies against West Nile virus induced by natural infection neutralize at a postattachment step.

    PubMed

    Vogt, Matthew R; Moesker, Bastiaan; Goudsmit, Jaap; Jongeneelen, Mandy; Austin, S Kyle; Oliphant, Theodore; Nelson, Steevenson; Pierson, Theodore C; Wilschut, Jan; Throsby, Mark; Diamond, Michael S

    2009-07-01

    West Nile virus (WNV) is a neurotropic flavivirus that is now a primary cause of epidemic encephalitis in North America. Studies of mice have demonstrated that the humoral immune response against WNV limits primary infection and protects against a secondary challenge. The most-potent neutralizing mouse monoclonal antibodies (MAbs) recognize an epitope on the lateral ridge of domain III (DIII-lr) of the envelope (E) protein. However, studies with serum from human patients show that antibodies against the DIII-lr epitope comprise, at best, a minor component of the human anti-WNV antibody response. Herein, we characterize in detail two WNV-specific human MAbs, CR4348 and CR4354, that were isolated from B-cell populations of convalescent patients. These MAbs strongly neutralize WNV infection of cultured cells, protect mice against lethal infection in vivo, and yet poorly recognize recombinant forms of the E protein. Instead, CR4348 and CR4354 bind determinants on intact WNV virions and subviral particles in a pH-sensitive manner, and neutralization is altered by mutations at the dimer interface in domain II and the hinge between domains I and II, respectively. CR4348 and CR4354 human MAbs neutralize infection at a postattachment step in the viral life cycle, likely by inhibiting acid-induced fusion within the endosome.

  20. Proteomic Profiling of Human Liver Biopsies: Hepatitis C Virus-Induced Fibrosis and Mitochondrial Dysfunction

    SciTech Connect

    Diamond, Deborah L.; Jacobs, Jon M.; Paeper, Bryan; Proll, Sean; Gritsenko, Marina A.; Carithers, Jr., Robert L.; Larson , Anne M.; Yeh, Matthew M.; Camp, David G.; Smith, Richard D.; Katze, Michael G.

    2007-09-01

    Liver biopsies from HCV-infected patients offer the unique opportunity to study human liver biology and disease in vivo. However, the low protein yields associated with these small samples present a significant challenge for proteomic analysis. In this study we describe the application of an ultra-sensitive proteomics platform for performing robust quantitative proteomic studies on microgram amounts of HCV-infected human liver tissue from 15 patients at different stages of fibrosis. A high quality liver protein data base containing 5,920 unique protein identifications supported high throughput quantitative studies using 16O:18O stable isotope labeling in combination with the accurate mass and time (AMT) tag approach. A total of 1,641 liver biopsy proteins were quantified and ANOVA identified 210 proteins exhibiting statistically significant differences associated with fibrosis stage. Hierarchical clustering revealed that biopsies representative of later fibrosis stages (e.g. Batts-Ludwig stages 3-4) exhibited a distinct protein expression profile indicating an apparent down-regulation of many proteins when compared to samples from earlier fibrosis stages (e.g. Batts-Ludwig stages 0-2). Functional analysis of these signature proteins suggests that impairment of key mitochondrial processes including fatty acid oxidation and oxidative phosphorylation, and response to oxidative stress and reactive oxygen species occurs during advanced stage 3-4 fibrosis. In conclusion, the results reported here represent a significant advancement in clinical proteomics providing to our knowledge, the first demonstration of global proteomic alterations accompanying liver disease progression in patients chronically infected with HCV. Our findings contribute to a generally emerging theme associating oxidative stress and hepatic mitochondrial dysfunction with HCV pathogenesis.

  1. Protection against polyoma virus-induced tumors is perforin-independent

    SciTech Connect

    Byers, Anthony M.; Hadley, Annette; Lukacher, Aron E. . E-mail: alukach@emory.edu

    2007-02-20

    CD8 T cells are necessary for controlling tumors induced by mouse polyoma virus (PyV), but the effector mechanism(s) responsible have not been determined. We examined the PyV tumorigenicity in C57BL/6 mice mutated in Fas or carrying targeted disruptions in the perforin gene or in both TNF receptor type I and type II genes. Surprisingly, none of these mice developed tumors. Perforin/Fas double-deficient radiation bone marrow chimeric mice were also resistant to PyV-induced tumors. Anti-PyV CD8 T cells in perforin-deficient mice were found not to differ from wild type mice with respect to phenotype, capacity to produce cytokines or maintenance of memory T cells, indicating that perforin does not modulate the PyV-specific CD8 T cell response. In addition, virus was cleared and persisted to similar extents in wild type and perforin-deficient mice. In summary, perforin/granzyme exocytosis is not an essential effector pathway for protection against PyV infection or tumorigenesis.

  2. Respiratory syncytical virus-induced chemokine expression in the lower airways: eosinophil recruitment and degranulation.

    PubMed

    Harrison, A M; Bonville, C A; Rosenberg, H F; Domachowske, J B

    1999-06-01

    Characterization of chemokine expression patterns in virus-infected epithelial cells provides important clues to the pathophysiology of such infections. The aim of this study was to determine the chemokine response pattern of respiratory epithelium when infected with respiratory syncytial virus (RSV). Macrophage inflammatory protein-1-alpha (MIP-1-alpha), interleukin-8 (IL-8), and RANTES concentrations were measured from RSV-infected HEp-2, MRC-5, and WI-38 cell culture supernatants daily following infection. Additionally, MIP-1-alpha, IL-8, and RANTES concentrations were measured from lower respiratory secretions obtained from 10 intubated infants (0-24 mo) with RSV bronchiolitis, and from 10 control subjects. Our results indicate that respiratory epithelial cells respond to RSV infection by producing MIP-1-alpha, IL-8, and RANTES. Production of MIP-1-alpha required ongoing viral replication, whereas RANTES and IL-8 could be elicited by inactivated forms of the virus. MIP-1-alpha, RANTES, and IL-8 were also present in lower airway secretions obtained from patients with RSV bronchiolitis. Eosinophil cationic protein (ECP) and eosinophil-derived neurotoxin (EDN), the eosinophil secretory ribonucleases, were detected in lower airway secretions from RSV-infected patients; ECP concentrations correlated with MIP-1-alpha concentrations (r = 0.93). We conclude that MIP-1-alpha is present in the lower airways during severe RSV disease. The correlation between MIP-1-alpha and ECP concentrations suggests a role for eosinophil degranulation products in the pathogenesis of RSV bronchiolitis. PMID:10351940

  3. Venezuelan Equine Encephalitis Virus Induces Apoptosis through the Unfolded Protein Response Activation of EGR1

    PubMed Central

    Baer, Alan; Lundberg, Lindsay; Swales, Danielle; Waybright, Nicole; Pinkham, Chelsea; Dinman, Jonathan D.

    2016-01-01

    ABSTRACT Venezuelan equine encephalitis virus (VEEV) is a previously weaponized arthropod-borne virus responsible for causing acute and fatal encephalitis in animal and human hosts. The increased circulation and spread in the Americas of VEEV and other encephalitic arboviruses, such as eastern equine encephalitis virus and West Nile virus, underscore the need for research aimed at characterizing the pathogenesis of viral encephalomyelitis for the development of novel medical countermeasures. The host-pathogen dynamics of VEEV Trinidad donkey-infected human astrocytoma U87MG cells were determined by carrying out RNA sequencing (RNA-Seq) of poly(A) and mRNAs. To identify the critical alterations that take place in the host transcriptome following VEEV infection, samples were collected at 4, 8, and 16 h postinfection and RNA-Seq data were acquired using an Ion Torrent PGM platform. Differential expression of interferon response, stress response factors, and components of the unfolded protein response (UPR) was observed. The protein kinase RNA-like endoplasmic reticulum kinase (PERK) arm of the UPR was activated, as the expression of both activating transcription factor 4 (ATF4) and CHOP (DDIT3), critical regulators of the pathway, was altered after infection. Expression of the transcription factor early growth response 1 (EGR1) was induced in a PERK-dependent manner. EGR1−/− mouse embryonic fibroblasts (MEFs) demonstrated lower susceptibility to VEEV-induced cell death than isogenic wild-type MEFs, indicating that EGR1 modulates proapoptotic pathways following VEEV infection. The influence of EGR1 is of great importance, as neuronal damage can lead to long-term sequelae in individuals who have survived VEEV infection. IMPORTANCE Alphaviruses represent a group of clinically relevant viruses transmitted by mosquitoes to humans. In severe cases, viral spread targets neuronal tissue, resulting in significant and life-threatening inflammation dependent on a combination of virus-host interactions. Currently there are no therapeutics for infections cause by encephalitic alphaviruses due to an incomplete understanding of their molecular pathogenesis. Venezuelan equine encephalitis virus (VEEV) is an alphavirus that is prevalent in the Americas and that is capable of infecting horses and humans. Here we utilized next-generation RNA sequencing to identify differential alterations in VEEV-infected astrocytes. Our results indicated that the abundance of transcripts associated with the interferon and the unfolded protein response pathways was altered following infection and demonstrated that early growth response 1 (EGR1) contributed to VEEV-induced cell death. PMID:26792742

  4. Infection with Usutu Virus Induces an Autophagic Response in Mammalian Cells

    PubMed Central

    Blázquez, Ana-Belén; Escribano-Romero, Estela; Merino-Ramos, Teresa; Saiz, Juan-Carlos; Martín-Acebes, Miguel A.

    2013-01-01

    Usutu virus (USUV) is an African mosquito-borne flavivirus closely related to West Nile virus and Japanese encephalitis virus, which host range includes mainly mosquitoes and birds, although infections in humans have been also documented, thus warning about USUV as a potential health threat. Circulation of USUV in Africa was documented more than 50 years ago, but it was not until the last decade that it emerged in Europe causing episodes of avian mortality and some human severe cases. Since autophagy is a cellular pathway that can play important roles on different aspects of viral infections and pathogenesis, the possible implication of this pathway in USUV infection has been examined using Vero cells and two viral strains of different origin. USUV infection induced the unfolded protein response, revealed by the splicing of Xbp-1 mRNA. Infection with USUV also stimulated the autophagic process, which was demonstrated by an increase in the cytoplasmic aggregation of microtubule-associated protein 1 light chain 3 (LC3), a marker of autophagosome formation. In addition to this, an increase in the lipidated form of LC3, that is associated with autophagosome formation, was noticed following infection. Pharmacological modulation of the autophagic pathway with the inductor of autophagy rapamycin resulted in an increase in virus yield. On the other hand, treatment with 3-methyladenine or wortmannin, two distinct inhibitors of phosphatidylinositol 3-kinases involved in autophagy, resulted in a decrease in virus yield. These results indicate that USUV virus infection upregulates the cellular autophagic pathway and that drugs that target this pathway can modulate the infection of this virus, thus identifying a potential druggable pathway in USUV-infection. PMID:24205422

  5. Infection with Usutu virus induces an autophagic response in mammalian cells.

    PubMed

    Blázquez, Ana-Belén; Escribano-Romero, Estela; Merino-Ramos, Teresa; Saiz, Juan-Carlos; Martín-Acebes, Miguel A

    2013-01-01

    Usutu virus (USUV) is an African mosquito-borne flavivirus closely related to West Nile virus and Japanese encephalitis virus, which host range includes mainly mosquitoes and birds, although infections in humans have been also documented, thus warning about USUV as a potential health threat. Circulation of USUV in Africa was documented more than 50 years ago, but it was not until the last decade that it emerged in Europe causing episodes of avian mortality and some human severe cases. Since autophagy is a cellular pathway that can play important roles on different aspects of viral infections and pathogenesis, the possible implication of this pathway in USUV infection has been examined using Vero cells and two viral strains of different origin. USUV infection induced the unfolded protein response, revealed by the splicing of Xbp-1 mRNA. Infection with USUV also stimulated the autophagic process, which was demonstrated by an increase in the cytoplasmic aggregation of microtubule-associated protein 1 light chain 3 (LC3), a marker of autophagosome formation. In addition to this, an increase in the lipidated form of LC3, that is associated with autophagosome formation, was noticed following infection. Pharmacological modulation of the autophagic pathway with the inductor of autophagy rapamycin resulted in an increase in virus yield. On the other hand, treatment with 3-methyladenine or wortmannin, two distinct inhibitors of phosphatidylinositol 3-kinases involved in autophagy, resulted in a decrease in virus yield. These results indicate that USUV virus infection upregulates the cellular autophagic pathway and that drugs that target this pathway can modulate the infection of this virus, thus identifying a potential druggable pathway in USUV-infection.

  6. Dengue virus-induced thymus-derived suppressor cells in the spleen of mice.

    PubMed Central

    Tandon, P; Chaturvedi, U C; Mathur, A

    1979-01-01

    Adoptive transfer of spleen cells obtained from mice given three weekly i.p. doses of dengue type 2 virus (DV) suppressed DV antigen-specific antibody secretion as detected by the Jerne plaque technique. This suppression was produced by non-glass-adherent cells but not by glass-adherent cells. Immune spleen cells depleted of macrophages by carbonyl iron treatment had higher suppressor activity. Immune spleen cell homogenate could transfer the activity equally well. The immune spleen cells were separated into T and B lymphocytes by a nylon wool column. B lymphocytes had no suppressor activity; almost all the suppressor activity was present in T lymphocytes. Thus, macrophages and B lymphocytes had no suppressor activity; it was mediated by T lymphocytes through soluble factors. PMID:160396

  7. The New World arenavirus Tacaribe virus induces caspase-dependent apoptosis in infected cells.

    PubMed

    Wolff, Svenja; Groseth, Allison; Meyer, Bjoern; Jackson, David; Strecker, Thomas; Kaufmann, Andreas; Becker, Stephan

    2016-04-01

    The Arenaviridae is a diverse and growing family of viruses that already includes more than 25 distinct species. While some of these viruses have a significant impact on public health, others appear to be non-pathogenic. At present little is known about the host cell responses to infection with different arenaviruses, particularly those found in the New World; however, apoptosis is known to play an important role in controlling infection of many viruses. Here we show that infection with Tacaribe virus (TCRV), which is widely considered the prototype for non-pathogenic arenaviruses, leads to stronger induction of apoptosis than does infection with its human-pathogenic relative Junín virus. TCRV-induced apoptosis occurred in several cell types during late stages of infection and was shown to be caspase-dependent, involving the activation of caspases 3, 7, 8 and 9. Further, UV-inactivated TCRV did not induce apoptosis, indicating that the activation of this process is dependent on active viral replication/transcription. Interestingly, when apoptosis was inhibited, growth of TCRV was not enhanced, indicating that apoptosis does not have a direct negative effect on TCRV infection in vitro. Taken together, our data identify and characterize an important virus-host cell interaction of the prototypic, non-pathogenic arenavirus TCRV, which provides important insight into the growing field of arenavirus research aimed at better understanding the diversity in responses to different arenavirus infections and their functional consequences.

  8. The effect of infectious bursal disease virus induced immunosuppression on avian influenza virus vaccine efficacy

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In the field, poultry are exposed to a variety of infectious agents, many of which are immunosuppressive. Co-infections between these agents are common, and these co-infections have effects on disease, immune response, and vaccine efficacy. The effect of co-infections in poultry between immunosupp...

  9. Dysregulation of apoptotic death in the pathogenesis of virus-induced cytogenetic instability of blood lymphocytes.

    PubMed

    Ryazantseva, N V; Novitskii, V V; Zhukova, O B; Radzivil, T T; Mikheev, S L; Chechina, O E; Zima, A P; Shilov, B V

    2006-05-01

    The cytogenetic status and activity of regulatory systems for stability of the cell genome were evaluated in patients with chronic viral persistence. Hepatitis B and C viruses damage the chromosome apparatus of peripheral blood lymphocytes. Cytogenetic instability of immunocompetent cells during chronic viral infection was associated with inhibition of DNA excision repair system and dysregulation of apoptosis in target cells. PMID:17181065

  10. Virus-induced type I IFN stimulates generation of immunoproteasomes at the site of infection

    PubMed Central

    Shin, Eui-Cheol; Seifert, Ulrike; Kato, Takanobu; Rice, Charles M.; Feinstone, Stephen M.; Kloetzel, Peter-M.; Rehermann, Barbara

    2006-01-01

    IFN-γ is known as the initial and primary inducer of immunoproteasomes during viral infections. We now report that type I IFN induced the transcription and translation of immunoproteasome subunits, their incorporation into the proteasome complex, and the generation of an immunoproteasome-dependent CD8 T cell epitope in vitro and provide in vivo evidence that this mechanism occurs prior to IFN-γ responses at the site of viral infection. Type I IFN–mediated generation of immunoproteasomes was initiated by either poly(I:C) or HCV RNA in human hepatoma cells and was inhibited by neutralization of type I IFN. In serial liver biopsies of chimpanzees with acute HCV infection, increases in immunoproteasome subunit mRNA preceded intrahepatic IFN-γ responses by several weeks, instead coinciding with intrahepatic type I IFN responses. Thus, viral RNA–induced innate immune responses regulate the antigen-processing machinery, which occurs prior to the detection of IFN-γ at the site of infection. This mechanism may contribute to the high effectiveness (95%) of type I IFN–based therapies if administered early during HCV infection. PMID:17039255

  11. Four-segmented Rift Valley fever virus induces sterile immunity in sheep after a single vaccination.

    PubMed

    Wichgers Schreur, Paul J; Kant, Jet; van Keulen, Lucien; Moormann, Rob J M; Kortekaas, Jeroen

    2015-03-17

    Rift Valley fever virus (RVFV), a mosquito-borne virus in the Bunyaviridae family, causes recurrent outbreaks with severe disease in ruminants and occasionally humans. The virus comprises a segmented genome consisting of a small (S), medium (M) and large (L) RNA segment of negative polarity. The M-segment encodes a glycoprotein precursor (GPC) protein that is co-translationally cleaved into Gn and Gc, which are required for virus entry and fusion. Recently we developed a four-segmented RVFV (RVFV-4s) by splitting the M-genome segment, and used this virus to study RVFV genome packaging. Here we evaluated the potential of a RVFV-4s variant lacking the NSs gene (4s-ΔNSs) to induce protective immunity in sheep. Groups of seven lambs were either mock-vaccinated or vaccinated with 10(5) or 10(6) tissue culture infective dose (TCID50) of 4s-ΔNSs via the intramuscular (IM) or subcutaneous (SC) route. Three weeks post-vaccination all lambs were challenged with wild-type RVFV. Mock-vaccinated lambs developed high fever and high viremia within 2 days post-challenge and three animals eventually succumbed to the infection. In contrast, none of the 4s-ΔNSs vaccinated animals developed clinical signs during the course of the experiment. Vaccination with 10(5) TCID50 via the IM route provided sterile immunity, whereas a 10(6) dose was required to induce sterile immunity via SC vaccination. Protection was strongly correlated with the presence of RVFV neutralizing antibodies. This study shows that 4s-ΔNSs is able to induce sterile immunity in the natural target species after a single vaccination, preferably administrated via the IM route.

  12. Human immunodeficiency virus-induced pathology favored by cellular transmission and activation

    SciTech Connect

    Lewis, D.E.; Yoffe, B.; Bosworth, C.G.; Hollinger, F.B.; Rich, R.R.

    1988-03-01

    Epidemiological data suggest that transmission of human immunodeficiency virus (HIV) occurs primarily by transference of virally infected cells. However, the efficiency of lytic productive infection induced by HIV after transmission of cell-associated virus vs. free virus is difficult to assess. The present studies compare the extent of depletion of CD4+ (helper/inducer) T cells after mixing uninfected cells with either free HIV or irradiated HIV-infected allogeneic or autologous cells in vitro. Rapid CD4+ cellular depletion occurred only in cultures containing allogeneic infected cells or after addition of a nonspecific T cell activation signal to cultures with autologous infected cells. These in vitro observations strongly support the epidemiological implication that interactions between infected and uninfected cells are the most efficient means of transmission and HIV-induced cytopathology in vivo. They also provide direct support for the concept that immunological stimulation by foreign cells infected with HIV dramatically increases the likelihood of transmission. These in vitro observations suggest a model for the acquisition of HIV in vivo and the role of cellular activation in dissemination of the virus to uninfected cells in an infected individual.

  13. A VIRUS-INDUCED EPIZOOTIC HEMORRHAGIC DISEASE OF THE VIRGINIA WHITE-TAILED DEER (ODOCOILEUS VIRGINIANUS).

    PubMed

    Shope, R E; Macnamara, L G; Mangold, R

    1960-01-31

    A circumscribed natural outbreak of a highly fatal disease of deer, which we have designated epizootic hemorrhagic disease (EHD), has been studied. The disease has proven readily transmissible in deer but not in other experimental or domestic animals tested, nor in embryonating eggs or deer kidney cell cultures. The causative agent is a virus which is readily filterable and is capable of storage, either frozen or in glycerol, for relatively long periods of time. It produces a solid immunity in the few animals that survive and the blood sera of such convalescent animals contain virus-neutralizing antibodies. The disease is one in which large and small hemorrhages occur in both the viscera and skeletal structures of the body, as well as in the subcutaneous tissues. It is probably the same as one known popularly in the southeastern United States as "black tongue" of deer. It is unrelated to epidemic hemorrhagic fever of man or to the disease caused in horses by the equine arteritis virus. At least two serologically different types of EHD virus exist. The New Jersey strain is of greater lethality for experimental deer than the serologically different one obtained from an outbreak that occurred in South Dakota a year after the New Jersey epizootic.

  14. A Recombinant Adenovirus Expressing Ovine Interferon Tau Prevents Influenza Virus-Induced Lethality in Mice

    PubMed Central

    Pascual, E.; Avia, M.; Rangel, G.; de Molina, A.; Alejo, A.; Sevilla, N.

    2016-01-01

    Ovine interferon tau (IFN-τ) is a unique type I interferon with low toxicity and a broad host range in vivo. We report the generation of a nonreplicative recombinant adenovirus expressing biologically active IFN-τ. Using the B6.A2G-Mx1 mouse model, we showed that single-dose intranasal administration of recombinant Ad5-IFN-τ can effectively prevent lethality and disease induced by highly virulent hv-PR8 influenza virus by activating the interferon response and preventing viral replication. PMID:26739058

  15. Sirtuin 1 Regulates Dendritic Cell Activation and Autophagy during Respiratory Syncytial Virus-Induced Immune Responses.

    PubMed

    Owczarczyk, Anna B; Schaller, Matthew A; Reed, Michelle; Rasky, Andrew J; Lombard, David B; Lukacs, Nicholas W

    2015-08-15

    Respiratory syncytial virus (RSV) is the major cause of lower respiratory tract infection in children worldwide. Sirtuin 1 (SIRT1), an NAD(+)-dependent deacetylase, has been associated with the induction of autophagy and the regulation of inflammatory mediators. We found that Sirt1 was upregulated in mouse lung after RSV infection. Infected animals that received EX-527, a selective SIRT1 inhibitor, displayed exacerbated lung pathology, with increased mucus production, elevated viral load, and enhanced Th2 cytokine production. Gene expression analysis of isolated cell populations revealed that Sirt1 was most highly upregulated in RSV-treated dendritic cells (DCs). Upon RSV infection, EX-527-treated DCs, Sirt1 small interfering RNA-treated DCs, or DCs from conditional knockout (Sirt1(f/f)-CD11c-Cre(+)) mice showed downregulated inflammatory cytokine gene expression and attenuated autophagy. Finally, RSV infection of Sirt1(f/f)-CD11c-Cre(+) mice resulted in altered lung and lymph node cytokine responses, leading to exacerbated pathology. These data indicate that SIRT1 promotes DC activation associated with autophagy-mediated processes during RSV infection, thereby directing efficient antiviral immune responses.

  16. Rabies virus-induced apoptosis involves caspase-dependent and caspase-independent pathways.

    PubMed

    Sarmento, Luciana; Tseggai, Tesfai; Dhingra, Vikas; Fu, Zhen F

    2006-11-01

    Previously, it has been shown that the laboratory attenuated rabies virus CVS-B2C, but not the wild-type virus SHBRV, induces apoptosis in mice and the induction of apoptosis is mediated by viral glycoprotein. Induction of apoptosis by CVS-B2C limits the spread of the virus in the CNS. In the present study, we characterized the pathways by which CVS-B2C induces apoptosis. BSR cells were infected with CVS-B2C or SHBRV and harvested at different time points for detection of apoptosis by immunofluorescence and flow cytometry. Apoptosis was detected only in cells infected with CVS-B2C, but not SHBRV. Caspase activity and expression of several apoptotic proteins were analyzed by fluorometric assay and Western blotting. Activation of caspase-8 and -3, but not of caspase-9, was observed in CVS-B2C-infected cells. In addition, the level of expression of Apaf-1 did not change. Furthermore, PARP was cleaved confirming activation of downstream caspases. All these data suggest that CVS-B2C infection activates the extrinsic, but not the intrinsic, apoptotic pathway. In addition, AIF, a caspase-independent apoptotic protein was up-regulated and translocated from the cytoplasm to the nucleus post-infection, suggesting that apoptosis induced by CVS-B2C also involves the activation of a caspase-independent pathway.

  17. BTat, a trans-acting regulatory protein, contributes to bovine immunodeficiency virus-induced apoptosis.

    PubMed

    Xuan, Chenghao; Qiao, Wentao; Li, Jian; Peng, Guoyuan; Liu, Min; Chen, Qimin; Zhou, Jun; Geng, Yunqi

    2008-01-01

    Bovine immunodeficiency virus (BIV) is a member of the lentivirus subfamily of retroviruses highly related to human immunodeficiency virus in morphologic, antigenic and genomic features. BIV is known to induce chronic pathological changes in infected hosts, which are often associated with the development of immune-mediated lesions. However, the molecular events underlying the cytopathic effect of BIV remain poorly understood. In this study, BIV was found to induce apoptotic cell death, and a small trans-acting regulatory protein encoded by BIV, BTat, was found to participate in the pro-apoptotic action of BIV. Introduction of exogenous BTat to cells triggered apoptosis dramatically, as revealed by assays such as terminal deoxynucleotidyl transferase-mediated dUTP nick-end labelling, nuclear morphology analysis, flow cytometry, and cleavages of caspases and poly(ADP-ribose)polymerase. Interestingly, the pro-apoptotic effect of BTat was found to be mediated through its interaction with cellular microtubules and its interference with microtubule dynamics. These results provide the first evidence that induction of apoptosis may contribute to the cytopathic effect of BIV. In addition, these results uncover a novel role for BTat in regulating microtubule dynamics in addition to its conventional role in regulating gene transcription.

  18. The New World arenavirus Tacaribe virus induces caspase-dependent apoptosis in infected cells.

    PubMed

    Wolff, Svenja; Groseth, Allison; Meyer, Bjoern; Jackson, David; Strecker, Thomas; Kaufmann, Andreas; Becker, Stephan

    2016-04-01

    The Arenaviridae is a diverse and growing family of viruses that already includes more than 25 distinct species. While some of these viruses have a significant impact on public health, others appear to be non-pathogenic. At present little is known about the host cell responses to infection with different arenaviruses, particularly those found in the New World; however, apoptosis is known to play an important role in controlling infection of many viruses. Here we show that infection with Tacaribe virus (TCRV), which is widely considered the prototype for non-pathogenic arenaviruses, leads to stronger induction of apoptosis than does infection with its human-pathogenic relative Junín virus. TCRV-induced apoptosis occurred in several cell types during late stages of infection and was shown to be caspase-dependent, involving the activation of caspases 3, 7, 8 and 9. Further, UV-inactivated TCRV did not induce apoptosis, indicating that the activation of this process is dependent on active viral replication/transcription. Interestingly, when apoptosis was inhibited, growth of TCRV was not enhanced, indicating that apoptosis does not have a direct negative effect on TCRV infection in vitro. Taken together, our data identify and characterize an important virus-host cell interaction of the prototypic, non-pathogenic arenavirus TCRV, which provides important insight into the growing field of arenavirus research aimed at better understanding the diversity in responses to different arenavirus infections and their functional consequences. PMID:26769540

  19. Follicular dendritic cell disruption as a novel mechanism of virus-induced immunosuppression

    PubMed Central

    Melzi, Eleonora; Caporale, Marco; Rocchi, Mara; Martín, Verónica; Gamino, Virginia; di Provvido, Andrea; Marruchella, Giuseppe; Entrican, Gary; Sevilla, Noemí; Palmarini, Massimo

    2016-01-01

    Arboviruses cause acute diseases that increasingly affect global health. We used bluetongue virus (BTV) and its natural sheep host to reveal a previously uncharacterized mechanism used by an arbovirus to manipulate host immunity. Our study shows that BTV, similarly to other antigens delivered through the skin, is transported rapidly via the lymph to the peripheral lymph nodes. Here, BTV infects and disrupts follicular dendritic cells, hindering B-cell division in germinal centers, which results in a delayed production of high affinity and virus neutralizing antibodies. Moreover, the humoral immune response to a second antigen is also hampered in BTV-infected animals. Thus, an arbovirus can evade the host antiviral response by inducing an acute immunosuppression. Although transient, this immunosuppression occurs at the critical early stages of infection when a delayed host humoral immune response likely affects virus systemic dissemination and the clinical outcome of disease. PMID:27671646

  20. Hepatitis B virus-induced hepatocellular carcinoma: functional roles of MICA variants.

    PubMed

    Tong, H V; Toan, N L; Song, L H; Bock, C-T; Kremsner, P G; Velavan, T P

    2013-10-01

    Hepatitis B virus infection is a high-risk factor for hepatocellular carcinoma. The human major histocompatibility complex class I chain-related gene A (MICA) is a ligand of the NKG2D receptor that modulates the NK and T-cell-mediated immune responses and is associated with several diseases. This study determined the effects of MICA polymorphisms during HBV infection and HBV-induced HCC. We conducted a case-controlled study in a Vietnamese cohort and genotyped ten functional MICA polymorphisms including the microsatellite motif in 552 clinically classified hepatitis B virus patients and 418 healthy controls. The serum soluble MICA levels (sMICA) were correlated with MICA variants and liver enzyme levels. We demonstrated a significant contribution of MICA rs2596542G/A promoter variant and nonsynonymous substitutions MICA-129Met/Val, MICA-251Gln/Arg, MICA-175Gly/Ser, triplet repeat polymorphism and respective haplotypes with HBV-induced HCC and HBV persistence. The circulating sMICA levels in HBV patient groups were elevated significantly compared with healthy controls. A significant contribution of studied MICA variants to sMICA levels was also observed. The liver enzymes alanine amino transferase (ALT), aspartate transaminase (AST), total bilirubin and direct bilirubin were positively correlated with sMICA levels suggesting sMICA as a biomarker for liver injury. We conclude that MICA polymorphisms play a crucial role in modulating innate immune responses, tumour surveillance and regulate disease susceptibility during HBV infection.

  1. NITROTYROSINE INHIBITS RESPIRATORY SYNCTIAL VIRUS-INDUCED RANTES PRODUCTION IN HUMAN BRONCHIAL EPITHELIAL CELLS

    EPA Science Inventory

    3-Nitrotyrosine (NO2Tyr) produced during inflammation can substitute the C-terminus tyrosine of a-tubulin post-translationally altering microtubular functions. Since propagation of respiratory syncytial virus (RSV) infection may require an intact microtubular activity, we tested ...

  2. Mumps Virus Induces Protein-Kinase-R-Dependent Stress Granules, Partly Suppressing Type III Interferon Production.

    PubMed

    Hashimoto, Shin; Yamamoto, Soh; Ogasawara, Noriko; Sato, Toyotaka; Yamamoto, Keisuke; Katoh, Hiroshi; Kubota, Toru; Shiraishi, Tsukasa; Kojima, Takashi; Himi, Tetsuo; Tsutsumi, Hiroyuki; Yokota, Shin-Ichi

    2016-01-01

    Stress granules (SGs) are cytoplasmic granular aggregations that are induced by cellular stress, including viral infection. SGs have opposing antiviral and proviral roles, which depend on virus species. The exact function of SGs during viral infection is not fully understood. Here, we showed that mumps virus (MuV) induced SGs depending on activation of protein kinase R (PKR). MuV infection strongly induced interferon (IFN)-λ1, 2 and 3, and IFN-β through activation of IFN regulatory factor 3 (IRF3) via retinoic acid inducible gene-I (RIG-I) and the mitochondrial antiviral signaling (MAVS) pathway. MuV-induced IFNs were strongly upregulated in PKR-knockdown cells. MuV-induced SG formation was suppressed by knockdown of PKR and SG marker proteins, Ras-GTPase-activating protein SH3-domain-binding protein 1 and T-cell-restricted intracellular antigen-1, and significantly increased the levels of MuV-induced IFN-λ1. However, viral titer was not altered by suppression of SG formation. PKR was required for induction of SGs by MuV infection and regulated type III IFN (IFN-λ1) mRNA stability. MuV-induced SGs partly suppressed type III IFN production by MuV; however, the limited suppression was not sufficient to inhibit MuV replication in cell culture. Our results provide insight into the relationship between SGs and IFN production induced by MuV infection. PMID:27560627

  3. Conserved epitopes of influenza A virus inducing protective immunity and their prospects for universal vaccine development.

    PubMed

    Staneková, Zuzana; Varečková, Eva

    2010-11-30

    Influenza A viruses belong to the best studied viruses, however no effective prevention against influenza infection has been developed. The emerging of still new escape variants of influenza A viruses causing epidemics and periodic worldwide pandemics represents a threat for human population. Therefore, current, hot task of influenza virus research is to look for a way how to get us closer to a universal vaccine. Combination of chosen conserved antigens inducing cross-protective antibody response with epitopes activating also cross-protective cytotoxic T-cells would offer an attractive strategy for improving protection against drift variants of seasonal influenza viruses and reduces the impact of future pandemic strains. Antigenically conserved fusion-active subunit of hemagglutinin (HA2 gp) and ectodomain of matrix protein 2 (eM2) are promising candidates for preparation of broadly protective HA2- or eM2-based vaccine that may aid in pandemic preparedness. Overall protective effect could be achieved by contribution of epitopes recognized by cytotoxic T-lymphocytes (CTL) that have been studied extensively to reach much broader control of influenza infection. In this review we present the state-of-art in this field. We describe known adaptive immune mechanisms mediated by influenza specific B- and T-cells involved in the anti-influenza immune defense together with the contribution of innate immunity. We discuss the mechanisms of neutralization of influenza infection mediated by antibodies, the role of CTL in viral elimination and new approaches to develop epitope based vaccine inducing cross-protective influenza virus-specific immune response.

  4. Marek’s disease virus-induced transient cecal tonsil atrophy

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Marek’s disease (MD) is a lymphoproliferative disease of domestic chickens that is caused by a highly cell-associated oncogenic '-herpesvirus, Marek’s disease virus (MDV). MDV replicates in chicken lymphocytes and establishes a latent infection within CD4+ T cells. MD is characterized by bursal/th...

  5. Dengue Virus Induces Novel Changes in Gene Expression of Human Umbilical Vein Endothelial Cells

    PubMed Central

    Warke, Rajas V.; Xhaja, Kris; Martin, Katherine J.; Fournier, Marcia F.; Shaw, Sunil K.; Brizuela, Nathaly; de Bosch, Norma; Lapointe, David; Ennis, Francis A.; Rothman, Alan L.; Bosch, Irene

    2003-01-01

    Endothelial cells are permissive to dengue virus (DV) infection in vitro, although their importance as targets of DV infection in vivo remains a subject of debate. To analyze the virus-host interaction, we studied the effect of DV infection on gene expression in human umbilical vein endothelial cells (HUVECs) by using differential display reverse transcription-PCR (DD-RTPCR), quantitative RT-PCR, and Affymetrix oligonucleotide microarrays. DD identified eight differentially expressed cDNAs, including inhibitor of apoptosis-1, 2′-5′ oligoadenylate synthetase (OAS), a 2′-5′ OAS-like (OASL) gene, galectin-9, myxovirus protein A (MxA), regulator of G-protein signaling, endothelial and smooth muscle cell-derived neuropilin-like protein, and phospholipid scramblase 1. Microarray analysis of 22,000 human genes confirmed these findings and identified an additional 269 genes that were induced and 126 that were repressed more than fourfold after DV infection. Broad functional responses that were activated included the stress, defense, immune, cell adhesion, wounding, inflammatory, and antiviral pathways. These changes in gene expression were seen after infection of HUVECs with either laboratory-adapted virus or with virus isolated directly from plasma of DV-infected patients. Tumor necrosis factor alpha, OASL, and MxA and h-IAP1 genes were induced within the first 8 to 12 h after infection, suggesting a direct effect of DV infection. These global analyses of DV effects on cellular gene expression identify potentially novel mechanisms involved in dengue disease manifestations such as hemostatic disturbance. PMID:14557666

  6. γδ T Cells Play a Protective Role in Chikungunya Virus-Induced Disease

    PubMed Central

    Ferris, Martin T.; Whitmore, Alan C.; Montgomery, Stephanie A.; Thurlow, Lance R.; McGee, Charles E.; Rodriguez, Carlos A.; Lim, Jean K.; Heise, Mark T.

    2015-01-01

    ABSTRACT Chikungunya virus (CHIKV) is an alphavirus responsible for causing epidemic outbreaks of polyarthralgia in humans. Because CHIKV is initially introduced via the skin, where γδ T cells are prevalent, we evaluated the response of these cells to CHIKV infection. CHIKV infection led to a significant increase in γδ T cells in the infected foot and draining lymph node that was associated with the production of proinflammatory cytokines and chemokines in C57BL/6J mice. γδ T cell−/− mice demonstrated exacerbated CHIKV disease characterized by less weight gain and greater foot swelling than occurred in wild-type mice, as well as a transient increase in monocytes and altered cytokine/chemokine expression in the foot. Histologically, γδ T cell−/− mice had increased inflammation-mediated oxidative damage in the ipsilateral foot and ankle joint compared to wild-type mice which was independent of differences in CHIKV replication. These results suggest that γδ T cells play a protective role in limiting the CHIKV-induced inflammatory response and subsequent tissue and joint damage. IMPORTANCE Recent epidemics, including the 2004 to 2007 outbreak and the spread of CHIKV to naive populations in the Caribbean and Central and South America with resultant cases imported into the United States, have highlighted the capacity of CHIKV to cause explosive epidemics where the virus can spread to millions of people and rapidly move into new areas. These studies identified γδ T cells as important to both recruitment of key inflammatory cell populations and dampening the tissue injury due to oxidative stress. Given the importance of these cells in the early response to CHIKV, this information may inform the development of CHIKV vaccines and therapeutics. PMID:26491151

  7. Impaired cellular energy metabolism contributes to bluetongue-virus-induced autophagy.

    PubMed

    Lv, Shuang; Xu, Qingyuan; Sun, Encheng; Zhang, Jikai; Wu, Donglai

    2016-10-01

    Bluetongue virus (BTV) has been found to trigger autophagy to favor its replication, but the underlying mechanisms have not been clarified. Here, we show that cellular energy metabolism is involved in BTV-induced autophagy. Cellular ATP synthesis was impaired by BTV1 infection, causing metabolic stress, which was responsible for activation of autophagy, since the conversion of LC3 and aggregation of GFP-LC3 (autophagy markers) were suppressed when infection-caused energy depletion was reversed via MP (metabolic substrate) treatment. The reduced virus yields with MP further supported this view. Overall, our findings suggest that BTV1-induced disruption of cellular energy metabolism contributes to autophagy, and this provides new insights into BTV-host interactions.

  8. A complement-microglial axis drives synapse loss during virus-induced memory impairment.

    PubMed

    Vasek, Michael J; Garber, Charise; Dorsey, Denise; Durrant, Douglas M; Bollman, Bryan; Soung, Allison; Yu, Jinsheng; Perez-Torres, Carlos; Frouin, Arnaud; Wilton, Daniel K; Funk, Kristen; DeMasters, Bette K; Jiang, Xiaoping; Bowen, James R; Mennerick, Steven; Robinson, John K; Garbow, Joel R; Tyler, Kenneth L; Suthar, Mehul S; Schmidt, Robert E; Stevens, Beth; Klein, Robyn S

    2016-06-22

    Over 50% of patients who survive neuroinvasive infection with West Nile virus (WNV) exhibit chronic cognitive sequelae. Although thousands of cases of WNV-mediated memory dysfunction accrue annually, the mechanisms responsible for these impairments are unknown. The classical complement cascade, a key component of innate immune pathogen defence, mediates synaptic pruning by microglia during early postnatal development. Here we show that viral infection of adult hippocampal neurons induces complement-mediated elimination of presynaptic terminals in a murine WNV neuroinvasive disease model. Inoculation of WNV-NS5-E218A, a WNV with a mutant NS5(E218A) protein leads to survival rates and cognitive dysfunction that mirror human WNV neuroinvasive disease. WNV-NS5-E218A-recovered mice (recovery defined as survival after acute infection) display impaired spatial learning and persistence of phagocytic microglia without loss of hippocampal neurons or volume. Hippocampi from WNV-NS5-E218A-recovered mice with poor spatial learning show increased expression of genes that drive synaptic remodelling by microglia via complement. C1QA was upregulated and localized to microglia, infected neurons and presynaptic terminals during WNV neuroinvasive disease. Murine and human WNV neuroinvasive disease post-mortem samples exhibit loss of hippocampal CA3 presynaptic terminals, and murine studies revealed microglial engulfment of presynaptic terminals during acute infection and after recovery. Mice with fewer microglia (Il34(-/-) mice with a deficiency in IL-34 production) or deficiency in complement C3 or C3a receptor were protected from WNV-induced synaptic terminal loss. Our study provides a new murine model of WNV-induced spatial memory impairment, and identifies a potential mechanism underlying neurocognitive impairment in patients recovering from WNV neuroinvasive disease.

  9. Protective effects of macrophage-derived interferon against encephalomyocarditis virus-induced diabetes mellitus in mice.

    PubMed

    Hirasawa, K; Ogiso, Y; Takeda, M; Lee, M J; Itagaki, S; Doi, K

    1995-12-01

    The involvement of macrophages in protection against diabetes mellitus in mice of BALB/c (susceptible) and C57BL (resistant) strains infected with the B (non-diabetogenic) or D (highly diabetogenic) variant of encephalomyocarditis (EMC) virus was examined. Pretreatment with the B variant of EMC virus (EMC-B), avirulent interferon (IFN) inducer, or Corynebacterium parvum inhibited diabetes in BALB/c mice infected with the D variant of EMC virus (EMC-D). Treatment of C57BL mice with carrageenan to compromise macrophage function rendered C57BL mice susceptible to EMC-D-induced diabetes. In macrophage culture for BALB/c mice, EMC-B induced IFN at an earlier stage than did EMC-D. The C57BL mouse-derived macrophages produced more IFN than did BALB/c mouse-derived macrophages after stimulation with EMC-D. Moreover, C. parvum increased IFN production in macrophage cultures from BALB/c mice, whereas carrageenan inhibited that in macrophage cultures from C57BL mice. These results suggest that IFN derived from macrophages may have an important role in protecting mice against EMC virus infection. PMID:8746525

  10. Neutrophil Extracellular Traps Enhance Early Inflammatory Response in Sendai Virus-Induced Asthma Phenotype

    PubMed Central

    Akk, Antonina; Springer, Luke E.; Pham, Christine T. N.

    2016-01-01

    Paramyxoviral infection in childhood has been linked to a significant increased rate of asthma development. In mice, paramyxoviral infection with the mouse parainfluenza virus type I, Sendai virus (Sev), causes a limited bronchiolitis followed by persistent asthma traits. We have previously shown that the absence of cysteine protease dipeptidyl peptidase I (DPPI) dampened the acute lung inflammatory response and the subsequent asthma phenotype induced by Sev. Adoptive transfer of wild-type neutrophils into DPPI-deficient mice restored leukocyte influx, the acute cytokine response, and the subsequent mucous cell metaplasia that accompanied Sev-induced asthma phenotype. However, the exact mechanism by which DPPI-sufficient neutrophils promote asthma development following Sev infection is still unknown. We hypothesize that neutrophils recruited to the alveolar space following Sev infection elaborate neutrophil extracellular traps (NETs) that propagate the inflammatory cascade, culminating in the eventual asthma phenotype. Indeed, we found that Sev infection was associated with NET formation in the lung and release of cell-free DNA complexed to myeloperoxidase in the alveolar space and plasma that peaked on day 2 post infection. Absence of DPPI significantly attenuated Sev-induced NET formation in vivo and in vitro. Furthermore, concomitant administration of DNase 1, which dismantled NETs, or inhibition of peptidylarginine deiminase 4 (PAD4), an essential mediator of NET formation, suppressed the early inflammatory responses to Sev infection. Lastly, NETs primed bone marrow-derived cells to release cytokines that can amplify the inflammatory cascade. PMID:27617014

  11. Immuno-pathological studies on broiler chicken experimentally infected with Escherichia coli and supplemented with neem (Azadirachta indica) leaf extract

    PubMed Central

    Sharma, Vikash; Jakhar, K. K.; Dahiya, Swati

    2016-01-01

    Aim: The present study was conducted to evaluate the effects of neem leaf extract (NLE) supplementation on immunological response and pathology of different lymphoid organs in experimentally Escherichia coli challenged broiler chickens. Materials and Methods: For this study, we procured 192-day-old broiler chicks from local hatchery and divided them into Groups A and Group B containing 96 birds each on the first day. Chicks of Group A were supplemented with 10% NLE in water, whereas chicks of Group B were not supplemented with NLE throughout the experiment. At 7th day of age, chicks of Group A were divided into A1 and A2 and Group B into B1 and B2 with 54 and 42 chicks, respectively, and chicks of Groups A1 and B1 were injected with E. coli O78 at 107 colony-forming units/0.5 ml intraperitoneally. Six chicks from each group were sacrificed at 0, 2, 4, 7, 14, 21, and 28 days post infection; blood was collected and thorough post-mortem examination was conducted. Tissue pieces of spleen and bursa of Fabricius were collected in 10% buffered formalin for histopathological examination. Serum was separated for immunological studies. Result: E. coli specific antibody titer was significantly higher in Group A1 in comparison to Group B1. Delayed-type hypersensitivity response against 2,4 dinirochlorobenzene (DNCB) antigen was significantly higher in Group A1 as compared to Group B1. Pathological studies revealed that E. coli infection caused depletion of lymphocytes in bursa of Fabricius and spleen. Severity of lesions in Group A1 was significantly lower in comparison to Group B1. Conclusion: 10% NLE supplementation enhanced the humoral as well as cellular immune responses attributed to its immunomodulatory property in experimentally E. coli infected broiler chicken. PMID:27536035

  12. Killer Cell Immunoglobulin-like Receptors and Their HLA Ligands are Related with the Immunopathology of Chagas Disease.

    PubMed

    Ayo, Christiane Maria; Reis, Pâmela Guimarães; Dalalio, Márcia Machado de Oliveira; Visentainer, Jeane Eliete Laguila; Oliveira, Camila de Freitas; de Araújo, Silvana Marques; de Oliveira Marques, Divina Seila; Sell, Ana Maria

    2015-05-01

    The aim of this study was to investigate the influence of killer cell immunoglobulin-like receptor (KIR) genes and their human leucocyte antigen (HLA) ligands in the susceptibility of chronic Chagas disease. This case-control study enrolled 131 serologically-diagnosed Chagas disease patients (59 men and 72 women, mean age of 60.4 ± 9.8 years) treated at the University Hospital of Londrina and the Chagas Disease Laboratory of the State University of Maringa. A control group was formed of 165 healthy individuals - spouses of patients or blood donors from the Regional Blood Bank in Maringa (84 men and 81 women, with a mean age of 59.0 ± 11.4 years). Genotyping of HLA and KIR was performed by PCR-SSOP. KIR2DS2-C1 in the absence of KIR2DL2 (KIR2DS2+/2DL2-/C1+) was more frequent in Chagas patients (P = 0.020; Pc = 0.040; OR = 2.14) and, in particular, those who manifested chronic chagasic cardiopathy-CCC (P = 0.0002; Pc = 0.0004; OR = 6.64; 95% CI = 2.30-18.60) when compared to the control group, and when CCC group was compared to the patients without heart involvement (P = 0.010; Pc = 0.020; OR = 3.97). The combination pair KIR2DS2+/2DL2-/KIR2DL3+/C1+ was also positively associated with chronic chagasic cardiopathy. KIR2DL2 and KIR2DS2 were related to immunopathogenesis in Chagas disease. The combination of KIR2DS2 activating receptor with C1 ligand, in the absence of KIR2DL2, may be related to a risk factor in the chronic Chagas disease and chronic chagasic cardiopathy.

  13. The TNF-Family Cytokine TL1A Promotes Allergic Immunopathology through Group 2 Innate Lymphoid Cells

    PubMed Central

    Meylan, Françoise; Hawley, Eric T.; Barron, Luke; Barlow, Jillian L.; Penumetcha, Pallavi; Pelletier, Martin; Sciumè, Giuseppe; Richard, Arianne C.; Hayes, Erika T.; Gomez-Rodriguez, Julio; Chen, Xi; Paul, William E.; Wynn, Thomas A.; McKenzie, Andrew N.J.; Siegel, Richard M.

    2014-01-01

    The TNF-family cytokine TL1A (TNFSF15) costimulates T cells and promotes diverse T-cell dependent models of autoimmune disease through its receptor DR3. TL1A polymorphisms also confer susceptibility to inflammatory bowel disease. Here we find that allergic pathology driven by constitutive TL1A expression depends on IL-13, but not T, NKT, mast cells or commensal intestinal flora. Group 2 innate lymphoid cells (ILC2) express surface DR3 and produce IL-13 and other type 2 cytokines in response to TL1A. DR3 is required for ILC2 expansion and function in the setting of T cell dependent and independent models of allergic disease. By contrast, DR3 deficient ILC2 can still differentiate, expand and produce IL-13 when stimulated by IL-25 or IL-33, and mediate expulsion of intestinal helminths. These data identify costimulation of ILC2 as a novel function of TL1A important for allergic lung disease, and suggest that TL1A may be a therapeutic target in these settings. PMID:24368564

  14. Myxoid angioblastomatosis of bones. A case report of a rare, multifocal entity with light, ultramicroscopic, and immunopathologic correlation.

    PubMed

    Mirra, J M; Kameda, N

    1985-06-01

    An example of multicentric, skeletal, myxoid angioblastomas in a Japanese woman is reported. The disease was symptomatic at age 12 years and was characterized by slowly progressive, multiple, lytic bone defects. In addition the patient had juvenile hypertension, and, at age 20 years, had focal brain infarction. The primitive vascular nature of the process was supported by the following observations: occasional erythrocytes within cytoplasmic lumina and capillary-like cellular tubes; Weibel-Palade bodies, numerous pinocytotic vesicles, prominent microvilli, elaborate intercellular contacts, desmosomes, and numerous arrays of fine intracytoplasmic filaments by electron microscopy; and, in addition, Factor VIII positivity. The clinical findings in this case are more consistent with a multicentric, rather than a metastatic process. The name myxoid angioblastomatosis of bones is appropriate. PMID:4091181

  15. Blockage of Galectin-receptor Interactions by α-lactose Exacerbates Plasmodium berghei-induced Pulmonary Immunopathology.

    PubMed

    Liu, Jinfeng; Huang, Shiguang; Su, Xin-Zhuan; Song, Jianping; Lu, Fangli

    2016-01-01

    Malaria-associated acute lung injury (ALI) is a frequent complication of severe malaria that is often caused by "excessive" immune responses. To better understand the mechanism of ALI in malaria infection, here we investigated the roles of galectin (Gal)-1, 3, 8, 9 and the receptors of Gal-9 (Tim-3, CD44, CD137, and PDI) in malaria-induced ALI. We injected alpha (α)-lactose into mice-infected with Plasmodium berghei ANKA (PbANKA) to block galectins and found significantly elevated total proteins in bronchoalveolar lavage fluid, higher parasitemia and tissue parasite burden, and increased numbers of CD68(+) alveolar macrophages as well as apoptotic cells in the lungs after blockage. Additionally, mRNA levels of Gal-9, Tim-3, CD44, CD137, and PDI were significantly increased in the lungs at day 5 after infection, and the levels of CD137, IFN-α, IFN-β, IFN-γ, IL-4, and IL-10 in the lungs were also increased after α-lactose treatment. Similarly, the levels of Gal-9, Tim-3, IFN-α, IFN-β, IFN-γ, and IL-10 were all significantly increased in murine peritoneal macrophages co-cultured with PbANKA-infected red blood cells in vitro; but only IFN-α and IFN-β were significantly increased after α-lactose treatment. Our data indicate that Gal-9 interaction with its multiple receptors play an important role in murine malaria-associated ALI. PMID:27554340

  16. Primary polymorphous hemangioendothelioma of the maxillary soft tissue: clinical and immunopathological aspects of a rare vascular neoplasm.

    PubMed

    Rullo, Rosario; Addabbo, Francesco; Rullo, Francesco; Festa, Vincenzo Maria

    2014-01-01

    Polymorphous hemangioendothelioma (PH) is an uncommon vascular neoplasm of borderline malignant potential characterized by a considerable variability in patterns of cellular growth. Morphologically, PH may be confused with other lesions, from benign vasoformative neoplasms and reactive inflammatory conditions to malignancies such as angiosarcoma or squamous cell carcinoma. Most occur in the lymph nodes, and to the best of our knowledge, lesions involving the maxillary soft tissue have not been described in the literature to date. A potential for local recurrence, as well as the ability to metastasize, has been for this type of neoplasm. Here we reported on a rare case of polymorphous hemangioendothelioma which presented as an asymptomatic subcutaneous mass in the right zygomatic region of a 22-year-old white female. We discuss the histopathological aspects of this tumor, with emphasis on the role of immunohistochemical analysis in differential diagnosis. PMID:24632981

  17. Blockage of Galectin-receptor Interactions by α-lactose Exacerbates Plasmodium berghei-induced Pulmonary Immunopathology

    PubMed Central

    Liu, Jinfeng; Huang, Shiguang; Su, Xin-zhuan; Song, Jianping; Lu, Fangli

    2016-01-01

    Malaria-associated acute lung injury (ALI) is a frequent complication of severe malaria that is often caused by “excessive” immune responses. To better understand the mechanism of ALI in malaria infection, here we investigated the roles of galectin (Gal)-1, 3, 8, 9 and the receptors of Gal-9 (Tim-3, CD44, CD137, and PDI) in malaria-induced ALI. We injected alpha (α)-lactose into mice-infected with Plasmodium berghei ANKA (PbANKA) to block galectins and found significantly elevated total proteins in bronchoalveolar lavage fluid, higher parasitemia and tissue parasite burden, and increased numbers of CD68+ alveolar macrophages as well as apoptotic cells in the lungs after blockage. Additionally, mRNA levels of Gal-9, Tim-3, CD44, CD137, and PDI were significantly increased in the lungs at day 5 after infection, and the levels of CD137, IFN-α, IFN-β, IFN-γ, IL-4, and IL-10 in the lungs were also increased after α-lactose treatment. Similarly, the levels of Gal-9, Tim-3, IFN-α, IFN-β, IFN-γ, and IL-10 were all significantly increased in murine peritoneal macrophages co-cultured with PbANKA-infected red blood cells in vitro; but only IFN-α and IFN-β were significantly increased after α-lactose treatment. Our data indicate that Gal-9 interaction with its multiple receptors play an important role in murine malaria-associated ALI. PMID:27554340

  18. Immunopathologic changes in the thymus during the acute stage of experimentally induced feline immunodeficiency virus infection in juvenile cats.

    PubMed Central

    Woo, J C; Dean, G A; Pedersen, N C; Moore, P F

    1997-01-01

    The feline thymus is a target organ and site of viral replication during the acute stage of feline immunodeficiency virus (FIV) infection. This was demonstrated by histologic, immunohistologic, flow cytometric, and virologic tests. Thymic lesions developed after 28 days postinoculation (p.i.) and included thymitis, premature cortical involution, and medullary B-cell hyperplasia with germinal center formation and epithelial distortion. Alterations in thymocyte subsets also developed. Fewer CD4+ CD8- cells were detected at 28 days p.i., while an increase in CD4- CD8+ cells resulted in an inversion of the thymic CD4/CD8 ratio of single-positive cells, similar to events in peripheral blood. Provirus was present in all thymocyte subpopulations including cortical CD1(hi), CD1(lo), and B cells. The CD1(hi) thymocyte proviral burden increased markedly after 56 days p.i., coincident with the presence of infiltrating inflammatory cells. Increased levels of provirus in the CD1(lo) thymocyte subpopulation were detected prior to 56 days p.i. This was likely due to inclusion of infected infiltrating inflammatory cells which could not be differentiated from mature, medullary thymocytes. Proviral levels in B cells also increased from 70 days p.i. Morphologic alterations, productive viral infection, and altered thymocyte subpopulations suggest that thymic function is compromised, thus contributing to the inability of FIV-infected cats to replenish the peripheral T-cell pool. PMID:9343221

  19. Alcohol intake alters immune responses and promotes CNS viral persistence in mice.

    PubMed

    Loftis, Jennifer M; Taylor, Jonathan; Raué, Hans-Peter; Slifka, Mark K; Huang, Elaine

    2016-10-01

    Chronic hepatitis C virus (HCV) infection leads to progressive liver disease and is associated with a variety of extrahepatic effects, including central nervous system (CNS) damage and neuropsychiatric impairments. Alcohol abuse can exacerbate these adverse effects on brain and behavior, but the molecular mechanisms are not well understood. This study investigated the role of alcohol in regulating viral persistence and CNS immunopathology in mice infected with lymphocytic choriomeningitis virus (LCMV), a model for HCV infections in humans. Female and male BALB/c mice (n=94) were exposed to alcohol (ethanol; EtOH) and water (or water only) using a two-bottle choice paradigm, followed one week later by infection with either LCMV clone 13 (causes chronic infection similar to chronic HCV), LCMV Armstrong (causes acute infection), or vehicle. Mice were monitored for 60days post-infection and continued to receive 24-h access to EtOH and water. Animals infected with LCMV clone 13 drank more EtOH, as compared to those with an acute or no viral infection. Six weeks after infection with LCMV clone 13, mice with EtOH exposure evidenced higher serum viral titers, as compared to mice without EtOH exposure. EtOH intake was also associated with reductions in virus-specific CD8(+) T cell frequencies (particularly CD11a(hi) subsets) and evidence of persistent CNS viremia in chronically infected mice. These findings support the hypothesis that EtOH use and chronic viral infection can result in combined toxic effects accelerating CNS damage and neuropsychiatric dysfunction and suggest that examining the role of EtOH in regulating viral persistence and CNS immunopathology in mice infected with LCMV can lead to a more comprehensive understanding of comorbid alcohol use disorder and chronic viral infection. PMID:27269869

  20. Infection with street strain rabies virus induces modulation of the microRNA profile of the mouse brain

    PubMed Central

    2012-01-01

    Background Rabies virus (RABV) causes a fatal infection of the central nervous systems (CNS) of warm-blooded animals. Once the clinical symptoms develop, rabies is almost invariably fatal. The mechanism of RABV pathogenesis remains poorly understood. Recent studies have shown that microRNA (miRNA) plays an important role in the pathogenesis of viral infections. Our recent findings have revealed that infection with laboratory-fixed rabies virus strain can induce modulation of the microRNA profile of mouse brains. However, no previous report has evaluated the miRNA expression profile of mouse brains infected with RABV street strain. Results The results of microarray analysis show that miRNA expression becomes modulated in the brains of mice infected with street RABV. Quantitative real-time PCR assay of the differentially expressed miRNAs confirmed the results of microarray assay. Functional analysis showed the differentially expressed miRNAs to be involved in many immune-related signaling pathways, such as the Jak-STAT signaling pathway, the MAPK signaling pathway, cytokine-cytokine receptor interactions, and Fc gamma R-mediated phagocytosis. The predicted expression levels of the target genes of these modulated miRNAs were found to be correlated with gene expression as measured by DNA microarray and qRT-PCR. Conclusion RABV causes significant changes in the miRNA expression profiles of infected mouse brains. Predicted target genes of the differentially expression miRNAs are associated with host immune response, which may provide important information for investigation of RABV pathogenesis and therapeutic method. PMID:22882874