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Articles 91 - 107 of 107

Full-Text Articles in Immunology and Infectious Disease

Human Macrophages Degrade Tryptophan Upon Induction By Interferon-Gamma, Ernst Werner, Gabriele Bitterlich, Dietmar Fuchs, Arno Hausen, Gilbert Reibnegger, Gyongyi Szabo, Manfred Dierich, Helmut Wachter Apr 2010

Human Macrophages Degrade Tryptophan Upon Induction By Interferon-Gamma, Ernst Werner, Gabriele Bitterlich, Dietmar Fuchs, Arno Hausen, Gilbert Reibnegger, Gyongyi Szabo, Manfred Dierich, Helmut Wachter

Gyongyi Szabo

Human peripheral blood mononuclear cells, monocytes-macrophages and T-cells were stimulated with human recombinant interferon-gamma, interferon-alpha and phytohemagglutinin. The culture supernatants were analyzed for tryptophan, kynurenine, 3-hydroxyanthranilic acid, anthranilic acid and neopterin by high performance liquid chromatography. Tryptophan was decreased and the four other compounds were increased in supernatants of peripheral blood mononuclear cells activated by interferon-gamma (250 U/ml), interferon-alpha (10.000 U/ml) and phytohemagglutinin (1 microgram/ml). After splitting of peripheral blood mononuclear cells by adherence, the monocytes and macrophages but not the T-cells degraded tryptophan upon stimulation by interferon-gamma in a dose dependent manner. Supernatants of phytohemagglutinin stimulated but not of …


New Insights Into The The Molecular Mechanisms Of Alcoholic Hepatitis: A Potential Role For Nf-Kappab Activation, Gyongyi Szabo Apr 2010

New Insights Into The The Molecular Mechanisms Of Alcoholic Hepatitis: A Potential Role For Nf-Kappab Activation, Gyongyi Szabo

Gyongyi Szabo

No abstract provided.


Regulation Of Monocyte Interleukin-12 Production By Acute Alcohol: A Role For Inhibition By Interleukin-10, Linda Girouard, Pranoti Mandrekar, Donna Catalano, Gyongyi Szabo Apr 2010

Regulation Of Monocyte Interleukin-12 Production By Acute Alcohol: A Role For Inhibition By Interleukin-10, Linda Girouard, Pranoti Mandrekar, Donna Catalano, Gyongyi Szabo

Gyongyi Szabo

Acute ethanol treatment results in decreased antigen presentation capacity (Th1-type immunity) and elevated interleukin IL-10 (Th2 cytokine) production in human monocytes. Monocytes can contribute to both Th1 (IL-12) and Th2 (IL-10) immune responses via production of IL-12 and IL-10, respectively. Thus, we tested the hypothesis that acute alcohol treatment might affect Th1/Th2 immune balance by altering monocyte production of IL-12 and IL-10. Neither acute ethanol treatment alone (25 to 100 mM) nor its combination with a bacterial challenge Staphylococcal enterotoxin B (SEB) induced IL-12 production in isolated blood monocytes. In contrast, the same physiological alcohol concentrations increased monocyte IL-10 levels, …


Hepatitis C Core And Nonstructural 3 Proteins Trigger Toll-Like Receptor 2-Mediated Pathways And Inflammatory Activation, Angela Dolganiuc, Shilpa Oak, Karen Kodys, Douglas Golenbock, Robert Finberg, Evelyn Kurt-Jones, Gyongyi Szabo Apr 2010

Hepatitis C Core And Nonstructural 3 Proteins Trigger Toll-Like Receptor 2-Mediated Pathways And Inflammatory Activation, Angela Dolganiuc, Shilpa Oak, Karen Kodys, Douglas Golenbock, Robert Finberg, Evelyn Kurt-Jones, Gyongyi Szabo

Gyongyi Szabo

BACKGROUND AND AIMS: Recent evidence suggests that toll-like receptors (TLRs) recognize certain viruses. We reported that hepatitis C virus (HCV) core and nonstructural 3 (NS3) proteins activate inflammatory pathways in monocytes. The aim of this study was to investigate the role of TLRs in innate immune cell activation by core and NS3 proteins. METHODS: Human monocytes, human embryonic kidney cells transfected with TLR2, and peritoneal macrophages from TLR2, MyD88 knockout, and wild-type mice were studied to determine intracellular signaling and proinflammatory cytokine induction by HCV proteins. RESULTS: HCV core and NS3 proteins triggered inflammatory cell activation via the pattern recognition …


Subversion Of Plasmacytoid And Myeloid Dendritic Cell Functions In Chronic Hcv Infection, Gyongyi Szabo, Angela Dolganiuc Apr 2010

Subversion Of Plasmacytoid And Myeloid Dendritic Cell Functions In Chronic Hcv Infection, Gyongyi Szabo, Angela Dolganiuc

Gyongyi Szabo

Insufficient elimination of the hepatitis C virus (HCV) during acute infection results in chronic disease in the majority of patients due to weak virus-specific immune responses. Dendritic cells (DC) play a central role in recognition of HCV and in induction of innate and adaptive immune responses. In this study, we evaluated the frequency and functions of plasmacytoid dendritic cells (PDC) and myeloid dendritic cells (MDC) in patients with chronic HCV infection. We found that both the numbers and IFNalpha production capacity of blood PDC were significantly reduced in patients with chronic HCV infection compared to normal controls. While the frequency …


Inhibition Of Antigen-Presenting Cell Functions By Alcohol: Implications For Hepatitis C Virus Infection, Gyongyi Szabo, Angela Dolganiuc, Pranoti Mandrekar, Bernadette White Apr 2010

Inhibition Of Antigen-Presenting Cell Functions By Alcohol: Implications For Hepatitis C Virus Infection, Gyongyi Szabo, Angela Dolganiuc, Pranoti Mandrekar, Bernadette White

Gyongyi Szabo

The mechanisms of alcohol-induced immunosuppression include defects in innate and adaptive immune responses. Monocytes and dendritic cells (DCs) link innate and adaptive immune responses as they recognize viral antigens and induce antigen-specific T-cell activation. We investigated the effects of alcohol on antigen-presenting cell functions. Acute alcohol consumption by healthy volunteers (vodka, 2 ml/kg) resulted in significantly reduced antigen-presenting cell function of monocyte-derived DCs. Reduced allostimulatory capacity of DCs treated with alcohol in vitro correlated with decreased co-stimulatory molecule (B7.1 and B7.2) expression, as well as with reduced interleukin (IL)-12 and increased IL-10 concentrations, in mixed lymphocyte cultures. Dendritic cells recognize …


Regulation Of Monocyte Il-12 Production: Augmentation By Lymphocyte Contact And Acute Ethanol Treatment, Inhibition By Elevated Intracellular Camp, Gyongyi Szabo, Linda Girouard, Pranoti Mandrekar, Donna Catalano Apr 2010

Regulation Of Monocyte Il-12 Production: Augmentation By Lymphocyte Contact And Acute Ethanol Treatment, Inhibition By Elevated Intracellular Camp, Gyongyi Szabo, Linda Girouard, Pranoti Mandrekar, Donna Catalano

Gyongyi Szabo

IL-12, a monocyte-derived cytokine, is pivotal in activation of cellular immune response and inflammation. Both inflammatory response and cellular immunity are impaired by acute ethanol consumption. Here, we found that in vitro acute ethanol treatment (25-100 mM) results in a dose-dependent and significant increase of IL-12 in IFN-gamma (100 U/ml) plus Staphylococcal enterotoxin B (SEB; 1 microg/ml) stimulated monocytes and mononuclear cells but not in unstimulated cells from non-alcoholic blood donors. There was significantly greater IL-12 production in the MNC population compared to isolated Mphi (P < 0.001). Prevention of monocyte surface contact with either purified T lymphocytes or monocyte-depleted MNC resulted in a significant, 65+/-20%, decrease in IL-12 production regardless of IFN-gamma, SEB or ethanol stimulation suggesting that Mphi T-cell surface contact provides an additional signal for IL-12 production. In addition to cell surface contact, soluble mediators, particularly IL-10 and PGE2 may regulate IL-12 production. The cyclooxygenase inhibitor, Indomethacin (10(-6)M), augmented both IL-12 and IL-10 levels in isolated monocytes and mononuclear cells whether induced by medium, SEB or SEB plus 25 mM ethanol suggesting that regulation of IL-12 production via the cyclooxygenase pathway is independent of IL-10. Finally, elevation of intracellular cAMP levels by dbcAMP treatment consistently inhibited IL-12 as well as IL-10 production in monocytes induced by IFN-gamma or IFN-gamma plus 25 mM ethanol. These data suggest that augmentation of monocyte IL-12 by acute ethanol is not mediated via the cAMP pathway.


The Role Of Plasmacytoid Dendritic Cell-Derived Ifn Alpha In Antiviral Immunity, Gyongyi Szabo, Angela Dolganiuc Apr 2010

The Role Of Plasmacytoid Dendritic Cell-Derived Ifn Alpha In Antiviral Immunity, Gyongyi Szabo, Angela Dolganiuc

Gyongyi Szabo

Viral infections represent a major source of acute and chronic human disease. The immune system plays a central role in the elimination of viruses through its ability to recognize pathogens and to induce virus-specific cellular activation, accompanied by a robust production of soluble molecules with antiviral effects. Interferons are among the most powerful natural soluble antiviral molecules. Upon viral infection, interferons are produced by a variety of cell types, with immune cells being the main contributors. The immune system works as a well-orchestrated team composed of multiple cell types. The mechanisms of intercellular cooperation that includes dendritic cells (DCs), their …


Ethanol-Mediated Regulation Of Transcription Factors In Immunocompetent Cells, Gyongyi Szabo, Pranoti Mandrekar Apr 2010

Ethanol-Mediated Regulation Of Transcription Factors In Immunocompetent Cells, Gyongyi Szabo, Pranoti Mandrekar

Gyongyi Szabo

The immunomodulatory effects of acute and chronic alcohol use are characterized by impaired antigen-specific immune activation and by increased susceptibility to infections due to alterations in innate immune responses and inflammatory mediator production. The central feature of cellular responses to inflammatory and stress signals is the activation of the nuclear regulatory kappa B/Rel family of transcriptional factors via various surface receptor systems in immunocompetent cells. Activation of NF-kappa B, however, is regulated at multiple levels including I-kappa B degradation, nuclear translocation, and by interaction of NF-kappa B/Rel with other transcription factors. Data from our and other laboratories demonstrate that acute …


Stimulating Effect Of Tuftsin And Its Analogues On The Defective Monocyte Chemotaxis In Systemic Lupus Erythematosus, Katalin Lukacs, Gyongyi Szabo, Ildiko Sonkoly, Eva Vegh, Janos Gacs, Maria Szekerke, Gyula Szegedi Apr 2010

Stimulating Effect Of Tuftsin And Its Analogues On The Defective Monocyte Chemotaxis In Systemic Lupus Erythematosus, Katalin Lukacs, Gyongyi Szabo, Ildiko Sonkoly, Eva Vegh, Janos Gacs, Maria Szekerke, Gyula Szegedi

Gyongyi Szabo

Monocytes and macrophages are engaged at various levels of cellular immune reactivity. In addition to their function in the defensive mechanism directed at infective agents, they also play a basic role in immune complex elimination and antigen handling. Previous experiments revealed that systemic lupus erythematosus (SLE), the main representative of the autoimmune diseases, is associated with impaired monocyte chemotaxis. The endogenous basic tetrapeptide tuftsin and 6 of its analogues were examined in vitro for their stimulating capacity on the chemotactic responsiveness of monocytes derived from patients with SLE. The monocyte migration assay was carried out by a modified Boyden technique …


Selective Induction Of Mononuclear Phagocytes To Produce Neopterin By Interferons, Gabriele Bitterlich, Gyongyi Szabo, Ernst Werner, C. Larcher, Dietmar Fuchs, Arno Hausen, Gilbert Reibnegger, T.F. Schulz, J. Troppmair, Helmut Wachter Apr 2010

Selective Induction Of Mononuclear Phagocytes To Produce Neopterin By Interferons, Gabriele Bitterlich, Gyongyi Szabo, Ernst Werner, C. Larcher, Dietmar Fuchs, Arno Hausen, Gilbert Reibnegger, T.F. Schulz, J. Troppmair, Helmut Wachter

Gyongyi Szabo

Interferon-gamma (IFN-gamma) has been shown to be a potent inducer of neopterin secretion by human peripheral blood monocytes/macrophages (1). In this paper, it is shown that other known stimuli of monocytes (e.g., to secrete proteases or to migrate) such as zymosan-activated human serum, lipopolysaccharide, human C3/iC3 and zymosan coated with complement were unable to trigger monocytes/macrophages to release neopterin. Monocytes/macrophages could be stimulated solely by IFN-gamma (25 U/ml) and IFN-alpha at very high concentrations (10,000 U/ml). In the case of human peripheral blood mononuclear cells (PBMNC), basically the same pattern was observed. If however, in the buffer controls PBMNC showed …


Hepatitis C Virus Ns5a Protein--A Master Regulator, Gyongyi Szabo Apr 2010

Hepatitis C Virus Ns5a Protein--A Master Regulator, Gyongyi Szabo

Gyongyi Szabo

No abstract provided.


Acute Ethanol Treatment Modulates Toll-Like Receptor-4 Association With Lipid Rafts, Angela Dolganiuc, Genadyi Bakis, Karen Kodys, Pranoti Mandrekar, Gyongyi Szabo Apr 2010

Acute Ethanol Treatment Modulates Toll-Like Receptor-4 Association With Lipid Rafts, Angela Dolganiuc, Genadyi Bakis, Karen Kodys, Pranoti Mandrekar, Gyongyi Szabo

Gyongyi Szabo

BACKGROUND: Alcohol, a substance that is most frequently abused, suppresses innate immune responses to microbial pathogens. The host senses pathogens via Toll-like receptors (TLRs). Recent studies indicate that alcohol affects TLR signaling. METHODS: Here, we hypothesized that acute alcohol treatment may interfere with early steps of membrane-associated TLR2 and TLR4 signaling at the level of lipid rafts. Human monocytes and Chinese hamster ovary (CHO) cells, transfected with human TLR2, TLR4, or CD14, were stimulated with peptidoglycan (PGN, TLR2 ligand) or lipopolysaccharide (LPS, TLR4 ligand) with or without alcohol (50 mM) and analyzed for cytokine production (enzyme-linked immunosorbent assay), nuclear factor-kappaB …


Hepatitis C And Innate Immunity: Recent Advances, Gyongyi Szabo, Angela Dolganiuc Apr 2010

Hepatitis C And Innate Immunity: Recent Advances, Gyongyi Szabo, Angela Dolganiuc

Gyongyi Szabo

Eradication of hepatitis C virus (HCV) infection requires a complex and coordinated interplay between innate and adaptive immune responses that, when it fails, leads to chronic infection. In this review, the innate immune mechanisms by which HCV is sensed and by which HCV undermines host defense are discussed. The critical role of dendritic cells in antigen presentation and T-cell activation in addition to type I interferon production and interference of HCV with innate immune cell functions are reviewed. Finally, current and emerging therapeutic approaches targeting innate immune pathways are evaluated.


Plant Vaccines: An Immunological Perspective., Douglas C. Hooper Apr 2009

Plant Vaccines: An Immunological Perspective., Douglas C. Hooper

Department of Cancer Biology Faculty Papers

The advent of technologies to express heterologous proteins in planta has led to the proposition that plants may be engineered to be safe, inexpensive vehicles for the production of vaccines and possibly even vectors for their delivery. The immunogenicity of a variety of antigens of relevance to vaccination expressed in different plants has been assessed. The purpose of this article is to examine the utility of plant-expression systems in vaccine development from an immunological perspective.


Direct Inhibition Of Cdk9 Blocks Hiv-1 Replication Without Preventing T Cell Activation In Primary Human Peripheral Blood Lymphocytes, Dominic Salerno, Muneer G Hasham, Renée Marshall Demarest, Judit Garriga, Alexander Y Tsygankov, Xavier Graña Dec 2007

Direct Inhibition Of Cdk9 Blocks Hiv-1 Replication Without Preventing T Cell Activation In Primary Human Peripheral Blood Lymphocytes, Dominic Salerno, Muneer G Hasham, Renée Marshall Demarest, Judit Garriga, Alexander Y Tsygankov, Xavier Graña

Rowan-Virtua School of Osteopathic Medicine Faculty Scholarship

HIV-1 transcription is essential for the virus replication cycle. HIV-1 Tat is a viral transactivator that strongly stimulates the processivity of RNA polymerase II (RNAPII) via recruitment of the cyclin T1/CDK9 positive transcription elongation factor, which phosphorylates the C-terminal domain (CTD) of RNAPII. Consistently, HIV-1 replication in transformed cells is very sensitive to direct CDK9 inhibition. Thus, CDK9 could be a potential target for anti-HIV-1 therapy. A clearer understanding of the requirements for CDK9 activity in primary human T cells is needed to assess whether the CDK9-dependent step in HIV-1 transcription can be targeted clinically. We have investigated the effects …


Studies On The Ascaris Lumbricoides, H. M. Martin Dec 1926

Studies On The Ascaris Lumbricoides, H. M. Martin

Historical Research Bulletins of the Nebraska Agricultural Experiment Station

The Ascaris lumbricoides, in one phase or another, has attracted the attention of parasitologists for many years, and during the last decade this parasite has been studied by a large number of investigators. The recent observations have been, to a great extent, directed along one line, the study of its life history. These investigators have established two important points: (a) That the life history of Ascaris is more complex than was supposed, as it has been found that a vasculo-pulmonary circuit of the larvae is necessary before they settle down in the intestine, where they develop to the adult …