Medicine and Health Sciences Commons^™

Another Armed Cd4(+) T Cell Ready To Battle Hepatocellular Carcinoma, Roniel Cabrera, Gyongyi Szabo

Gyongyi Szabo

No abstract provided.

T Cell Receptor Vbeta Gene Usage In Thai Children With Dengue Virus Infection, Susan Gagnon, Anita Leporati, Sharone Green, Siripen Kalayanarooj, David Vaughn, Henry Stephens, Saroj Suntayakorn, Ichiro Kurane, Francis Ennis, Alan Rothman

Alan Rothman

T lymphocyte activation during dengue is thought to contribute to the pathogenesis of dengue hemorrhagic fever (DHF). We examined the T cell receptor Vbeta gene usage by a reverse transcriptase-polymerase chain reaction assay during infection and after recovery in 13 children with DHF and 13 children with dengue fever (DF). There was no deletion of specific Vbeta gene families. We detected significant expansions in usage of single Vbeta families in six subjects with DHF and three subjects with DF over the course of infection, but these did not show an association with clinical diagnosis, viral serotype, or HLA alleles. Differences …

Treatment With Monoclonal Antibodies Against Clostridium Difficile Toxins, Israel Lowy, Deborah Molrine, Brett Leav, Barbara Blair, Roger Baxter, Dale Gerding, Geoffrey Nichol, William Thomas, Mark Leney, Susan Sloan, Catherine Hay, Donna Ambrosino

William D Thomas Jr

BACKGROUND: New therapies are needed to manage the increasing incidence, severity, and high rate of recurrence of Clostridium difficile infection.

METHODS: We performed a randomized, double-blind, placebo-controlled study of two neutralizing, fully human monoclonal antibodies against C. difficile toxins A (CDA1) and B (CDB1). The antibodies were administered together as a single infusion, each at a dose of 10 mg per kilogram of body weight, in patients with symptomatic C. difficile infection who were receiving either metronidazole or vancomycin. The primary outcome was laboratory-documented recurrence of infection during the 84 days after the administration of monoclonal antibodies or placebo.

RESULTS: …

Role Of Elevated Monocyte Transforming Growth Factor Beta (Tgf Beta) Production In Posttrauma Immunosuppression, Carol Miller-Graziano, Gyongyi Szabo, Katherine Griffey, Bela Mehta, Karen Kodys, Donna Catalano

Gyongyi Szabo

We previously reported that increased production of prostaglandin E2 by monocytes is a pivotal mechanism in posttrauma immunopathology. Here we characterize monocyte levels of transforming growth factor beta and examine the effects of elevated transforming growth factor beta on prostaglandin E2 release by patients' monocytes. Trauma patients' and normals' monocyte supernates (+/- stimulation with muramyl dipeptide) were acid treated and assayed for transforming growth factor beta using the mink lung-cell bioassay. Alternatively, human transforming growth factor beta was added to patients' and normals' monocytes and prostaglandin E2 production assayed. Significantly elevated transforming growth factor beta levels (median = 181.7 pmol/10(6) …

Effect Of Ethanol On Inflammatory Responses. Implications For Pancreatitis, Gyongyi Szabo, Pranoti Mandrekar, Shilpa Oak, Julia Mayerle

Gyongyi Szabo

BACKGROUND/AIMS: Alcohol use alters inflammatory cell responses. While alcohol has direct effects on pancreatic acinar cells, activation of inflammatory cells is a major component of the pathology of alcoholic pancreatitis.

METHODS: The effects of acute or chronic alcohol exposure were evaluated in human monocytes on the production of TNFalpha or IL-10 production, pro-inflammatory gene and nuclear factor-kappaB (NF-kappaB) activation.

RESULTS: Moderate, acute alcohol consumption or equivalent doses of alcohol in vitro had anti-inflammatory effects on monocyte activation via inhibition of pro-inflammatory genes and NF-kappaB activation, inhibition of TNFalpha production and augmentation of the anti-inflammatory cytokine, IL-10. In contrast, acute alcohol …

Reduced Alloreactive T-Cell Activation After Alcohol Intake Is Due To Impaired Monocyte Accessory Cell Function And Correlates With Elevated Il-10, Il-13, And Decreased Ifngamma Levels, Gyongyi Szabo, Pranoti Mandrekar, Angela Dolganiuc, Donna Catalano, Karen Kodys

Gyongyi Szabo

BACKGROUND: Immunosuppression associated with chronic alcohol use is characterized by reduced antigen-specific T-cell response and impaired delayed type hypersensitivity. Increasing evidence suggests in chronic alcohol consumption models that reduced antigen-specific T-cell proliferation is due to insufficient accessory cell function. Accessory cell function, a critical step in recognition of viral antigens, is reduced in chronic hepatitis C. The severity of hepatitis C is increased by alcohol consumption. Thus, we investigated the effects of alcohol consumption on accessory cell activity of monocytes in supporting alloreactive T-cell proliferation. METHODS: Alloreactive T-cell proliferation was evaluated in a one-way mixed lymphocyte reaction (MLR). Mononuclear cells …

Regulation Of Human Monocyte Functions By Acute Ethanol Treatment: Decreased Tumor Necrosis Factor-Alpha, Interleukin-1 Beta And Elevated Interleukin-10, And Transforming Growth Factor-Beta Production, Gyongyi Szabo, Pranoti Mandrekar, Linda Girouard, Donna Catalano

Gyongyi Szabo

We and others have previously shown that even acute ethanol exposure has the capacity to modulate immune functions, particularly monocyte functions. Herein, we tested the hypothesis that acute ethanol treatment inhibits inflammatory, while increasing inhibitory cytokine production in human blood monocytes that, in turn, could contribute to the overall immune abnormalities seen after alcohol use. Our data show that in vitro treatment of blood monocytes with a physiologically relevant dose of alcohol (25 mM) results in significantly decreased induction of tumor necrosis factor-alpha (TNF alpha) and interleukin (IL)-1 beta by bacterial stimulation of either Gram-positive [staphylococcal enterotoxin B (SEB), 1 …

Monocytes, Alcohol Use, And Altered Immunity, Gyongyi Szabo

Gyongyi Szabo

The immunomodulatory capacity of acute, moderate alcohol consumption was investigated in this study in nonalcoholic volunteers after 2 ml of vodka/kg body weight of alcohol consumption. There was a significant, transient increase in interleukin-12 and interferon-gamma (IFNgamma) levels in whole blood samples collected 4 hr after alcohol consumption in response to an ex vivo bacterial challenge with lipopolysaccharide (p < 0.02). However, decreased IFNgamma levels were produced by mononuclear cells collected later after alcohol consumption (16 hr), suggesting that acute alcohol consumption has a biphasic effect on IFNgamma inducibility. Furthermore, isolated blood monocytes collected 16 hr after alcohol consumption showed significantly …

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, …

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 …

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 …

The Critical Role Of Toll-Like Receptor (Tlr) 4 In Alcoholic Liver Disease Is Independent Of The Common Tlr Adapter Myd88, Istvan Hritz, Pranoti Mandrekar, Arumugam Velayudham, Donna Catalano, Angela Dolganiuc, Karen Kodys, Evelyn Kurt-Jones, Gyongyi Szabo

Gyongyi Szabo

The Toll-like receptor 4 (TLR4) that recognizes endotoxin, a trigger of inflammation in alcoholic liver disease (ALD), activates two signaling pathways utilizing different adapter molecules: the common TLR adapter, myeloid differentiation factor 88 (MyD88), or Toll/interleukin immune-response-domain-containing adaptor inducing interferon (IFN)-beta. The MyD88 pathway induces proinflammatory cytokine activation, a critical mediator of ALD. Here we evaluated the role of MyD88 in alcohol-induced liver injury in wild-type, TLR2-deficient, TLR4-deficient, or MyD88-deficient (knockout [KO]) mice after administration of the Lieber-De-Carli diet (4.5% volume/volume ethanol) or an isocaloric liquid control diet for 5 weeks. Alcohol feeding resulted in a significant increase in serum …

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 …