Medicine and Health Sciences Commons^™

Development And Characterization Of A Severe Acute Respiratory Syndrome-Associated Coronavirus-Neutralizing Human Monoclonal Antibody That Provides Effective Immunoprophylaxis In Mice, Thomas Greenough, Gregory Babcock, Anjeanette Roberts, Hector Hernandez, William Thomas, Jennifer Coccia, Robert Graziano, Mohan Srinivasan, Israel Lowy, Robert Finberg, Kanta Subbarao, Leatrice Vogel, Mohan Somasundaran, Katherine Luzuriaga, John Sullivan, Donna Ambrosino

William D Thomas Jr

BACKGROUND: Severe acute respiratory syndrome (SARS) remains a significant public health concern after the epidemic in 2003. Human monoclonal antibodies (MAbs) that neutralize SARS-associated coronavirus (SARS-CoV) could provide protection for exposed individuals. METHODS: Transgenic mice with human immunoglobulin genes were immunized with the recombinant major surface (S) glycoprotein ectodomain of SARS-CoV. Epitopes of 2 neutralizing MAbs derived from these mice were mapped and evaluated in a murine model of SARS-CoV infection. RESULTS: Both MAbs bound to S glycoprotein expressed on transfected cells but differed in their ability to block binding of S glycoprotein to Vero E6 cells. Immunoprecipitation analysis revealed …

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: …

Therapy With A Severe Acute Respiratory Syndrome-Associated Coronavirus-Neutralizing Human Monoclonal Antibody Reduces Disease Severity And Viral Burden In Golden Syrian Hamsters, Anjeanette Roberts, William Thomas, Jeannette Guarner, Elaine Lamirande, Gregory Babcock, Thomas Greenough, Leatrice Vogel, Norman Hayes, John Sullivan, Sherif Zaki, Kanta Subbarao, Donna Ambrosino

William D Thomas Jr

BACKGROUND: Immunotherapy with monoclonal antibodies (MAbs) offers safe interventions for the prevention of infection in patients after organ transplantation and for the treatment of cancers and autoimmune diseases. MAb 201 is a severe acute respiratory syndrome-associated coronavirus (SARS-CoV)-specific MAb that prevents establishment of viral replication in vitro and prevents viral replication in vivo when administered prophylactically. The efficacy of MAb 201 in the treatment of SARS was evaluated in golden Syrian hamsters, an animal model that supports SARS-CoV replication to high levels and displays severe pathological changes associated with infection, including pneumonitis and pulmonary consolidation. METHODS: Golden Syrian hamsters that …

Alcohol Facilitates Hcv Rna Replication Via Up-Regulation Of Mir-122 Expression And Inhibition Of Cyclin G1 In Human Hepatoma Cells, Wei Hou, Terence Bukong, Karen Kodys, Gyongyi Szabo

Gyongyi Szabo

BACKGROUND: Clinical studies demonstrate synergistic liver damage by alcohol and hepatitis C virus (HCV); however, the mechanisms by which alcohol promotes HCV infection remain obscure. The liver-specific microRNA-122 (miR-122) regulates HCV replication and expression of host genes, including Cyclin G1. Here, we hypothesized that alcohol regulates miR-122 expression and thereby modulates HCV RNA replication. METHODS: The J6/JFH/Huh-7.5 model of HCV infection was used in this study. Real-time quantitative polymerase chain reaction, Western blotting, electrophoretic mobility shift assay, and confocal microscopy were used for experimental analysis. RESULTS: We found that acute alcohol exposure (25 mM) significantly increased intracellular HCV RNA as …

Structural And Thermodynamic Basis Of Amprenavir/Darunavir And Atazanavir Resistance In Hiv-1 Protease With Mutations At Residue 50, Seema Mittal, Rajintha Bandaranayake, Nancy King, Moses Prabu-Jeyabalan, Madhavi Nalam, Ellen Nalivaika, Nese Yilmaz, Celia Schiffer

Celia A. Schiffer

Drug resistance occurs through a series of subtle changes that maintain substrate recognition but no longer permit inhibitor binding. In HIV-1 protease, mutations at I50 are associated with such subtle changes that confer differential resistance to specific inhibitors. Residue I50 is located at the protease flap tips, closing the active site upon ligand binding. Under selective drug pressure, I50V/L substitutions emerge in patients, compromising drug susceptibility and leading to treatment failure. The I50V substitution is often associated with amprenavir (APV) and darunavir (DRV) resistance, while the I50L substitution is observed in patients failing atazanavir (ATV) therapy. To explain how APV, …

Ifn-Gamma Production By Human Natural Killer Cells In Response To Hcv-Infected Hepatoma Cells Is Dependent On Accessory Cells, Shuye Zhang, Banishree Saha, Karen Kodys, Gyongyi Szabo

Gyongyi Szabo

BACKGROUND and AIMS: Interferon-gamma (IFN-gamma), a cytokine produced by activated natural killer cell (NK) and T lymphocytes, is an important regulator of innate and adaptive immunity during hepatitis C virus (HCV) infection. However, the cellular sources and mechanisms of IFN-gamma induction in HCV-infection are not fully understood. METHODS: We cultured normal human peripheral blood mononuclear cells (PBMCs) with different populations of immune cells and JFH-1 HCV-infected Huh7.5 (JFH-1/Huh7.5) cells. RESULTS: We found that PBMCs produced large amounts of IFN-gamma after co-culture with JFH-1/Huh7.5 cells. Using intracellular cytokine staining we confirmed that NK cells and NKT cells (to a lesser extent) …

Human Monoclonal Antibody Mbl-Hcv1 Delays Hcv Viral Rebound Following Liver Transplantation: A Randomized Controlled Study, R. Chung, F. Gordon, M. Curry, T. Schiano, S. Emre, K. Corey, J. Markmann, M. Hertl, J. Pomposelli, E. Pomfret, S. Florman, M. Schilsky, Teresa Broering, Robert Finberg, Gyongyi Szabo, Phillip Zamore, U. Khettry, Gregory Babcock, Donna Ambrosino, Brett Leav, Mark Leney, H. Smith, Deborah Molrine

Gyongyi Szabo

Rapid allograft infection complicates liver transplantation (LT) in patients with hepatitis C virus (HCV). Pegylated interferon-alpha and ribavirin therapy after LT has significant toxicity and limited efficacy. The effect of a human monoclonal antibody targeting the HCV E2 glycoprotein (MBL-HCV1) on viral clearance was examined in a randomized, double-blind, placebo-controlled pilot study in patients infected with HCV genotype 1a undergoing LT. Subjects received 11 infusions of 50 mg/kg MBL-HCV1 (n=6) or placebo (n=5) intravenously with three infusions on day of transplant, a single infusion on days 1 through 7 and one infusion on day 14 after LT. MBL-HCV1 was well-tolerated …

Tca Cycle Inactivation In Staphylococcus Aureus Alters Nitric Oxide Production In Raw 264.7 Cells, Chandirasegaran Massilamany, Arunakumar Gangaplara, Donald Gardner, James Musser, David Steffen, Greg Somerville, Jay Reddy

Greg A. Somerville

Inactivation of the Staphylococcus aureus tricarboxylic acid (TCA) cycle delays the resolution of cutaneous ulcers in a mouse soft tissue infection model. In this study, it was observed that cutaneous lesions in mice infected with wild-type or isogenic aconitase mutant S. aureus strains contained comparable inflammatory infiltrates, suggesting the delayed resolution was independent of the recruitment of immune cells. These observations led us to hypothesize that staphylococcal metabolism can modulate the host immune response. Using an in vitro model system involving RAW 264.7 cells, the authors observed that cells cultured with S. aureus aconitase mutant strains produced significantly lower amounts …

Genome Sequence Of Lactobacillus Pentosus Kca1: Vaginal Isolate From A Healthy Premenopausal Woman, Kingsley Anukam

Kingsley C Anukam

The vaginal microbiota, in particular Lactobacillus species, play an important role in female health through modulation of immunity, countering pathogens and maintaining a pH below 4.7. We report the isolation and genome sequence of Lactobacillus pentosus strain KCA1 (formally known as L. plantarum) from the vagina of a healthy Nigerian woman. The genome was sequenced using Illumina GA II technology. The resulting 16,920,226 paired-end reads were assembled with the Velvet tool. Contigs were annotated using the RAST server, and manually curated. A comparative analysis with the available genomes of L. pentosus IG1 and L. plantarum WCFS1 showed that over 15% …

Increased Toll-Like Receptor (Tlr) Mrna Expression In Monocytes Is A Feature Of Metabolic Syndrome In Adolescents, Olga Hardy, Albert Kim, Carol Ciccarelli, Laura Hayman, Jean Wiecha

Laura L. Hayman

BACKGROUND: Metabolic syndrome (MetSyn) is diagnosed frequently in some but not all overweight adolescents. Chronic inflammation, as seen in obesity, is strongly associated with MetSyn. OBJECTIVES: The aim of this pilot study was to assess the correlation between activation of the innate immune system and MetSyn, independent of body mass index (BMI), in a young population. METHODS: We quantitatively measured both systemic pro-inflammatory cytokines and gene expression of Toll-like receptors (TLRs) and downstream cytokines in circulating monocytes obtained from nine adolescents with metabolic syndrome (Overwt-MetSyn) and eight BMI-matched controls (Overwt-Healthy). RESULTS: The Overwt-MetSyn group demonstrated a significant elevation in expression …

Type Iii Interferons, Il-28 And Il-29, Are Increased In Chronic Hcv Infection And Induce Myeloid Dendritic Cell-Mediated Foxp3+ Regulatory T Cells, Angela Dolganiuc, Karen Kodys, Christopher Marshall, Banishree Saha, Shuye Zhang, Shashi Bala, Gyongyi Szabo

Gyongyi Szabo

BACKGROUND AND AIMS: Hepatitis C virus (HCV) is difficult to eradicate and type III interferons (IFN-lambda, composed of IL-28A, IL-28B and IL-29) are novel therapeutic candidates. We hypothesized that IFN-lambda have immunomodulatory effects in HCV- infected individuals. MATERIALS AND METHODS: We analyzed the expression of IFN-lambda and its receptor (composed of IL-10R2 and IFN-lambdaR subunits) in the blood and livers of patients with chronic (c)HCV infection compared to controls (those who cleared HCV by sustained virological response, SVR, and those with liver inflammation of non-viral origin, non-alcoholic steatohepatitis, NASH). We also compared the proliferative capacity of dendritic cells (DCs) obtained …