Bacterial Infections and Mycoses | Open Access Articles

Iiv-6 Inhibits Nf-Kappab Responses In Drosophila, Cara C. West, Florentina Rus, Ying Chen, Anni Kleino, Monique Gangloff, Don B. Gammon, Neal S. Silverman

Neal Silverman

The host immune response and virus-encoded immune evasion proteins pose constant, mutual selective pressure on each other. Virally encoded immune evasion proteins also indicate which host pathways must be inhibited to allow for viral replication. Here, we show that IIV-6 is capable of inhibiting the two Drosophila NF-kappaB signaling pathways, Imd and Toll. Antimicrobial peptide (AMP) gene induction downstream of either pathway is suppressed when cells infected with IIV-6 are also stimulated with Toll or Imd ligands. We find that cleavage of both Imd and Relish, as well as Relish nuclear translocation, three key points in Imd signal transduction, occur …

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Type I Interferon Induction By Neisseria Gonorrhoeae: Dual Requirement Of Cyclic Gmp-Amp Synthase And Toll-Like Receptor 4, Warrison A. Andrade, Sarika Agarwal, Shunyan Mo, Scott A. Shaffer, Joseph P. Dillard, Tobias Schmidt, Veit Hornung, Katherine A. Fitzgerald, Evelyn A. Kurt-Jones, Douglas T. Golenbock

Katherine A. Fitzgerald

The innate immune system is the first line of defense against Neisseria gonorrhoeae (GC). Exposure of cells to GC lipooligosaccharides induces a strong immune response, leading to type I interferon (IFN) production via TLR4/MD-2. In addition to living freely in the extracellular space, GC can invade the cytoplasm to evade detection and elimination. Double-stranded DNA introduced into the cytosol binds and activates the enzyme cyclic-GMP-AMP synthase (cGAS), which produces 2'3'-cGAMP and triggers STING/TBK-1/IRF3 activation, resulting in type I IFN expression. Here, we reveal a cytosolic response to GC DNA that also contributes to type I IFN induction. We demonstrate that …

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Structural And Molecular Analysis Of A Protective Epitope Of Lyme Disease Antigen Ospa And Antibody Interactions, Shivender Shandilya, Nese Kurt Yilmaz, Ejemel Monir, Andrew Sadowski, William D. Thomas, Mark S. Klempner, Celia A. Schiffer, Yan Wang

Celia A. Schiffer

The murine monoclonal antibody LA-2 recognizes a clinically protective epitope on outer surface protein (OspA) of Borrelia burgdorferi, the causative agent of Lyme disease in North America. Human antibody equivalence to LA-2 is the best serologic correlate of protective antibody responses following OspA vaccination. Understanding the structural and functional basis of the LA-2 protective epitope is important for developing OspA-based vaccines and discovering prophylactic antibodies against Lyme disease. Here, we present a detailed structure-based analysis of the LA-2/OspA interaction interface and identification of residues mediating antibody recognition. Mutations were introduced into both OspA and LA-2 based on computational predictions on …

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Malaria-Induced Nlrp12/Nlrp3-Dependent Caspase-1 Activation Mediates Inflammation And Hypersensitivity To Bacterial Superinfection, Marco A. Ataide, Warrison A. Andrade, Dario S. Zamboni, Donghai Wang, Maria Do Carmo Souza, Bernardo S. Franklin, Samir Elian, Flaviano S. Martins, Dhelio Pereira, George W. Reed, Katherine A. Fitzgerald, Douglas T. Golenbock, Ricardo T. Gazzinelli

Katherine A. Fitzgerald

Cyclic paroxysm and high fever are hallmarks of malaria and are associated with high levels of pyrogenic cytokines, including IL-1beta. In this report, we describe a signature for the expression of inflammasome-related genes and caspase-1 activation in malaria. Indeed, when we infected mice, Plasmodium infection was sufficient to promote MyD88-mediated caspase-1 activation, dependent on IFN-gamma-priming and the expression of inflammasome components ASC, P2X7R, NLRP3 and/or NLRP12. Pro-IL-1beta expression required a second stimulation with LPS and was also dependent on IFN-gamma-priming and functional TNFR1. As a consequence of Plasmodium-induced caspase-1 activation, mice produced extremely high levels of IL-1beta upon a second …

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Full-Text Articles in Bacterial Infections and Mycoses

Iiv-6 Inhibits Nf-Kappab Responses In Drosophila, Cara C. West, Florentina Rus, Ying Chen, Anni Kleino, Monique Gangloff, Don B. Gammon, Neal S. Silverman

Neal Silverman

Katherine A. Fitzgerald

Structural And Molecular Analysis Of A Protective Epitope Of Lyme Disease Antigen Ospa And Antibody Interactions, Shivender Shandilya, Nese Kurt Yilmaz, Ejemel Monir, Andrew Sadowski, William D. Thomas, Mark S. Klempner, Celia A. Schiffer, Yan Wang

Celia A. Schiffer

Katherine A. Fitzgerald