Medical Microbiology Commons^™

Vaccination With A Genetically Modified Brugia Malayi Cysteine Protease Inhibitor-2 Reduces Adult Parasite Numbers And Affects The Fertility Of Female Worms Following A Subcutaneous Challenge Of Mongolian Gerbils (Meriones Unguiculatus) With B. Malayi Infective Larvae., Sridhar Arumugam, Junfei Wei, Danielle Ward, David Abraham, Sara Lustigman, Bin Zhan, Thomas R. Klei

Department of Microbiology and Immunology Faculty Papers

Vaccination of Mongolian gerbils with Brugia malayi cysteine protease inhibitor-2 in which the amino acid Asn66 was mutated to Lys66 (Bm-CPI-2M) resulted in reduced parasite numbers of 48.6% and 48.0% at 42 and 90 days p.i. with B. malayi L3s. Fertility of female worms was also affected at 90 days p.i. In vitro killing of L3s observed in the presence of gerbil peritoneal exudate cells and anti-Bm-CPI-2M sera suggests antibody-dependent cell-mediated cytotoxicity as a putative protective mechanism. These observations suggest that Bm-CPI-2M is a promising prophylactic and anti-fecundity vaccine candidate.

Hemichannels In Neurodegenerative Diseases: Is There A Link To Pathology?, Megan Bosch, Tammy Kielian

Journal Articles: Pathology and Microbiology

Although originally considered a structural component of gap junctions, connexin hemichannels (HCs) are now recognized as functional entities capable of influencing metabolic gradients within the CNS, allowing direct communication between the intra- and extracellular milieus. Besides connexins, HCs can also be formed by pannexins, which are not capable of gap junction assembly. Both positive and negative effects have been attributed to HC activity in the context of neurodegenerative diseases. For example, HCs can exert neuroprotective effects by promoting the uptake of neurotoxic molecules, whereas chronic HC opening can disrupt molecular gradients leading to cellular dysfunction and death. The latter scenario …

Epoxide-Mediated Differential Packaging Of Cif And Other Virulence Factors Into Outer Membrane Vesicles, A. E. Ballok, L. M. Filkins, J.. M. Bomberger, B. A. Stanton, George A. O'Toole

Dartmouth Scholarship

Pseudomonas aeruginosa produces outer membrane vesicles (OMVs) that contain a number of secreted bacterial proteins, including phospholipases, alkaline phosphatase, and the CFTR inhibitory factor (Cif). Previously, Cif, an epoxide hydrolase, was shown to be regulated at the transcriptional level by epoxides, which serve as ligands of the repressor, CifR. Here, we tested whether epoxides have an effect on Cif levels in OMVs. We showed that growth of P. aeruginosa in the presence of specific epoxi

Cyclic Di-Gmp-Dependent Signaling Pathways In The Pathogenic Firmicute Listeria Monocytogenes, Li-Hong Chen, Volkan K. Köseoğlu, Zehra T. Güvener, Tanya Myers-Morales, Joseph M. Reed, Sarah E. F. D'Orazio, Kurt W. Miller, Mark Gomelsky

Microbiology, Immunology, and Molecular Genetics Faculty Publications

We characterized key components and major targets of the c-di-GMP signaling pathways in the foodborne pathogen Listeria monocytogenes, identified a new c-di-GMP-inducible exopolysaccharide responsible for motility inhibition, cell aggregation, and enhanced tolerance to disinfectants and desiccation, and provided first insights into the role of c-di-GMP signaling in listerial virulence. Genome-wide genetic and biochemical analyses of c-di-GMP signaling pathways revealed that L. monocytogenes has three GGDEF domain proteins, DgcA (Lmo1911), DgcB (Lmo1912) and DgcC (Lmo2174), that possess diguanylate cyclase activity, and three EAL domain proteins, PdeB (Lmo0131), PdeC (Lmo1914) and PdeD (Lmo0111), that possess c-di-GMP phosphodiesterase activity. Deletion of all phosphodiesterase …

Cyclic Di-Gmp-Dependent Signaling Pathways In The Pathogenic Firmicute Listeria Monocytogenes, Li-Hong Chen, Volkan K. Köseoğlu, Zehra T. Güvener, Tanya Myers-Morales, Joseph M. Reed, Sarah E. F. D'Orazio, Kurt W. Miller, Mark Gomelsky

Microbiology, Immunology, and Molecular Genetics Faculty Publications

We characterized key components and major targets of the c-di-GMP signaling pathways in the foodborne pathogen Listeria monocytogenes, identified a new c-di-GMP-inducible exopolysaccharide responsible for motility inhibition, cell aggregation, and enhanced tolerance to disinfectants and desiccation, and provided first insights into the role of c-di-GMP signaling in listerial virulence. Genome-wide genetic and biochemical analyses of c-di-GMP signaling pathways revealed that L. monocytogenes has three GGDEF domain proteins, DgcA (Lmo1911), DgcB (Lmo1912) and DgcC (Lmo2174), that possess diguanylate cyclase activity, and three EAL domain proteins, PdeB (Lmo0131), PdeC (Lmo1914) and PdeD (Lmo0111), that possess c-di-GMP phosphodiesterase activity. Deletion of all …

Clinical And Biochemical Function Of Polymorphic Nr0b1 Ggaa-Microsatellites In Ewing Sarcoma: A Report From The Children's Oncology Group., Michael J. Monument, Kirsten M. Johnson, Elizabeth Mcilvaine, Lisa Abegglen, W. Scott Watkins, Lynn B. Jorde, Richard B. Womer, Natalie Beeler, Laura Monovich, Elizabeth R. Lawlor, Julia A. Bridge, Joshua D. Schiffman, Mark D Krailo, R. Lor Randall, Stephen L. Lessnick

Journal Articles: Pathology and Microbiology

BACKGROUND: The genetics involved in Ewing sarcoma susceptibility and prognosis are poorly understood. EWS/FLI and related EWS/ETS chimeras upregulate numerous gene targets via promoter-based GGAA-microsatellite response elements. These microsatellites are highly polymorphic in humans, and preliminary evidence suggests EWS/FLI-mediated gene expression is highly dependent on the number of GGAA motifs within the microsatellite.

OBJECTIVES: Here we sought to examine the polymorphic spectrum of a GGAA-microsatellite within the NR0B1 promoter (a critical EWS/FLI target) in primary Ewing sarcoma tumors, and characterize how this polymorphism influences gene expression and clinical outcomes.

RESULTS: A complex, bimodal pattern of EWS/FLI-mediated gene expression was observed …

Vaccines To Combat River Blindness: Expression, Selection And Formulation Of Vaccines Against Infection With Onchocerca Volvulus In A Mouse Model., Jessica A. Hess, Bin Zhan, Sandra Bonne-Annee, Jessica M. Deckman, Maria Elena Bottazzi, Peter J. Hotez, Thomas R R. Klei, Sara Lustigman, David Abraham

Department of Microbiology and Immunology Faculty Papers

Human onchocerciasis is a neglected tropical disease caused by Onchocerca volvulus and an important cause of blindness and chronic disability in the developing world. Although mass drug administration of ivermectin has had a profound effect on control of the disease, additional tools are critically needed including the need for a vaccine against onchocerciasis. The objectives of the present study were to: (i) select antigens with known vaccine pedigrees as components of a vaccine; (ii) produce the selected vaccine antigens under controlled conditions, using two expression systems and in one laboratory and (iii) evaluate their vaccine efficacy using a single immunisation …

Vcam-1/Α4Β1 Integrin Interaction Is Crucial For Prompt Recruitment Of Immune T Cells Into The Brain During The Early Stage Of Reactivation Of Chronic Infection With Toxoplasma Gondii To Prevent Toxoplasmic Encephalitis, Qila Sa, Eri Ochiai, Tomoko Sengoku, Melinda E. Wilson, Morgan Brogli, Stephen Crutcher, Sara A. Michie, Baohui Xu, Laura Payne, Xisheng Wang, Yasuhiro Suzuki

Microbiology, Immunology, and Molecular Genetics Faculty Publications

Reactivation of chronic infection with Toxoplasma gondii can cause life-threatening toxoplasmic encephalitis in immunocompromised individuals. We examined the role of VCAM-1/α4β1 integrin interaction in T cell recruitment to prevent reactivation of the infection in the brain. SCID mice were infected and treated with sulfadiazine to establish a chronic infection. VCAM-1 and ICAM-1 were the endothelial adhesion molecules detected on cerebral vessels of the infected SCID and wild-type animals. Immune T cells from infected wild-type mice were treated with anti-α4 integrin or control antibodies and transferred into infected SCID or nude mice, and the animals received the same antibody every other …

Small-Molecule Probes Targeting The Viral Ppxy-Host Nedd4 Interface Block Egress Of A Broad Range Of Rna Viruses., Ziying Han, Jianhong Lu, Yuliang Liu, Benjamin Davis, Michael S Lee, Mark A Olson, Gordon Ruthel, Bruce D Freedman, Matthias J. Schnell, Jay E Wrobel, Allen B Reitz, Ronald N Harty

Department of Microbiology and Immunology Faculty Papers

Budding of filoviruses, arenaviruses, and rhabdoviruses is facilitated by subversion of host proteins, such as Nedd4 E3 ubiquitin ligase, by viral PPxY late (L) budding domains expressed within the matrix proteins of these RNA viruses. As L domains are important for budding and are highly conserved in a wide array of RNA viruses, they represent potential broad-spectrum targets for the development of antiviral drugs. To identify potential competitive blockers, we used the known Nedd4 WW domain-PPxY interaction interface as the basis of an in silico screen. Using PPxY-dependent budding of Marburg (MARV) VP40 virus-like particles (VLPs) as our model system, …

Systemic Hematogenous Maintenance Of Memory Inflation By Mcmv Infection., Corinne J Smith, Holly Turula, Christopher M. Snyder

Department of Microbiology and Immunology Faculty Papers

Several low-grade persistent viral infections induce and sustain very large numbers of virus-specific effector T cells. This was first described as a response to cytomegalovirus (CMV), a herpesvirus that establishes a life-long persistent/latent infection, and sustains the largest known effector T cell populations in healthy people. These T cells remain functional and traffic systemically, which has led to the recent exploration of CMV as a persistent vaccine vector. However, the maintenance of this remarkable response is not understood. Current models propose that reservoirs of viral antigen and/or latently infected cells in lymph nodes stimulate T cell proliferation and effector differentiation, …

Fty720 (Fingolimod) Provides Insight Into The Molecular Mechanisms Of Multiple Sclerosis, Madelyn Elizabeth Crawford

Pursuit - The Journal of Undergraduate Research at The University of Tennessee

Multiple sclerosis (MS) is a neurodegenerative disorder caused by a prolonged immune- mediated inflammatory response that targets myelin. Nearly all of the drugs approved for the treatment of MS are general immunosuppressants or only function in symptom management. The oral medication fingolimod, however, is reported to have direct therapeutic effects on cells of the central nervous system in addition to immunomodulatory functions. Fingolimod is known to interact with sphingosine-1-phosphate (S1P) receptors, and the most widely- accepted theory for its mechanism of action is functional antagonism of the receptor. This review examines significant neuromodulatory effects achieved by functional antagonism of the …

A Central Role For Carbon-Overflow Pathways In The Modulation Of Bacterial Cell Death., Vinai Chittezham Thomas, Marat Sadykov, Sujata S. Chaudhari, Joselyn Jones, Jennifer L. Endres, Todd J. Widhelm, Jong-Sam Ahn, Randeep S. Jawa, Matthew C. Zimmerman, Kenneth W. Bayles

Journal Articles: Pathology and Microbiology

Similar to developmental programs in eukaryotes, the death of a subpopulation of cells is thought to benefit bacterial biofilm development. However mechanisms that mediate a tight control over cell death are not clearly understood at the population level. Here we reveal that CidR dependent pyruvate oxidase (CidC) and α-acetolactate synthase/decarboxylase (AlsSD) overflow metabolic pathways, which are active during staphylococcal biofilm development, modulate cell death to achieve optimal biofilm biomass. Whereas acetate derived from CidC activity potentiates cell death in cells by a mechanism dependent on intracellular acidification and respiratory inhibition, AlsSD activity effectively counters CidC action by diverting carbon flux …

Immunomodulatory Activity Of Interferon-Beta, Lloyd H. Kasper, Anthony T. Reder

Dartmouth Scholarship

Multiple sclerosis (MS) is a complex disorder of the central nervous system that appears to be driven by a shift in immune functioning toward excess inflammation that results in demyelination and axonal loss. Beta interferons were the first class of disease-modifying therapies to be approved for patients with MS after treatment with this type I interferon improved the course of MS on both clinical and radiological measures in clinical trials. The mechanism of action of interferon-beta appears to be driven by influencing the immune system at many levels, including antigen-presenting cells, T cells, and B cells. One effect of these …

Intrinsic Innate Immunity Fails To Control Herpes Simplex Virus And Vesicular Stomatitis Virus Replication In Sensory Neurons And Fibroblasts, Pamela C. Rosato, David A. Leib

Dartmouth Scholarship

Herpes simplex virus 1 (HSV-1) establishes lifelong latent infections in the sensory neurons of the trigeminal ganglia (TG), wherein it retains the capacity to reactivate. The interferon (IFN)-driven antiviral response is critical for the control of HSV-1 acute replication. We therefore sought to further investigate this response in TG neurons cultured from adult mice deficient in a variety of IFN signaling components. Parallel experiments were also performed in fibroblasts isolated concurrently. We showed that HSV-1 replication was comparable in wild-type (WT) and IFN signaling-deficient neurons and fibroblasts. Unexpectedly, a similar pattern was observed for the IFN-sensitive vesicular stomatitis virus (VSV). …

Investigating The Viability Of Two Stenotrophomonas Maltophilia Isolates After Air-Drying, Samantha Lane, Joanna Brooke

DePaul Discoveries

Abstract

Stenotrophomonas maltophilia is a water-borne infectious bacterium that is found in both clinical (hospitals) and non-clinical environments. This human pathogen is commonly recovered from respiratory tract infections. A recent study at a hospital in Taiwan suggested that dry patient charts can serve as a vehicle of transmission of this bacterium⁷. As S. maltophilia is not commonly isolated from dry surfaces, this current study tested the hypothesis that this pathogen can remain viable for some time on a dry surface. This study was designed to determine how long S. maltophilia could remain viable after air-drying by observing …

New Clues To Understanding Hiv Nonprogressors: Low Cholesterol Blocks Hiv Trans Infection, Vinayaka R. Prasad, Michael I. Bukrinsky

Microbiology, Immunology, and Tropical Medicine Faculty Publications

A small percentage of HIV-infected subjects (2 to 15%) are able to control disease progression for many years without antiretroviral therapy. Years of intense studies of virologic and immunologic mechanisms of disease control in such individuals yielded a number of possible host genes that could be responsible for the preservation of immune functions, from immune surveillance genes, chemokines, or their receptors to anti-HIV restriction factors. A recent mBiopaper by Rappocciolo et al. (G. Rappocciolo, M. Jais, P. Piazza, T. A. Reinhart, S. J. Berendam, L. Garcia-Exposito, P. Gupta, and C. R. Rinaldo, mBio 5:e01031-13, 2014) describes another potential factor …

Characterizing The Response Of Multidrug-Resistant Klebsiella Pneumoniae Species To The Application Of A Phage Cocktail, Steven Liu

Symposium

Project Summary: The application of bacteriophages to treat bacterial infections is known as phage therapy, which takes advantage of bacteriophage’s natural ability to infect and lyse bacterial hosts. Phages have been shaped by billions of years of evolution to be highly specialized deliverers of bactericidal agents to the cytoplasm of their target bacteria. Ever since discovery of bacteriophages in 1915, phage therapy was recognized as a potentially powerful tool for eliminating bacterial infections. The effectiveness of phage therapy can be increased by creating a mixture of multiple phages to target a wider variety of bacterial strains. Furthermore, phage therapy has …

Genome-Wide Analysis Of Regulatory Proteases Sequences Identified Through Bioinformatics Data Mining In Taenia Solium, Hong-Bin Yan, Zhong-Zi Lou, Li Li, Paul J. Brindley, Yadong Zheng, Xuenong Luo, Junling Hou, Aijiang Guo, Wan-Zhong Jia, Xuepeng Cai

Microbiology, Immunology, and Tropical Medicine Faculty Publications

Background

Cysticercosis remains a major neglected tropical disease of humanity in many regions, especially in sub-Saharan Africa, Central America and elsewhere. Owing to the emerging drug resistance and the inability of current drugs to prevent re-infection, identification of novel vaccines and chemotherapeutic agents against Taenia solium and related helminth pathogens is a public health priority. The T. solium genome and the predicted proteome were reported recently, providing a wealth of information from which new interventional targets might be identified. In order to characterize and classify the entire repertoire of protease-encoding genes of T. solium, which act fundamental biological roles in …

Secretory Iga Is Concentrated In The Outer Layer Of Colonic Mucus Along With Gut Bacteria, Eric W. Rogier, Aubrey L. Frantz, Maria E. C. Bruno, Charlotte S. Kaetzel

Microbiology, Immunology, and Molecular Genetics Faculty Publications

Antibodies of the secretory IgA (SIgA) class comprise the first line of antigen-specific immune defense, preventing access of commensal and pathogenic microorganisms and their secreted products into the body proper. In addition to preventing infection, SIgA shapes the composition of the gut microbiome. SIgA is transported across intestinal epithelial cells into gut secretions by the polymeric immunoglobulin receptor (pIgR). The epithelial surface is protected by a thick network of mucus, which is composed of a dense, sterile inner layer and a loose outer layer that is colonized by commensal bacteria. Immunofluorescence microscopy of mouse and human colon tissues demonstrated that …

Extracellular Traps Are Associated With Human And Mouse Neutrophil And Macrophage Mediated Killing Of Larval Strongyloides Stercoralis., Sandra Bonne-Annee, Laura A. Kerepesi, Jessica A. Hess, Jordan Wesolowski, Fabienne Paumet, James B. Lok, Thomas J. Nolan, David Abraham

Department of Microbiology and Immunology Faculty Papers

Neutrophils are multifaceted cells that are often the immune system's first line of defense. Human and murine cells release extracellular DNA traps (ETs) in response to several pathogens and diseases. Neutrophil extracellular trap (NET) formation is crucial to trapping and killing extracellular pathogens. Aside from neutrophils, macrophages and eosinophils also release ETs. We hypothesized that ETs serve as a mechanism of ensnaring the large and highly motile helminth parasite Strongyloides stercoralis thereby providing a static target for the immune response. We demonstrated that S. stercoralis larvae trigger the release of ETs by human neutrophils and macrophages. Analysis of NETs revealed …