Life Sciences Commons^™

The Crispr/Cas Adaptive Immune System Of Pseudomonas Aeruginosa Mediates Resistance To Naturally Occurring And Engineered Phages, Kyle C. Cady, Joe Bondy-Denomy, Gary E. Heussler, Alan R. Davidson, George A. O'Toole

Dartmouth Scholarship

Here we report the isolation of 6 temperate bacteriophages (phages) that are prevented from replicating within the laboratory strain Pseudomonas aeruginosa PA14 by the endogenous CRISPR/Cas system of this microbe. These phages are only the second identified group of naturally occurring phages demonstrated to be blocked for replication by a nonengineered CRISPR/Cas system, and our results provide the first evidence that the P. aeruginosa type I-F CRISPR/Cas system can function in phage resistance. Previous studies have highlighted the importance of the protospacer adjacent motif (PAM) and a proximal 8-nucleotide seed sequence in mediating CRISPR/Cas-based immunity. Through engineering of a protospacer …

Interactome-Wide Analysis Identifies End-Binding Protein 1 As A Crucial Component For The Speck-Like Particle Formation Of Activated Absence In Melanoma 2 (Aim2) Inflammasomes, Li-Jie Wang, Chia-Wei Hsu, Chiu-Chin Chen, Ying Liang, Lih-Chyang Chen, David M. Ojcius, Ngan-Ming Tsang, Chuen Hsueh, Chih-Ching Wu, Yu-Sun Chang

All Dugoni School of Dentistry Faculty Articles

Inflammasomes are cytoplasmic receptors that can recognize intracellular pathogens or danger signals and are critical for interleukin 1β production. Although several key components of inflammasome activation have been identified, there has not been a systematic analysis of the protein components found in the stimulated complex. In this study, we used the isobaric tags for relative and absolute quantification approach to systemically analyze the interactomes of the NLRP3, AIM2, and RIG-I inflammasomes in nasopharyngeal carcinoma cells treated with specific stimuli of these interactomes (H2O2, poly (dA:dT), and EBV noncoding RNA, respectively). We identified a number of proteins that appeared to be …

Minor Pilins Of The Type Iv Pilus System Participate In The Negative Regulation Of Swarming Motility, S L. Kuchma, E. F. Griffin, G. A. O'Toole

Dartmouth Scholarship

Pseudomonas aeruginosa exhibits distinct surface-associated behaviors, including biofilm formation, flagellum-mediated swarming motility, and type IV pilus-driven twitching. Here, we report a role for the minor pilins, PilW and PilX, components of the type IV pilus assembly machinery, in the repression of swarming motility. Mutating either the pilW or pilX gene alleviates the inhibition of swarming motility observed for strains with elevated levels of the intracellular signaling molecule cyclic di-GMP (c-di-GMP) due to loss of BifA, a c-di-GMP-degrading phosphodiesterase. Blocking PilD peptidase-mediated processing of PilW and PilX renders the unprocessed proteins defective for pilus assembly but still functional in c-di-GMP-mediated swarming …

Weaponizing Tear Gas: Bahrain’S Unprecedented Use Of Toxic Chemical Agents Against Civilians., Richard Sollom, Holly G. Atkinson

Publications and Research

The Bahraini government’s response to the early 2011 pro-democracy protests was brutal, systematic, and violent. In addition to birdshot and rubber bullets, government law enforcement attacked unarmed protestors with toxic chemical agents including tear gas. The government’s crackdown on the medical profession was especially harmful, as security forces arrested and detained doctors, raided health facilities, and obstructed patients from receiving necessary care. This report’s findings are based on field research that the authors conducted in Bahrain (April 2012) to investigate excessive use of force by law enforcement officials since June 2011—the end of Bahrain’s state of emergency. The medico-legal team …

The Use Of Cortisol And Hba1c As Biomarkers Of Stress In University Administrators, Jacilyn Marie Olson

Graduate Theses and Dissertations

PURPOSE: The purpose of this study was to explore the impact of perceived stress and cardiorespiratory fitness on cortisol and HbA1c, biomarkers of stress, in a group of select university administrators. The impact of gender on these relationships was of special concern. METHODS: University administrators with job titles of Chancellor, Provost, Vice Chancellors and Vice Provosts of the university, and Deans and Associate Deans at the college level were recruited. Twenty-five administrators (15 males and 10 females) agreed to participate and completed a battery of assessments that included completion of the University Administrative Concerns Questionnaire, a finger-stick blood test for …

Leptospiral Hemolysins Induce Proinflammatory Cytokines Through Toll-Like Receptor 2-And 4-Mediated Jnk And Nf-Κb Signaling Pathways, Huan Wang, Yifei Hu, David M. Ojcius, X. Frank Yang, Chenglin Zhang, Shibiao Ding, Xu'ai Lin, Jie Yan

All Dugoni School of Dentistry Faculty Articles

Infection with pathogenic Leptospira species causes serious systemic inflammation in patients. Although a few leptospiral proinflammatory molecules have been identified, Leptospira likely encodes other unidentified strong inflammation stimulators. The pathogenic L. interrogans genome encodes numerous putative hemolysin genes. Since hemolysins from other bacteria can cause inflammatory reactions, we hypothesized that leptospiral hemolysins may function as proinflammatory stimulators that contribute to the strong inflammation associated with Leptospira infection.

Melanopsin Mediates Retrograde Visual Signaling In The Retina, Dao-Qi Zhang, Michael A. Belenky, Patricia J. Sollars, Gary E. Pickard, Douglas G. Mcmahon

School of Veterinary and Biomedical Sciences: Faculty Publications

The canonical flow of visual signals proceeds from outer to inner retina (photoreceptors→bipolar cells→ganglion cells). However, melanopsin-expressing ganglion cells are photosensitive and functional sustained light signaling to retinal dopaminergic interneurons persists in the absence of rods and cones. Here we show that the sustained-type light response of retinal dopamine neurons requires melanopsin and that the response is mediated by AMPA-type glutamate receptors, defining a retrograde retinal visual signaling pathway that fully reverses the usual flow of light signals in retinal circuits.

Peptoid Based Slide Coatings For Disease Detection Via Elisa Microarray Analysis, Melissa Lea Hebert

Graduate Theses and Dissertations

Poly-N-substituted glycines (peptoids) are a very versatile family of synthetic molecules that can be customized for any number of applications. In this study, we chose to use peptoids as a foundation for sandwich ELISA microarray analysis with a long term goal of creating an early detection device for complex diseases such as cancer. The peptoids were designed to self-assemble into microspheres to be used in coatings on the surface of the microarray substrates to increase the surface area available for antibody attachment. This increased antibody density would lead to an increase in the microarray analysis sensitivity and dynamic range. Studies …

Epoxide-Mediated Cifr Repression Of Cif Gene Expression Utilizes Two Binding Sites In Pseudomonas Aeruginosa, Alicia E. Ballok, Christopher D. Bahl, Emily L. Dolben, Allia K. Lindsay, Jessica D. St. Laurent, Deborah Hogan, Dean Madden, George A. O'Toole

Dartmouth Scholarship

Pseudomonas aeruginosa secretes an epoxide hydrolase virulence factor that reduces the apical membrane expression of ABC transporters such as the cystic fibrosis transmembrane conductance regulator (CFTR). This virulence factor, named CFTR inhibitory factor (Cif), is regulated by a TetR-family, epoxide-responsive repressor known as CifR via direct binding and repression. We identified two sites of CifR binding in the intergenic space between cifR and morB, the first gene in the operon containing the cif gene. We have mapped these binding sites and found they are 27 bp in length, and they overlap the -10 and +1 sites of both the cifR …

The Anti-Tumorigenic Mushroom Agaricus Blazei Murill Enhances Il-1Β Production And Activates The Nlrp3 Inflammasome In Human Macrophages, Tsung-Teng Huang, David M. Ojcius, John Ding-E. Young, Yi-Hui Wu, Yun-Fei Ko, Tsui-Yin Wong, Cheng-Yeu Wu, Chia-Chen Lu, Hsin-Chih Lai

All Dugoni School of Dentistry Faculty Articles

Agaricus blazei Murill (AbM) has been reported to possess immune activity against tumors and infections through stimulation of mononuclear phagocytes. Recently, AbM extract was shown to induce the production of the pro-inflammatory cytokine, interleukin-1β (IL-1β), in human monocytes. IL-1β is a key pro-inflammatory cytokine produced by activated macrophages and monocytes and its secretion is strictly controlled by the inflammasome. The purpose of this study is to investigate the effect of AbM water extracts on the regulation of IL-1β production and activation of the NLRP3 inflammasome in human THP-1 macrophages. The NLRP3 inflammasome consists of an NLRP3 receptor, an adaptor protein …

Surveillance Of Mosquitoes For Arthropod-Borne Viruses In El Paso, Tx., Stephanie Coronado, Douglas Watts

COURI Symposium Abstracts, Summer 2012

West Nile encephalitis is the only arthropod-borne virus that causes annual cases of human illness in El Paso, Texas. Cases more commonly affect the young and elderly and the illness may range from a mild febrile disease to fatal encephalitis. The primary vector(s) of West Nile virus are Culex species mosquitoes, including Culex tarsalis and Culex quinquefaciatus. Further, surveillance is needed to determine the relative importance of these and possibly other mosquito species. More recently, cases of dengue fever and fatal hemorrhagic fever have been occurring in communities along the USA-Mexico border. Dengue has been endemic in Mexico since the …

Gastrointestinal Cell Mediated Immunity And The Microsporidia, Magali M. Moretto, Imtiaz A. Khan, Louis M. Weiss

Microbiology, Immunology, and Tropical Medicine Faculty Publications

No abstract provided.

Germline Transgenesis And Insertional Mutagenesis In Schistosoma Mansoni Mediated By Murine Leukemia Virus, Gabriel Rinaldi, Sabine E. Eckert, Isheng J. Tsai, Suttas Suttiprapa, Kristine J. Kines, Jose F. Tort, Victoria H. Mann, Daniel J. Turner, Matthew Berriman, Paul J. Brindley

Microbiology, Immunology, and Tropical Medicine Faculty Publications

Functional studies will facilitate characterization of role and essentiality of newly available genome sequences of the human schistosomes, Schistosoma mansoni, S. japonicum and S. haematobium. To develop transgenesis as a functional approach for these pathogens, we previously demonstrated that pseudotyped murine leukemia virus (MLV) can transduce schistosomes leading to chromosomal integration of reporter transgenes and short hairpin RNA cassettes. Here we investigated vertical transmission of transgenes through the developmental cycle of S. mansoni after introducing transgenes into eggs. Although MLV infection of schistosome eggs from mouse livers was efficient in terms of snail infectivity, >10-fold higher transgene copy …

Microbial Co-Occurrence Relationships In The Human Microbiome, Karoline Faust, J. Fah Sathirapongsasuti, Jacques Izard, Dirk Gevers, Jeroen Raes, Curtis Huttenhower

Department of Food Science and Technology: Faculty Publications

The healthy microbiota show remarkable variability within and among individuals. In addition to external exposures, ecological relationships (both oppositional and symbiotic) between microbial inhabitants are important contributors to this variation. It is thus of interest to assess what relationships might exist among microbes and determine their underlying reasons. The initial Human Microbiome Project (HMP) cohort, comprising 239 individuals and 18 different microbial habitats, provides an unprecedented resource to detect, catalog, and analyze such relationships. Here, we applied an ensemble method based on multiple similarity measures in combination with generalized boosted linear models (GBLMs) to taxonomic marker (16S rRNA gene) profiles …

Lapg, Required For Modulating Biofilm Formation By Pseudomonas Fluorescens Pf0-1, Is A Calcium-Dependent Protease, Chelsea D. Boyd, Debashree Chatterjee, Holger Sondermann, George A. O'Toole

Dartmouth Scholarship

Biofilm formation by Pseudomonas fluorescens Pf0-1 requires the cell surface adhesin LapA. We previously reported that LapG, a periplasmic cysteine protease of P. fluorescens, cleaves the N terminus of LapA, thus releasing this adhesin from the cell surface and resulting in loss of the ability to make a biofilm. The activity of LapG is regulated by the inner membrane-localized cyclic-di-GMP receptor LapD via direct protein-protein interactions. Here we present chelation and metal add-back studies demonstrating that calcium availability regulates biofilm formation by P. fluorescens Pf0-1. The determination that LapG is a calcium-dependent protease, based on in vivo and in vitro …

Structure, Function And Diversity Of The Healthy Human Microbiome, Curtis Huttenhower, Jacques Izard

Department of Food Science and Technology: Faculty Publications

Studies of the human microbiome have revealed that even healthy individuals differ remarkably in the microbes that occupy habitats such as the gut, skin and vagina. Much of this diversity remains unexplained, although diet, environment, host genetics and early microbial exposure have all been implicated. Accordingly, to characterize the ecology of human-associated microbial communities, the Human Microbiome Project has analysed the largest cohort and set of distinct, clinically relevant body habitats so far. We found the diversity and abundance of each habitat’s signature microbes to vary widely even among healthy subjects, with strong niche specialization both within and among individuals. …

Vasa-Like Dead-Box Rna Helicases Of Schistosoma Mansoni, Danielle E. Skinner, Gabriel Rinaldi, Sutas Suttiprapa, Victoria H. Mann, Pablo Smircich, Alexis A. Cogswell, David L. Williams, Paul J. Brindley

Microbiology, Immunology, and Tropical Medicine Faculty Publications

Genome sequences are available for the human blood flukes, Schistosoma japonicum, S. mansoni and S. haematobium. Functional genomic approaches could aid in identifying the role and importance of these newly described schistosome genes. Transgenesis is established for functional genomics in model species, which can lead to gain- or loss-of-functions, facilitate vector-based RNA interference, and represents an effective forward genetics tool for insertional mutagenesis screens. Progress toward routine transgenesis in schistosomes might be expedited if germ cells could be reliably localized in cultured schistosomes. Vasa, a member of the ATP-dependent DEAD-box RNA helicase family, is a prototypic marker of …

Development Of A Protocol To Measure Gene Expression In The Mouse Tibia, Daniel Hoover

Biomedical Engineering

Numerous molecular factors active in bone tissue direct fracture repair and remodeling which can be altered by disease conditions such as Peripheral Arterial Disease (PAD) and Osteoporosis. Methods of molecular biology are commonly applied to investigate the expression and role of these molecular factors. This project presents a robust three-step protocol for examining gene expression in the mouse tibia. The protocol begins with isolating RNA from a flash frozen tibia sample. The isolated RNA is reverse transcribed into cDNA. Finally, PCR is performed to indentify expressed genes. Establishing this protocol will allow further research into the mechanisms of bone remodeling …

Composition Of The Adult Digestive Tract Bacterial Microbiome Based On Seven Mouth Surfaces, Tonsils, Throat And Stool Samples, Nicola Segata, Susan Kinder Haake, Peter Mannon, Katherine P. Lemon, Levi Waldron, Dirk Gevers, Curtis Huttenhower, Jacques Izard

Department of Food Science and Technology: Faculty Publications

Background: To understand the relationship between our bacterial microbiome and health, it is essential to define the microbiome in the absence of disease. The digestive tract includes diverse habitats and hosts the human body’s greatest bacterial density. We describe the bacterial community composition of ten digestive tract sites from more than 200 normal adults enrolled in the Human Microbiome Project, and metagenomically determined metabolic potentials of four representative sites.

Results: The microbiota of these diverse habitats formed four groups based on similar community compositions: buccal mucosa, keratinized gingiva, hard palate; saliva, tongue, tonsils, throat; sub- and supra-gingival plaques; …

Metabolic Reconstruction For Metagenomic Data And Its Application To The Human Microbiome, Sahar Abubucker, Nicola Segata, Johannes Goll, Alyxandria M. Schubert, Jacques Izard, Brandi L. Cantarel, Beltran Rodriguez-Mueller, Jeremy Zucker, Mathangi Thiagarajan, Bernard Henrissat, Owen White, Scott T. Scott, Barbara Methé, Patrick D. Schloss, Dirk Gever, Makedonka Mitreva, Curtis Huttenhower

Department of Food Science and Technology: Faculty Publications

Microbial communities carry out the majority of the biochemical activity on the planet, and they play integral roles in processes including metabolism and immune homeostasis in the human microbiome. Shotgun sequencing of such communities’ metagenomes provides information complementary to organismal abundances from taxonomic markers, but the resulting data typically comprise short reads from hundreds of different organisms and are at best challenging to assemble comparably to single-organism genomes. Here, we describe an alternative approach to infer the functional and metabolic potential of a microbial community metagenome. We determined the gene families and pathways present or absent within a community, as …

Roles Of Resveratrol And Genistein In Invasion And Metastasis Of Breast Cancer, Brittany Wolfe

College of Science and Health Theses and Dissertations

Breast cancer is a cellular disease characterized by the exploitation of several cellular and molecular mechanisms involved in cell proliferation, apoptosis, motility, and invasion. Effective treatment is available for non-invasive breast cancer at diagnosis, leading to a very high survival rate compared to the low survival rate for those where the breast cancer has spread. Thus, identifying effective therapies and preventative agents is imperative to successfully treat breast cancer. Since diet compromises a large component of the risk factors for breast cancer, it would be beneficial to examine dietary compounds that could potentially play a beneficial role in inhibiting cancer …

Risk Factors Associated With Acl Injuries In Females, Kiersten Young, Lindsey Eberman

Symposium 2012

No abstract provided.

Can Slap Lesions Be Clinically Diagnosed?, Eric Bales

Symposium 2012

No abstract provided.

Pv1 Down-Regulation Via Shrna Inhibits The Growth Of Pancreatic Adenocarcinoma Xenografts, Sophie J. Deharvengt, Dan Tse, Olga Sideleva, Caitlin Mcgarry, Jason R. Gunn, Daniel S. Longnecker, Catherine Carriere, Radu V. Stan

Dartmouth Scholarship

PV1 is an endothelial-specific protein with structural roles in the formation of diaphragms in endothelial cells of normal vessels. PV1 is also highly expressed on endothelial cells of many solid tumours. On the basis of in vitro data, PV1 is thought to actively participate in angiogenesis. To test whether or not PV1 has a function in tumour angiogenesis and in tumour growth in vivo, we have treated pancreatic tumour-bearing mice by single-dose intratumoural delivery of lentiviruses encoding for two different shRNAs targeting murine PV1. We find that PV1 down-regulation by shRNAs inhibits the growth of established tumours derived from two …

Corneal Replication Is An Interferon Response-Independent Bottleneck For Virulence Of Herpes Simplex Virus 1 In The Absence Of Virion Host Shutoff, Tracy J. Pasieka, Vineet D. Menachery, Pamela C. Rosato, David A. Leib

Dartmouth Scholarship

Herpes simplex viruses lacking the virion host shutoff function (Δvhs) are avirulent and hypersensitive to type I and type II interferon (IFN). In this study, we demonstrate that even in the absence of IFN responses in AG129 (IFN-αβγR^−/−) mice, Δvhs remains highly attenuated via corneal infection but is fully virulent via intracranial infection. The data demonstrate that the interferon-independent inherent replication defect of Δvhs has a significant impact upon peripheral replication and neuroinvasion.

Elevated Plasma Il-6 Associates With Increased Risk Of Advanced Fibrosis And Cholangiocarcinoma In Individuals Infected By Opisthorchis Viverrini, Banchob Sripa, Bandit Thinkhamrop, Eimorn Mairiang, Thewarach Laha, Sasithorn Kaewkes, Paiboon Sithithaworn, Maria V. Periago, Vajarabhongsa Bhudhisawasdi, Ponlapat Yonglitthipagon, Jason Mulvenna, Paul J. Brindley, Alex Loukas, Jeffrey M. Bethony

Microbiology, Immunology, and Tropical Medicine Faculty Publications

Opisthorchis viverrini is considered among the most important of the food-borne trematodes due to its strong association with advanced periductal fibrosis and bile duct cancer (cholangiocarcinoma). We investigated the relationship between plasma levels of Interleukin (IL)-6 and the risk of developing advanced fibrosis and bile duct cancer from chronic Opisthorchis infection. We show that IL-6 circulates in plasma at concentrations 58 times higher in individuals with advanced fibrosis than age, sex, and nearest-neighbor matched controls and 221 times higher in individuals with bile duct cancer than controls. We also observed a dose-response relationship between increasing levels of plasma IL-6 and …

Environmental Friendly Synthesis, Characterization Of Surface Modifiable Starch Encapsulated Gold Nanoparticles With Bactericidal And Catalytic Activity, Dillon Pender

Mahurin Honors College Capstone Experience/Thesis Projects

In the present study, we report the green synthesis of gold nanoparticles (GNPs), using potato starch as a reducing as well as a stabilizing agent in an aqueous buffer medium. The resulting starch-GNPs (St-GNPs) were near spherical in shape with an average diameter of 15 ± 5 nm. In this approach, St-GNPs were characterized and investigated for their antibacterial properties against both gram negative (Escherichia coli) and gram positive (Staphylococcus epidermidis) bacteria. These St-GNPs were found to possess significant dose dependent antibacterial activity against bacteria. Also, St-GNPs showed a significant catalytic activity and can easily be …

The Prevalence Of Essential Hypertension In Kasigau, Kenya, Lindsay Williams

Mahurin Honors College Capstone Experience/Thesis Projects

Hypertension is the leading cause of cardiovascular disease worldwide. Cardiovascular disease (CVD) is a widespread chronic non-communicable disease (NCD) which is on the rise in developing countries. Evidence based on extensive research studies on risk factors for NCDs suggests that they could be easily significantly decreased by simply controlling their risk factors. Although high blood pressure has been recognized as a leading risk factor for CVD, little research has been done to document the prevalence and incidence of essential hypertension (EH) in lower socioeconomic developing countries. One such country is Kenya. It was found in our research study that Kasigau …

Effects Of Moderate Swim Exercise On Adiposity And Metabolic Function In Mice, Roberta L. Pohlman, Ana Carneiro, Vera Farah, Lynn K. Hartzler, Mariana Morris

Biological Sciences Faculty Publications

No abstract provided.

Biomass Assisted Synthesis Of Antibacterial Gold Nanoparticles And Commentary On Its Future Potential And Applications In Medicine, Chad Willis

Mahurin Honors College Capstone Experience/Thesis Projects

Xylose is a natural monosaccharide found in biomass such as straw, pecan shells, cottonseed hulls, and corncobs. Using this monosaccharide, we report the green synthesis and characterization of biocompatible, biodegradable xylose encapsulated gold nanoparticles (Xyl-GNPs) with potential antibacterial activity. GNPs were synthesized using the bioreduction property of xylose on the chloroaurate anions in an aqueous solution at room temperature and at atmospheric pressure. The characterization of synthesized GNPs was examined by UV-vis spectroscopy; transmission electron microscopy (TEM), energy-dispersive x-ray spectroscopy (EDS) and fourier transform infrared spectroscopy (FTIR). Results indicate that the particles were stable; near spherical in shape with an …