Digital Commons Network^™

Factors Associated With The Acquisition And Severity Of Gestational Listeriosis, M. M. Suyemoto, P. A. Spears, T. S. Hamrick, J. A. Barnes, E. A. Havell, P. E. Orndorff

Osteopathic Medicine, Jerry M. Wallace School of

No abstract provided.

Distinct Macrophage Subpopulations Regulate Viral Encephalitis But Not Viral Clearance In The Cns, Christina D. Steel, Woong-Ki Kim, Larry Sanford, Laurie Wellman, Sandra Burnett, Nico Van Rooijen, Rochard P. Ciavarra

Biological Sciences Faculty Publications

Intranasal application of vesicular stomatitis virus (VSV) induces acute encephalitis characterized by a pronounced myeloid and T cell infiltrate. The role of distinct phagocytic populations on VSV encephalitis was therefore examined in this study. Ablation of peripheral macrophages did not impair VSV encephalitis or viral clearance from the brain, whereas, depletion of splenic marginal dendritic cells impaired this response and enhanced morbidity/mortality. Selective depletion of brain perivascular macrophages also suppressed this response without altering viral clearance. Thus, two anatomically distinct phagocytic populations regulate VSV encephalitis in a non-redundant fashion although neither population is essential for viral clearance in the CNS. …

A Role For The Histone Deacetylase Hdac4 In The Life-Cycle Of Hiv-1-Based Vectors., Johanna A Smith, Jennifer Yeung, Gary D Kao, René Daniel

Department of Medicine Faculty Papers

HIV-1 integration is mediated by the HIV-1 integrase protein, which joins 3'-ends of viral DNA to host cell DNA. To complete the integration process, HIV-1 DNA has to be joined to host cell DNA also at the 5'-ends. This process is called post-integration repair (PIR). Integration and PIR involve a number of cellular co-factors. These proteins exhibit different degrees of involvement in integration and/or PIR. Some are required for efficient integration or PIR. On the other hand, some reduce the efficiency of integration. Finally, some are involved in integration site selection. We have studied the role of the histone deacetylase …

Acaricidal Activity Of Eugenol Based Compounds Against Scabies Mites, Cielo Pasay, Kate Mounsey, Graeme Stevenson, Rohan Davis, Larry G. Arlian, Marjorie Morgan, Diann Vyszenski-Moher, Kathy Andrews, James Mccarthy

Biological Sciences Faculty Publications

Background

Human scabies is a debilitating skin disease caused by the “itch mite” Sarcoptes scabiei. Ordinary scabies is commonly treated with topical creams such as permethrin, while crusted scabies is treated with topical creams in combination with oral ivermectin. Recent reports of acaricide tolerance in scabies endemic communities in Northern Australia have prompted efforts to better understand resistance mechanisms and to identify potential new acaricides. In this study, we screened three essential oils and four pure compounds based on eugenol for acaricidal properties.

Methodology/Principal Findings

Primary Human Mammary Epithelial Cells Endocytose Hiv-1 And Facilitate Viral Infection Of Cd4+ T Lymphocytes, Stephanie M. Dorosko, Ruth I. Connor

Dartmouth Scholarship

The contribution of mammary epithelial cells (MEC) to human immunodeficiency virus type 1 (HIV-1) in breast milk remains largely unknown. While breast milk contains CD4(+) cells throughout the breast-feeding period, it is not known whether MEC directly support HIV-1 infection or facilitate infection of CD4(+) cells in the breast compartment. This study evaluated primary human MEC for direct infection with HIV-1 and for indirect transfer of infection to CD4(+) target cells. Primary human MEC were isolated and assessed for expression of HIV-1 receptors. MEC were exposed to CCR5-, CXCR4- and dual-tropic strains of HIV-1 and evaluated for viral reverse transcription …

The Staphylococcus-Specific Gene Rsr Represses Agr And Virulence In Staphylococcus Aureus, Sandeep Tamber, Dindo Reyes, Niles P. Donegan, Joseph D. Schwartzman, Ambrose L. Cheung, Guido Memmi

Dartmouth Scholarship

The expression of virulence factors in Staphylococcus aureus is tightly coordinated by a vast network of regulatory molecules. In this report, we characterize a genetic locus unique to staphylococci called rsr that has a role in repressing two key virulence regulators, sarR and agr. Using strain SH1000, we showed that the transcription of virulence effectors, such as hla, sspA, and spa, is altered in an rsr mutant in a way consistent with agr upregulation. Analysis of RNAIII expression of the agr locus in rsr and rsr-sarR mutants indicated that rsr likely contributes to agr expression independently …

Mononucleosis And Antigen-Driven T Cell Responses Have Different Requirements For Interleukin-2 Signaling In Murine Gammaherpesvirus Infection, Michael Molloy, Weijun Zhang, Edward Usherwood

Dartmouth Scholarship

Interleukin-2 (IL-2) has been implicated as being necessary for the optimal formation of primary CD8⁺ T cell responses against various pathogens. Here we have examined the role that IL-2 signaling plays in several aspects of a CD8⁺ T cell response against murine gammaherpesvirus 68 (MHV-68). Exposure to MHV-68 causes a persistent infection, along with infectious mononucleosis, providing a model for studying these processes in mice. Our study indicates that CD25 is necessary for optimal expansion of the antigen-specific CD8⁺ T cell response but not for the long-term memory response. Contrastingly, IL-2 signaling through CD25 is absolutely required …

Cross-Reactivity Of Antibodies Against Leptospiral Recurrent Uveitis-Associated Proteins A And B (Lrua And Lrub) With Eye Proteins, Ashutosh Verma, Pawan Kumar, Kelly Babb, John F. Timoney, Brian Stevenson

Microbiology, Immunology, and Molecular Genetics Faculty Publications

Infection by Leptospira interrogans has been causally associated with human and equine uveitis. Studies in our laboratories have demonstrated that leptospiral lipoprotein LruA and LruB are expressed in the eyes of uveitic horses, and that antibodies directed against LruA and LruB react with equine lenticular and retinal extracts, respectively. These reactivities were investigated further by performing immunofluorescent assays on lenticular and retinal tissue sections. Incubation of lens tissue sections with LruA-antiserum and retinal sections with LruB-antiserum resulted in positive fluorescence. By employing two-dimensional gel analyses followed by immunoblotting and mass spectrometry, lens proteins cross-reacting with LruA antiserum were identified to …

Defining The Role Of Il-15 Trans-Presentation By Distinct Cell-Types During The Development And Homeostasis Of Natural Killer And Invariant Natural Killer T Cells, Eliseo F. Castillo

Dissertations and Theses (Open Access)

The immuno-regulatory functions displayed by NK and iNKT cells have highlighted their importance as key lymphocytes involved in innate and adaptive immunity. Therefore, understanding the dynamics influencing the generation of NK and iNKT cells is extremely important. IL-15 has been shown to provide a critical signal throughout the development and homeostasis of NK and iNKT cells; however, the cellular source of IL-15 has remained unclear. In this investigation, I provide evidence that the cell-type providing IL-15 to NK and iNKT cells via trans-presentation is determined by the tissue site and the maturation status of NK and iNKT cells. For NK …

Immune Recognition Of Self Nucleic Acids Driven By Endogenous Antimicrobial Peptides: Role In Autoimmunity, Dipyaman Ganguly

Dissertations and Theses (Open Access)

Innate immune recognition of extracellular host-derived self-DNA and self-RNA is prevented by endosomal seclusion of the Toll-like receptors (TLRs) in the dendritic cells (DCs). However, in psoriasis plasmacytoid dendritic cells have been found to be able to sense self-DNA molecules in complex with the endogenous cationic antimicrobial peptide LL37, which are internalized into the endosomal compartments and thus can access TLR9. We investigated whether this endogenous peptide can also interact with extracellular self-RNA and lead to DC activation. We found that LL37 binds self-RNA as well as self-DNA going into an electrostatic interaction; forms micro-aggregates of nano-scale particles protected from …

Avirulent Uracil Auxotrophs Based On Disruption Of Orotidine-5′-Monophosphate Decarboxylase Elicit Protective Immunity To Toxoplasma Gondii, Barbara A. Fox, David J. Bzik

Dartmouth Scholarship

The orotidine-5'-monophosphate decarboxylase (OMPDC) gene, encoding the final enzyme of the de novo pyrimidine biosynthesis pathway, was deleted using Toxoplasma gondii KU80 knockouts to develop an avirulent nonreverting pyrimidine auxotroph strain. Additionally, to functionally address the role of the pyrimidine salvage pathway, the uridine phosphorylase (UP) salvage activity was knocked out and a double knockout of UP and OMPDC was also constructed. The nonreverting DeltaOMPDC, DeltaUP, and DeltaOMPDC DeltaUP knockout strains were evaluated for pyrimidine auxotrophy, for attenuation of virulence, and for their ability to elicit potent immunity to reinfection. The DeltaUP knockout strain was replication competent and virulent. In …

Human Papillomavirus And Survival Of Patients With Oropharyngeal Cancer., K Kian Ang, Jonathan Harris, Richard Wheeler, Randal Weber, David I Rosenthal, Phuc Felix Nguyen-Tân, William H Westra, Christine H Chung, Richard C Jordan, Charles Lu, Harold Kim, Rita S. Axelrod, Md, C Craig Silverman, Kevin P Redmond, Maura L Gillison

Jefferson Hospital Staff Papers and Presentations

BACKGROUND: Oropharyngeal squamous-cell carcinomas caused by human papillomavirus (HPV) are associated with favorable survival, but the independent prognostic significance of tumor HPV status remains unknown.

METHODS: We performed a retrospective analysis of the association between tumor HPV status and survival among patients with stage III or IV oropharyngeal squamous-cell carcinoma who were enrolled in a randomized trial comparing accelerated-fractionation radiotherapy (with acceleration by means of concomitant boost radiotherapy) with standard-fractionation radiotherapy, each combined with cisplatin therapy, in patients with squamous-cell carcinoma of the head and neck. Proportional-hazards models were used to compare the risk of death among patients with HPV-positive …

Probiotic Therapy - Recruiting Old Friends To Fight New Foes, Roy D. Sleator

Department of Biological Sciences Publications

Against a backdrop of increasing antibiotic resistance, and the emergence of new and evolving pathogens, clinicians are increasingly forced to consider alternative therapies - probiotics are one such alternative.

The Efficacy And Safety Of Insulin-Sensitizing Drugs In Hiv-Associated Lipodystrophy Syndrome: A Meta-Analysis Of Randomized Trials, Siddharth H. Sheth, Robin J. Larson

Dartmouth Scholarship

HIV-associated lipodystrophy syndrome (HALS) is characterized by insulin resistance, abnormal lipid metabolism and redistribution of body fat. To date, there has been no quantitative summary of the effects of insulin sensitizing-agents for the treatment of this challenging problem. We searched MEDLINE, the Cochrane Library, clinical trial registries, conference proceedings and references for randomized trials evaluating rosiglitazone, pioglitazone or metformin in patients with evidence of HALS (last update December 2009). Two reviewers independently abstracted data and assessed quality using a standard form. We contacted authors for missing data and calculated weighted mean differences (WMD) and 95% confidence intervals (CI) for each …

Role Of Pknb Kinase In Antibiotic Resistance And Virulence In Community-Acquired Methicillin-Resistant Staphylococcus Aureus Strain Usa300, S. Tamber, J. Schwartzman, A. L. Cheung

Dartmouth Scholarship

The regulation of cellular processes by eukaryote-like serine/threonine kinases is widespread in bacteria. In the last 2 years, several studies have examined the role of serine/threonine kinases in Staphylococcus aureus on cell wall metabolism, autolysis, and virulence, mostly in S. aureus laboratory isolates in the 8325-4 lineage. In this study, we showed that the pknB gene (also called stk1) of methicillin-resistant S. aureus (MRSA) strain COL and the community-acquired MRSA (CA-MRSA) strain USA300 is involved in cell wall metabolism, with the pknB mutant exhibiting enhanced sensitivity to β-lactam antibiotics but not to other classes of antibiotics, including aminoglycosides, ciprofloxacin, …

Sizing Up Pharmacotherapy For Obesity., Michael A. Valentino, Andre Terzic, Scott A. Waldman

Department of Pharmacology and Experimental Therapeutics Faculty Papers

Obesity has increased over the last 20 years, from a condition affecting only a small portion of populations in developed countries, into a global pandemic. The impact of obesity can be appreciated in the context of the populations at risk, and it is estimated that >1 billion adults worldwide are overweight (BMI >25 kg/m2), 300 million of whom are clinically obese (BMI >30 kg/m2). In the United States, 65% of adults are overweight, and 32.2% of them are obese, a prevalence that has doubled over 20 years. In industrialized countries, obesity rates have tripled, coinciding with adoption of a Western …

Epistatic Relationships Between Sara And Agr In Staphylococcus Aureus Biofilm Formation, Karen E. Beenken, Lara N. Mrak, Linda M. Griffin, Agnieszka K. Zielinska, Lindsey N. Shaw, Kelly C. Rice, Alexander R. Horswill, Kenneth W. Bayles, Mark S. Smeltzer

Molecular Biosciences Faculty Publications

Background: The accessory gene regulator (agr) and staphylococcal accessory regulator (sarA) play opposing roles in Staphylococcus aureus biofilm formation. There is mounting evidence to suggest that these opposing roles are therapeutically relevant in that mutation of agr results in increased biofilm formation and decreased antibiotic susceptibility while mutation of sarA has the opposite effect. To the extent that induction of agr or inhibition of sarA could potentially be used to limit biofilm formation, this makes it important to understand the epistatic relationships between these two loci.

Methodology/Principal Findings: We generated isogenic sarA and agr mutants in clinical isolates of S. …

Pseudomonas Aeruginosa Evasion Of Phagocytosis Is Mediated By Loss Of Swimming Motility And Is Independent Of Flagellum Expression, Eyal Amiel, Rustin R. Lovewell, George A. O'Toole, Deborah A. Hogan, Brent Berwin

Dartmouth Scholarship

Pseudomonas aeruginosa is a pathogenic Gram-negative bacterium that causes severe opportunistic infections in immunocompromised individuals; in particular, severity of infection with P. aeruginosa positively correlates with poor prognosis in cystic fibrosis (CF) patients. Establishment of chronic infection by this pathogen is associated with downregulation of flagellar expression and of other genes that regulate P. aeruginosa motility. The current paradigm is that loss of flagellar expression enables immune evasion by the bacteria due to loss of engagement by phagocytic receptors that recognize flagellar components and loss of immune activation through flagellin-mediated Toll-like receptor (TLR) signaling. In this work, we employ bacterial …

Organophosphorus Pesticides Decrease M2 Muscarinic Receptor Function In Guinea Pig Airway Nerves Via Indirect Mechanisms, Becky J. Proskocil, Donald A. Bruun, Charles M. Thompson, Allison D. Fryer, Pamela J. Lein

Biomedical and Pharmaceutical Sciences Faculty Publications

Background: Epidemiological studies link organophosphorus pesticide (OP) exposures to asthma, and we have shown that the OPs chlorpyrifos, diazinon and parathion cause airway hyperreactivity in guinea pigs 24 hr after a single subcutaneous injection. OP-induced airway hyperreactivity involves M2 muscarinic receptor dysfunction on airway nerves independent of acetylcholinesterase (AChE) inhibition, but how OPs inhibit neuronal M2 receptors in airways is not known. In the central nervous system, OPs interact directly with neurons to alter muscarinic receptor function or expression; therefore, in this study we tested whether the OP parathion or its oxon metabolite, paraoxon, might decrease M2 receptor function on …

Immunomodulatory Properties Of Noni (Morinda Citrifolia), Madhukar Lohani

All Theses

Noni (Morinda citrifolia) is a popular medicinal plant of family Rubiaceae. Its fruit is rich in various phytochemicals and polysaccharides. Anecdotal evidence indicates that it was used to stimulate the immune system and, thus, to fight various infections. Limited in vitro studies also support the immunomodulatory role of Noni, however only one study utilized an animal model. The purpose of this study was to examine the immunomodulatory properties of Noni fruit the broiler chicken.
Different concentrations of dietary Noni were added to diets and fed to day-old broiler chickens for 3 to 6 weeks. Gut tissue and blood were sampled …

Use Of An Animal Model To Explore Prenatal Predictors Of Insulin And Glucose Metabolism In Southwestern Alaskan Yupiit, Julie Jo Kachinski

UNLV Theses, Dissertations, Professional Papers, and Capstones

Compared to other North American indigenous populations, Southwest Alaskan Yupiit exhibit very low rates of type 2 diabetes despite the occurrence of common risk factors. Contemporary Yupiit obtain a substantial portion of their calories from traditional foods, which contain high amounts of omega-3 polyunsaturated fatty acids. Epidemiological and experimental animal research has linked glucose and insulin homeostasis with a diet high in omega-3s. This study used an experimental animal model to explore potential diabetes protective effects (for adult offspring) of prenatal maternal nutrition modeled on traditional locally-obtained Yupiit diets. The results of this study showed that the adult offspring whose …

Systems Biology Approach To Identifying Host Interactive Pathways Modulating The Severity Of Streptococcal Sepsis, Nourtan Fatthy Abdeltawab

Theses and Dissertations (ETD)

Clinical outcomes of infectious diseases are controlled by complex interactions between the host and the pathogen. Epidemiological, genetic and molecular studies in my mentor’s laboratory provided evidence that in invasive Group A streptococcal (GAS) infections, genetic variations in both bacteria and patients influenced the severity of GAS sepsis. Allelic variations in class II human leukocyte antigens (HLA) contributed significantly to differences in the severity of group A streptococcal sepsis caused by the same virulent strain of the bacteria. HLA class II molecules present streptococcal superantigens (SAgs) to T cells, and variations in HLA class II molecules can strongly influence SAg …

The Role Of Map Kinases On The Functional Heterogeneity Of Human Cd8+ T Cell Maturation Subsets, Tae Kon Kim

Dissertations and Theses (Open Access)

While prior studies have focused on naïve (CD45RA+CD27+) and early stage memory (CD45RA-CD27+) CD8+ T cells, late memory CD8+ T cells (CD45RA+CD27) have received less interest because this subset of T cells is generally recognized as effectors, which produce IFNγ (but no IL-2) and perforin. However, multiple studies suggest that late memory CD8+ T cells may provide inadequate protection in infectious diseases and cancer models.

To better understand the unique function of late memory CD8+ T cells, I optimized multi-color flow cytometry techniques to assess the cytokine production of each human CD8+ T cell maturation subset. I demonstrated that late …

Aspergillus Fumigatus Stimulates The Nlrp3 Inflammasome Through A Pathway Requiring Ros Production And The Syk Tyrosine Kinase, Najwane Saïd-Sadier, Eduardo V. Padilla, Gordon Langsley, David M. Ojcius

All Dugoni School of Dentistry Faculty Articles

Invasive aspergillosis (IA) is a life-threatening disease that occurs in immunodepressed patients when infected with Aspergillus fumigatus. This fungus is the second most-common causative agent of fungal disease after Candida albicans. Nevertheless, much remains to be learned about the mechanisms by which A. fulmigatus activates the innate immune system. We investigated the inflammatory response to conidia and hyphae of A. fumigatus and specifically, their capacity to trigger activation of an inflammasome. Our results show that in contrast to conidia, hyphal fragments induce NLRP3 inflammasome assembly, caspase-1 activation and IL-1β release from a human monocyte cell line. The ability of Aspergillus …

Paracoccidiomycosis And Hiv/Aids: A Common Problem In An Uncommon Location, Astrid Radermacher Do, Joseph L. Yozviak Do, Facp, Marcelo Gareca Md

Department of Medicine

No abstract provided.

Role Of All Of The Prrsv Glycoproteins In Protective Immune Response, Asit K. Pattnaik

School of Veterinary and Biomedical Sciences: Faculty Publications

Porcine reproductive and respiratory syndrome virus (PRRSV) contains the major glycoprotein, GP5, as well as three other minor glycoproteins, namely, GP2a, GP3, and GP4, on the virion envelope, all of which are required for generation of infectious virions. To study their interactions amongst each other and with the cellular receptor for PRRSV, we have cloned each of the viral glycoproteins and CD163 receptor in expression vectors and examined their expression and interaction with each other in transfected cells by co-immunoprecipitation (co-IP) assay using monospecific antibodies. Our results show that strong interaction exists between GP4 and GP5 proteins, although weak interactions …

Cell-Type Specific Distribution Of Chloride Transporters In The Rat Suprachiasmatic Nucleus, Michael A. Belenky, Patricia J. Sollars, David B. Mount, Seth L. Alper, Yosef Yarom, Gary E. Pickard

School of Veterinary and Biomedical Sciences: Faculty Publications

The suprachiasmatic nucleus (SCN) is a circadian oscillator and biological clock. Cell-to-cell communication is important for synchronization among SCN neuronal oscillators and the great majority of SCN neurons use γ-aminobutyric acid (GABA) as a neurotransmitter, the principal inhibitory neurotransmitter in the adult central nervous system. Acting via the ionotropic GABAA receptor, a chloride ion channel, GABA typically evokes inhibitory responses in neurons via Cl− influx. Within the SCN GABA evokes both inhibitory and excitatory responses although the mechanism underlying GABA-evoked excitation in the SCN is unknown. GABA-evoked depolarization in immature neurons in several regions of the brain is a function …

Structure Of Vibrio Cholerae Toxt Reveals A Mechanism For Fatty Acid Regulation Of Virulence Genes, Michael J. Lowden, Karen Skorupski, Maria Pellegrini, Michael G. Chiorazzo, Ronald K. Taylor, F. Jon Kull

Dartmouth Scholarship

Cholera is an acute intestinal infection caused by the bacterium Vibrio cholerae. In order for V. cholerae to cause disease, it must produce two virulence factors, the toxin-coregulated pilus (TCP) and cholera toxin (CT), whose expression is controlled by a transcriptional cascade culminating with the expression of the AraC-family regulator, ToxT. We have solved the 1.9 A resolution crystal structure of ToxT, which reveals folds in the N- and C-terminal domains that share a number of features in common with AraC, MarA, and Rob as well as the unexpected presence of a buried 16-carbon fatty acid, cis-palmitoleate. The finding that …

Porcine Reproductive And Respiratory Syndrome Virus Nonstructural Protein 1Β Modulates Host Innate Immune Response By Antagonizing Irf3 Activation, Lalit Beura, Saumendra Sarkar, Byungjoon Kwon, Sakthivel Subramaniam, Clinton J. Jones, Asit K. Pattnaik, Fernando A. Osorio

School of Veterinary and Biomedical Sciences: Faculty Publications

Porcine reproductive and respiratory syndrome virus (PRRSV) infection of swine leads to a serious disease characterized by a delayed and defective adaptive immune response. It is hypothesized that a suboptimal innate immune response is responsible for the disease pathogenesis. In the study presented here we tested this hypothesis and identified several nonstructural proteins (NSPs) with innate immune evasion properties encoded by the PRRS viral genome. Four of the total ten PRRSV NSPs tested were found to have strong to moderate inhibitory effects on beta interferon (IFN-β) promoter activation. The strongest inhibitory effect was exhibited by NSP1 followed by, NSP2, NSP11, …

The Minor Envelope Glycoproteins Gp2a And Gp4 Of Porcine Reproductive And Respiratory Syndrome Virus Interact With The Receptor Cd163, Phani B. Das, Phat X. Dinh, Israrul H. Ansari, Marcelo De Lima, Fernando A. Osorio, Asit K. Pattnaik

School of Veterinary and Biomedical Sciences: Faculty Publications

Porcine reproductive and respiratory syndrome virus (PRRSV) contains the major glycoprotein, GP5, as well as three other minor glycoproteins, namely, GP2a, GP3, and GP4, on the virion envelope, all of which are required for generation of infectious virions. To study their interactions with each other and with the cellular receptor for PRRSV, we have cloned each of the viral glycoproteins and CD163 receptor in expression vectors and examined their expression and interaction with each other in transfected cells by coimmunoprecipitation (co-IP) assay using monospecific antibodies. Our results show that a strong interaction exists between the GP4 and GP5 proteins, although …