Open Access. Powered by Scholars. Published by Universities.®

Medicine and Health Sciences Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 30 of 33

Full-Text Articles in Medicine and Health Sciences

Acute Hypersensitivity Of Pluripotent Testicular Cancer-Derived Embryonal Carcinoma To Low-Dose 5-Aza Deoxycytidine Is Associated With Global Dna Damage-Associated P53 Activation, Anti-Pluripotency And Dna Demethylation, Bijesh K. Biswal, Maroun J. Beyrouthy, Mary P. Hever-Jardine, David Armstrong, Craig R. Tomlinson, Brock C. Christensen, Carmen J. Marsit, Michael J. Spinella Dec 2012

Acute Hypersensitivity Of Pluripotent Testicular Cancer-Derived Embryonal Carcinoma To Low-Dose 5-Aza Deoxycytidine Is Associated With Global Dna Damage-Associated P53 Activation, Anti-Pluripotency And Dna Demethylation, Bijesh K. Biswal, Maroun J. Beyrouthy, Mary P. Hever-Jardine, David Armstrong, Craig R. Tomlinson, Brock C. Christensen, Carmen J. Marsit, Michael J. Spinella

Dartmouth Scholarship

Human embryonal carcinoma (EC) cells are the stem cells of nonseminoma testicular germ cells tumors (TGCTs) and share remarkable similarities to human embryonic stem (ES) cells. In prior work we found that EC cells are hypersensitive to low nanomolar doses of 5-aza deoxycytidine (5-aza) and that this hypersensitivity partially depended on unusually high levels of the DNA methyltransferase, DNMT3B. We show here that low-dose 5-aza treatment results in DNA damage and induction of p53 in NT2/D1 cells. In addition, low-dose 5-aza results in global and gene specific promoter DNA hypomethylation. Low- dose 5-aza induces a p53 transcriptional signature distinct from …


Multiple Subject Barycentric Discriminant Analysis (Musubada): How To Assign Scans To Categories Without Using Spatial Normalization, Hervé Abdi, Lynne J. Williams, Andrew C. Connolly, M. Ida Gobbini Dec 2012

Multiple Subject Barycentric Discriminant Analysis (Musubada): How To Assign Scans To Categories Without Using Spatial Normalization, Hervé Abdi, Lynne J. Williams, Andrew C. Connolly, M. Ida Gobbini

Dartmouth Scholarship

We present a new discriminant analysis (DA) method called Multiple Subject Barycentric Discriminant Analysis (MUSUBADA) suited for analyzing fMRI data because it handles datasets with multiple participants that each provides different number of variables (i.e., voxels) that are themselves grouped into regions of interest (ROIs). Like DA, MUSUBADA (1) assigns observations to predefined categories, (2) gives factorial maps displaying observations and categories, and (3) optimally assigns observations to categories. MUSUBADA handles cases with more variables than observations and can project portions of the data table (e.g., subtables, which can represent participants or ROIs) on the factorial maps. Therefore MUSUBADA can …


Microrna Mir-155 Affects Antiviral Effector And Effector Memory Cd8 T Cell Differentiation, Ching-Yi Tsai, S. Rameeza Allie, Weijun Zhang, Edward J. Usherwood Dec 2012

Microrna Mir-155 Affects Antiviral Effector And Effector Memory Cd8 T Cell Differentiation, Ching-Yi Tsai, S. Rameeza Allie, Weijun Zhang, Edward J. Usherwood

Dartmouth Scholarship

MicroRNAs are key regulators of the immune response, but their role in CD8 T cell differentiation in vivo is not known. We show that miR-155 is important in both effector and memory antiviral CD8 T cell responses. Without miR-155, there was a weaker effector response and a skewing toward memory precursor cells. At the memory stage, miR-155-deficient CD8 T cells preferentially differentiated into central memory cells and were capable of mounting a potent secondary response.


Myeloid-Derived Suppressor Cells In Murine Retrovirus-Induced Aids Inhibit T- And B-Cell Responses In Vitro That Are Used To Define The Immunodeficiency, Kathy A. Green, W. James Cook, William R. Green Dec 2012

Myeloid-Derived Suppressor Cells In Murine Retrovirus-Induced Aids Inhibit T- And B-Cell Responses In Vitro That Are Used To Define The Immunodeficiency, Kathy A. Green, W. James Cook, William R. Green

Dartmouth Scholarship

Myeloid-derived suppressor cells (MDSCs) have been characterized in several disease settings, especially in many tumor systems. Compared to their involvement in tumor microenvironments, however, MDSCs have been less well studied in their responses to infectious disease processes, in particular to retroviruses that induce immunodeficiency. Here, we demonstrate for the first time the development of a highly immunosuppressive MDSC population that is dependent on infection by the LP-BM5 retrovirus, which causes murine acquired immunodeficiency. These MDSCs express a cell surface marker signature (CD11b Gr-1 Ly6C ) characteristic of monocyte-type MDSCs. Such MDSCs profoundly inhibit immune responsiveness by a cell dose- and …


Comparative Study Of Influenza Virus Replication In Mdck Cells And In Primary Cells Derived From Adenoids And Airway Epithelium, Natalia A. Ilyushina, Mine R. Ikizler, Yoshihiro Kawaoka, Larisa G. Rudenko Nov 2012

Comparative Study Of Influenza Virus Replication In Mdck Cells And In Primary Cells Derived From Adenoids And Airway Epithelium, Natalia A. Ilyushina, Mine R. Ikizler, Yoshihiro Kawaoka, Larisa G. Rudenko

Dartmouth Scholarship

Although clinical trials with human subjects are essential for determination of safety, infectivity, and immunogenicity, it is de- sirable to know in advance the infectiousness of potential candidate live attenuated influenza vaccine strains for human use. We compared the replication kinetics of wild-type and live attenuated influenza viruses, including H1N1, H3N2, H9N2, and B strains, in Madin-Darby canine kidney (MDCK) cells, primary epithelial cells derived from human adenoids, and human bron- chial epithelium (NHBE cells). Our data showed that despite the fact that all tissue culture models lack a functional adaptive im- mune system, differentiated cultures of human epithelium exhibited …


Regulatory T-Cells And Associated Pathways In Metastatic Renal Cell Carcinoma (Mrcc) Patients Undergoing Dc-Vaccination And Cytokine-Therapy, Adrian Schwarzer, Benita Wolf, Jan L. Fisher, Thomas Schwaab, Sven Olek, Udo Baron, Craig R. Tomlinson, John D. Seigne, Nancy A. Crosby, Jiang Gui, Thomas H. Hampton, Camilo E. Fadul, John A. Heaney, Marc S. Ernstoff Oct 2012

Regulatory T-Cells And Associated Pathways In Metastatic Renal Cell Carcinoma (Mrcc) Patients Undergoing Dc-Vaccination And Cytokine-Therapy, Adrian Schwarzer, Benita Wolf, Jan L. Fisher, Thomas Schwaab, Sven Olek, Udo Baron, Craig R. Tomlinson, John D. Seigne, Nancy A. Crosby, Jiang Gui, Thomas H. Hampton, Camilo E. Fadul, John A. Heaney, Marc S. Ernstoff

Dartmouth Scholarship

Purpose: To evaluate CD4+CD25+FOXP3+ T regulatory cells (TREG) and associated immune-regulatory pathways in peripheral blood lymphocytes (PBL) of metastatic renal cell carcinoma (mRCC) patients and healthy volunteers. We subsequently investigated the effects of immunotherapy on circulating TREG combining an extensive phenotype examination, DNA methylation analysis and global transcriptome analysis.

Design: Eighteen patients with mRCC and twelve volunteers (controls) were available for analysis. TREG phenotype was examined using flow cytometry (FCM). TREG were also quantified by analyzing the epigenetic status of the FOXP3 locus using methylation specific PCR. As a third approach, RNA of the PBL was hybridized to Affymetrix GeneChip …


Genetic Association Analysis Of Complex Diseases Incorporating Intermediate Phenotype Information, Yafang Li, Jian Huang, Christopher I. Amos Oct 2012

Genetic Association Analysis Of Complex Diseases Incorporating Intermediate Phenotype Information, Yafang Li, Jian Huang, Christopher I. Amos

Dartmouth Scholarship

Genetic researchers often collect disease related quantitative traits in addition to disease status because they are interested in understanding the pathophysiology of disease processes. In genome-wide association (GWA) studies, these quantitative phenotypes may be relevant to disease development and serve as intermediate phenotypes or they could be behavioral or other risk factors that predict disease risk. Statistical tests combining both disease status and quantitative risk factors should be more powerful than case-control studies, as the former incorporates more information about the disease. In this paper, we proposed a modified inverse-variance weighted meta-analysis method to combine disease status and quantitative intermediate …


Thr 163 Phosphorylation Causes Mcl-1 Stabilization When Degradation Is Independent Of The Adjacent Gsk3-Targeted Phosphodegron, Promoting Drug Resistance In Cancer, Shanna K. Nifoussi, Julie A. Vrana, Aaron M. Domina, Alfredo De Biasio, Jingang Gui, Mark A. Gregory, Stephen R. Hann, Ruth W. Craig Oct 2012

Thr 163 Phosphorylation Causes Mcl-1 Stabilization When Degradation Is Independent Of The Adjacent Gsk3-Targeted Phosphodegron, Promoting Drug Resistance In Cancer, Shanna K. Nifoussi, Julie A. Vrana, Aaron M. Domina, Alfredo De Biasio, Jingang Gui, Mark A. Gregory, Stephen R. Hann, Ruth W. Craig

Dartmouth Scholarship

The antiapoptotic Bcl-2 family member Mcl-1 is a PEST protein (containing sequences enriched in proline, glutamic acid, serine, and threonine) and is subject to rapid degradation via multiple pathways. Impaired degradation leading to the maintenance of Mcl-1 expression is an important determinant of drug resistance in cancer. Phosphorylation at Thr 163 in the PEST region, stimulated by 12-O-tetradecanoylphorbol acetic acid (TPA)-induced activation of extracellular signal-regulated kinase (ERK), is associated with Mcl-1 stabilization in BL41-3 Burkitt lymphoma cells. This contrasts with the observation that Thr 163 phosphorylation in normal fibroblasts primes glycogen synthase kinase (GSK3)-induced phosphorylation at Ser 159, producing a …


Influenza-Infected Neutrophils Within The Infected Lungs Act As Antigen Presenting Cells For Anti-Viral Cd8+ T Cells, Matthew M. Hufford, Graham Richardson, Haixia Zhou, Balaji Manicassamy, Adolfo Garcia-Sastre, Richard I. Enelow, Thomas J. Braciale Oct 2012

Influenza-Infected Neutrophils Within The Infected Lungs Act As Antigen Presenting Cells For Anti-Viral Cd8+ T Cells, Matthew M. Hufford, Graham Richardson, Haixia Zhou, Balaji Manicassamy, Adolfo Garcia-Sastre, Richard I. Enelow, Thomas J. Braciale

Dartmouth Scholarship

Influenza A virus (IAV) is a leading cause of respiratory tract disease worldwide. Anti-viral CD8+ T lymphocytes responding to IAV infection are believed to eliminate virally infected cells by direct cytolysis but may also contribute to pulmonary inflammation and tissue damage via the release of pro-inflammatory mediators following recognition of viral antigen displaying cells. We have previously demonstrated that IAV antigen expressing inflammatory cells of hematopoietic origin within the infected lung interstitium serve as antigen presenting cells (APC) for infiltrating effector CD8+ T lymphocytes; however, the spectrum of inflammatory cell types capable of serving as APC was not …


Herpes Simplex Virus 34.5 Interferes With Autophagosome Maturation And Antigen Presentation In Dendritic Cells, Philipe A. M. Gobeil, David A. Leib Sep 2012

Herpes Simplex Virus 34.5 Interferes With Autophagosome Maturation And Antigen Presentation In Dendritic Cells, Philipe A. M. Gobeil, David A. Leib

Dartmouth Scholarship

The cellular autophagy response induced by herpes simplex virus 1 (HSV-1) is countered by the viral γ34.5 protein. γ34.5 modulates autophagy by binding to the host autophagy protein Beclin-1 and through this binding inhibits the formation of autophagosomes in fibroblasts and neurons. In contrast, in this study dendritic cells (DCs) infected with HSV-1 showed an accumulation of autophagosomes and of the long-lived protein p62. No such accumulations were observed in DCs infected with a γ34.5-null virus or a virus lacking the Beclin-binding domain (BBD) of γ34.5. To explore this further, we established stably transduced DC lines to show that γ34.5 …


Tryptophan Hydroxylase-1 Regulates Immune Tolerance And Inflammation, Elizabeth C. Nowak, Victor C. De Vries, Anna Wasiuk, Cory Ahonen, Kathryn A. Bennett, Isabelle Le Mercier, Dae-Gon Ha, Randolph J. Noelle Aug 2012

Tryptophan Hydroxylase-1 Regulates Immune Tolerance And Inflammation, Elizabeth C. Nowak, Victor C. De Vries, Anna Wasiuk, Cory Ahonen, Kathryn A. Bennett, Isabelle Le Mercier, Dae-Gon Ha, Randolph J. Noelle

Dartmouth Scholarship

Nutrient deprivation based on the loss of essential amino acids by catabolic enzymes in the microenvironment is a critical means to control in ammatory responses and immune tolerance. Here we report the novel nding that Tph-1 (tryptophan hydroxylase-1), a synthase which catalyses the conversion of tryptophan to serotonin and exhausts tryptophan, is a potent regulator of immunity. In models of skin allograft tolerance, tumor growth, and experimental autoimmune encephalomyelitis, Tph-1 de ciency breaks allograft tolerance, induces tumor remission, and intensi es neuroin ammation, respectively. All of these effects of Tph-1 de ciency are independent of its downstream product serotonin. Because …


Serial Analysis Of The Gut And Respiratory Microbiome In Cystic Fibrosis In Infancy: Interaction Between Intestinal And Respiratory Tracts And Impact Of Nutritional Exposures, J. C. Madan, D. C. Koestler, B. A. Stanton, L. Davidson, L. A. Moulton, M. L. Housman, J. H. Moore, M. F. Guill, H. G. Morrison, M. L. Sogin, T. H. Hampton, M. R. Karagas, P. E. Palumbo, J. A. Foster, P. L. Hibberd, G. A. O’Toole Aug 2012

Serial Analysis Of The Gut And Respiratory Microbiome In Cystic Fibrosis In Infancy: Interaction Between Intestinal And Respiratory Tracts And Impact Of Nutritional Exposures, J. C. Madan, D. C. Koestler, B. A. Stanton, L. Davidson, L. A. Moulton, M. L. Housman, J. H. Moore, M. F. Guill, H. G. Morrison, M. L. Sogin, T. H. Hampton, M. R. Karagas, P. E. Palumbo, J. A. Foster, P. L. Hibberd, G. A. O’Toole

Dartmouth Scholarship

Pulmonary damage caused by chronic colonization of the cystic fibrosis (CF) lung by microbial communities is the proximal cause of respiratory failure. While there has been an effort to document the microbiome of the CF lung in pediatric and adult patients, little is known regarding the developing microflora in infants. We examined the respiratory and intestinal microbiota development in infants with CF from birth to 21 months. Distinct genera dominated in the gut compared to those in the respiratory tract, yet some bacteria overlapped, demonstrating a core microbiota dominated by Veillonella and Streptococcus. Bacterial diversity increased significantly over time, …


Microbiological Components In Mainstream And Sidestream Cigarette Smoke, Lennart Larsson, Christina Pehrson, Tenzin Dechen, Mardi Crane-Godreau Aug 2012

Microbiological Components In Mainstream And Sidestream Cigarette Smoke, Lennart Larsson, Christina Pehrson, Tenzin Dechen, Mardi Crane-Godreau

Dartmouth Scholarship

Research has shown that tobacco smoke contains substances of microbiological origin such as ergosterol (a fungal membrane lipid) and lipopolysaccharide (LPS) (in the outer membrane of Gram-negative bacteria). The aim of the present study was to compare the amounts of ergosterol and LPS in the tobacco and mainstream (MS) and sidestream (SS) smoke of some popular US cigarettes. We measured LPS 3-hydroxy fatty acids and fungal biomass biomarker ergosterol in the tobacco and smoke from cigarettes of 11 popular brands purchased in the US. University of Kentucky reference cigarettes were also included for comparison.


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 Aug 2012

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 …


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 Aug 2012

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 …


Measurement Of The Oxidation State Of Mitochondrial Cytochrome C From The Neocortex Of The Mammalian Brain, Y. Sakata, M. Abajian, M. O. Ripple, R. Springett Aug 2012

Measurement Of The Oxidation State Of Mitochondrial Cytochrome C From The Neocortex Of The Mammalian Brain, Y. Sakata, M. Abajian, M. O. Ripple, R. Springett

Dartmouth Scholarship

Diffuse optical remission spectra from the mammalian neocortex at visible wavelengths contain spectral features originating from the mitochondria. A new algorithm is presented, based on analytically relating the first differential of the attenuation spectrum to the first differential of the chromophore spectra, that can separate and calculate the oxidation state of cytochrome c as well as the absolute concentration and saturation of hemoglobin. The algorithm is validated in phantoms and then tested on the neocortex of the rat during an anoxic challenge. Implementation of the algorithm will provide detailed information of mitochondrial oxygenation and mitochondrial function in physiological studies of …


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 Jul 2012

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 …


Prevalence Of Streptococci And Increased Polymicrobial Diversity Associated With Cystic Fibrosis Patient Stability, L. M. Filkins, T. H. Hampton, A. H. Gifford, M. J. Gross, D. A. Hogan, M. L. Sogin, H. G. Morrison, B. J. Paster, G. A. O'Toole Jun 2012

Prevalence Of Streptococci And Increased Polymicrobial Diversity Associated With Cystic Fibrosis Patient Stability, L. M. Filkins, T. H. Hampton, A. H. Gifford, M. J. Gross, D. A. Hogan, M. L. Sogin, H. G. Morrison, B. J. Paster, G. A. O'Toole

Dartmouth Scholarship

Diverse microbial communities chronically colonize the lungs of cystic fibrosis patients. Pyrosequencing of amplicons for hypervariable regions in the 16S rRNA gene generated taxonomic profiles of bacterial communities for sputum genomic DNA samples from 22 patients during a state of clinical stability (outpatients) and 13 patients during acute exacerbation (inpatients). We employed quantitative PCR (qPCR) to confirm the detection of Pseudomonas aeruginosa and Streptococcus by the pyrosequencing data and human oral microbe identification microarray (HOMIM) analysis to determine the species of the streptococci identified by pyrosequencing. We show that outpatient sputum samples have significantly higher bacterial diversity than inpatients, but …


Associations Between Toenail Arsenic Concentration And Dietary Factors In A New Hampshire Ppopulation, Joann F. Gruber, Margaret R. Karagas, Diane Gilbert-Diamond, Pamela J. Bagley, M Scot Zens, Vicki Sayarath, Tracy Punshon, J Steven Morris, Kathryn L. Cottingham Jun 2012

Associations Between Toenail Arsenic Concentration And Dietary Factors In A New Hampshire Ppopulation, Joann F. Gruber, Margaret R. Karagas, Diane Gilbert-Diamond, Pamela J. Bagley, M Scot Zens, Vicki Sayarath, Tracy Punshon, J Steven Morris, Kathryn L. Cottingham

Dartmouth Scholarship

Background: Dietary factors such as folate, vitamin B12, protein, and methionine are important for the excretion of arsenic via one-carbon metabolism in undernourished populations exposed to high levels of arsenic via drinking water. However, the effects of dietary factors on toenail arsenic concentrations in well-nourished populations exposed to relatively low levels of water arsenic are unknown.

Methods: As part of a population-based case-control study of skin and bladder cancer from the USA, we evaluated relationships between consumption of dietary factors and arsenic concentrations in toenail clippings. Consumption of each dietary factor was determined from a validated food frequency questionnaire. We …


Cofactor Molecules Maintain Infectious Conformation And Restrict Strain Properties In Purified Prions, Nathan R. Deleault, Daniel J. Walsh, Justin R. Piro, Fei Wang, Xinhe Wang, Jiyan Ma, Judy R. Rees, Surachai Supattapone Jun 2012

Cofactor Molecules Maintain Infectious Conformation And Restrict Strain Properties In Purified Prions, Nathan R. Deleault, Daniel J. Walsh, Justin R. Piro, Fei Wang, Xinhe Wang, Jiyan Ma, Judy R. Rees, Surachai Supattapone

Dartmouth Scholarship

No abstract provided.


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 Jun 2012

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 …


Med5(Nut1) And Med17(Srb4) Are Direct Targets Of Mediator Histone H4 Tail Interactions, Zhongle Liu, Lawrence C. Myers Jun 2012

Med5(Nut1) And Med17(Srb4) Are Direct Targets Of Mediator Histone H4 Tail Interactions, Zhongle Liu, Lawrence C. Myers

Dartmouth Scholarship

The Mediator complex transmits activation signals from DNA bound transcription factors to the core transcription machinery. In addition to its canonical role in transcriptional activation, recent studies have demonstrated that S. cerevisiae Mediator can interact directly with nucleosomes, and their histone tails. Mutations in Mediator subunits have shown that Mediator and certain chromatin structures mutually impact each other structurally and functionally in vivo. We have taken a UV photo cross-linking approach to further delineate the molecular basis of Mediator chromatin interactions and help determine whether the impact of certain Mediator mutants on chromatin is direct. Specifically, by using histone …


Selective Impact Of Hiv Disease Progression On The Innate Immune System In The Human Female Reproductive Tract, Timothy Lahey, Mimi Ghosh, John V. Fahey, Zheng Shen, Lucy R. Mukura, Yan Song, Susan Cu-Uvin, Kenneth H. Mayer, Peter F. Wright, John C. Kappes, Christina Ochsenbauer, Charles R. Wira Jun 2012

Selective Impact Of Hiv Disease Progression On The Innate Immune System In The Human Female Reproductive Tract, Timothy Lahey, Mimi Ghosh, John V. Fahey, Zheng Shen, Lucy R. Mukura, Yan Song, Susan Cu-Uvin, Kenneth H. Mayer, Peter F. Wright, John C. Kappes, Christina Ochsenbauer, Charles R. Wira

Dartmouth Scholarship

Background: We have previously demonstrated intrinsic anti-HIV activity in cervicovaginal lavage (CVL) from HIV-infected women with high CD4 counts and not on antiretroviral therapy. However, the impact of HIV disease progression on CVL innate immune responses has not been delineated.

Methods: CVL from 57 HIV-infected women not on antiretroviral therapy were collected by washing the cervicovaginal area with 10 ml of sterile normal saline. We characterized subject HIV disease progression by CD4 count strata: >500 cells/µl, 200-500 cells/µl, or <200 cells/µl of blood. To assess CVL anti-HIV activity, we incubated TZM-bl cells with HIV plus or minus CVL. Antimicrobials, cytokines, chemokines and anti-gp160 HIV IgG antibodies were measured by ELISA and Luminex.


Molecular Epidemiology Of Hiv-Associated Tuberculosis In Dar Es Salaam, Tanzania: Strain Predominance, Clustering, And Polyclonal Disease, Lisa V. Adams, Barry N. Kreiswirth, Robert D. Arbeit, Hanna Soini, Lillian Mtei, Mecky Matee, Muhammad Bakari, Timothy Lahey, Wendy Wieland-Alter May 2012

Molecular Epidemiology Of Hiv-Associated Tuberculosis In Dar Es Salaam, Tanzania: Strain Predominance, Clustering, And Polyclonal Disease, Lisa V. Adams, Barry N. Kreiswirth, Robert D. Arbeit, Hanna Soini, Lillian Mtei, Mecky Matee, Muhammad Bakari, Timothy Lahey, Wendy Wieland-Alter

Dartmouth Scholarship

Molecular typing of Mycobacterium tuberculosis can be used to elucidate the epidemiology of tuberculosis, including the rates of clustering, the frequency of polyclonal disease, and the distribution of genotypic families. We performed IS6110 typing and spoligotyping on M. tuberculosis strains isolated from HIV-infected subjects at baseline or during follow-up in the DarDar Trial in Tanzania and on selected community isolates. Clustering occurred in 203 (74%) of 275 subjects: 124 (80%) of 155 HIV-infected subjects with baseline isolates, 56 (69%) of 81 HIV-infected subjects with endpoint isolates, and 23 (59%) of 39 community controls. Overall, 113 (41%) subjects had an …


Isolation Of Phosphatidylethanolamine As A Solitary Cofactor For Prion Formation In The Absence Of Nucleic Acids, Nathan R. Deleault, Justin R. Piro, Daniel J. Walsh, Fei Wang, Jiyan Ma, James C. Geoghegan, Surachai Supattapone May 2012

Isolation Of Phosphatidylethanolamine As A Solitary Cofactor For Prion Formation In The Absence Of Nucleic Acids, Nathan R. Deleault, Justin R. Piro, Daniel J. Walsh, Fei Wang, Jiyan Ma, James C. Geoghegan, Surachai Supattapone

Dartmouth Scholarship

Infectious prions containing the pathogenic conformer of the mammalian prion protein (PrP(Sc)) can be produced de novo from a mixture of the normal conformer (PrP(C)) with RNA and lipid molecules. Recent reconstitution studies indicate that nucleic acids are not required for the propagation of mouse prions in vitro, suggesting the existence of an alternative prion propagation cofactor in brain tissue. However, the identity and functional properties of this unique cofactor are unknown. Here, we show by purification and reconstitution that the molecule responsible for the nuclease-resistant cofactor activity in brain is endogenous phosphatidylethanolamine (PE). Synthetic PE alone facilitates conversion of …


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 May 2012

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.


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 May 2012

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 …


Mitogen Activated Protein Kinase Phosphatase-1 Prevents The Development Of Tactile Sensitivity In A Rodent Model Of Neuropathic Pain, Christian Ndong, Russell P. Landry, Joyce A. Deleo, Edgar A. Romero-Sandoval Apr 2012

Mitogen Activated Protein Kinase Phosphatase-1 Prevents The Development Of Tactile Sensitivity In A Rodent Model Of Neuropathic Pain, Christian Ndong, Russell P. Landry, Joyce A. Deleo, Edgar A. Romero-Sandoval

Dartmouth Scholarship

Neuropathic pain due to nerve injury is one of the most difficult types of pain to treat. Following peripheral nerve injury, neuronal and glial plastic changes contribute to central sensitization and perpetuation of mechanical hypersensitivity in rodents. The mitogen activated protein kinase (MAPK) family is pivotal in this spinal cord plasticity. MAPK phosphatases (MKPs) limit inflammatory processes by dephosphorylating MAPKs. For example, MKP-1 preferentially dephosphorylates p-p38. Since spinal p-p38 is pivotal for the development of chronic hypersensitivity in rodent models of pain, and p-p38 inhibitors have shown clinical potential in acute and chronic pain patients, we hypothesize that induction of …


Caveolae, Fenestrae And Transendothelial Channels Retain Pv1 On The Surface Of Endothelial Cells, Eugene Tkachenko, Dan Tse, Olga Sideleva, Sophie J. Deharvengt, Marcus R. Luciano, Yan Xu, Caitlin L. Mcgarry, John Chidlow, Paul F. Pilch, William C. Sessa, Derek K. Toomre, Radu V. Stan Mar 2012

Caveolae, Fenestrae And Transendothelial Channels Retain Pv1 On The Surface Of Endothelial Cells, Eugene Tkachenko, Dan Tse, Olga Sideleva, Sophie J. Deharvengt, Marcus R. Luciano, Yan Xu, Caitlin L. Mcgarry, John Chidlow, Paul F. Pilch, William C. Sessa, Derek K. Toomre, Radu V. Stan

Dartmouth Scholarship

PV1 protein is an essential component of stomatal and fenestral diaphragms, which are formed at the plasma membrane of endothelial cells (ECs), on structures such as caveolae, fenestrae and transendothelial channels. Knockout of PV1 in mice results in in utero and perinatal mortality. To be able to interpret the complex PV1 knockout phenotype, it is critical to determine whether the formation of diaphragms is the only cellular role of PV1. We addressed this question by measuring the effect of complete and partial removal of structures capable of forming diaphragms on PV1 protein level. Removal of caveolae in mice by knocking …


An Inside Job: Hacking Into Janus Kinase/Signal Transducer And Activator Of Transcription Signaling Cascades By The Intracellular Protozoan Toxoplasma Gondii, Eric Y. Denkers, David J. Bzik, Barbara A. Fox, Barbara A. Butcher Feb 2012

An Inside Job: Hacking Into Janus Kinase/Signal Transducer And Activator Of Transcription Signaling Cascades By The Intracellular Protozoan Toxoplasma Gondii, Eric Y. Denkers, David J. Bzik, Barbara A. Fox, Barbara A. Butcher

Dartmouth Scholarship

The intracellular protozoan Toxoplasma gondii is well known for its skill at invading and living within host cells. New discoveries are now also revealing the astounding ability of the parasite to inject effector proteins into the cytoplasm to seize control of the host cell. This review summarizes recent advances in our understanding of one such secretory protein called ROP16. This molecule is released from rhoptries into the host cell during invasion. The ROP16 molecule acts as a kinase, directly activating both signal transducer and activator of transcription 3 (STAT3) and STAT6 signaling pathways. In macrophages, an important and preferential target …