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Full-Text Articles in Medicine and Health Sciences

Immunogenicity And Protective Efficacy Of The Dar-901 Booster Vaccine In A Murine Model Of Tuberculosis, Timothy Lahey, Dominick Laddy, Krystal Hill, Jacqueline Schaeffer Dec 2016

Immunogenicity And Protective Efficacy Of The Dar-901 Booster Vaccine In A Murine Model Of Tuberculosis, Timothy Lahey, Dominick Laddy, Krystal Hill, Jacqueline Schaeffer

Dartmouth Scholarship

The development of a novel tuberculosis vaccine is a leading global health priority. SRL172, an inactivated, whole-cell mycobacterial vaccine, was safe, immunogenic and reduced the incidence of culture-confirmed tuberculosis in a phase III trial in HIV-infected and BCG immunized adults in Tanzania. Here we describe the immunogenicity and protective efficacy of DAR-901, a booster vaccine against tuberculosis manufactured from the same seed strain using a new scalable method.


The Vibrio Cholerae Minor Pilin Tcpb Initiates Assembly And Retraction Of The Toxin-Coregulated Pilus, Dixon Ng, Tony Harn, Tuba Altindal, Subramania Kolappan, Jarrad Marles, Rajan Lala, Ingrid Spielman, Yang Gao, Caitlyn Hauke, Gabriela Kovacikova Dec 2016

The Vibrio Cholerae Minor Pilin Tcpb Initiates Assembly And Retraction Of The Toxin-Coregulated Pilus, Dixon Ng, Tony Harn, Tuba Altindal, Subramania Kolappan, Jarrad Marles, Rajan Lala, Ingrid Spielman, Yang Gao, Caitlyn Hauke, Gabriela Kovacikova

Dartmouth Scholarship

Type IV pilus (T4P) systems are complex molecular machines that polymerize major pilin proteins into thin filaments displayed on bacterial surfaces. Pilus functions require rapid extension and depolymerization of the pilus, powered by the assembly and retraction ATPases, respectively. A set of low abundance minor pilins influences pilus dynamics by unknown mechanisms. The Vibrio cholerae toxin-coregulated pilus (TCP) is among the simplest of the T4P systems, having a single minor pilin TcpB and lacking a retraction ATPase. Here we show that TcpB, like its homolog CofB, initiates pilus assembly. TcpB co-localizes with the pili but at extremely low levels, equivalent …


Use Of A Multiplex Transcript Method For Analysis Of Pseudomonas Aeruginosa Gene Expression Profiles In The Cystic Fibrosis Lung, Alex H. Gifford, Sven D. Willger, Emily L. Dolben, Lisa A. Moulton, Dana Dorman, Heather Bean, Jane Hill, Thomas Hampton, Alix Ashare, Deborah Hogan Oct 2016

Use Of A Multiplex Transcript Method For Analysis Of Pseudomonas Aeruginosa Gene Expression Profiles In The Cystic Fibrosis Lung, Alex H. Gifford, Sven D. Willger, Emily L. Dolben, Lisa A. Moulton, Dana Dorman, Heather Bean, Jane Hill, Thomas Hampton, Alix Ashare, Deborah Hogan

Dartmouth Scholarship

The discovery of therapies that modulate Pseudomonas aeruginosa virulence or that can eradicate chronic P. aeruginosa lung infections associated with cystic fibrosis (CF) will be advanced by an improved understanding of P. aeruginosa behavior in vivo We demonstrate the use of multiplexed Nanostring technology to monitor relative abundances of P. aeruginosa transcripts across clinical isolates, in serial samples, and for the purposes of comparing microbial physiology in vitro and in vivo The expression of 75 transcripts encoded by genes implicated in CF lung disease was measured in a variety of P. aeruginosa strains as well as RNA serial sputum samples …


Pyrimidine Pathway-Dependent And -Independent Functions Of The Toxoplasma Gondii Mitochondrial Dihydroorotate Dehydrogenase, Miryam Andrea Hortua Triana, Daniela Cajiao Herrera, Barbara H. Zimmermann, Barbara A. Fox, David Bzik Oct 2016

Pyrimidine Pathway-Dependent And -Independent Functions Of The Toxoplasma Gondii Mitochondrial Dihydroorotate Dehydrogenase, Miryam Andrea Hortua Triana, Daniela Cajiao Herrera, Barbara H. Zimmermann, Barbara A. Fox, David Bzik

Dartmouth Scholarship

Dihydroorotate dehydrogenase (DHODH) mediates the fourth step of de novo pyrimidine biosynthesis and is a proven drug target for inducing immunosuppression in therapy of human disease as well as a rapidly emerging drug target for treatment of malaria. In Toxoplasma gondii, disruption of the first, fifth, or sixth step of de novo pyrimidine biosynthesis induced uracil aux- otrophy. However, previous attempts to generate uracil auxotrophy by genetically deleting the mitochondrion-associated DHODH of T. gondii (Tg DHODH) failed. To further address the essentiality of Tg DHODH, mutant gene alleles deficient in Tg DHODH activity were designed to ablate the enzyme activity. …


Immune- And Nonimmune-Compartment-Specific Interferon Responses Are Critical Determinants Of Herpes Simplex Virus-Induced Generalized Infections And Acute Liver Failure, Zachary M. Parker, Tracy Jo Pasieka, George A. Parker, David A. Leib Sep 2016

Immune- And Nonimmune-Compartment-Specific Interferon Responses Are Critical Determinants Of Herpes Simplex Virus-Induced Generalized Infections And Acute Liver Failure, Zachary M. Parker, Tracy Jo Pasieka, George A. Parker, David A. Leib

Dartmouth Scholarship

The interferon (IFN) response to viral pathogens is critical for host survival. In humans and mouse models, defects in IFN responses can result in lethal herpes simplex virus 1 (HSV-1) infections, usually from encephalitis. Although rare, HSV-1 can also cause fulminant hepatic failure, which is often fatal. Although herpes simplex encephalitis has been extensively studied, HSV-1 generalized infections and subsequent acute liver failure are less well understood. We previously demonstrated that IFN-αβγR-/- mice are exquisitely susceptible to liver infection following corneal infection with HSV-1. In this study, we used bone marrow chimeras of IFN-αβγR-/- (AG129) and wild-type (WT; 129SvEv) mice …


Heterogeneity Among Isolates Reveals That Fitness In Low Oxygen Correlates With Aspergillus Fumigatus Virulence, Caitlin H. Kowalski, Sarah R. Beattie, Kevin K. Fuller, Elizabeth A. Mcgurk, Yi-Wei Tang, Tobias Hohl, Joshua Obar, Robert Cramer Jr. Sep 2016

Heterogeneity Among Isolates Reveals That Fitness In Low Oxygen Correlates With Aspergillus Fumigatus Virulence, Caitlin H. Kowalski, Sarah R. Beattie, Kevin K. Fuller, Elizabeth A. Mcgurk, Yi-Wei Tang, Tobias Hohl, Joshua Obar, Robert Cramer Jr.

Dartmouth Scholarship

Previous work has shown that environmental and clinical isolates of Aspergillus fumigatus represent a diverse population that occupies a variety of niches, has extensive genetic diversity, and exhibits virulence heterogeneity in a number of animal models of invasive pulmonary aspergillosis (IPA). However, mechanisms explaining differences in virulence among A. fumigatus isolates remain enigmatic. Here, we report a significant difference in virulence of two common lab strains, CEA10 and AF293, in the murine triamcinolone immunosuppression model of IPA, in which we previously identified severe low oxygen microenvironments surrounding fungal lesions. Therefore, we hypothesize that the ability to thrive within these lesions …


Requirements For Pseudomonas Aeruginosa Type I-F Crispr-Cas Adaptation Determined Using A Biofilm Enrichment Assay, Gary E. Heussler, Jon L. Miller, Courtney E. Price, Alan J. Collins Aug 2016

Requirements For Pseudomonas Aeruginosa Type I-F Crispr-Cas Adaptation Determined Using A Biofilm Enrichment Assay, Gary E. Heussler, Jon L. Miller, Courtney E. Price, Alan J. Collins

Dartmouth Scholarship

CRISPR (clustered regularly interspaced short palindromic repeat)-Cas (CRISPR-associated protein) systems are diverse and found in many archaea and bacteria. These systems have mainly been characterized as adaptive immune systems able to protect against invading mobile genetic elements, including viruses. The first step in this protection is acquisition of spacer sequences from the invader DNA and incorporation of those sequences into the CRISPR array, termed CRISPR adaptation. Progress in understanding the mechanisms and requirements of CRISPR adaptation has largely been accomplished using overexpression of cas genes or plasmid loss assays; little work has focused on endogenous CRISPR-acquired immunity from viral predation. …


Microrna Mir-155 Is Necessary For Efficient Gammaherpesvirus Reactivation From Latency, But Not For Establishment Of Latency, Rebecca L. Crepeau, Peisheng Zhang, Edward J. Usherwood Jun 2016

Microrna Mir-155 Is Necessary For Efficient Gammaherpesvirus Reactivation From Latency, But Not For Establishment Of Latency, Rebecca L. Crepeau, Peisheng Zhang, Edward J. Usherwood

Dartmouth Scholarship

MicroRNA-155 (miR-155) has been shown to play significant roles in the immune response, including in the formation of germinal centers (GC) and the development and maturation of T follicular helper (Tfh) cells. There is in vitro evidence to support a critical role for cellular miR-155 and viral miR-155 homologs in the establishment of gammaherpesvirus latency in B cells. We sought to determine the contribution of miR-155 to the establishment and maintenance of latency in vivousing murine gammaherpesvirus (MHV-68) infection. MHV-68-infected mice deficient in miR-155 exhibited decreases in GC B cells and Tfh cells. However, the frequencies of spleen cells …


Signaling In Effector Lymphocytes: Insights Toward Safer Immunotherapy, Kamalakannan Rajasekaran, Matthew J. Riese, Sridhar Rao, Li Wang, Monica Thakar, Charles Sentman, Subramaniam Malarkannan May 2016

Signaling In Effector Lymphocytes: Insights Toward Safer Immunotherapy, Kamalakannan Rajasekaran, Matthew J. Riese, Sridhar Rao, Li Wang, Monica Thakar, Charles Sentman, Subramaniam Malarkannan

Dartmouth Scholarship

Receptors on T and NK cells systematically propagate highly complex signaling cascades that direct immune effector functions, leading to protective immunity. While extensive studies have delineated hundreds of signaling events that take place upon receptor engagement, the precise molecular mechanism that differentially regulates the induction or repression of a unique effector function is yet to be fully defined. Such knowledge can potentiate the tailoring of signal transductions and transform cancer immunotherapies. Targeted manipulations of signaling cascades can augment one effector function such as antitumor cytotoxicity while contain the overt generation of pro-inflammatory cytokines that contribute to treatment-related toxicity such as …


Friendly Fire: Biological Functions And Consequences Of Chromosomal Targeting By Crispr-Cas Systems, Gary E. Heussler, George A. O'Toole May 2016

Friendly Fire: Biological Functions And Consequences Of Chromosomal Targeting By Crispr-Cas Systems, Gary E. Heussler, George A. O'Toole

Dartmouth Scholarship

Clustered regularly interspaced short palindromic repeat (CRISPR)-associated (Cas) systems in bacteria and archaea target foreign elements, such as bacteriophages and conjugative plasmids, through the incorporation of short sequences (termed spacers) from the foreign element into the CRISPR array, thereby allowing sequence-specific targeting of the invader. Thus, CRISPR-Cas systems are typically considered a microbial adaptive immune system. While many of these incorporated spacers match targets on bacteriophages and plasmids, a noticeable number are derived from chromosomal DNA. While usually lethal to the self-targeting bacteria, in certain circumstances, these self-targeting spacers can have profound effects in regard to microbial biology, including functions …


Herpes Simplex Virus And Interferon Signaling Induce Novel Autophagic Clusters In Sensory Neurons, Sarah Katzenell, David A. Leib Feb 2016

Herpes Simplex Virus And Interferon Signaling Induce Novel Autophagic Clusters In Sensory Neurons, Sarah Katzenell, David A. Leib

Dartmouth Scholarship

Herpes simplex virus 1 (HSV-1) establishes lifelong infection in the neurons of trigeminal ganglia (TG), cycling between productive infection and latency. Neuronal antiviral responses are driven by type I interferon (IFN) and are crucial to controlling HSV-1 virulence. Autophagy also plays a role in this neuronal antiviral response, but the mechanism remains obscure. In this study, HSV-1 infection of murine TG neurons triggered unusual clusters of autophagosomes, predominantly in neurons lacking detectable HSV-1 antigen. Treatment of neurons with IFN-β induced a similar response, and cluster formation by infection or IFN treatment was dependent upon an intact IFN-signaling pathway. The autophagic …


The Gras Sensor In Staphylococcus Aureus Mediates Resistance To Host Defense Peptides Differing In Mechanisms Of Action, Siyang Chaili, Ambrose L. L. Cheung, Arnold S. Bayer, Yan Q. Xiong, Alan Waring, Guido Memmi, Niles Donegan Feb 2016

The Gras Sensor In Staphylococcus Aureus Mediates Resistance To Host Defense Peptides Differing In Mechanisms Of Action, Siyang Chaili, Ambrose L. L. Cheung, Arnold S. Bayer, Yan Q. Xiong, Alan Waring, Guido Memmi, Niles Donegan

Dartmouth Scholarship

Staphylococcus aureus uses the two-component regulatory system GraRS to sense and respond to host defense peptides (HDPs). However, the mechanistic impact of GraS or its extracellular sensing loop (EL) on HDP resistance is essentially unexplored. Strains with null mutations in the GraS holoprotein (ΔgraS) or its EL (ΔEL) were compared for mechanisms of resistance to HDPs of relevant immune sources: neutrophil α-defensin (human neutrophil peptide 1 [hNP-1]), cutaneous β-defensin (human β-defensin 2 [hBD-2]), or the platelet kinocidin congener RP-1. Actions studied by flow cytometry included energetics (ENR); membrane permeabilization (PRM); annexin V binding (ANX), and cell death protease activation (CDP). …


Characterization Of Rna Helicase Csha And Its Role In Protecting Mrnas And Small Rnas Of Staphylococcus Aureus Strain Newman, Samin Kim, Anna-Rita Corvaglia, Stefano Léo, Ambrose Cheung, Patrice Francois Jan 2016

Characterization Of Rna Helicase Csha And Its Role In Protecting Mrnas And Small Rnas Of Staphylococcus Aureus Strain Newman, Samin Kim, Anna-Rita Corvaglia, Stefano Léo, Ambrose Cheung, Patrice Francois

Dartmouth Scholarship

The toxin MazFsa in Staphylococcus aureus is a sequence-specific endoribonuclease that cleaves the majority of the mRNAs in vivo but spares many essential mRNAs (e.g., secY mRNA) and, surprisingly, an mRNA encoding a regulatory protein (i.e., sarA mRNA). We hypothesize that some mRNAs may be protected by RNA-binding protein(s) from degradation by MazFsa. Using heparin-Sepharose-enriched fractions that hybridized to sarA mRNA on Northwestern blots, we identified among multiple proteins the DEAD box RNA helicase CshA (NWMN_1985 or SA1885) by mass spectroscopy. Purified CshA exhibits typical RNA helicase activities, as exemplified by RNA-dependent ATPase activity and unwinding of …


In Vitro Modeling Of The Interaction Between Human Epithelial Cells And Lymphocytes Upon Influenza Infection, Natalia A. Ilyushina, Pete F. Wright Jan 2016

In Vitro Modeling Of The Interaction Between Human Epithelial Cells And Lymphocytes Upon Influenza Infection, Natalia A. Ilyushina, Pete F. Wright

Dartmouth Scholarship

Influenza viruses are a continuous threat to humans because of their ability to cross species barriers and adapt to new hosts. Data from murine studies, along with limited human data, suggest that CD8(+) cytotoxic T lymphocytes (CTL) that recognize conserved epitopes of structural influenza proteins are the main mediators of influenza virus clearance. Additionally, the fact that many CTLs recognize epitopes shared between different influenza strains offers the potential for broad cross-strain immunity. However, the mechanisms of cellular immunity against influenza viruses are poorly defined in humans, where the CTL response has been hard to measure and interpret. We developed …