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Theses/Dissertations

Microbiology

2011

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Full-Text Articles in Life Sciences

The Role Of Adaptive Stress Responses In Hiv Replication And Macrophage-Mediated Neurotoxicity, Stephanie Cross Dec 2011

The Role Of Adaptive Stress Responses In Hiv Replication And Macrophage-Mediated Neurotoxicity, Stephanie Cross

Publicly Accessible Penn Dissertations

Despite antiretroviral therapy (ART), HIV infection promotes cognitive dysfunction and neurodegeneration through persistent inflammation and neurotoxin release from infected and/or activated macrophages. Inflammation and immune activation within both the central nervous system (CNS) and periphery correlate with disease progression and morbidity in ART-treated individuals. Accordingly, drugs targeting these pathological processes are needed for effective, adjunctive therapy. Using our in vitro model of HIV-mediated neurotoxicity, in which HIV infected monocyte-derived macrophages (HIV/MDM) release excitatory neurotoxins, we demonstrate that HIV infection dysregulates adaptive stress responses, including the antioxidant response and the unfolded protein response (UPR). HIV infected macrophages have dramatic ...


Interleukin-22 Regulates Immunity, Inflammation And Tissue Homeostasis At Mucosal Sites, Gregory Field Sonnenberg Dec 2011

Interleukin-22 Regulates Immunity, Inflammation And Tissue Homeostasis At Mucosal Sites, Gregory Field Sonnenberg

Publicly Accessible Penn Dissertations

At mucosal sites, a single layer of epithelial cells separates the connective tissues of the mammalian body from the external environment. The gastrointestinal tract is the largest mucosal surface exposed to the environment and is colonized with an estimated 300 trillion beneficial commensal bacteria. These properties of mucosal sites help facilitate critical biological processes, including nutrient absorption, gas exchange and excretion of wastes, yet also renders mucosal sites particularly vulnerable to infection and inflammation. In order to maintain a state of health, complex immunoregulatory networks have evolved at mucosal sites to promote immunity, limit inflammation and maintain tissue homeostasis. Interleukin ...


Design Of A Tetracycline Operon Inducible System For The Control Of Vaccinia Virus Replication: Implications For Vaccine Development, Caitlin J. Hagen Dec 2011

Design Of A Tetracycline Operon Inducible System For The Control Of Vaccinia Virus Replication: Implications For Vaccine Development, Caitlin J. Hagen

Master's Theses

The use of vaccinia virus (VACV) as a vaccine resulted in the eradication of smallpox in 1979. Characteristics that contribute to the effectiveness of VACV as a vaccine and viral vector include its ability to elicit strong, long-lived humoral and cell-mediated immune responses as a live-replicating virus and to accept large inserts of DNA into its genome. However, adverse events associated with its use as the smallpox vaccine have constrained it from being more widely utilized in vaccines and therapies. We propose to improve the safety of VACV as a live-replicating vector by using elements of the tet operon to ...


Isolation Of A Rhodococcus Soil Bacterium That Produces A Strong Antibacterial Compound., Ralitsa Bogomilova Borisova Dec 2011

Isolation Of A Rhodococcus Soil Bacterium That Produces A Strong Antibacterial Compound., Ralitsa Bogomilova Borisova

Electronic Theses and Dissertations

Rhodococci are notable for their ability to degrade a variety of natural and xenobiotic compounds. Recently, interest in Rhodococcus has increased due to the discovery of a large number of genes for secondary metabolism. Only a few secondary metabolites have been characterized from the rhodococci (including 3 recently described antibiotics). Twenty-four new Rhodococcus strains were isolated from soils in East Tennessee using acetonitrile enrichment culturing and identified using 16S rRNA analysis. Forty-seven Rhodococcus strains were screened for antibiotic production using a growth inhibition assay. One strain, MTM3W5.2, had 90% similarity to the Rhodococcus opacus 16S rRNA gene sequence and ...


Characterization Of The Role Nuclear Bmp2 (Nbmp2) Plays In Regulating Gene Expression, Fialka Grigorova Dec 2011

Characterization Of The Role Nuclear Bmp2 (Nbmp2) Plays In Regulating Gene Expression, Fialka Grigorova

Theses and Dissertations

The nBmp2 protein was first identified in a DNA affinity chromatography/mass spectrometry screen designed to detect proteins that interact with a cartilage-specific enhancer element (called D/E) from the type XI collagen gene Col11a2. The transcription factor SOX9, a protein from the Sox (SRY-related HMG box) family, binds to and activates gene expression from this enhancer. nBmp2 has no transcriptional activity of its own on this enhancer, but when co-transfected with SOX9 it increases SOX9's activation of D/E nearly 2-fold. SOX9 also activates cartilage-specific enhancer elements from the Col2a1, Col27a1, and Col9a1 genes. The purpose of this ...


Development And Application Of Liquid Chromatography-Tandem Mass Spectrometry Methods To The Understanding Of Metabolism And Cell-Cell Signaling In Several Biological Systems, Jessica Renee Gooding Dec 2011

Development And Application Of Liquid Chromatography-Tandem Mass Spectrometry Methods To The Understanding Of Metabolism And Cell-Cell Signaling In Several Biological Systems, Jessica Renee Gooding

Doctoral Dissertations

Liquid chromatography tandem mass spectrometry has become a powerful tool for investigating biological systems. Herein we describe the development of both isotope dilution mass spectrometry methods and targeted metabolomics methods for the study of metabolic and cell-cell signaling applications.

A putative yeast enzyme was characterized by discovery metabolite profiling, kinetic flux profiling, transcriptomics and structural biology. These experiments demonstrated that the enzyme shb17 was a sedoheptulose bisphosphatase that provides a thermodynamically dedicated step towards riboneogenesis, leading to the redefinition of the canonical pentose phosphate pathway.

An extension of metabolic profiling and kinetic flux profiling methods was developed for a set ...


Investigation Of Host Responses Upon Infection Of Distinct Toxoplasma Strains, Rachel Devonne Hill Dec 2011

Investigation Of Host Responses Upon Infection Of Distinct Toxoplasma Strains, Rachel Devonne Hill

Doctoral Dissertations

Toxoplasma gondii is the causative agent of Toxoplasmosis in human and animals. T. gondii isolates are highly diverse. Hundreds of genotypes have been identified, but only three clonal lineages, namely Type I, II and III are prevalent worldwide. In mouse model, T. gondii strains can be divided into three groups based on their virulence, including the virulent (LD100=1), the intermediately virulent (LD50 = 103-104) and the non virulent (LD50 > 105). The clonal Type I, II and III T. gondii strains belong to these three groups, respectively. Epidemiologic studies suggest the difference of virulence ...


Interaction Of A G Protein-Coupled Receptor (Ste2p) Of Saccharomyces Cerevisiae With Its Ligand And Its G-Protein Alpha Subunit, Li-Yin Huang Dec 2011

Interaction Of A G Protein-Coupled Receptor (Ste2p) Of Saccharomyces Cerevisiae With Its Ligand And Its G-Protein Alpha Subunit, Li-Yin Huang

Doctoral Dissertations

The G protein-coupled receptor (GPCR) family is composed of hundreds of members and is expressed in eukaryotes. Each GPCR has seven transmembrane domains and is in charge of sensing changes from the environment, transducing signals, and activating a series of biological responses. The signal transduction pathway of the receptor starts from sensing outside signal and then activates G proteins. This signaling requires a tight control for activation without which impaired cellular function leads to pathology. We have used the pheromone alpha-factor receptor (Ste2p) of the yeast Saccharomyces cerevisiae as a model system to understand ligand binding, receptor activation, and G ...


Systematics Of Protosteloid Amoebae, Lora Lindley Shadwick Dec 2011

Systematics Of Protosteloid Amoebae, Lora Lindley Shadwick

Theses and Dissertations

Because of their simple fruiting bodies consisting of one to a few spores atop a finely tapering stalk, protosteloid amoebae, previously called protostelids, were thought of as primitive members of the Eumycetozoa sensu Olive 1975. The studies presented here have precipitated a change in the way protosteloid amoebae are perceived in two ways: (1) by expanding their known habitat range and (2) by forcing us to think of them as amoebae that occasionally form fruiting bodies rather than as primitive fungus-like organisms. Prior to this work protosteloid amoebae were thought of as terrestrial organisms. Collection of substrates from aquatic habitats ...


In Vitro Selection Of Aptamers Against Avian Influenza Virus H5n1, Jingjing Zhao Dec 2011

In Vitro Selection Of Aptamers Against Avian Influenza Virus H5n1, Jingjing Zhao

Theses and Dissertations

Over $10 billion losses in the poultry industry were caused by avian influenza (AI) so far. Rapid and specific detection of avian influenza virus is urgently needed with the concerns over the outbreaks of highly pathogenic H5N1 influenza virus and cases of animal and human infection. Aptamers are oligonucleic acid or peptide molecules that bind a specific target molecule with good affinity. They show better thermal stability than antibodies. The goal of this research was to select DNA-aptamers as the specific recognition element of AI H5N1virus to be used in detection assays specific for field application. In this study, Systematic ...


Host-Virus Interactions Of Infectious Laryngotracheitis Virus Infection In Cultured Cells, Jeong Yoon Lee Dec 2011

Host-Virus Interactions Of Infectious Laryngotracheitis Virus Infection In Cultured Cells, Jeong Yoon Lee

Theses and Dissertations

Infectious laryngotracheitis virus (ILTV; Gallid herpesvirus 1) causes upper respiratory diseases in mainly chickens and exhibits 90-100% of high morbidity and up to 70% of mortality, resulting in huge economic losses in the poultry industry worldwide.

To study host-ILTV interactions, the changes in genome-wide gene expressions in response to wild-type and vaccine ILTV infections in primary chicken embryo lung cells were investigated using microarray analysis. Results provide crucial insights into host cell pathogenic and immunogenic responses against wild-type and vaccine ILTV infections. Using microarray method and Ingenuity Pathway Analysis (IPA) bioinformatics tool, 273 and 306 differentially expressed genes were identified ...


Detection Of Two Pathogens Of High Importance To The National Poultry Improvement Plan: Salmonella Spp. And Mycoplasma Spp., Robin Levi Jarquin Dec 2011

Detection Of Two Pathogens Of High Importance To The National Poultry Improvement Plan: Salmonella Spp. And Mycoplasma Spp., Robin Levi Jarquin

Theses and Dissertations

In 1935, the National Poultry Improvement Plan (NPIP) was created to control Salmonella gallinarum and Salmonella pullorum . These two pathogens were devastating economically for poultry producers. Through cooperative efforts using vaccination and strict biosecurity, these two pathogens were eradicated from the United States. Currently, the NPIP program is targeting two other poultry pathogens, Salmonella enterica serovar Enteritidis and Mycoplasma . In the broiler industry it targets 2 specific Mycoplasma species (synoviae, gallisepticum). Vaccinations for these bacteria are available, but are not fully effective at controlling all strains and serovars. Thus, constant monitoring systems and strict biosecurity measures are necessary in order ...


Synthesis Of An Antimicrobial Textile Coating, William M. Morris Dec 2011

Synthesis Of An Antimicrobial Textile Coating, William M. Morris

Chemistry and Biochemistry

A titania nanosol was synthesized and coated onto nylon/cotton blended textile substrates. The substrates were characterized via SEM for adhesion and nanoparticle formation, then subjected to antimicrobial efficacy tests. The titania nanosol was successfully coated on to textiles samples. Particles were observed to be around 2 by 3 micrometers and formed between the interstitial space of textile fibers. Although larger than typical nanoparticles, the coatings exhibited what seemed to be antimicrobial activity. Titania nanosol coated textile samples were subjected to Kirby Bauer Assay in the presence of S. aureus. The coated textile sample exhibited an inhibition of growth around ...


Microbial Impacts On Endocrine Disrupting Contaminants: Las Vegas Wash And Lake Mead, Nevada, Susanna May Blunt Dec 2011

Microbial Impacts On Endocrine Disrupting Contaminants: Las Vegas Wash And Lake Mead, Nevada, Susanna May Blunt

UNLV Theses, Dissertations, Professional Papers, and Capstones

International concern over endocrine disrupting chemicals (EDCs) has become heightened in recent years as more studies reveal their persistence in the environment and their detrimental effects on wildlife. However, little is known about the role of microorganisms in the fate and transport of these compounds in surface waters. Las Vegas Wash, a stream flowing into Lake Mead and fed primarily by treated wastewater effluent, provided a unique experimental system in which to study the role microorganisms play in the dispersal of these compounds in aquatic systems. Samples were collected from the Las Vegas Wash downstream of the Las Vegas Valley ...


A Polymerase Chain Reaction Method For The Detection Of Selenomonas Noxia, Arthuro Mehretu Dec 2011

A Polymerase Chain Reaction Method For The Detection Of Selenomonas Noxia, Arthuro Mehretu

UNLV Theses, Dissertations, Professional Papers, and Capstones

In recent studies, periodontal health has been linked to being overweight and/or obese. Among common oral bacteria, Selenomonas noxia has been implicated in converting periodontal health to disease. Selenomonas spp. have also been found in gastric ulcers, and were misdiagnosed as Helicobacter -like organisms, but no further studies were conducted. The increasing clinical and epidemiological importance of S. noxia necessitates the development of a rapid detection method. In this study, a TaqMan 16S rRNA based real-time Polymerase Chain Reaction (PCR) method was developed, optimized and evaluated for the rapid and specific detection of S. noxia . The 16S PCR assay ...


Retrospective Evaluation Of Microbial Presence In Existing Saliva Repository: A Pcr Based Molecular Survey Of Oral Microbial Populations From Existing Saliva Samples, Jay Ericksen Davis Dec 2011

Retrospective Evaluation Of Microbial Presence In Existing Saliva Repository: A Pcr Based Molecular Survey Of Oral Microbial Populations From Existing Saliva Samples, Jay Ericksen Davis

UNLV Theses, Dissertations, Professional Papers, and Capstones

The overall purpose of this research project is to explore the link between oral health and disease in the University of Nevada, Las Vegas - School of Dental Medicine (UNLV-SDM) clinic patient population. More specifically, the population of interest is the UNLV-SDM orthodontic clinic patient population, which is mostly composed of adults, females, and minorities. The University of Nevada, Las Vegas, School of Dental Medicine, with more than 70,000 active patients and a post-graduate specialty program in Orthodontics is uniquely positioned to perform this type of oral health epidemiology survey, as well as targeted oral microbial testing among populations within ...


Impact Of Collateral Enlargement On Smooth Muscle Phenotype, Alexander Jerome Bynum Dec 2011

Impact Of Collateral Enlargement On Smooth Muscle Phenotype, Alexander Jerome Bynum

Master's Theses and Project Reports

Peripheral Artery Disease is a very serious disease characterized by an arterial occlusion due to atherosclerotic plaques. In response to an arterial occlusion, arteriogenesis occurs, causing smooth muscle cells to transition from a contractile to synthetic state. Also following an arterial occlusion, functional impairment was seen in the collateral circuit. An immunofluorescence protocol was developed in order to assess the impact of collateral enlargement (arteriogenesis) on smooth muscle phenotype at various time points. Smooth muscle α-actin was used to mark all smooth muscle cells, Ki-67 was used to label proliferating smooth muscle cells, and a fluorescent nuclear stain was used ...


A Bioinformatics Approach To Identifying Novel Genes Involved In Ebolavirus Entry, Andrew Steven Kondratowicz Dec 2011

A Bioinformatics Approach To Identifying Novel Genes Involved In Ebolavirus Entry, Andrew Steven Kondratowicz

Theses and Dissertations

Ebolavirus (EBOV) is a negative sense, single stranded RNA virus that causes Ebola hemorrhagic fever. This disease causes substantial morbidity and mortality in humans, with death occurring in 50-90% of cases. Despite years of intensive research, much of the molecular mechanism underlying the entry of EBOV remains unknown. We performed a bioinformatics screen to identify novel entry cofactors by correlating mRNA expression in a panel of human cancer cell lines with permissivity to the EBOV entry glycoprotein. This assay identified several known EBOV entry cofactors such as actin and the tyrosine kinase Axl. In addition, several genes involved in macropinocytosis ...


Effects Of Larval Exposure To Bacterial Species In Three Genera On Life History Traits And Oviposition Behavior In The Southern House Mosquito, Culex Quinquefasciatus, Jonathan Gravgaard Dec 2011

Effects Of Larval Exposure To Bacterial Species In Three Genera On Life History Traits And Oviposition Behavior In The Southern House Mosquito, Culex Quinquefasciatus, Jonathan Gravgaard

All Theses

The biofilm is the most common niche for microorganisms living in aquatic environments. Forming a biofilm provides the means to resist shear forces, adverse osmolarity, chemical agents, and other environmental stressors. Biofilms also provide a major food source for aquatic arthropods like mosquito larvae. Culex quinquefasciatus larvae are found in freshwater pools with high organic content, and have the ability to graze on bacterial biofilms. To study how C. quinquefasciatus mosquitoes interact with bacteria in their environment I developed an experimental system that allows mosquito larvae to freely graze on bacteria in either the planktonic or biofilm state. The efficacy ...


Thermal Inactivation Of Stress Adapted Pathogens In Compost, Randhir Singh Dec 2011

Thermal Inactivation Of Stress Adapted Pathogens In Compost, Randhir Singh

All Dissertations

In the United States, 1.3 billion tons of animal wastes are produced annually. Disposal of this huge amount of waste on agricultural land without proper treatment is a public health safety issue as animal waste is a potential source of several human pathogens. Therefore, composting of animal wastes is an economical solution to this problem. The high temperature reached during this process also brings about inactivation of pathogens in the waste. However, survival of pathogens has still been reported from different composting studies, indicating the complex nature of this process. The objectives of this study were to: 1) study ...


Developing Strategies To Control Human Pathogens In Minimally-Maintained Dairy Manure-Based Compost Heaps, Marion Shepherd Dec 2011

Developing Strategies To Control Human Pathogens In Minimally-Maintained Dairy Manure-Based Compost Heaps, Marion Shepherd

All Dissertations

Composting has been proven to be an effective method used to inactivate pathogens in dairy manure. However, research has shown that if the compost heaps are unturned pathogens can persist, especially on the surface of the heaps for extended periods of time. As such, it is important to evaluate potential interventions that can be used to ensure that pathogens are inactivated at all locations of minimally maintained compost heaps under field conditions. The objectives of this study were to: 1) determine the impact of compost initial carbon-to-nitrogen (C:N) ratio on pathogen destruction when composting dairy manure in unturned heaps ...


The Intracellular Behaviour Of Burkholderia Cenocepacia In Murine Macrophages, Jennifer S. Tolman Nov 2011

The Intracellular Behaviour Of Burkholderia Cenocepacia In Murine Macrophages, Jennifer S. Tolman

Electronic Thesis and Dissertation Repository

Burkholderia cenocepacia is an opportunistic pathogen causing life-threatening infections in cystic fibrosis and other immunocompromised patients. The bacterium survives within macrophages by interfering with typical endocytic trafficking, resulting in delayed maturation of a B. cenocepacia-containing phagosome. We hypothesize that B. cenocepacia alters gene expression after internalization by macrophages, inducing genes involved in intracellular survival and host adaptation. Furthermore, we hypothesize that specialized bacterial secretion systems are involved in the interactions between intracellular bacteria and macrophages. In this work, we characterize later-stage infection of macrophages by B. cenocepacia, showing replication within an acidified endosomal compartment suggestive of a phagolysosome. We ...


Using Vesicular Stomatitis Virus Glycoprotein To Pseudotype Bacmam Viruses For Enhancement Of Transduction Efficiency, Lydia Sanchez Oct 2011

Using Vesicular Stomatitis Virus Glycoprotein To Pseudotype Bacmam Viruses For Enhancement Of Transduction Efficiency, Lydia Sanchez

PCOM Biomedical Studies Student Scholarship

Baculovirus has been a common tool for protein production since the mid 1980s. The virus has an exclusive tropism only capable of infecting the larval stages of insects. Originally, baculovirus recombinant gene expression used Spodoptera frugiperda (Sf9) insect cells as the host cells for protein production. However, in 1995, it was discovered that baculoviruses could be modified to transduce mammalian cells with the insertion of a mammalian promoter and gene of interest. Due to its ease of generation and low biology safety hazards, this technology, known as BacMam (Baculovirus Mammalian) is popular in the research field for protein production and ...


Critical Stages In Viral Replication - Entry, Gene Regulation And Egress, Matthew S. Miller Sep 2011

Critical Stages In Viral Replication - Entry, Gene Regulation And Egress, Matthew S. Miller

Electronic Thesis and Dissertation Repository

Despite the amazing biological diversity exhibited by viruses, their very existence relies upon their ability to overcome a set of common barriers. The nature of these barriers reflects the nature of viruses themselves. During their extracellular phase, viruses are metabolically inert obligate parasites. Upon encountering a host cell, productive infection necessitates that the virus successfully enter the cell, regulate the expression of its genes, and after assembling new progeny particles, egress such that the cycle of infection can continue. These three basic processes are not only attractive candidates for therapeutic intervention, but also reveal much about virus biology in the ...


Structure-Function Analysis Of Enzymes Of The Polyisoprenyl-Phosphate Hexose-1-Phosphate Transferase Family, Kinnari B. Patel Sep 2011

Structure-Function Analysis Of Enzymes Of The Polyisoprenyl-Phosphate Hexose-1-Phosphate Transferase Family, Kinnari B. Patel

Electronic Thesis and Dissertation Repository

Enzymes of the polyisoprenyl-phosphate hexose-1-phosphate transferase (PHPT) family are integral membrane proteins that initiate the synthesis of glycans by catalyzing the transfer of a hexose-1-phosphate sugar from UDP-hexose to the lipid carrier undecaprenyl phosphate (Und-P). These glycans such as O antigen and exopolysaccharide (EPS) provide bacteria with protection and adaptation to the environment and host immune factors. The role of PHPT proteins in initiation and the absence of any eukaryotic homologues make them an attractive target for novel antimicrobials; however study of these proteins is difficult due to the presence of multiple transmembrane helices. A requirement of the C-terminal domain ...


M.Tb Killing By Macrophage Innate Immune Mechanisms: A Dissertation, Michelle L. Hartman Sep 2011

M.Tb Killing By Macrophage Innate Immune Mechanisms: A Dissertation, Michelle L. Hartman

GSBS Dissertations and Theses

Macrophages infected with a heavy burden of M.tb Erdman undergo a cell death that initially resembles apoptosis but quickly transitions to necrosis. Unlike the previously reported TNF dependent apoptosis induced by avirulent Mycobacterium [1], this form of macrophage cell death is not microbicidal [2]. Microbicidal effects are observed however, when the heavily infected macrophage encounters an uninfected naïve macrophage. My studies describe in part, the crosstalk between the uninfected and infected macrophage that results in the killing of the intracellular M.tb Cell contact between the two cell populations is not necessary for this killing of bacilli to occur ...


Role Of Protein Flexibility In Function, Resistance Pathways And Substrate Recognition Specificity In Hiv-1 Protease: A Dissertation, Seema Mittal Aug 2011

Role Of Protein Flexibility In Function, Resistance Pathways And Substrate Recognition Specificity In Hiv-1 Protease: A Dissertation, Seema Mittal

GSBS Dissertations and Theses

In the 30 years since the Center for Disease Control's Morbidity and Mortality Weekly Report published the first mention of what later was determined to be AIDS (Acquired immunodeficiency syndrome) and HIV (Human immunodeficiency virus) recognized as the causative pathogen, much has been done to understand this disease’s pathogenesis, development of drugs and emergence of drug resistance under selective drug therapy. Highly Active Antiretroviral Therapy (HAART), a combination of drugs that includes HIV-1 reverse transcriptase, protease, and more recently, integrase and entry inhibitors, have helped stabilize the HIV prevalence at extraordinarily high levels. Despite the recent stabilization of ...


Exploring Bacterial Nanowires: From Properties To Functions And Implications, Kar Man Leung Aug 2011

Exploring Bacterial Nanowires: From Properties To Functions And Implications, Kar Man Leung

Electronic Thesis and Dissertation Repository

The discovery of electrically conductive bacterial nanowires from a broad range of microbes provides completely new insights into microbial physiology. Shewanella oneidensis strain MR-1, a dissimilatory metal-reducing bacterium, produces extracellular bacterial nanowires up to tens of micrometers long, with a lateral dimension of ~10 nm. The Shewanella bacterial nanowires are efficient electrical conductors as revealed by scanning probe techniques such as CP-AFM and STM.

Direct electrical transport measurements along Shewanella nanowires reveal a measured nanowire resistivity on the order of 1 Ω∙cm. With electron transport rates up to 109/s at 100 mV, bacterial nanowires can serve as ...


Subcellular Localization In Bacteria: From Envz/Ompr To Transertion, Elizabeth Libby Aug 2011

Subcellular Localization In Bacteria: From Envz/Ompr To Transertion, Elizabeth Libby

Publicly Accessible Penn Dissertations

The internal structures of the bacterial cell and the associated dynamic changes as a function of physiological state have only recently begun to be characterized. Here we explore two aspects of subcellular localization in E. coli cells: the cytoplasmic distribution of the response regulator OmpR and its regulated chromosomal genes, and the subcellular repositioning of chromosomal loci encoding membrane proteins upon induction. To address these questions by quantitative fluorescence microscopy, we developed a simple system to tag virtually any chromosomal location with arrays of lacO or tetO by extending and modifying existing tools.

An unexplained subcellular localization was reported for ...


Mechanisms Of Antibody-Mediated Protection For A Protein-Based Smallpox Vaccine, Matthew E. Cohen Aug 2011

Mechanisms Of Antibody-Mediated Protection For A Protein-Based Smallpox Vaccine, Matthew E. Cohen

Publicly Accessible Penn Dissertations

Protein-based smallpox vaccines have shown to be effective alternatives to live virus vaccines in animal model challenge studies. It is believed that subunit vaccine protection is mainly mediated through the generation of antibodies. We, and others, have shown that Th1-type antibody responses are important for protection against poxvirus infections. This finding suggests that antibody-mediated protection by a protein-based smallpox vaccine may involve antibody that can fix complement and/or activate Fc receptors. Vaccinia virus, the prototype member of the poxvirus family, produces two infectious forms of virus: mature virus (MV) and extracellular virus (EV). EV is relatively resistant to neutralization ...