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Full-Text Articles in Microbiology

Optimization Of Bacterial Luciferase For Expression In Mammalian Cells, Stacey Swiger Patterson Dec 2003

Optimization Of Bacterial Luciferase For Expression In Mammalian Cells, Stacey Swiger Patterson

Doctoral Dissertations

This study describes the optimization of expression of the bacterial luciferase enzyme in mammalian cells. Previous attempts to express this heterodimeric enzyme complex in mammalian cells have been met with only modest success. In this research effort, several vector formats were evaluated to fully determine the optimal format for the expression of these genes. It was determined that the bacterial luciferase enzyme produced optimal bioluminescence in mammalian cells when the genes were cloned and expressed as a bicistronic transcript fused with an internal ribosomal entry site (IRES). To optimize the enzyme expression further, a novel approach to codon optimize the …


Transgenic Approaches To Study Nodulation In The Model Legume, Lotus Japonicus, Crystal Bickley Mcalvin Dec 2003

Transgenic Approaches To Study Nodulation In The Model Legume, Lotus Japonicus, Crystal Bickley Mcalvin

Doctoral Dissertations

The soybean apyrase, GS52, characterized as an early nodulin, was further investigated for its possible role in nodulation. GS52 is expressed in roots and localized to the plasma membrane. In addition, it is rapidly induced upon rhizobial inoculation. Treatment of soybean roots with anti-GS52 antibodies blocked nodulation by Bradyrhizobium japonicum. Transgenic Lotus japonicus plants were generated expressing gs52 and showed enhanced nodulation and infection thread formation upon inoculation with Mesorhizobium loti that correlated with expression of the transgene. Surprisingly, expression of GS52 allowed L. japonicus plants to be infected but not nodulated by B. japonicum, the natural symbiont of soybean. …


Cd43 Modulates Severity And Onset Of Experimental Autoimmune Encephalomyelitis., Thandi M. Onami, M. L. Ford, A. Sperling, R. Ahmed, B. D. Evavold Dec 2003

Cd43 Modulates Severity And Onset Of Experimental Autoimmune Encephalomyelitis., Thandi M. Onami, M. L. Ford, A. Sperling, R. Ahmed, B. D. Evavold

Microbiology Publications and Other Works

Experimental autoimmune encephalomyelitis (EAE) is a mouse model of multiple sclerosis characterized by infiltration of activated CD4(+) T lymphocytes into tissues of the CNS. This study investigated the role of CD43 in the induction and progression of EAE. Results demonstrate that CD43-deficient mice have reduced and delayed clinical and histological disease severity relative to CD43(+/+) mice. This reduction was characterized by decreased CD4(+) T cell infiltration of the CNS of CD43(-/-) mice but similar numbers of Ag-specific T cells in the periphery, suggesting a defect in T cell trafficking to the CNS. The absence of CD43 also affected cytokine production, …


Evaluation Of Microbial Inocula For Initiation Of Biological Life Support Systems For Wastewater Processing On Long Term And Deep Space Missions, Kimberly L. Cook Aug 2003

Evaluation Of Microbial Inocula For Initiation Of Biological Life Support Systems For Wastewater Processing On Long Term And Deep Space Missions, Kimberly L. Cook

Doctoral Dissertations

A fundamental goal of ecological research is to better understand the relationship between structural diversity, functional diversity and ecosystem stability. Insight into the mechanisms that regulate microbial ecosystem function should provide important new information to improve system control for ecological, agricultural and biotechnological applications that depend on microbial processes. For example, defined microbial consortia have been employed to improve plant growth through enhanced nutrient uptake, production of plant growth promoting hormones or control of pathogens. However, a lack of consistency of results in field application has limited the widespread use of microbial inoculants. A major goal in rhizosphere studies, therefore, …


Expression Of Luxi In Bacillus Thuringiensis For The Development Of A Bacteriophage-Based Bioreporter System For The Detection Of Anthrax, Amy Tomaszewski Aug 2003

Expression Of Luxi In Bacillus Thuringiensis For The Development Of A Bacteriophage-Based Bioreporter System For The Detection Of Anthrax, Amy Tomaszewski

Masters Theses

In light of the recent anthrax attacks of 2001in the United States, the need for a rapid, sensitive, and real-time surveillance system for detecting pathogenic bacteria has become readily apparent. A proof-of-principle study involving development of a bacteriophage-based bioreporter system for the detection of Bacillus anthracis spores has been initiated in the surrogate strain Bacillus thuringiensis 4Q7. The final goal of the project is to develop an engineered bacteriophage with the luxI gene from Vibrio fischeri, which upon infection of the target organism, would produce the signal molecule, N-(3-oxohexanoyl)-L-homoserine lactone (OHHL), capable of inducing bioluminescence in a neighboring …


Primary And Secondary Immunocompetence In Mixed Allogeneic Chimeras, Thandi M. Onami, M. A. Williams, A. B. Adams, M. B. Walsh, N. Shirasugi, T. C. Pearson, R. Ahmed, C. P. Larsen Mar 2003

Primary And Secondary Immunocompetence In Mixed Allogeneic Chimeras, Thandi M. Onami, M. A. Williams, A. B. Adams, M. B. Walsh, N. Shirasugi, T. C. Pearson, R. Ahmed, C. P. Larsen

Microbiology Publications and Other Works

Targeted disruption of T cell costimulatory pathways, particularly CD28 and CD40, has allowed for the development of minimally myeloablative strategies for the induction of mixed allogeneic chimerism and donor-specific tolerance across full MHC barriers. In this study we analyze in depth the ability of mixed allogeneic chimeras in two strain combinations to mount effective host-restricted and donor-restricted antiviral CD4 and CD8 responses, as well as the impact of development of mixed chimerism on the maintenance of pre-existing memory populations. While antiviral CD8 responses in mixed chimeras following acute viral infection with lymphocytic choriomeningitis virus Armstrong or vaccinia virus are largely …


Tcr Signal Transduction In Antigen-Specific Memory Cd8 T Cells, Thandi M. Onami, Ellen N. Kersh, Susan M. Kaech, Miriana Moran, E. John Wherry, M. Carrie Miceli, Rafi Ahmed Jan 2003

Tcr Signal Transduction In Antigen-Specific Memory Cd8 T Cells, Thandi M. Onami, Ellen N. Kersh, Susan M. Kaech, Miriana Moran, E. John Wherry, M. Carrie Miceli, Rafi Ahmed

Microbiology Publications and Other Works

Memory T cells are more responsive to Ag than naive cells. To determine whether memory T cells also have more efficient TCR signaling, we compared naive, effector, and memory CD8 T cells of the same antigenic specificity. Surprisingly, initial CD3 signaling events are indistinguishable. However, memory T cells have more extensive lipid rafts with higher phosphoprotein content before TCR engagement. Upon activation in vivo, they more efficiently induce phosphorylation of-LAT (linker for activation of T cells), ERK (extracellular signal-regulated kinase), JNK (c-Jun N-terminal kinase), and p38. Thus, memory CD8 T cells do not increase their TCR sensitivity, but are better …