Microbiology Commons^™

Characterizing The Physiology And Genetics Of Contact Dependent Growth Inhibiton Systems In Burkholderia Species, Alice Elizabeth Oates

Theses and Dissertations--Microbiology, Immunology, and Molecular Genetics

Contact-dependent growth inhibition (CDI) systems mediate interbacterial competition. The genes encoding these systems are widespread among Gram-negative bacteria, including Burkholderia pathogens. CDI systems of Burkholderia species are composed of two-partner secretion pathway proteins and function to deliver the toxic C-terminus of a polymorphic surface-exposed exoprotein BcpA (Burkholderia CDI protein A) to the cytoplasm of neighboring recipient bacteria upon cell-cell contact. Specific outer and inner membrane proteins facilitate BcpA translocation both out of the donor bacterium and into the recipient cell cytoplasm. Most Burkholderia species-specific CDI translocation factors in recipient cells are unknown. BcpA intoxication functions as a mechanism by …

A Comparison Of Oral And Intravenous Mouse Models Of Listeriosis, Michelle G. Pitts, Sarah E. F. D'Orazio

Microbiology, Immunology, and Molecular Genetics Faculty Publications

Listeria monocytogenes is one of several enteric microbes that is acquired orally, invades the gastric mucosa, and then disseminates to peripheral tissues to cause systemic disease in humans. Intravenous (i.v.) inoculation of mice with L. monocytogenes has been the most widely-used small animal model of listeriosis over the past few decades. The infection is highly reproducible and has been invaluable in deciphering mechanisms of adaptive immunity in vivo, particularly CD8+ T cell responses to intracellular pathogens. However, the i.v. model completely bypasses the gut phase of the infection. Recent advances in generating both humanized mice and murinized bacteria, as well …

Differential Roles For Inner Membrane Complex Proteins Across Toxoplasma Gondii And Sarcocystis Neurona Development, Rashmi Dubey, Brooke Harrison, Sriveny Dangoudoubiyam, Giulia Bandini, Katherine Cheng, Aziz Kosber, Carolina Agop-Nersesian, Daniel K. Howe, John Samuelson, David J. P. Ferguson, Marc-Jan Gubbels

Maxwell H. Gluck Equine Research Center Faculty Publications

The inner membrane complex (IMC) of apicomplexan parasites contains a network of intermediate filament-like proteins. The 14 alveolin domain-containing IMC proteins in Toxoplasma gondii fall into different groups defined by their distinct spatiotemporal dynamics during the internal budding process of tachyzoites. Here, we analyzed representatives of different IMC protein groups across all stages of the Toxoplasma life cycle and during Sarcocystis neurona asexual development. We found that across asexually dividing Toxoplasma stages, IMC7 is present exclusively in the mother’s cytoskeleton, whereas IMC1 and IMC3 are both present in mother and daughter cytoskeletons (IMC3 is strongly enriched in daughter buds). In …

Spyb, A Small Heme-Binding Protein, Affects The Composition Of The Cell Wall In Streptococcus Pyogenes, Rebecca J. Edgar, Jing Chen, Sashi Kant, Elena Rechkina, Jeffrey S. Rush, Lennart S. Forsberg, Bernhard Jaehrig, Parastoo Azadi, Veronika Tchesnokova, Evgeni V. Sokurenko, Haining Zhu, Konstantin V. Korotkov, Vijay Pancholi, Natalia Korotkova

Molecular and Cellular Biochemistry Faculty Publications

Streptococcus pyogenes (Group A Streptococcus or GAS) is a hemolytic human pathogen associated with a wide variety of infections ranging from minor skin and throat infections to life-threatening invasive diseases. The cell wall of GAS consists of peptidoglycan sacculus decorated with a carbohydrate comprising a polyrhamnose backbone with immunodominant N-acetylglucosamine side-chains. All GAS genomes contain the spyBA operon, which encodes a 35-amino-acid membrane protein SpyB, and a membrane-bound C3-like ADP-ribosyltransferase SpyA. In this study, we addressed the function of SpyB in GAS. Phenotypic analysis of a spyB deletion mutant revealed increased bacterial aggregation, and reduced sensitivity to β-lactams of the …

Targeting The Wnt/Β-Catenin Signaling Pathway In Liver Cancer Stem Cells And Hepatocellular Carcinoma Cell Lines With Fh535, Roberto Gedaly, Roberto Galuppo, Michael F. Daily, Malay B. Shah, Erin Colleen Maynard, Changguo Chen, Xiping Zhang, Karyn A. Esser, Donald A. Cohen, B. Mark Evers, Jieyun Jiang, Brett T. Spear

Surgery Faculty Publications

Activation of the Wnt/β-catenin pathway has been observed in at least 1/3 of hepatocellular carcinomas (HCC), and a significant number of these have mutations in the β-catenin gene. Therefore, effective inhibition of this pathway could provide a novel method to treat HCC. The purposed of this study was to determine whether FH535, which was previously shown to block the β-catenin pathway, could inhibit β-catenin activation of target genes and inhibit proliferation of Liver Cancer Stem Cells (LCSC) and HCC cell lines. Using β-catenin responsive reporter genes, our data indicates that FH535 can inhibit target gene activation by endogenous and exogenously …

Inflammatory Cytokine Gene Expression In Mesenteric Adipose Tissue During Acute Experimental Colitis, William Conan Mustain, Marlene E. Starr, Joseph Daniel Valentino, Donald A. Cohen, Daiki Okamura, Chi Wang, B. Mark Evers, Hiroshi Saito

Markey Cancer Center Faculty Publications

BACKGROUND: Production of inflammatory cytokines by mesenteric adipose tissue (MAT) has been implicated in the pathogenesis of inflammatory bowel disease (IBD). Animal models of colitis have demonstrated inflammatory changes within MAT, but it is unclear if these changes occur in isolation or as part of a systemic adipose tissue response. It is also unknown what cell types are responsible for cytokine production within MAT. The present study was designed to determine whether cytokine production by MAT during experimental colitis is depot-specific, and also to identify the source of cytokine production within MAT.

METHODS: Experimental colitis was induced in 6-month-old C57BL/6 …