Current Search: disease (x)
Pages
-
-
Title
-
USING THE YEAST TWO-HYBRID SYSTEM TO DETERMINE THE FUNCTION OF PARKIN E3 UBIQUITIN LIGASE.
-
Creator
-
Nguyen, Vanessa, Zervos, Antonis, University of Central Florida
-
Abstract / Description
-
Parkin is a cytosolic E3 ubiquitin ligase that is recruited to the mitochondria during cellular stress and has been suggested to be involved in a variety of biological processes such as mitophagy. The recruitment of Parkin (PARK2) to the mitochondria is dependent upon the kinase activity and the accumulation of PINK1 on damaged mitochondria. Mutations in either PINK1 or Parkin genes disrupt this protective pathway and lead to the accumulation of damaged mitochondria. From a clinical...
Show moreParkin is a cytosolic E3 ubiquitin ligase that is recruited to the mitochondria during cellular stress and has been suggested to be involved in a variety of biological processes such as mitophagy. The recruitment of Parkin (PARK2) to the mitochondria is dependent upon the kinase activity and the accumulation of PINK1 on damaged mitochondria. Mutations in either PINK1 or Parkin genes disrupt this protective pathway and lead to the accumulation of damaged mitochondria. From a clinical standpoint, mutations in the PARK2 gene have been associated with the progression and onset of autosomal recessive juvenile parkinsonism. Without the presence of a quality control system such as that of the PINK1/Parkin pathway, the accumulation of damaged mitochondria could lead to increased levels of oxidative stress, a decrease in ATP, and the progression towards cellular death. However, many of the details regarding the mechanism of Parkin-mediated ubiquitination and its involvement in mitophagy are not fully established. The intent of this thesis is to further explore the function of Parkin by utilizing the yeast-two hybrid system to identify novel Parkin interactors/substrates. A HeLa (cervical cell carcinoma) cDNA library was screened using Parkin124-465 as the "bait" protein. From this screening, six positive Parkin interactors were isolated and characterized. Using this approach it is possible to gain a better understanding of the function of Parkin in regulating cellular processes such as mitophagy.
Show less
-
Date Issued
-
2014
-
Identifier
-
CFH0004679, ucf:45269
-
Format
-
Document (PDF)
-
PURL
-
http://purl.flvc.org/ucf/fd/CFH0004679
-
-
Title
-
AMYLOID-BETA42 TOXICITY REDUCTION IN HUMAN NEUROBLASTOMA CELLS USING CHOLERA TOXIN B SUBUNIT-MYELIN BASIC PROTEIN EXPRESSED IN CHLOROPLASTS.
-
Creator
-
Ayache, Alexandra, Daniell, Henry, University of Central Florida
-
Abstract / Description
-
Alzheimer's disease (AD) is an age progressive neurodegenerative brain disorder, affecting 37 million people worldwide. Cleavage of amyloid precursor protein by β- and γ-secretase produces the amyloid-beta (Aβ) protein, which significantly contributes to AD pathogenesis. The Aβ aggregates, formed at the surface of neurons and intracellularly, cause neurotoxicity and decrease synaptic function. Inhibiting or degrading Aβ accumulation is a key goal for development of new AD treatments. Evidence...
Show moreAlzheimer's disease (AD) is an age progressive neurodegenerative brain disorder, affecting 37 million people worldwide. Cleavage of amyloid precursor protein by β- and γ-secretase produces the amyloid-beta (Aβ) protein, which significantly contributes to AD pathogenesis. The Aβ aggregates, formed at the surface of neurons and intracellularly, cause neurotoxicity and decrease synaptic function. Inhibiting or degrading Aβ accumulation is a key goal for development of new AD treatments. Evidence shows that human Myelin Basic Protein (MBP) binds to and degrades Aβ thereby, preventing cytotoxicity. A potential method for oral drug delivery that will allow plant-derived bioencapsulated MBP to pass through intestinal epithelium and bypass denaturing stomach acidity is quite novel. Cholera Toxin B subunit (CTB), when fused with MBP, can serve as a vehicle for oral delivery of this chloroplast expressed therapeutic protein into the systemic circulation. Within chloroplast, CTB forms a pentameric structure that binds to GM1 ganglioside receptors, allowing receptor-mediated endocytosis. In order to investigate protein entry through neuronal GM1 receptors, we first created CTB fused to the green fluorescent protein (GFP). Incubation of this fusion protein with human neuroblastoma cells resulted in GFP entry into these cells whereas GFP alone was unable to enter. Similarly, co-incubation of CTB-MBP, via neuronal GM1 binding, allowed MBP to reduce neurotoxicity of Aβ42 treated cells by 37.1%. Delivery of CTB-MBP through GM1 receptor mediated binding should therefore facilitate oral administration, storage, heat stability and low cost AD treatment.
Show less
-
Date Issued
-
2012
-
Identifier
-
CFH0004249, ucf:44916
-
Format
-
Document (PDF)
-
PURL
-
http://purl.flvc.org/ucf/fd/CFH0004249
-
-
Title
-
Role of Single Nucleotide Polymorphisms (SNPs) in PTPN2/22 and Mycobacterium avium subspecies paratuberculosis (MAP) in Rheumatoid Arthritis and Crohn's Disease.
-
Creator
-
Sharp, Robert, Naser, Saleh, Parks, Griffith, Roy, Herve, Singla, Dinender, University of Central Florida
-
Abstract / Description
-
Both genetic pre-disposition and potential environmental triggers are shared between Rheumatoid arthritis (RA) and Crohn's disease (CD). We hypothesized that single nucleotide polymorphisms (SNPs) in the negative T-cell regulators Protein Tyrosine Phosphatase Non-receptor type 2 and 22 (PTPN2/22) lead to a dysregulated immune response as seen in RA and CD. To test the hypothesis, peripheral leukocytes samples from 204 consented subjects were TaqMan genotyped for 9 SNPs in PTPN2/22. The SNPs...
Show moreBoth genetic pre-disposition and potential environmental triggers are shared between Rheumatoid arthritis (RA) and Crohn's disease (CD). We hypothesized that single nucleotide polymorphisms (SNPs) in the negative T-cell regulators Protein Tyrosine Phosphatase Non-receptor type 2 and 22 (PTPN2/22) lead to a dysregulated immune response as seen in RA and CD. To test the hypothesis, peripheral leukocytes samples from 204 consented subjects were TaqMan genotyped for 9 SNPs in PTPN2/22. The SNPs effect on PTPN2/22 and IFN-y expression was determined using RT-PCR. Blood samples were analyzed for the Mycobacterium avium subspecies paratuberculosis (MAP) IS900 gene by nPCR. T-cell proliferation and response to phytohematoagglutonin (PHA) mitogen and MAP cell lysate were determined by BrdU proliferation assay. Out of 9 SNPs, SNP alleles of PTPN2:rs478582 occurred in 79% RA compared to 60% control (p-values ? 0.05). SNP alleles of PTPN22:rs2476601 occurred in 29% RA compared to 6% control (p-values ? 0.05). For the haplotype combination of PTPN2:rs478582/PTPN22rs2476601, 21.4% RA had both SNPs (C-A) compared to 2.4% control (p-values ? 0.05). PTPN2/22 expression in RA was decreased by an average of 1.2 fold. PTPN2:rs478582 upregulated IFN-y in RA by an average of 1.5 fold. Combined PTPN2:rs478582/PTPN22:rs2476601 increased T-cell proliferation by an average of 2.7 fold when treated with PHA. MAP DNA was detected in 34% RA compared to 8% controls (p-values ? 0.05), where samples with PTPN2:rs478582 and/or PTPN22:rs2476601 were more MAP positive. PTPN2:rs478582/PTPN22:rs2476601 together with MAP infection significantly increased T-cell response and IFN-y expression in RA samples. The same experimental approach was followed on blood samples from CD patients. Both PTPN2:rs478582/PTPN22:rs2476601 affected PTPN2/22 and IFN-y expression along with T-cell proliferation significantly more than in RA. MAP DNA was detected in 64% of CD. This is the first study to report the correlation between SNPs in PTPN2/22, IFN-y expression and MAP in autoimmune disease.
Show less
-
Date Issued
-
2018
-
Identifier
-
CFE0007371, ucf:52094
-
Format
-
Document (PDF)
-
PURL
-
http://purl.flvc.org/ucf/fd/CFE0007371
-
-
Title
-
Investigating changes in quiescence in oral and esophageal epithelium in response to injury.
-
Creator
-
Rothaus, Alexandra, Andl, Claudia, Chakrabarti, Ratna, Singla, Dinender, University of Central Florida
-
Abstract / Description
-
More than 570,000 new cases of esophageal cancer are estimated to be diagnosed annually worldwide. Risk factors include gender, age, tobacco use and dietary habits leading to tissue injury and ultimately cancer. While prognoses for other cancers have improved, the 5-year survival for patients with esophageal cancer is only 20%. During the repair process, cell proliferation is increased and is associated with inflammation. Slow-cycling lifetime residential stem cells, called quiescent cells,...
Show moreMore than 570,000 new cases of esophageal cancer are estimated to be diagnosed annually worldwide. Risk factors include gender, age, tobacco use and dietary habits leading to tissue injury and ultimately cancer. While prognoses for other cancers have improved, the 5-year survival for patients with esophageal cancer is only 20%. During the repair process, cell proliferation is increased and is associated with inflammation. Slow-cycling lifetime residential stem cells, called quiescent cells, facilitate repair but are thought to accumulate mutations during DNA replication eventually giving rise to cancer. We hypothesize that esophageal stem cells become activated upon injury and are regulated by Transforming Growth Factor beta 1 (TGF?1), a known regulator of cell proliferation and differentiation. We established an in vitro model of quiescence using normal esophageal epithelial (STR) and oral (OKF6) cells treated with recombinant human TGF?1. Flow cytometry showed increases in cells arrested in G1/G0 phase of the cell cycle in TGF?1 treated cells for both cell lines (STR p(<)0.01, OKF6 p(<)0.05). EdU (5-ethynyl-2'-deoxyuridine) positive recovery cells indicated quiescence in both cell lines (p(<)0.01). Analysis of TGF?1 regulation of putative stem cell markers via western blot and qRT-PCR showed increases in ITGB1, PDPN and K15 as well as XPC, and MeCP2 in treated cells. To apply our in vitro findings, we performed immunohistochemistry staining on tissue microarrays. Proliferation marker Ki67 increased in disease progression from normal to inflammation to hyperplasia (p(<)0.001) while TGF?1 target markers decrease. Our data indicate that the onset of cancer-associated inflammation correlates with the loss of TGF?1 mediated stemness markers and increased basal proliferation suggesting cancer is a stem cell disease.
Show less
-
Date Issued
-
2019
-
Identifier
-
CFE0007903, ucf:52754
-
Format
-
Document (PDF)
-
PURL
-
http://purl.flvc.org/ucf/fd/CFE0007903
-
-
Title
-
Downregulation in IFNGR1 increases suspectiblity to Mycobacterium avium subspecies paratuberculosis infection in Crohn's disease.
-
Creator
-
Htun, Zin Mar, Naser, Saleh, Andl, Claudia, Tigno-Aranjuez, Justine, University of Central Florida
-
Abstract / Description
-
BACKGROUND: Crohn's disease (CD) is an inflammatory bowel disease (IBD) and has been associated with Mycobacterium avium subspecies paratuberculosis (MAP). MAP has been detected in stool, tissue and blood samples from patients with CD. Gamma interferon (?-IFN) is an inflammatory cytokine that plays a crucial role in killing intracellular pathogens like MAP, and its receptor (IFNGR1) mutations cause immunodeficiency and severe disseminated mycobacterial infections. The role of MAP in...
Show moreBACKGROUND: Crohn's disease (CD) is an inflammatory bowel disease (IBD) and has been associated with Mycobacterium avium subspecies paratuberculosis (MAP). MAP has been detected in stool, tissue and blood samples from patients with CD. Gamma interferon (?-IFN) is an inflammatory cytokine that plays a crucial role in killing intracellular pathogens like MAP, and its receptor (IFNGR1) mutations cause immunodeficiency and severe disseminated mycobacterial infections. The role of MAP in association with IFNGR1 mutation in CD patients have not been investigated.METHODS: In this study, we investigated blood samples of 79 human subjects for MAP infection in association with IFNGR1 gene dysfunction. Samples were divided into 22 CD, 6 Ulcerative colitis (UC), 32 normal healthy and 19 non-inflammatory bowel disease (NIBD). Five variants of IFNGR1 single nucleotide polymorphisms (SNP) were investigated using Taqman Genotyping assay, then IFNGR1 expression measured by RT-PCR and serum IFNGR1 and ?-IFN levels were measured using ELISA. MAP infection was detected using nested PCR. RESULTS: Among 28 IBD patients, 4/6 (66.67%) of UC and 18/22 (81.82%) of CD are tested positive for at least one SNP homozygous minor form compared to 21.88% and 47.37%% in 32 healthy and 19 NIBD (P (<)0.05). IFNGR1 gene expression was downregulated 1.4-fold in IBD patients (P =0.07) and 1.7-fold downregulated in MAP positive IBD patients compared to MAP negative IBD patients (P=0.06). Serum IFNGR1 protein levels were downregulated 1.53-fold in IBD patients compared to normal, and 1.4-fold downregulated in MAP positive IBD patients compared to MAP negative IBD patients. MAP infection is more common in rs2234711 SNP positive patients (5/7 =71.42%) (P(<)0.05). Serum ?-IFN levels were not elevated in both groups.CONCLUSION: IFNGR1 SNP's, MAP infection and IFNGR1 downregulation were found in higher incidence in IBD, suggesting role of IFNGR1 in susceptibility of MAP infection in IBD patients.
Show less
-
Date Issued
-
2017
-
Identifier
-
CFE0007121, ucf:51951
-
Format
-
Document (PDF)
-
PURL
-
http://purl.flvc.org/ucf/fd/CFE0007121
-
-
Title
-
Fluid Dynamics Modeling and Sound Analysis of a Bileaflet Mechanical Heart Valve.
-
Creator
-
Khalili, Fardin, Mansy, Hansen, Kassab, Alain, Steward, Robert, Zaurin, Ricardo, University of Central Florida
-
Abstract / Description
-
Cardiovascular disease (CVD) is one of the main causes of death in the world. Some CVD involve severe heart valve disease that require valve replacement. There are more than 300,000 heart valves implanted worldwide, and about 85,000 heart valve replacements in the US. Approximately half of these valves are mechanical. Artificial valves may dysfunction leading to adverse hemodynamic conditions. Understanding the normal and abnormal valve function is important as it help improve valve designs....
Show moreCardiovascular disease (CVD) is one of the main causes of death in the world. Some CVD involve severe heart valve disease that require valve replacement. There are more than 300,000 heart valves implanted worldwide, and about 85,000 heart valve replacements in the US. Approximately half of these valves are mechanical. Artificial valves may dysfunction leading to adverse hemodynamic conditions. Understanding the normal and abnormal valve function is important as it help improve valve designs. Modeling of heart valve hemodynamics using computational fluid dynamics (CFD) provides a comprehensive analysis of flow, which can potentially help explain clinical observations and support therapeutic decision-making. This detailed information might not be accessible with in-vivo measurements. On the other hand, finite element analysis (FEA), is an efficient way to analyze the interactions of blood flow with blood vessel and tissue layers. In this project both CFD and FEA simulations were performed to investigate the flow-induced sound generation and propagation of sound waves through a tissue-like material. This method is based on mapping the transient pressure (force) fluctuations on the vessel wall and solving for the structural vibrations in the frequency domain. These vibrations would then be detected as sound on the epidermal surface. Advantages of the methods used in the current study include: (a) capability of providing accurate solution with a faster solution time; (b) inclusion of the fluid(-)structure interaction between blood flow and the arterial wall; and (c) accurately capturing some of the spectral features of the velocity fluctuation measured over the epidermal surface.
Show less
-
Date Issued
-
2018
-
Identifier
-
CFE0007029, ucf:52038
-
Format
-
Document (PDF)
-
PURL
-
http://purl.flvc.org/ucf/fd/CFE0007029
-
-
Title
-
Multi-target high-throughput screening assays for antimicrobial drug discovery.
-
Creator
-
Grube, Christopher, Roy, Herve, Chakrabarti, Debopam, Moore, Sean, Koculi, Eda, University of Central Florida
-
Abstract / Description
-
The rise of antibiotic resistant microbes (bacteria, fungi, and parasites), combined with the current void of new drugs entering the clinical setting, has created an urgent need for the discovery of new antimicrobials. High-throughput screening (HTS) assays represent a fast and cost-efficient method for identifying new therapeutic compounds and have been the longstanding gold standard for drug discovery. The focus of this dissertation is on the development and implementation of novel...
Show moreThe rise of antibiotic resistant microbes (bacteria, fungi, and parasites), combined with the current void of new drugs entering the clinical setting, has created an urgent need for the discovery of new antimicrobials. High-throughput screening (HTS) assays represent a fast and cost-efficient method for identifying new therapeutic compounds and have been the longstanding gold standard for drug discovery. The focus of this dissertation is on the development and implementation of novel methodologies to increase the throughput of target-based HTS by designing assays that allow multiple drug targets to be probed simultaneously. During my graduate studies, I developed three distinct HTS assays. In each of these assays, drug targets were incorporated into synthetic pathways obeying various reaction topologies (e.g., cyclical, parallel, or linear). Each of these reaction topologies conferred specific advantages and limitations to the individual assays. The first assay reconstitutes the bacterial tRNA-dependent pathway for lipid aminoacylation. This two-step pathway combines a tRNA aminoacylation step catalyzed by an aminoacyl-tRNA synthetase (aaRS), and a transferase step, which transfers the amino acid born by the tRNA onto membrane lipids. aaRSs are essential enzymes in all domains of life and represent longstanding drug targets in pathogenic species. The transferase reaction in the pathway is also an appealing drug target since it impacts the cellular permeability of antibiotics. Inhibitors of this reaction could dramatically increase the efficacy of existing therapeutics. The second assay I developed also targets aaRSs, but utilizes a parallel topology that permits the probing of the synthetic and editing activities of up to four aaRSs simultaneously. The third assay utilizes a linear topology that reconstitutes the entire purine salvage pathway from Plasmodium falciparum. Because parasites are unable to synthesize purines de novo, this pathway represents an appealing target for novel antimalarials. Pilot screens using this assay revealed inhibitors for multiple enzymes in the pathway, validating the design of the system. This body of work aims to shift the current paradigm of single-target systems that have historically dominated the HTS field, toward multi-target designs that can be used to more efficiently screen compound libraries against essential pathways in pathogenic microbes.
Show less
-
Date Issued
-
2019
-
Identifier
-
CFE0007642, ucf:52469
-
Format
-
Document (PDF)
-
PURL
-
http://purl.flvc.org/ucf/fd/CFE0007642
-
-
Title
-
Mechanisms of Alpha-Synuclein-Induced Neurodegenertaion in Parkinson's Disease and Stroke.
-
Creator
-
Belal, Cherine, Chan, Sic, Ebert, Steven, Self, William, Teter, Kenneth, University of Central Florida
-
Abstract / Description
-
Parkinson's disease (PD) is a debilitating neurodegenerative disorder affecting one million Americans. Despite its social and economic impact, the pathological cascades that lead to neuron dysfunction and degeneration in PD are poorly understood. Endoplasmic reticulum (ER) stress has been implicated as an initiator or contributing factor in neurodegenerative diseases including PD. The ER is an organelle central to protein folding and intracellular Ca2+ homeostasis. Perturbations of these...
Show moreParkinson's disease (PD) is a debilitating neurodegenerative disorder affecting one million Americans. Despite its social and economic impact, the pathological cascades that lead to neuron dysfunction and degeneration in PD are poorly understood. Endoplasmic reticulum (ER) stress has been implicated as an initiator or contributing factor in neurodegenerative diseases including PD. The ER is an organelle central to protein folding and intracellular Ca2+ homeostasis. Perturbations of these functions result in ER stress and upregulation of ER stress proteins, of which some have been implicated in counteracting ER stress-induced cell death. The mechanisms that lead to ER stress and how ER stress proteins contribute to the degenerative cascades remain unclear but their understanding is critical to devising effective therapies for PD. Both the accumulation of mutant a-synuclein (aSyn), which causes an inherited form of PD, and the inhibition of mitochondrial complex I function by PD-inducing neurotoxin lead to ER stress. The critical involvement of ER stress in experimental models of PD supports its potential relevance to PD pathogenesis and led us to test the hypothesis whether the homocysteine-inducible ER protein (Herp), an ubiquitin-like domain (UBD) containing ER-resident protein, can counteract mutant Alpha Syn- and neurotoxin- induced pathological cascades.
Show less
-
Date Issued
-
2011
-
Identifier
-
CFE0004470, ucf:49310
-
Format
-
Document (PDF)
-
PURL
-
http://purl.flvc.org/ucf/fd/CFE0004470
-
-
Title
-
Determinants of Health-related Quality of Life of Patients with End-stage Renal Disease.
-
Creator
-
Varghese, Shabu, Dziegielewski, Sophia, Burg, Mary Ann, Zhang, Ning, Jacinto, George, University of Central Florida
-
Abstract / Description
-
End-stage Renal Disease (ESRD) or Chronic Kidney Disease (CKD) constitutes a serious public health problem in the United States. According to the United States Renal Data System (USRDS), in 2013, Medicare spending alone accounts for $30.9 billion for the treatment-related expenses for ESRD. The purpose of this study was to examine the causal relationship of two important determinants, perceived social support and treatment adherence with health-related quality of life (HRQOL) of ESRD patients...
Show moreEnd-stage Renal Disease (ESRD) or Chronic Kidney Disease (CKD) constitutes a serious public health problem in the United States. According to the United States Renal Data System (USRDS), in 2013, Medicare spending alone accounts for $30.9 billion for the treatment-related expenses for ESRD. The purpose of this study was to examine the causal relationship of two important determinants, perceived social support and treatment adherence with health-related quality of life (HRQOL) of ESRD patients. Using the health belief model and Bandura's self-efficacy theory, the study explained the theoretical underpinnings of the causal relationships of the patient's perspectives of perceived social support and treatment adherence in predicting the HRQOL of ESRD patients. The study utilized a non-experimental research design and the statistical tool Structural Equation Modeling (SEM), in evaluating the causal relationships between the variables. With a convenience sample size of 413 ESRD patients from the Central West region of Florida, the findings of the study validated a statistically significant relationship between perceived social support and HRQOL as well as between perceived social support and treatment adherence in ESRD patients. However, the study didn't find any significant relationships between treatment adherence and HRQOL. The results of the study enhanced the body of knowledge relating to HRQOL of ESRD patients, provided foundation for interventions and policy formation in improving the HRQOL of patients with ESRD.
Show less
-
Date Issued
-
2016
-
Identifier
-
CFE0006512, ucf:51366
-
Format
-
Document (PDF)
-
PURL
-
http://purl.flvc.org/ucf/fd/CFE0006512
-
-
Title
-
Role of Lipid Peroxide Derived Dicarboxylic Acids in Atherosclerotic Calcification.
-
Creator
-
Riad, Aladdin, Parthasarathy, Sampath, Altomare, Deborah, Masternak, Michal, Naser, Saleh, University of Central Florida
-
Abstract / Description
-
Cardiovascular diseases, including atherosclerosis, are the leading cause of death in the United States. Atherosclerotic lesions are formed by deposition of lipids in the intima of arteries. Upon exposure to oxidative stresses, low-density lipoprotein (LDL) is converted to highly atherogenic oxidized LDL (ox-LDL) particles, contributing to disease development and progression. Advanced disease stages may result in calcification of lesions. This calcification process is important, as it has...
Show moreCardiovascular diseases, including atherosclerosis, are the leading cause of death in the United States. Atherosclerotic lesions are formed by deposition of lipids in the intima of arteries. Upon exposure to oxidative stresses, low-density lipoprotein (LDL) is converted to highly atherogenic oxidized LDL (ox-LDL) particles, contributing to disease development and progression. Advanced disease stages may result in calcification of lesions. This calcification process is important, as it has been shown to be associated with stable plaques that are less prone to rupture. Calcification is present in lipid rich domains of lesions, however neither the composition of the mineralized calcium deposits nor its relationship to lipid peroxidation or the lipid rich atherosclerotic core has previously been identified. This study provides evidence that the lipid peroxide derived dicarboxylic acid (DCA), azelaic acid (AzA) induces calcification in smooth muscle cells, thereby providing the link between calcification and overall plaque burden, and association of calcification with the lipophilic region of the lesion. The potential of lipid peroxide-derived lipophilic DCAs to promote calcification upon exposure to vascular smooth muscle cells was tested. 13-hydroperoxylinoleic acid (HPODE) treatment resulted in the cellular conversion to 9-oxononanoic acid (ONA) and AzA as determined by mass spectrometry analysis. Delivery of AzA via lysophosphatidylcholine (Lyso-PtdCho) micelles induced calcification of human aortic smooth muscle cells (HASMC). AzA was identified in calcified human and mouse atherosclerotic plaques. Calcification of HASMC due to AzA treatment resulted in a less inflammatory and oxidative environment as indicated by genetic expression. These results demonstrate that DCAs may contribute to atherosclerotic calcification thus accounting for the latter's relationship to plaque burden and association with lipids. This study also challenges the dogma that arterial calcification represents the deposition of calcium phosphate and has implications with the development of new therapeutic strategies in treating late stage atherosclerosis.
Show less
-
Date Issued
-
2018
-
Identifier
-
CFE0007413, ucf:52730
-
Format
-
Document (PDF)
-
PURL
-
http://purl.flvc.org/ucf/fd/CFE0007413
-
-
Title
-
Determining differential effects of Interleukin-2 on innate and adaptive immune cells in lymphoid organs and the gastrointestinal Tract.
-
Creator
-
Singh, Ayushi, McKinstry, Karl, Naser, Saleh, Copik, Alicja, University of Central Florida
-
Abstract / Description
-
Interleukin-2 (IL-2) is a pleiotropic cytokine demonstrated to be effective in treating cancer. However, the clinical use of IL-2 can be associated with severe side effects including gastrointestinal toxicity (GT). Similar GT symptoms are observed in inflammatory diseases such as CD (CD). Interestingly mounting evidence indicates a role for IL-2 in CD, but the underlying mechanisms are unknown. Indeed, studies on the in-vivo activities of IL-2 have mostly focused on secondary lymphoid organs...
Show moreInterleukin-2 (IL-2) is a pleiotropic cytokine demonstrated to be effective in treating cancer. However, the clinical use of IL-2 can be associated with severe side effects including gastrointestinal toxicity (GT). Similar GT symptoms are observed in inflammatory diseases such as CD (CD). Interestingly mounting evidence indicates a role for IL-2 in CD, but the underlying mechanisms are unknown. Indeed, studies on the in-vivo activities of IL-2 have mostly focused on secondary lymphoid organs and immune cells associated with them. Very few studies have addressed how IL-2 signals impact populations of immune cells in the gut. Here, we aim to identify and compare the effects of systemic IL-2 administration on six major leukocyte population and their subsets in mice using multicolor flow cytometry. While we confirmed previously observed changes in specific immune cell populations in the spleen, very few changes were seen in the gut and gut associated lymphoid tissues. Unexpectedly, a sharp decline was seen in B cells, most notably in Peyer's Patches, in mice treated with IL-2. Our data furthermore indicates that B cells in IL-2 treated mice undergo enhanced apoptosis in Peyer's Patches. Some studies suggest that changes in B cells may contribute to development of CD. Thus, this study may aid in defining ways in which IL-2 can contribute to disease etiology, and lead to novel treatments for CD.
Show less
-
Date Issued
-
2019
-
Identifier
-
CFE0007865, ucf:52777
-
Format
-
Document (PDF)
-
PURL
-
http://purl.flvc.org/ucf/fd/CFE0007865
-
-
Title
-
Light Scattering Property of Gold Nanoparticles with Applications to Biomolecule Detection and Analysis.
-
Creator
-
Zheng, Tianyu, Huo, Qun, Zou, Shengli, Gesquiere, Andre, Kang, Hyeran, Zhai, Lei, University of Central Florida
-
Abstract / Description
-
Gold nanoparticles (AuNPs) have unique optical and chemical properties. Dynamic light scattering (DLS) is an analytical tool used routinely for nanoparticle size measurement. The combined use of AuNPs and DLS has led to a novel analytical assay technology called D2Dx (from diameter to diagnostics). Herein, my dissertation highlights the extended use of D2Dx for biomolecule detection and analysis. Under this general theme, Chapter 1 provides some background information of AuNPs, DLS, the...
Show moreGold nanoparticles (AuNPs) have unique optical and chemical properties. Dynamic light scattering (DLS) is an analytical tool used routinely for nanoparticle size measurement. The combined use of AuNPs and DLS has led to a novel analytical assay technology called D2Dx (from diameter to diagnostics). Herein, my dissertation highlights the extended use of D2Dx for biomolecule detection and analysis. Under this general theme, Chapter 1 provides some background information of AuNPs, DLS, the principle of D2Dx technique and its potential applications. Chapter 2 summarizes a study on the effect of AuNP concentrations and laser power on the hydrodynamic size measurement of AuNPs by DLS. This study demonstrated the multiple scattering effect on DLS analysis, and how to use the exceptionally high sensitivity of DLS in AuNP aggregate detection for bioassay design and development. Chapter 3 explores a cooperative interaction between AuNP and certain proteins in blood serum that are key to the immune system, leading to a novel diagnostic tool that can conveniently monitor the humoral immunity development from neonates to adults and detect active infections in animals. Chapter 4 reports an application of D2Dx technique for acute viral infection detection based on the active immune responses elicited from mouse models infected with influenza virus. Chapter 5 describes another application of D2Dx for prostate cancer detection. The D2Dx assay identifies prostate cancer patients from non-cancer controls with improved specificity and sensitivity than PSA test. Chapter 6 demonstrates the use of AuNPs and DLS for hydrodynamic size measurement of protein disulfide isomerase with two different conformations. Chapter 7 investigates the concentration-dependent self-assembling behavior of ribostamycin through its interaction with AuNPs in aqueous solution. Overall, this dissertation established several lines of applications of using AuNPs and DLS for biomolecular research and in vitro diagnostics.
Show less
-
Date Issued
-
2018
-
Identifier
-
CFE0007385, ucf:52056
-
Format
-
Document (PDF)
-
PURL
-
http://purl.flvc.org/ucf/fd/CFE0007385
-
-
Title
-
Characterization of Novel Borrelia burgdorferi Transcripts Expressed during Tick and Mammalian Infection.
-
Creator
-
Adams, Philip, Jewett, Mollie, Rohde, Kyle, Moore, Sean, Fernandez-Valle, Cristina, University of Central Florida
-
Abstract / Description
-
The purpose of this dissertation is to characterize the transcriptome of Borrelia (Borreliella) burgdorferi to discover novel transcripts, important for pathogenesis. As a spirochete and the etiological agent of Lyme disease, the foremost vector-borne bacterial infection in the world, B. burgdorferi fulfills a distinctive niche among bacterial pathogens. Persisting in the disparate environments of a tick vector and mammalian reservoirs, it is absolutely dependent on its hosts for transmission...
Show moreThe purpose of this dissertation is to characterize the transcriptome of Borrelia (Borreliella) burgdorferi to discover novel transcripts, important for pathogenesis. As a spirochete and the etiological agent of Lyme disease, the foremost vector-borne bacterial infection in the world, B. burgdorferi fulfills a distinctive niche among bacterial pathogens. Persisting in the disparate environments of a tick vector and mammalian reservoirs, it is absolutely dependent on its hosts for transmission and nutrient acquisition. B. burgdorferi harbors a complex fragmented genome which is largely linear, unlike that of most prokaryotes, lacks an array of classically described metabolic genes, and contains an unusually large percentage of unique genomic sequences specific to Borrelia (Borreliella) species. To date, few regulatory mechanisms have been identified which contribute to the ability of the spirochete to sense and respond to its environment. Efforts to use global transcript analysis to elucidate the molecular mechanisms of B. burgdorferi host adaptation have proven challenging due to the low numbers of the pathogen present during infection. Previously, our laboratory successfully developed an in vivo expression technology based approach for B. burgdorferi (BbIVET) to identify spirochete promoter sequences that are active during a murine infection. This screen identified 233 unique putative promoters which mapped to locations across the entire genome. These putative infection-active B. burgdorferi promoters were not only located at the 5' end of annotated open reading frames (ORFs), but also mapped to unannotated locations antisense, intergenic, and intragenic to ORFs. Given the limited characterization of the B. burgdorferi transcriptome, this dissertation applies an RNA sequencing approach (5'RNA-seq) to globally annotate the transcriptional start sites (TSSs) and 5' processed ends of the spirochete's RNA during in vitro cultivation. This resulted in the discovery of numerous novel internal, intergenic, and antisense transcripts. Synergistic analysis combining Northern blotting techniques, alignments of these transcripts to BbIVET proposed promoters, and interrogation of promoter activity via in vivo live imaging of mice, confirmed the expression of a variety of RNAs during laboratory culture and mammalian infection. Further, as a means to improve quantitation of the expression of these transcripts, a new methodology was developed and applied to measure B. burgdorferi promoter activity during tick-pathogen interactions, in a strand specific manner. Finally, because the Lyme disease spirochete harbors many unclassified and unique genomic sequences, the mammalian infection-expressed gene bb0562, identified through BbIVET and 5'RNA-seq, was selected for targeted deletion and evaluation throughout B. burgdorferi's infectious cycle. This demonstrated that gene bb0562 encodes a membrane associated protein, whose presence is critical for establishing murine infection through the bite of an infected tick. In sum, this work contributes significant insight into the transcriptome of B. burgdorferi, provides an innovative approach for the analysis of RNA transcripts at the tick-pathogen interface, and identifies a novel gene critical for Lyme disease pathogenesis.
Show less
-
Date Issued
-
2017
-
Identifier
-
CFE0006707, ucf:51915
-
Format
-
Document (PDF)
-
PURL
-
http://purl.flvc.org/ucf/fd/CFE0006707
-
-
Title
-
Biomechanical Models of Human Upper and Tracheal Airway Functionality.
-
Creator
-
Kuruppumullage, Don Nadun, Ilegbusi, Olusegun, Kassab, Alain, Moslehy, Faissal, Santhanam, Anand, Mansy, Hansen, Hoffman Ruddy, Bari, University of Central Florida
-
Abstract / Description
-
The respiratory tract, in other words, the airway, is the primary airflow path for several physiological activities such as coughing, breathing, and sneezing. Diseases can impact airway functionality through various means including cancer of the head and neck, Neurological disorders such as Parkinson's disease, and sleep disorders and all of which are considered in this study. In this dissertation, numerical modeling techniques were used to simulate three distinct airway diseases: a weak...
Show moreThe respiratory tract, in other words, the airway, is the primary airflow path for several physiological activities such as coughing, breathing, and sneezing. Diseases can impact airway functionality through various means including cancer of the head and neck, Neurological disorders such as Parkinson's disease, and sleep disorders and all of which are considered in this study. In this dissertation, numerical modeling techniques were used to simulate three distinct airway diseases: a weak cough leading to aspiration, upper airway patency in obstructive sleep apnea, and tongue cancer in swallow disorders. The work described in this dissertation, therefore, divided into three biomechanical models, of which fluid and particulate dynamics model of cough is the first. Cough is an airway protective mechanism, which results from a coordinated series of respiratory, laryngeal, and pharyngeal muscle activity. Patients with diminished upper airway protection often exhibit cough impairment resulting in aspiration pneumonia. Computational Fluid Dynamics (CFD) technique was used to simulate airflow and penetrant behavior in the airway geometry reconstructed from Computed Tomography (CT) images acquired from participants. The second study describes Obstructive Sleep Apnea (OSA) and the effects of dilator muscular activation on the human retro-lingual airway in OSA. Computations were performed for the inspiration stage of the breathing cycle, utilizing a fluid-structure interaction (FSI) method to couple structural deformation with airflow dynamics. The spatiotemporal deformation of the structures surrounding the airway wall was predicted and found to be in general agreement with observed changes in luminal opening and the distribution of airflow from upright to supine posture. The third study describes the effects of cancer of the tongue base on tongue motion during swallow. A three-dimensional biomechanical model was developed and used to calculate the spatiotemporal deformation of the tongue under a sequence of movements which simulate the oral stage of swallow.
Show less
-
Date Issued
-
2018
-
Identifier
-
CFE0007034, ucf:51986
-
Format
-
Document (PDF)
-
PURL
-
http://purl.flvc.org/ucf/fd/CFE0007034
-
-
Title
-
Neurological profile of older ApoE-PON1 double knockout mice.
-
Creator
-
Mitra, Connie, Parthasarathy, Sampath, Kim, Yoon-Seong, Zhao, Jihe, University of Central Florida
-
Abstract / Description
-
Atherosclerosis is a cardiovascular disease where plaques made up of lipids in the form of cholesterol ester build up in the carotid and innominate arteries that supply blood to the brain. Accumulation of the plaques limit the flow of blood and nutrients to the brain, leading to diminished oxygen supply, increased oxidative stress and cell death. All these have been implicated in Alzheimer's disease (AD). Alzheimer's disease, a chronic, progressive, age related neurodegenerative disorder is...
Show moreAtherosclerosis is a cardiovascular disease where plaques made up of lipids in the form of cholesterol ester build up in the carotid and innominate arteries that supply blood to the brain. Accumulation of the plaques limit the flow of blood and nutrients to the brain, leading to diminished oxygen supply, increased oxidative stress and cell death. All these have been implicated in Alzheimer's disease (AD). Alzheimer's disease, a chronic, progressive, age related neurodegenerative disorder is the most common form of dementia in the elderly accounting for 60-80% of the cases. Clinically, Alzheimer's disease is characterized by loss of memory, damage of brain tissues, and neuronal and synaptic loss. Pathologically, it is delineated by accumulation of amyloid beta and tau proteins forming senile plaques and neurofibrillary tangles respectively. Apolipoprotein E (ApoE) polymorphism, increased oxidative stress and products of lipid peroxidation are associated with atherosclerosis and Alzheimer's disease. ApoE is a glycosylated protein that mediates plasma lipoprotein metabolism. ApoE isoforms have differential effect on amyloid beta aggregation and clearance, thus playing an important role in Alzheimer's pathology. Serum paraoxonase 1 (PON1) is a lipoprotein associated antioxidant enzyme that prevents lipid peroxidation. S100B protein is a plasma biomarker, altered expression of which has been implied in AD. We propose the hypothesis that combined deficiencies in apolipoprotein E and antioxidant defense (established by the lack of PON1), together with dyslipidemia and development of carotid atherosclerosis in aging mice would reflect Alzheimer's pathology. The brains of young and old ApoE-PON1 double knockout (DKO) mice and control C57BL/6J mice were harvested. Atherosclerotic lesions were quantified by Image J. RNA was isolated, cDNA was synthesized and quantitative RT-PCR was performed to detect mRNA levels of S100B. Blood levels of S100B protein was measured by ELISA. Brain tissues were stained with Hematoxylin and Eosin stain and 4G8 immunostain to detect histopathological changes. The blood brain barrier (BBB) is altered in AD resulting in increased permeability and vascular dysfunction. The vascular permeability of BBB was analyzed by Evans Blue Dye (EBD) assay. The results showed that the older DKO mice had severe carotid atherosclerosis, increased levels of serum S100B protein and elevated mRNA levels of S100B. Histological examination showed the presence of characteristic hallmarks of AD. The leakage of EBD into brain parenchyma indicated disruption of BBB. The results suggest that diminished blood flow and nutrient supply to the brain due to atherosclerosis and increased oxidative stress might contribute to Alzheimer's pathology. We suggest that older ApoE-PON1 DKO mice may serve as a model of Alzheimer's disease and prevention of atherosclerosis might promote regression of Alzheimer's disease.
Show less
-
Date Issued
-
2016
-
Identifier
-
CFE0006483, ucf:51407
-
Format
-
Document (PDF)
-
PURL
-
http://purl.flvc.org/ucf/fd/CFE0006483
-
-
Title
-
Alpha-Tocopherol Reduces VLDL Secretion Through Modulation of the VLDL Transport Vesicle.
-
Creator
-
Clay, Ryan, Siddiqi, Shadab, Altomare, Deborah, Masternak, Michal, University of Central Florida
-
Abstract / Description
-
The liver distributes serum triacylglycerol (TAG) via the very low-density lipoprotein (VLDL), and an increase in VLDL production may result in hyperlipidemia. VLDL synthesis consists of lipidation of Apolipoprotein B100 (ApoB) as it is co- translationally translocated across the endoplasmic reticulum (ER) membrane, and this nascent VLDL particle must undergo subsequent maturation and post-translational modification in the Golgi. The ER-to-Golgi trafficking of VLDL represents the rate...
Show moreThe liver distributes serum triacylglycerol (TAG) via the very low-density lipoprotein (VLDL), and an increase in VLDL production may result in hyperlipidemia. VLDL synthesis consists of lipidation of Apolipoprotein B100 (ApoB) as it is co- translationally translocated across the endoplasmic reticulum (ER) membrane, and this nascent VLDL particle must undergo subsequent maturation and post-translational modification in the Golgi. The ER-to-Golgi trafficking of VLDL represents the rate-limiting step in VLDL secretion and is mediated by the VLDL Transport Vesicle (VTV). Many in vivo studies have indicated that vitamin E (alpha-tocopherol) supplementation protects against atherosclerosis and can reduce hepatic steatosis in nonalcoholic fatty liver disease (NAFLD), but its effects at the molecular level on hepatic lipid metabolism are poorly understood. To investigate the effects of alpha-tocopherol on hepatic VLDL secretion and cellular lipid retention, we performed several experiments in HepG2 (human) and McARH- 7777 (rat) hepatoma cell lines including pulse-chase experiments using 3H-oleic acid (3H- OA), confocal microscopy with BODIPY lipid droplet staining, and an in vitro VTV budding assay. Our results demonstrate a significant reduction of 3H-TAG secretion and ApoB media expression in response to 100 uM alpha-tocopherol, with a corresponding decrease in markers of VTV biogenesis in western blots of whole cell lysates (WCL) and retention of ApoB within the cell, indicating disruption of an early step in VLDL biogenesis. Further evidence indicates an increase in size and lipidation of the VTV and VLDL particle. BODIPY staining as well as 3H-TAG retention in WCLs was also sharply reduced. Overall, these results indicate that alpha-tocopherol reduces VLDL secretion, partially disrupts hepatic VLDL synthesis and VTV biogenesis, increases the lipidation of remaining VLDL particles, and diminishes overall cellular lipid droplet retention.
Show less
-
Date Issued
-
2019
-
Identifier
-
CFE0007617, ucf:52538
-
Format
-
Document (PDF)
-
PURL
-
http://purl.flvc.org/ucf/fd/CFE0007617
-
-
Title
-
Infectious Disease Risks in Developing Countries: A Non-Market Valuation Exercise.
-
Creator
-
Samajpati, Shreejata, Gerking, Shelby, Dickie, Mark, Caputo, Michael, Roy, Joyashree, University of Central Florida
-
Abstract / Description
-
This dissertation focuses on the non-market valuation of health-risks of malaria, an infectious disease that imposes a substantive public health burden across the globe, hitting particularly hard the tropical developing nations of Africa and Asia. The United Nations Millennium Development Goals include malaria control as a priority and large investments are underway to promote effective prevention and treatment. Despite such concerted supply-side efforts, malaria-related mortality and...
Show moreThis dissertation focuses on the non-market valuation of health-risks of malaria, an infectious disease that imposes a substantive public health burden across the globe, hitting particularly hard the tropical developing nations of Africa and Asia. The United Nations Millennium Development Goals include malaria control as a priority and large investments are underway to promote effective prevention and treatment. Despite such concerted supply-side efforts, malaria-related mortality and morbidity still abound due to a complex interface of factors like climate-change, poverty, inadequate control behavior, infection and prevention externalities, parasite resistance etc. This research project digs into the demand-side of the health problem, considers the "externality" dimension to prevention, and primarily asks the question: how do individuals in developing countries view competing disease-control (prevention) measures, viz. a publicly-administered community-level malaria control measure as against private preventive choices. A theoretical model is developed to help explore the public-private interplay of health risks of malaria. The malaria-endemic regions of Kolkata (India) and its rural fringes comprise the site for an empirical investigation. A field survey (Malaria Risk and Prevention Survey, October-December, 2011) incorporating a mix of stated and revealed preference techniques of health valuation is implemented. Risk-perceptions of respondents are elicited using a measurable visual-aid and individuals' perceived valuations of health-risk reductions, randomly offered with the public and private health treatments, are empirically ascertained. Using a Likelihood Ratio Test on the structural risk parameters, it is seen that individuals' valuations of health risk reductions are the same across the private and public treatments. The comparative valuation exercise, thus, corroborates the externality dimension to malaria control, calling for greater public action to combat malaria. The viability of such a scaled-up public malaria program, in the context of Kolkata, is discussed by comparing the public treatment willingness to pay estimates with the annual estimated costs that the Kolkata Municipal Corporation, the civic body in the city of Kolkata, maintains on account of vector control. Results from the comparative valuation exercises also support the idea that private prevention is generally responsive to prevention costs, indicating the importance of price incentives to induce greater prevention. The issues of health valuation and price sensitivity are further explored across various split-samples differentiated on the basis of socio-economic attributes, disease exposure, actual prevention efforts and perceived malaria risks of survey respondents. Such auxiliary exercises help analyze the valuation question in greater depth, and generate policy insights into the potential factors that shape private prevention behavior.
Show less
-
Date Issued
-
2012
-
Identifier
-
CFE0004594, ucf:49195
-
Format
-
Document (PDF)
-
PURL
-
http://purl.flvc.org/ucf/fd/CFE0004594
-
-
Title
-
Dimensions of State Fragility: Determinants of Violent Group Grievance, Political Legitimacy, (&) Economic Capacity.
-
Creator
-
Christensen, Jason, Kinsey, Barbara, Mousseau, Demet, Hamann, Kerstin, Kircher, Amy, University of Central Florida
-
Abstract / Description
-
State fragility has severe political implications. In the literature, fragile states have been referred to as (")chaotic breeding grounds(") for human rights violations, terrorism, violent extremism, crime, instability, and disease (Patrick 2011, 3-4). International organizations have also expressed concern regarding the potential of (")fragile states(") to disrupt collective security as threats such as transnational terrorism and human displacement from violent conflict have the potential to...
Show moreState fragility has severe political implications. In the literature, fragile states have been referred to as (")chaotic breeding grounds(") for human rights violations, terrorism, violent extremism, crime, instability, and disease (Patrick 2011, 3-4). International organizations have also expressed concern regarding the potential of (")fragile states(") to disrupt collective security as threats such as transnational terrorism and human displacement from violent conflict have the potential to permeate borders (Patrick 2011, 5). This research project aims at extending our understanding of state fragility by examining three distinct dimensions of state fragility proposed in the literature: i) state authority, ii) state legitimacy, and iii) state capacity. I narrow the scope of these dimensions by focusing on 1) violent group grievance, 2) political legitimacy, and 3) state economic capacity, respectively. The first dimension, state authority, is related to a government's control of unlawful intrastate violence. The second dimension, legitimacy, is linked to the public acceptance of the right of an authority to govern law through its practice and influence (Weber 1958, 32-36; Gilley 2006, 48; Connolly 1984, 34). The third dimension, capacity, represents a state-society relationship characterized mainly by the state's ability to provide public goods and protection of citizens and residents from (")harm(") such as natural disasters and economic downfalls (Gr(&)#228;vingholt, Ziaja, and Kreibaum 2012, 7). This dissertation examines each of these dimensions using quantitative analyses based on large-N datasets and cross-sectional longitudinal models to fill gaps in the literature on state fragility. In particular, I hypothesize 1) number of refugees increases the level of intrastate violent group grievance (state authority), 2) state human rights violations decreases popular support and thus public perceptions of state legitimacy, and 3) population constraints, such as food insecurity and disease increase economic decline and thus compromise the state's economic capacity. Internal violence, loss of legitimacy, and a weakened economy may increase levels of state fragility. Each of these three studies controls for alternative explanations and covers the time period between 2006 and 2014. The analysis results confirm the main hypotheses of this study and are expected to offer a more concise conceptual framework of state fragility, and better empirical understanding of potential contributors to state fragility.
Show less
-
Date Issued
-
2017
-
Identifier
-
CFE0006728, ucf:51876
-
Format
-
Document (PDF)
-
PURL
-
http://purl.flvc.org/ucf/fd/CFE0006728
-
-
Title
-
Chlamydia trachomatis Transformants Show a Significant Reduction in Rates of Invasion upon Removal of Key Tarp Domains.
-
Creator
-
Parrett, Christopher, Jewett, Travis, Roy, Herve, Moore, Sean, University of Central Florida
-
Abstract / Description
-
Chlamydia trachomatis is an obligate, intracellular bacterium which is known to cause multiple human infections including nongonococcal urethritis (serovars D-K), lymphogranuloma venereum (serovars L1, L2, L3) and trachoma (serovars A-C). The infectious form of the bacterium, called the elementary body (EB), harbors a type III secreted effector known as Tarp (translocated actin recruiting phosphoprotein) which is a candidate virulence factor and is hypothesized to play a role in C....
Show moreChlamydia trachomatis is an obligate, intracellular bacterium which is known to cause multiple human infections including nongonococcal urethritis (serovars D-K), lymphogranuloma venereum (serovars L1, L2, L3) and trachoma (serovars A-C). The infectious form of the bacterium, called the elementary body (EB), harbors a type III secreted effector known as Tarp (translocated actin recruiting phosphoprotein) which is a candidate virulence factor and is hypothesized to play a role in C. trachomatis' ability to invade and grow within epithelial cells in a human host. C. trachomatis L2 Tarp harbors five unique protein domains which include the Phosphorylation Domain, the Proline Rich Domain, the Actin Binding Domain, and two F-Actin Binding Domains. Tarp has been biochemically characterized in vitro, but it has yet to be characterized in vivo due to a lack of genetic tools in C. trachomatis. Through the recent generation of a chlamydial transformation system, we have created transformants which express epitope tagged wild type or mutant Tarp effectors. In this thesis, C. trachomatis transformants expressing Tarp lacking one of the five biochemically defined protein domains were used to examine both bacterial invasion and bacterial development within mammalian host cells. Our results demonstrate that those EBs which harbor mutant Tarp missing either its Phosphorylation Domain or its Actin Binding Domain were less capable of host cell invasion. However, these transformants, once internalized, were capable of normal development when compared to wild type C. trachomatis or C. trachomatis harboring an epitope tagged wild type Tarp effector. These results suggest that transformant expressed Tarp lacking the Phosphorylation Domain or Actin Binding Domain may be acting as a dominant-negative effector protein. Ultimately, these results support the hypothesis that Tarp is a virulence factor for Chlamydia trachomatis. Furthermore, this data indicates that through the manipulation of the Tarp effector, C. trachomatis pathogenesis may be attenuated.
Show less
-
Date Issued
-
2016
-
Identifier
-
CFE0006159, ucf:51142
-
Format
-
Document (PDF)
-
PURL
-
http://purl.flvc.org/ucf/fd/CFE0006159
Pages