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(1 - 13 of 13)
- Title
- RETROCYCLIN RC-101 OVERCOMES CATIONIC MUTATIONS ON THE HEPTAD REPEAT 2 OF HIV-1 GP41.
- Creator
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Fuhrman, Christopher, Cole, Alexander, University of Central Florida
- Abstract / Description
-
Retrocyclin RC-101, a θ-defensin with lectin-like properties, potently inhibits infection by many HIV-1 subtypes by binding to the heptad repeat (HR)-2 region of gp41 and preventing six-helix bundle formation. In the present study, we used in silico computational exploration to identify residues of HR2 that interacted with RC-101 and then analyzed the HIV-1 Sequence Database at LANL for residue variations in the HR1 and HR2 segments that could plausibly impart in vivo resistance. Docking...
Show moreRetrocyclin RC-101, a θ-defensin with lectin-like properties, potently inhibits infection by many HIV-1 subtypes by binding to the heptad repeat (HR)-2 region of gp41 and preventing six-helix bundle formation. In the present study, we used in silico computational exploration to identify residues of HR2 that interacted with RC-101 and then analyzed the HIV-1 Sequence Database at LANL for residue variations in the HR1 and HR2 segments that could plausibly impart in vivo resistance. Docking RC-101 to gp41 peptides in silico confirmed its strong preference for HR2 over HR1, and implicated residues crucial for its ability to bind HR2. We mutagenized these residues in pseudotyped HIV-1 JR.FL reporter viruses, and subjected them to single round replication assays in the presence of 1.25-10ug/ml RC-101. Except for one mutant that was partially resistant to RC-101, the other pseudotyped viruses with single-site cationic mutations in HR2 manifested absent or impaired infectivity or retained wild-type susceptibility to RC-101. Overall, these data suggest that most mutations capable of rendering HIV-1 resistant to RC-101 will also exert deleterious effects on the ability of HIV-1 to initiate infections - an interesting and novel property for a potential topical microbicide.
Show less - Date Issued
- 2007
- Identifier
- CFE0001707, ucf:47333
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0001707
- Title
- GEOGRAPHIC VARIATION IN POST-MATING IMMUNE GENE EXPRESSION INDROSOPHILA MELANOGASTER.
- Creator
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Pinzone, Cheryl, Fedorka, Kenneth, University of Central Florida
- Abstract / Description
-
An organism's immune response may vary due to pathogen pressure in its environment, as well as due to interactions with other organisms. These factors, along with geographic rules (i.e. Gloger's rule) may influence the geographic distribution of the immune response within populations of a species. Here we use real-time quantitative PCR to measure the immune gene expression in six populations collected along the eastern U.S. of Drosophila melanogaster after mating. Antimicrobial genes...
Show moreAn organism's immune response may vary due to pathogen pressure in its environment, as well as due to interactions with other organisms. These factors, along with geographic rules (i.e. Gloger's rule) may influence the geographic distribution of the immune response within populations of a species. Here we use real-time quantitative PCR to measure the immune gene expression in six populations collected along the eastern U.S. of Drosophila melanogaster after mating. Antimicrobial genes did not show significant differences in expression due to location, whereas we did observe differences in anti-fungal and pro-phenoloxidase (anti-macromolecule) related genes. These differences in anti-macromolecule resistance are correlated with the latitude of the population opposite of which we would expect by Gloger's rule. We also determined that males and females from different populations tended to drive the differences we detected. Taken together, these results suggest that geographic factors influence genes involved in fungal and macro-pathogens defense post-mating.
Show less - Date Issued
- 2010
- Identifier
- CFE0003159, ucf:48617
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0003159
- Title
- Climate Change and the Evolution of Insect Immune Function.
- Creator
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Perry, Danae, Fedorka, Kenneth, Jenkins, David, Hoffman, Eric, University of Central Florida
- Abstract / Description
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Insects are ectothermic organisms that have physiological, behavioral and life-history traits directly influenced by their environment. Investigations have shown that many insects use melanin to permanently darken their cuticles in cooler or drier climates to improve thermoregulation and desiccation resistance. Melanin is a major component of pathogen defense in insects. This suggests that environmentally driven adaptive changes in cuticular melanin may non-adaptively shape insect immune...
Show moreInsects are ectothermic organisms that have physiological, behavioral and life-history traits directly influenced by their environment. Investigations have shown that many insects use melanin to permanently darken their cuticles in cooler or drier climates to improve thermoregulation and desiccation resistance. Melanin is a major component of pathogen defense in insects. This suggests that environmentally driven adaptive changes in cuticular melanin may non-adaptively shape insect immune function. This hypothesis has been referred to as climate-related Cuticle Dependent Immune Investment (climate-related CDII). Climate-related CDII also suggests that a warming climate could lead to the evolution of a weakened melanin-based immune response due to direct selection for lighter cuticles. Climate-related CDII has not been investigated with regard to climate change. Using Drosophila melanogaster, the first part of this study investigated if the documented pattern of lowered immune function in warmer temperatures offsets the expected gain in metabolic rate. The second part of this project investigated how a warming thermal environment will affect the evolution of insect immune function by quantifying changes in melanization and immune function over multiple generations in a changing thermal environment. In the first investigation there was evidence for weakened immune function in males, while females saw an offset by gaining a metabolic boost. The second investigation showed evidence that warming treatments evolved lowered overall immune function. This project gives evidence that insect immune function has the potential to be weakened by increasing temperatures. Insect immune function is a major contributing factor to insect abundances. A decrease in beneficial insects or an increase in harmful insects or pathogens they vector could have detrimental environment and human health consequences.?
Show less - Date Issued
- 2017
- Identifier
- CFE0006638, ucf:51256
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0006638
- Title
- The Effect of Parental Population Density on Offspring Immune Function.
- Creator
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Davis, Dana, Fedorka, Kenneth, Savage, Anna, Hoffman, Eric, University of Central Florida
- Abstract / Description
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It is well known that an individual's environment, genetic code, and gene by environment interactions have an effect on its overall phenotype. However, there is a growing body of work that shows that parents can have an effect on their offspring's phenotype beyond the inherited genetic code. Studies have shown that parents may affect their offspring through physiological mechanisms such as egg provisioning and epigenetic effects and through behavioral mechanisms such as maternal care. In many...
Show moreIt is well known that an individual's environment, genetic code, and gene by environment interactions have an effect on its overall phenotype. However, there is a growing body of work that shows that parents can have an effect on their offspring's phenotype beyond the inherited genetic code. Studies have shown that parents may affect their offspring through physiological mechanisms such as egg provisioning and epigenetic effects and through behavioral mechanisms such as maternal care. In many of these cases, the parental effect is triggered by an environmental cue. Previous work has shown that density can impact immune function and cuticle color in insects - two phenotypic traits that are pleiotropically linked. Additional work has shown that parental density can have impacts on offspring immune function, as well. However, previous studies utilized insect species that show a strict density dimorphic phenotype where individuals reared at high densities exhibit increased immune function and much darker cuticles than their low density counterparts, which is not an accurate representation of most insect systems as most insect systems show a more continuous response to density effects. Also, previous work has not determined the parental origin of density effects on offspring immune function and cuticle color. It has been suggested that parental density effects may be due to maternal egg provisioning and that paternal effects may be minimal. However, knowledge of parental origin would give us a better insight into the possible mechanisms of these density driven parental effects and provide a direction for future research. In my study, we used Drosophila melanogaster in order to determine (1) if density affects immune function and cuticle color in a species that shows a continuous response to density, (2) if parental density affects offspring immune function and cuticle color, and (3) if the source of these parental effects are of a maternal origin only or if these effects are of a paternal origin, as well. We found that there is an effect of density on immune function and cuticle color in the parents in a more common insect system and parental density had an effect on offspring phenotype, as well. Most notably, we found that, in addition to the effects of maternal density, these parental effects on offspring phenotype were a response to paternal density, as well.
Show less - Date Issued
- 2017
- Identifier
- CFE0006580, ucf:51355
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0006580
- Title
- THE EFFECT OF CLIMATE ON PHYSIOLOGY AND IMMUNE FUNCTION IN THE ASIAN CITRUS PSYLLID, DIAPHORINA CITRI.
- Creator
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Avecilla, Grace, Fedorka, Ken, University of Central Florida
- Abstract / Description
-
The variation in the insect immune system is an important regulator of insect populations and the pathogens they carry. A central component of insect immunity is melanin, whose production creates cytotoxic intermediates that help to protect against a broad spectrum of pathogens. Melanin is also used in insect cuticle where it helps to improve thermoregulation and desiccation resistance, with insects having less melanized cuticles in warmer and more humid environments. Considering that cuticle...
Show moreThe variation in the insect immune system is an important regulator of insect populations and the pathogens they carry. A central component of insect immunity is melanin, whose production creates cytotoxic intermediates that help to protect against a broad spectrum of pathogens. Melanin is also used in insect cuticle where it helps to improve thermoregulation and desiccation resistance, with insects having less melanized cuticles in warmer and more humid environments. Considering that cuticle melanin and immune melanin are formed by near identical biochemical pathways, they are pleiotropically linked (that is, one or more linked genes influence multiple traits). This has lead to the cuticle-dependent immune investment (CDII) hypothesis, which states that adaptive responses in the cuticle can lead to non-adaptive changes in immunity and could lead to an increase in transmission of insect vectored pathogens in warming climates, due to a weaker defense against the pathogen. However, the impact of CDII on cuticle melanin and immunity, as well as infection prevalence and intensity, under seasonal conditions in the field is still unclear. In this project, we study a population of Asian citrus psyllids, Diaphorina citri, in the field over four seasons. Diaphorina citri vectors a Gram-negative bacteria, Candidatus Liberbacter asiaticus (CLas), that is responsible for Huanglongbing, aka citrus greening disease, which has cost the Florida citrus industry several billion dollars. We assess pathogen load of CLas by quantitative PCR, and assess levels of phenoloxidase activity in the insect hemolymph to measure insect immune function. We assess levels of cuticle melanin. Our results show a significant correlation between temperature, cuticle melanin, and immune function. However, the affect of seasonality on infection prevalence and intensity remains unclear.
Show less - Date Issued
- 2016
- Identifier
- CFH2000080, ucf:45529
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFH2000080
- Title
- Regulation of Extra-Pituitary Prolactin in Monocytes and Macrophages.
- Creator
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Barrett, Richard, Parthasarathy, Sampath, McKinstry, Karl, Masternak, Michal, Zhao, Jihe, University of Central Florida
- Abstract / Description
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Recently it has been shown that leukocytes are capable of producing prolactin (PRL). Evidence of extra-pituitary PRL (ePRL) production is so far been limited to primates and is not shared across other mammal species such as mice and rats. While ePRL is characterized as an identical protein to traditional pituitary PRL, it is controlled under an alternative promoter and is thus regulated differently from pituitary PRL. Little is known about what regulates ePRL or its direct role in human...
Show moreRecently it has been shown that leukocytes are capable of producing prolactin (PRL). Evidence of extra-pituitary PRL (ePRL) production is so far been limited to primates and is not shared across other mammal species such as mice and rats. While ePRL is characterized as an identical protein to traditional pituitary PRL, it is controlled under an alternative promoter and is thus regulated differently from pituitary PRL. Little is known about what regulates ePRL or its direct role in human physiology, but given that PRL has well over 300 described functions, it is likely that the autocrine and paracrine effects of this hormone could have far reaching implications in overall physiology. This work takes some of the first steps in understanding how leukocyte ePRL is regulated. Our results show that, adrenergic hormones are one key stimulus in ePRL expression in monocytes/macrophages. This is particularly intriguing considering the opposing role of these two signals in settings such as adipose tissue where adipose tissue macrophages are constantly exposed to pro-lipolytic adrenergic hormones that would in turn stimulate production of an anti-lipolytic hormone, PRL. Further, our work shows that the inflammatory phenotype of the leukocytes influences basal expression of PRL and overall ePRL expression increases significantly as monocytes differentiate into macrophages, as is a common occurrence in adipose tissue. The final portion of our work shows how monocytes/macrophages also respond to preadipocytes directly. These stem cell precursors to mature adipose cells release an unknown factor that stimulates ePRL production in monocytes/macrophages. Analysis of our gene array shows many of the genes stimulated by adipose stem cells alongside PRL are important genes in tissue regeneration and remodeling, a possible role that fits well with known effects of PRL. Understanding such primate specific interactions between the immune system and major metabolic tissues such as adipose fills vital gaps in knowledge that may explain why so many treatments fail when transitioning from mouse models to humans.
Show less - Date Issued
- 2018
- Identifier
- CFE0007309, ucf:52164
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0007309
- Title
- Novel Immunogens of Cellular Immunity Revealed using in vitro Human Cell-Based Approach.
- Creator
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Schanen, Brian, Self, William, Warren, William, Khaled, Annette, Seal, Sudipta, Zervos, Antonis, University of Central Florida
- Abstract / Description
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Nanotechnology has undergone rapid expansion largely as a result of its enormous potential for applications as biomaterials, drug delivery vehicles, cancer therapeutics, and immunopotentiators. Despite this wave of interest and broad appeal for nanoparticles, evidence of their effect to the human immune system remains scarce. Concerns rise as studies on nanoparticle toxicology continue to emerge indicating that nanomaterials can be acutely toxic and can have long term inflammatory effects as...
Show moreNanotechnology has undergone rapid expansion largely as a result of its enormous potential for applications as biomaterials, drug delivery vehicles, cancer therapeutics, and immunopotentiators. Despite this wave of interest and broad appeal for nanoparticles, evidence of their effect to the human immune system remains scarce. Concerns rise as studies on nanoparticle toxicology continue to emerge indicating that nanomaterials can be acutely toxic and can have long term inflammatory effects as seen in animal models. Based on these findings and the rise in the development of nanoparticle technologies targeting in vivo applications, the urgency to characterize nanomaterial immunogenicity is paramount.Nanoparticles harbor great potential because they possess unique physicochemical properties compared to their larger counter parts as a result of quantum-size effects and their inherent large surface area to volume ratio. These physicochemical properties govern how a nanoparticle will behave in its environment. However, researchers have only just begun to catalogue the biological effect these properties illicit. We took it upon ourselves to investigate nanoparticle size-induced effects using TiO2, one of the most widely manufactured nanoparticles, as a model. We studied these effects in dendritic cells across a human donor pool. We examined dendritic cells because they have an inimitable functional role bridging the innate and adaptive arms of immunity. From this work we found that TiO2 nanoparticles can activate human dendritic cells to become pro-inflammatory in a size-dependent manner as compared to its micron-sized counterpart, revealing novel immune cell recognition and activation by a crystalline nanomaterial.Having identified nanomaterial size as a contributing feature of nanoparticle induced immunopotentiation, we became interested if additional physicochemical properties such as surface reactivity or catalytic behavior could also be immunostimulatory. Moreover, because we witnessed a stimulatory effect to dendritic cells following nanoparticle treatment, we were curious how these nanoparticle-touched dendritic cells would impact adaptive immunity. Since TiO2 acts as an oxidant we chose an antioxidant nanoparticle, CeO2, as a counterpart to explore how divergent nanoparticle surface reactivity impacts innate and adaptive immunity. We focused on the effect these nanoparticles had on human dendritic cells and TH cells as a strategy towards defining their impact to cellular immunity. Combined, we report that TiO2 nanoparticles potentiate DC maturation inducing the secretion of IL-12p70 and IL-1?, while treatment with CeO2 nanoparticles induced IL-10, a hallmark of suppression. When delivered to T cells alone TiO2 nanoparticles induced stronger proliferation in comparison to CeO2 which stimulated TReg differentiation. When co-cultured in allogeneic T cell assays, the materials directed alternate TH polarization whereby TiO2 drives largely a TH1 dominate response, whereas CeO2 was largely TH2 bias. Combined, we report a novel immunomodulatory capacity of nanomaterials with catalytic activity. While unintentional exposure to these nanomaterials could pose a serious health risk, development and targeted use of such immunomodulatory nanoparticles could provide researchers with new tools for novel adjuvant strategies or therapeutics.
Show less - Date Issued
- 2012
- Identifier
- CFE0004629, ucf:49927
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0004629
- Title
- PROTECTION OF THE FEMALE REPRODUCTIVE TRACT IN THE PREVENTION OF HIV.
- Creator
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Diaz, Camila, Cole, Alexander, University of Central Florida
- Abstract / Description
-
Worldwide, more than half of all HIV-infected individuals are women. Since mucosal surfaces are the primary gateway for HIV entry, maintaining the integrity of the female reproductive tract (FRT) is essential for preventing infection. The FRT employs many immune mechanisms that serve as the first line of defense against HIV transmission. Among these are vaginal fluid secretions rich in antimicrobial peptides, and commensal bacteria that colonize the vagina and prevent infections. We sought to...
Show moreWorldwide, more than half of all HIV-infected individuals are women. Since mucosal surfaces are the primary gateway for HIV entry, maintaining the integrity of the female reproductive tract (FRT) is essential for preventing infection. The FRT employs many immune mechanisms that serve as the first line of defense against HIV transmission. Among these are vaginal fluid secretions rich in antimicrobial peptides, and commensal bacteria that colonize the vagina and prevent infections. We sought to study vaginal fluid as an innate immune component of the FRT in the prevention of HIV infection. Additionally, we investigated the anti-HIV microbicide candidate RC-101 as a possible treatment against pathogenic bacteria that disrupt the healthy microbiota of the FRT and create a suboptimal immune state that increases host susceptibility to viruses, such as HIV. Here we report that vaginal fluid collected from healthy females inhibits HIV infection. Moreover, our studies reveal that vaginal fluid collected from Black and White women exhibit disparate anti-HIV activity, possibly rendering Black women more susceptible to HIV infection. In addition, we show that RC-101, which is active against HIV, can also inhibit pathogenic bacteria that compromise FRT innate immunity, providing a dual mechanism of protection against HIV acquisition. Overall, these findings show that vaginal fluid is an important part of female innate immunity that protects the host from heterosexual HIV acquisition. Furthermore, the microbicide RC-101 may prevent HIV infection by both directly preventing viral entry, and by restricting the growth of pathogenic bacteria that disrupt the protective commensal vaginal flora. Together, innate mechanisms and bolstered protection present a multifaceted approach to maintaining effective host immunity.
Show less - Date Issued
- 2012
- Identifier
- CFH0004150, ucf:44842
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFH0004150
- Title
- Role of Mycobacterium avium paratuberculosis (MAP) and TNFSF15 SNPs on TL1A in CD.
- Creator
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Hassouneh, Sayf Al-Deen, Naser, Saleh, Yooseph, Shibu, Parthasarathy, Sampath, University of Central Florida
- Abstract / Description
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Tumor Necrosis Factor-Like Ligand 1a (TL1A) is a cytokine encoded by Tumor Necrosis Factor Super Family 15 gene (TNFSF15) gene mostly in endothelial cells which binds to T-cells and foments the production of pro-inflammatory cytokines including TNF-?, IL-6, IL-1b, IFN- ? and IL-13. TL1A level is elevated in inflammatory diseases including Crohn's Disease (CD). Although Single Nucleotide Polymorphisms (SNPs) in TNFSF15 have been reported in CD, no studies have investigated the effect of these...
Show moreTumor Necrosis Factor-Like Ligand 1a (TL1A) is a cytokine encoded by Tumor Necrosis Factor Super Family 15 gene (TNFSF15) gene mostly in endothelial cells which binds to T-cells and foments the production of pro-inflammatory cytokines including TNF-?, IL-6, IL-1b, IFN- ? and IL-13. TL1A level is elevated in inflammatory diseases including Crohn's Disease (CD). Although Single Nucleotide Polymorphisms (SNPs) in TNFSF15 have been reported in CD, no studies have investigated the effect of these SNPs on TL1A, inflammation, and susceptibility to Mycobacterium avium subspecies paratuberculosis (MAP) infection. MAP is a strong candidate in CD pathogenesis. This study is designed to elucidate the combined effect of MAP and SNPs in TNFSF15 (rs4263839, rs7848647, rs6478108, or rs6478109) on TL1A secretion and downstream effect on pro-inflammatory cytokines. Peripheral blood from CD and healthy subjects was analyzed for MAP DNA, TNFSF15 genotyping, circulating TL1A level, and IFN- ? and TNF-? gene expression. Our data is first to report that rs4263839, rs7848647, rs6478108, and rs6478109 in TNFSF15 resulted in increase in circulating TL1A level in healthy and CD samples. Specifically, in CD samples with rs7848647, the average TL1A level was 146.9 pg/mL (&)#177; 124.5 compared 62.4 pg/mL (&)#177; 82.8 in normal samples. Similarly, TL1A level in CD samples with rs6478109 was 141.9 pg/mL (&)#177; 127.7 compared to 71.5 pg/mL (&)#177; 88.4 in normal samples (p(<)0.05). All 4 SNPs resulted in significant elevation in TL1A level in healthy samples (p(<)0.05). Moreover, IFN-? expression was significantly higher, by approximately 1.6-fold in CD patients with SNPs relative to CD patients with no SNPs (p(<)0.05). Interestingly, SNPs in TNFS15 had no significant effect on TNF-? expression. MAP was detected in the blood of 63% of CD compared to 6% healthy subjects (p(<).001). The data did not support a correlation between MAP presence and circulating TL1A levels, and no correlation between SNPs in TNSF15 and MAP susceptibility. This study strongly suggests, that SNPs in TNFSF15 increase TL1A levels and may be a contributory factor to the inflammation experienced by CD patients. Over all, the study emphasizes the need for a pharmacogenomic approach in treatment delivery for patients with CD by using TNFSF15 SNPs to identify patients that would benefit from biologics targeting TL1A rather than TNF-? for more efficacious treatment regiments for CD patients.
Show less - Date Issued
- 2018
- Identifier
- CFE0007189, ucf:52263
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0007189
- Title
- The Role of the Y-Chromosome in the Evolution of Autosomally Coded Traits.
- Creator
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Kutch, Ian, Fedorka, Kenneth, Vonkalm, Laurence, Hoffman, Eric, University of Central Florida
- Abstract / Description
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Recent work indicates that the Y-chromosome of the fruit fly Drosophila melanogaster can influence gene regulation on the autosomes and X chromosome. This newly discovered function of the Y has the potential to dramatically shape the regulatory evolution of numerous genes that reside throughout the genome; even for genes that code for both male and female traits. Given that the mechanism underlying the Y-linked influence on gene expression in D. melanogaster appears to exist in other...
Show moreRecent work indicates that the Y-chromosome of the fruit fly Drosophila melanogaster can influence gene regulation on the autosomes and X chromosome. This newly discovered function of the Y has the potential to dramatically shape the regulatory evolution of numerous genes that reside throughout the genome; even for genes that code for both male and female traits. Given that the mechanism underlying the Y-linked influence on gene expression in D. melanogaster appears to exist in other independently evolved heterogametic sex chromosomes, the evolutionary implications of Y-linked regulatory variation (YRV) deserves to be explored. These implications include the potential for Y-chromosomes to facilitate the adaptive evolution of sexually dimorphic gene expression, and the potential for the Y to constrain evolutionary rates in both males and females (depending on the nature of the YRV effect). Unfortunately, the evolutionary implications of this potentially widespread and significant phenomenon have yet to be explored. My dissertation addresses this knowledge gap by determining the influence YRV has on the evolution of autosomally coded traits in D. melanogaster. First, we address the potential for selection to shape YRV by determining if YRV (i) exists within natural populations (i.e. where natural selection operates), and (ii) has any influence on male fitness-related autosomal traits. Second, we address if YRV can facilitate the adaptive evolution of sexually dimorphic gene expression by testing for the presence of Y-linked additive genetic variation. To this end, we investigate the physiological properties of select Y-chromosomes across multiple genetic backgrounds. Third, we address if YRV can constrain adaptive evolution for autosomally coded traits by employing artificial selection on replicate populations that contain either multiple Y-chromosomes (i.e. contain YRV) or only a single Y-chromosome (no YRV). The following studies present evidence that YRV does exist within populations where natural selection operates. We show significant levels of YRV on X-linked and autosomal immune gene expression in wild caught D. melanogaster from a single natural population. Furthermore, YRV effects on immune related genes show a significantly positive correlation to a male fly's ability to fight an immune challenge (an important aspect of organismal fitness). Estimated physiological properties of YRV support previous interpopulation studies showing strong non-additive effect dependent on the autosomal genetic background with which Y-chromosome's are paired with. Physiological epistasis can manifest as additive genetic variation on a population level, but our experimental evolution study suggest that YRV constrains rather than facilitates the evolution of the autosomal coded geotaxis behavior. Ultimately, this dissertation provides evidence that YRV has the potential to influence how autosomal traits evolve and that population level studies of YRV indicate a potential constraint to the adaptive evolution of autosomal traits. If these trends are common and YRV is a wide spread phenomenon, Y-chromosomes have the potential to influence how autosomal traits evolve.
Show less - Date Issued
- 2017
- Identifier
- CFE0006756, ucf:51873
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0006756
- Title
- Role of host immune response and bacterial autolysin Atl in human nasal colonization by Staphylococcus aureus.
- Creator
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Paramanandam, Vanathy, Cole, Alexander, Naser, Saleh, Self, William, University of Central Florida
- Abstract / Description
-
Staphylococcus aureus (SA) is a major human pathogen that colonizes the anterior nares in 30% of the human population. Though nasal carriage of SA is a known risk factor for the subsequent spread of SA infections, the dynamics of SA nasal colonization is poorly understood. Our research focuses on understanding the host and bacterial factors that might contribute to the human nasal colonization by SA. In an attempt to elucidate the host response to SA, we performed an autologous human in vivo...
Show moreStaphylococcus aureus (SA) is a major human pathogen that colonizes the anterior nares in 30% of the human population. Though nasal carriage of SA is a known risk factor for the subsequent spread of SA infections, the dynamics of SA nasal colonization is poorly understood. Our research focuses on understanding the host and bacterial factors that might contribute to the human nasal colonization by SA. In an attempt to elucidate the host response to SA, we performed an autologous human in vivo nasal colonization study, which showed decreased survival rates of SA in hosts who elicited a robust immune response. We also identified a significant correlation between SA nasal colonization and the expression of host proinflammatory, chemotactic and growth factors.Additionally, we functionally disrupted a major autolysin, atl a surface expressed bacterial protein that plays multiple roles in cell separation, adhesion and biofilm formation of SA. Microscopic analysis of the ?atl strains showed phenotypic differences, including cell clumping and cluster formation due to defective cell separation, which confirmed the functional loss of atl. Subsequent analysis of the ?atl and wild-type strains revealed that there was no significant difference in their ability to adhere to human nasal epithelial cells (hNEC) in an ex vivo hNEC model. Similarly, our competitive in vivo human nasal colonization study, in which equal colony-forming units of each wild-type and ?atl SA strain were inoculated in the anterior nares of donors, showed similar survival rates between wild-type and ?atl. These results suggest that Atl might not be directly involved in the adherence and colonization of SA to the anterior nares. Furthermore, our study suggests that host factors might play a predominant role in determining SA colonization to human anterior nares.
Show less - Date Issued
- 2013
- Identifier
- CFE0005393, ucf:50463
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0005393
- Title
- SOURCE REPRESENTATION AND FRAMING IN CHILDHOOD IMMUNIZATION COMMUNICATION.
- Creator
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Raneri, April, Matusitz, Jonathan, University of Central Florida
- Abstract / Description
-
Research has indicated a strong interest in knowing who is being represented and how information is being represented in the communication about childhood immunization. This study uses a two-part analysis to look at source representation and framing in childhood immunization communication. A quantitative analysis of articles from the New York Times and USA Today were examined for their source representation, their use of fear appeals, through the Extended Parallel Processing Model (EPPM), and...
Show moreResearch has indicated a strong interest in knowing who is being represented and how information is being represented in the communication about childhood immunization. This study uses a two-part analysis to look at source representation and framing in childhood immunization communication. A quantitative analysis of articles from the New York Times and USA Today were examined for their source representation, their use of fear appeals, through the Extended Parallel Processing Model (EPPM), and the use of frames, through the application of Prospect Theory. A qualitative semiotic analysis was conducted on 36 images that appeared on www.yahoo.com and www.google.com to find common themes for who is being represented and how information is being portrayed through the images. Results found a high prevalence of representation from the Center for Disease Control and Prevention, other governmental agencies and views from health/medical professionals in both the articles and images.
Show less - Date Issued
- 2010
- Identifier
- CFE0003016, ucf:48343
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0003016
- 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
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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
