Induction and Evasion of Neutrophil Extracellular Traps by Campylobacter jejuni and its Implication in Disease

Campylobacteriosis, the foodborne disease caused by Campylobacter spp., infects one out of 10 individuals every year. C. jejuni accounts for 90% of these infections resulting in numerous postinfectious disorders including the development of colorectal cancer, Guillain-Barré syndrome, irritable bowel syndrome, and reactive arthritis. Despite its large impact on human health, the host immune response to the bacterium is largely uncharacterized. Chapter two of this dissertation addresses the development of neutrophil extracellular traps (NETs) within human and ferret campylobacteriosis. We observed NET-associated proteins increase in the feces of C. jejuni-infected patients and that in vitro C. jejuni induces NETs, which are cytotoxic to colonic epithelial cells. Furthermore, we observed NET-like structures within intestinal tissue of C. jejuni-infected ferrets where C. jejuni colonizes and causes tissue pathology. The work presented in chapter three of this dissertation characterizes a novel secreted C. jejuni effector, a sirtuin-like protein (SliP), which we found induces NETs. SliP is secreted into neutrophils, where it deacetylates proteins, specifically histone H3. As histone H3 acetylation plays a crucial role in chromatin structure and host transcription, activity of SliP could have immense impacts on the host cell physiology. Leveraging the murine model of campylobacteriosis, we determined a C. jejuni sliP mutant efficiently infects mice, but induction of proinflammatory cytokines and gastrointestinal pathology is decreased compared to wild-type C. jejuni infected mice demonstrating the importance of this protein in immune pathology in vivo. Finally, the work done in chapter four of this dissertation sought to characterize a C. jejuni nuclease (MugA) and its ability to assist in NET evasion. In this work, we performed a transposon screen of C. jejuni for nuclease production. We discovered that a mugA mutant was sensitive to NET killing and lacked nuclease activity. Interestingly, MugA degraded NETs lead to inflammasome activation within macrophages, and subsequent host inflammation. In conclusion, this dissertation demonstrates the influence of NETs within campylobacteriosis and highlights a potential target for therapeutic strategies. By specifically targeting SliP and MugA in C. jejuni for their role in immune modulation, these could be attractive therapeutics to reduce host inflammation and potential post-infectious disorder onset

The quorum-sensing regulation of Vibrio fischeri : novel components of the autoinducer/LuxR regulatory circuit

Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution June 1999In the marine bacterium Vibrio fischeri two intercellular homoserine-Iactone signal molecules (luxI-dependent 30C6-HSL and the ainS-dependent C8-HSL) and the transcriptional activator LuxR regulate the luminescence system in a cell-density dependent manner by a process termed quorum sensing. In this study, five additional proteins whose production is regulated by quorum sensing are described, and the genes encoding four of the five proteins, denoted as QsrP, RibB, QsrV, and AcfA, are analyzed. Each protein is positively regulated by 30C6-HSL and LuxR and negatively regulated at low population density by C8-HSL. Probable LuxR/autoinducer binding sites are found in the promoter region of each. QsrP and RibB are encoded monocistronically, whereas AcfA and QsrV appear to be encoded by a two-gene operon. On the basis of sequence similarity to proteins of known function from other organisms, RibB is believed to be an enzyme that catalyzes the transformation of ribulose 5-phosphate to 3,4-dihydroxy-2- butanone 4-phosphate, a precursor for the xylene ring of riboflavin; AcfA is believed to be a pilus subunit; and the functions of QsrP and QsrV are unknown at this time. A qsrP mutant was reduced in its ability to colonize its symbiotic partner, Euprymna scolopes when placed in competition with the parent strain. On the other hand, a mutant strain of V. fischeri containing an insertion in acfA, which is believed to be polar with respect to qsrV, displayed enhanced colonization competence in a competition assay. A ribB mutant grew well on media not supplemented with additional riboflavin and displayed normal induction of luminescence. Both phenotypes suggest that the lack of a functional ribB gene is complemented by another gene of similar function in the mutant. Oriented divergently from acfA are open reading frames that code for two putative proteins that are similar in sequence to members of the LysR family of transcriptional regulators. Organization of the two divergent sets of genes and the shared promoter region suggests that transcription of acfA and qsrV may be regulated by one or both of these divergently transcribed proteins. This work defines a quorum-sensing regulon in V. fischeri. A model describing its regulation is presented.Woods Hole Oceanographic Institution, including The J. Seward Johnson Fund, for contributing financiall

Growth of Bluegill, Largemouth Bass, and Channel Catfish in Relation to Fish Abundances, Food Availability, and Other Limnological Variables

Bluegill, largemouth bass, and channel catfish are widely distributed and popular sports species. We assessed growth of sympatric populations of these species in 14 reservoirs throughout Illinois, and attempted to relate growth to environmental factors. Principal components analysis (PCA) classified the lakes using 20 morphometric and limnological variables. We examined growth rate relationships with the principal components, via correlations, and also developed simple and multiple regression models using individual variables. Using size-specific growth for two size classes, percent littoral zone of a lake was correlated with growth of both channel catfish (300 and 450 mm) and small bluegill (50 mm). Lake latitude was correlated with growth of large bluegill (150 mm). There were no significant correlations for either size of largemouth bass (100 and 250 mm). Our empirical relationships provide working models of fish growth and suggest testable hypotheses for future study. The models, when tested against independent data sets, will provide managers with useful tools for making inexpensive, a priori assessments of a fishery resource

Principals\u27 Practices Contributing to the Attainment of Adequate Yearly Progress in Georgia

The leadership focus for school improvement has changed from managing the political environment of the school to focusing on continuous improvement. The purpose of this study was to examine Georgia school principals\u27 practices that are used to improve student achievement in order to meet Adequately Yearly Progress (AYP). The study included elementary, middle, and high school principals from selected schools that made AYP. Focus groups from each of the schools were also interviewed and included parents, teachers and other school leadership. The same interview questions asked of the principal were also asked of the focus groups. The responses from the unstructured interviews were reported in narrative form and identified leadership practices principals used to improve student achievement. After conducting a thorough review of literature in the area of school principals practices, the relationship of the impact of practices and student achievement was examined. The findings of the study included organizing the school to support students who are struggling academically, communication of expectations, and controlling the instructional program. This study also found differences between elementary and middle and high schools: The community and school leaders\u27 beliefs at the elementary level were primarily related to instructional practices, whereas at the middle and high school levels more focus was placed on programmatic practices. Based on the results, the study concluded that principals\u27 practices can impact the potential for a school making AYP, but continued educational research is needed to expand the understanding of the specific practices that principals need in order to create environments in which students can achieve higher levels of learning

Gerber Project for Lockheed Martin

Lockheed Martin, the world’s premier aerial combat vehicle manufacturer was pressed to find an eco-friendly way to package their impregnated epoxy. In the current system, the epoxy would be cut on the Gerber table to a pre-determined length and then sandwiched inside of two corrugated fiberboard sheets for storage inside of a freezer. The current process was not only labor intensive, but the corrugated fiberboard had to be disregarded after one use. In conjunction with the Cal Poly San Luis Obispo Packaging program and Melmat Incorporated, we were able to find a corrugated plastic substrate to replace the currently non-reusable fiberboard. Through a very tedious design process and multiple prototypes, we were able to construct a working prototype for Lockheed which they were able to test in a closed environment. The polypropylene material held up well after being subjected to cold and room temperature environments. The following report details the whole senior project in its entirety and summarizes how we found a solution for Lockheed Martin

Introduction to General Psychology (Georgia Highlands College)

This Grants Collection for Introduction to General Psychology was created under a Round Three ALG Textbook Transformation Grant. Affordable Learning Georgia Grants Collections are intended to provide faculty with the frameworks to quickly implement or revise the same materials as a Textbook Transformation Grants team, along with the aims and lessons learned from project teams during the implementation process. Documents are in .pdf format, with a separate .docx (Word) version available for download. Each collection contains the following materials: Linked Syllabus Initial Proposal Final Reporthttps://oer.galileo.usg.edu/psychology-collections/1000/thumbnail.jp

Introduction to Philosophy (GHC)

This Grants Collection for Introduction to Philosophy was created under a Round Eleven ALG Textbook Transformation Grant. Affordable Learning Georgia Grants Collections are intended to provide faculty with the frameworks to quickly implement or revise the same materials as a Textbook Transformation Grants team, along with the aims and lessons learned from project teams during the implementation process. Documents are in .pdf format, with a separate .docx (Word) version available for download. Each collection contains the following materials: Linked Syllabus Initial Proposal Final Reporthttps://oer.galileo.usg.edu/philosophy-collections/1001/thumbnail.jp

Introduction to Sociology (GHC)

This Grants Collection for Introduction to Sociology was created under a Round Five ALG Textbook Transformation Grant. Affordable Learning Georgia Grants Collections are intended to provide faculty with the frameworks to quickly implement or revise the same materials as a Textbook Transformation Grants team, along with the aims and lessons learned from project teams during the implementation process. Documents are in .pdf format, with a separate .docx (Word) version available for download. Each collection contains the following materials: Linked Syllabus Initial Proposal Final Reporthttps://oer.galileo.usg.edu/psychology-collections/1018/thumbnail.jp

Is There a Relationship Between Sport Gambling and Fandom?

Our group looked into the relatioship between sport gambling and the impact it has on the experience of viewing an event