This thesis focuses on the role of chemokine receptors CXCR3 and CCR2 in the inflammatory process and infection control using the zebrafish model. It describes the regulatory interplay between an... Show moreThis thesis focuses on the role of chemokine receptors CXCR3 and CCR2 in the inflammatory process and infection control using the zebrafish model. It describes the regulatory interplay between an atypical and a conventional chemokine receptor during chemotaxis in macrophages, the role of chemotactic signaling in cell polarization and explores an in vivo screening workflow for human anti-inflammatory drugs using zebrafish. Show less
Inflammation is an immune reaction of the body to the external stimuli such as toxins or pathogens, and is characterized by redness, swelling, pain, and heat. The process of inflammation is... Show moreInflammation is an immune reaction of the body to the external stimuli such as toxins or pathogens, and is characterized by redness, swelling, pain, and heat. The process of inflammation is regulated by several pro-inflammatory and antiinflammatory cytokines. Tumor necrosis factor-_ (TNF-_) is a major pro-inflammatory cytokine involved in the inflammatory response.Elevated TNF-_ expression has been found to be associated with the development of diabetes, atherosclerosis, septic shock, and tumorigenesis. Thus inhibition of TNF-_ at any step of inflammatory pathways provides an attractive treatment for inflammatory diseases as well as for series of other common diseases.Plants provide an alternative sources of medicines used traditionally by people worldwide since thousands of years ago. The aim of this thesis was to develop methods for the rapid identification of active compounds in plant extracts by correlating NMR metabolomics and bioassay results by means of multivariate data analysis. This work demonstrates the great potential of NMR spectroscopy in combination with chemometrics for the screening of large set of crude extracts, to study the effects of different variables on the activity, and identifying sets of active compounds in complex mixtures like plant extracts. Show less
In the last decade the study of the innate immune system has gained renewed scientific momentum as a result of the discovery of essential receptor families, such as the Toll-like receptor (TLR)... Show moreIn the last decade the study of the innate immune system has gained renewed scientific momentum as a result of the discovery of essential receptor families, such as the Toll-like receptor (TLR) family, that are required for pathogen recognition. These receptors detect specific molecular structures of microorganisms and in turn are able to trigger host immune responses. The work described in this thesis focuses on the use of the zebrafish embryo as a model to study the vertebrate immune system in order to gain new insights into the mechanisms of innate immune defence against bacterial infections and TLR signalling. Making use of a Salmonella infection model in combination with microarray technology and gene knock-down studies we were able to thoroughly characterize the embryonic host transcriptome response to a bacterial infection. Furthermore, we have demonstrated important functions for key signalling molecules in the innate immune response, including Tlr5, MyD88 and Traf6 and discovered new downstream targets of the TLR signalling pathway. The data presented here will enable in-depth functional follow-up studies that will provide new insights into the mechanisms of innate immune defence systems. This, in combination with future applications of zebrafish embryo infection models in high-throughput compound screens, holds much promise for the discovery of novel anti-microbial and anti-inflammatory drugs. Show less
