Loading...
Files
Date
Authors
Publisher
Philipps-Universität Marburg
Supervisors
Abstract
The airway epithelium is positioned at the interface with the environment. In addition to its passive barrier function it plays a direct role in the inflammation- and immune response. Several studies have shown that airway epithelial functionally express toll-like receptors and therefore have the capacity to detect microorganisms. They respond to microbial exposure with the secretion of cytokines, chemokines and antimicrobial substances. The epithelium is constantly exposed to a multiplicity of microbes, remarkably not each contact led to an inflammation. Therefore the reactivity of the epithelial cells must be somehow regulated. Macrophages are potent effector cells of the immune system. By the secretion of different cytokines they have the ability to influence the reactivity of other cells. The aim of this study was to characterize the interaction of airway epithelial cells and macrophages in the event of an infection. It could be shown that the secretion of TNF-α by the macrophages led to a pronounced expression of TLR2 and TLR5 the main receptors for the detection of gram positive and gram negative bacteria. This resulted in a better a better recognition of bacteria by the epithelial cells and therefore in an improved immune response of the epithelium.
Aspergillus fumigatus is a fungal pathogene of major clinical importance. Inhaltation of fungal spores may cause lung diseases, ranging from local inflammation of the airways to severe and life threatening infections of the lung. It is established that alveolar macrophages provide the first line of defence in the respiratory tract. Mice studies show that macrophage-mediated response to Aspergillus fumigatus conidia is MyD88-independent. Little is known about the role of the airway epithelium in Aspergillus fumigatus induced inflammation. It could be shown that airway epithelial cells recognize resting conidia but not other swollen conidia or hyphae of Aspergillus fumigatus. Detection of conidia by the cells was internalization dependent and resulted in a strong expression of IFN-ß and IRG´s (interferon-response-genes). Further investigation showed that the cells recognize doublestranded-RNA released by the conidia during endosomal digestion and that this reaction is TLR3-mediated.
Review
Metadata
Contributors
Supervisor:
Dates
Created: 2007Issued: 2007-06-08Updated: 2011-08-10
Faculty
Medizin
Publisher
Philipps-Universität Marburg
Language
ger
Data types
DoctoralThesis
Keywords
Toll-like-receptorInnate immunityAirway epithelial cellsAspergillus fumigatus
DFG-subjects
ImmunsystemInfektionLungeImmunreaktionToll-like-RezeptorenAspergillus
DDC-Numbers
610
show more
Hess, Christian: Die Rolle des Atemwegsepithels als Sensor der angeborenen Immunität. : Philipps-Universität Marburg 2007-06-08. DOI: https://doi.org/10.17192/z2007.0347.
License
This item has been published with the following license: In Copyright