| Veranstaltungskalender der Universität Osnabrück >> August 2013 >> | Angemeldet als: Gast |
| Titel: | Prof. Dr. Johannes Hegemann (Düsseldorf): How it starts...... establishing a chlamydial infection in humans |
| Startdatum/-zeit:: | 22.04.2010 16:15 |
| Enddatum/-zeit: | 22.04.2010 |
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| Adresse: | Prof. Dr. Jürgen Heinisch |
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| Homepage: | http://www.biologie.uni-osnabrueck.de/Fachbereich/?x=ae,expl,aaig |
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| Adresse: | Barbarastr. 11, Hörsaal 35/E01 FB Biologie/Chemie, Barbarastr. 11 49076 Osnabrück |
| Beschreibung: | Chlamydiae are obligate intracellular bacterial pathogens which cause important human diseases in animals and humans. Chlamydia trachomatis is the most prevalent sexually transmitted bacterial pathogen worldwide with more than 90 million new cases every year. Similarly, pulmonary infections with Chlamydia pneumoniae are increasingly recognized as a common cause of community acquired pneumonias. All chlamydial species possess a unique biphasic developmental cycle which is characterized by the extracellular infectious Elementary Body (EB) and the intracellular replicating Reticulate Body (RB). Pathogen adherence to host cell surfaces is the first and most critical step in the establishment of an infection. The specificity of the pathogen–host cell interaction is determined by bacterial surface proteins (adhesins) and receptors on the host cell surface. Using a novel yeast adhesion system we identify and characterize chlamydial proteins involved in bacterial adhesion to and invasion of human cells. The conserved chlamydial OmcB protein mediates adhesion to epithelial HEp-2 and endothelial HUVE cells. The OmcB adhesin binds Glycosaminoglycan (GAG) structures on the human cell surface and this is essential for infection. Recently we characterized members of the polymorphic membrane protein family (Pmp), the largest chlamydial protein family with up to 21 members, as a new class of adhesins. Chlamydia entry depends on invasion-mediating bacterial proteins and we identified the first chlamydial invasin-like protein which mediates uptake by interaction with the human membrane-remodeling SNX9 protein. Collectively the characterization of the early chlamydial steps involved in infection of the human cell provides us with candidate proteins to develop vaccines and to identify new targets for drug intervention. |
| Kategorie: | Biologisches Kolloqium |