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11 results on '"Barthel, Diana"'

2. Staphylococcus aureus proteins Sbi and Efb recruit human plasmin to degrade complement C3 and C3b

Author

Koch, Tina K., Reuter, Michael, Barthel, Diana, Böhm, Sascha, Elsen, Jean van den, Kraiczy, Peter, Zipfel, Peter F., Skerka, Christine, Koch, Tina K., Reuter, Michael, Barthel, Diana, Böhm, Sascha, Elsen, Jean van den, Kraiczy, Peter, Zipfel, Peter F., and Skerka, Christine

Abstract

Upon host infection, the human pathogenic microbe Staphylococcus aureus (S. aureus) immediately faces innate immune reactions such as the activated complement system. Here, a novel innate immune evasion strategy of S. aureus is described. The staphylococcal proteins surface immunoglobulin-binding protein (Sbi) and extracellular fibrinogen-binding protein (Efb) bind C3/C3b simultaneously with plasminogen. Bound plasminogen is converted by bacterial activator staphylokinase or by host-specific urokinase-type plasminogen activator to plasmin, which in turn leads to degradation of complement C3 and C3b. Efb and to a lesser extend Sbi enhance plasmin cleavage of C3/C3b, an effect which is explained by a conformational change in C3/C3b induced by Sbi and Efb. Furthermore, bound plasmin also degrades C3a, which exerts anaphylatoxic and antimicrobial activities. Thus, S. aureus Sbi and Efb comprise platforms to recruit plasmin(ogen) together with C3 and its activation product C3b for efficient degradation of these complement components in the local microbial environment and to protect S. aureus from host innate immune reactions.

Published
2012

3. BBA70 of Borrelia burgdorferi Is a Novel Plasminogen-binding Protein

Author

Koenigs, Arno, primary, Hammerschmidt, Claudia, additional, Jutras, Brandon L., additional, Pogoryelov, Denys, additional, Barthel, Diana, additional, Skerka, Christine, additional, Kugelstadt, Dominik, additional, Wallich, Reinhard, additional, Stevenson, Brian, additional, Zipfel, Peter F., additional, and Kraiczy, Peter, additional

Published
2013
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11. Borrelia burgdorferiInfection-Associated Surface Proteins ErpP, ErpA, and ErpC Bind Human Plasminogen

Author

Brissette, Catherine A., Haupt, Katrin, Barthel, Diana, Cooley, Anne E., Bowman, Amy, Skerka, Christina, Wallich, Reinhard, Zipfel, Peter F., Kraiczy, Peter, and Stevenson, Brian

Abstract

ABSTRACTHost-derived plasmin plays a critical role in mammalian infection by Borrelia burgdorferi. The Lyme disease spirochete expresses several plasminogen-binding proteins. Bound plasminogen is converted to the serine protease plasmin and thereby may facilitate the bacterium's dissemination throughout the host by degrading extracellular matrix. In this work, we demonstrate plasminogen binding by three highly similar borrelial outer surface proteins, ErpP, ErpA, and ErpC, all of which are expressed during mammalian infection. Extensive characterization of ErpP demonstrated that this protein bound in a dose-dependent manner to lysine binding site I of plasminogen. Removal of three lysine residues from the carboxy terminus of ErpP significantly reduced binding of plasminogen, and the presence of a lysine analog, ε-aminocaproic acid, inhibited the ErpP-plasminogen interaction, thus strongly pointing to a primary role for lysine residues in plasminogen binding. Ionic interactions are not required in ErpP binding of plasminogen, as addition of excess NaCl or the polyanion heparin did not have any significant effect on binding. Plasminogen bound to ErpP could be converted to the active enzyme, plasmin. The three plasminogen-binding Erp proteins can also bind the host complement regulator factor H. Plasminogen and factor H bound simultaneously and did not compete for binding to ErpP, indicating separate binding sites for both host ligands and the ability of the borrelial surface proteins to bind both host proteins.

Published
2009
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