| 1. |
- Gustafsson, Erika, et al.
(författare)
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Directed evolution of chemotaxis inhibitory protein of Staphylococcus aureus generates biologically functional variants with reduced interaction with human antibodies
- 2010
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Ingår i: Protein Engineering Design & Selection. - : Oxford University Press (OUP). - 1741-0126 .- 1741-0134. ; 23:2, s. 91-101
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Tidskriftsartikel (refereegranskat)abstract
- Chemotaxis inhibitory protein of Staphylococcus aureus (CHIPS) is a protein that binds and blocks the C5a receptor (C5aR) and formylated peptide receptor, thereby inhibiting the immune cell recruitment associated with inflammation. If CHIPS was less reactive with existing human antibodies, it would be a promising anti-inflammatory drug candidate. Therefore, we applied directed evolution and computational/rational design to the CHIPS gene in order to generate new CHIPS variants displaying lower interaction with human IgG, yet retaining biological function. The optimization was performed in four rounds: one round of random mutagenesis to add diversity into the CHIPS gene and three rounds of DNA recombination by Fragment INduced Diversity (FIND((R))). Every round was screened by phage selection and/or ELISA for decreased interaction with human IgG and retained C5aR binding. The mean binding of human anti-CHIPS IgG decreased with every round of evolution. For further optimization, new amino acid substitutions were introduced by rational design, based on the mutations identified during directed evolution. Finally, seven CHIPS variants with low interaction with human IgG and retained C5aR blocking capacity could be identified.
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| 2. |
- Koymans, Kirsten J, et al.
(författare)
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The TLR2 Antagonist Staphylococcal Superantigen-Like Protein 3 Acts as a Virulence Factor to Promote Bacterial Pathogenicity in vivo
- 2017
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Ingår i: Journal of Innate Immunity. - : S. Karger AG. - 1662-811X .- 1662-8128. ; 9, s. 561-573
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Tidskriftsartikel (refereegranskat)abstract
- Toll-like receptor (TLR) signaling is important in the initiation of immune responses and subsequent instigation of adaptive immunity. TLR2 recognizes bacterial lipoproteins and plays a central role in the host defense against bacterial infections, including those caused by Staphylococcus aureus. Many studies have demonstrated the importance of TLR2 in murine S. aureus infection. S. aureus evades TLR2 activation by secreting two proteins, staphylococcal superantigen-like protein 3 (SSL3) and 4 (SSL4). In this study, we demonstrate that antibodies against SSL3 and SSL4 are found in healthy individuals, indicating that humans are exposed to these proteins during S. aureus colonization or infection. To investigate the TLR2-antagonistic properties of SSL3 and SSL4, we compared the infection with wild-type and SSL3/4 knockout S. aureus strains in an intravenous murine infection model. Direct evaluation of the contribution of SSL3/4 to infection pathogenesis was hindered by the fact that the SSLs were not expressed in the murine system. To circumvent this limitation, an SSL3-overproducing strain (pLukM-SSL3) was generated, resulting in constitutive expression of SSL3. pLukM-SSL3 exhibited increased virulence compared to the parental strain in a murine model that was found to be TLR2 dependent. Altogether, these data indicate that SSL3 contributes to S. aureus virulence in vivo.
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