title: Directed evolution of chemotaxis inhibitory protein of Staphylococcus aureus generates biologically functional variants with reduced interaction with human antibodies.
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). 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.
authors: Alligator Bioscience AB, Scheelevägen 19A, S-223 70 Lund. erg@alligatorbioscience.com
authors: Erika
authors: E
authors: Gustafsson
authors: Anna
authors: A
authors: Rosén
authors: Karin
authors: K
authors: Barchan
authors: Kok P M
authors: KP
authors: van Kessel
authors: Karin
authors: K
authors: Haraldsson
authors: Stina
authors: S
authors: Lindman
authors: Cecilia
authors: C
authors: Forsberg
authors: Lill
authors: L
authors: Ljung
authors: Karin
authors: K
authors: Bryder
authors: Björn
authors: B
authors: Walse
authors: Pieter-Jan
authors: PJ
authors: Haas
authors: Jos A G
authors: JA
authors: van Strijp
authors: Christina
authors: C
authors: Furebring
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000032:analysis / Q000235:genetics* / Q000276:immunology* / Q000494:pharmacology; D002460:Cell Line; D019020:Directed Molecular Evolution; D015195:Drug Design; D015870:Gene Expression; D006801:Humans; D007074:Immunoglobulin G / Q000276:immunology*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009504:Neutrophils / Q000187:drug effects / Q000378:metabolism; D044087:Receptor, Anaphylatoxin C5a / Q000037:antagonists & inhibitors* / Q000378:metabolism; D011994:Recombinant Proteins / Q000032:analysis / Q000235:genetics / Q000276:immunology / Q000494:pharmacology; D016415:Sequence Alignment; D013211:Staphylococcus aureus / Q000235:genetics / Q000276:immunology*
chemical_list: D001426:Bacterial Proteins; D007074:Immunoglobulin G; D044087:Receptor, Anaphylatoxin C5a; D011994:Recombinant Proteins; C493134:chemotaxis inhibitory protein, Staphylococcus aureus