title: Thrombin-activatable fibrinolysis inhibitor binds to Streptococcus pyogenes by interacting with collagen-like proteins A and B.
abstract: Regulation of proteolysis is a critical element of the host immune system and plays an important role in the induction of pro- and anti-inflammatory reactions in response to infection. Some bacterial species take advantage of these processes and recruit host proteinases to their surface in order to counteract the host attack. Here we show that Thrombin-activatable Fibrinolysis Inhibitor (TAFI), a zinc-dependent procarboxypeptidase, binds to the surface of group A streptococci of an M41 serotype. The interaction is mediated by the streptococcal collagen-like surface proteins A and B (SclA and SclB), and the streptococcal-associated TAFI is then processed at the bacterial surface via plasmin and thrombin-thrombomodulin. These findings suggest an important role for TAFI in the modulation of host responses by streptococci.
authors.affiliation: Department of Clinical Sciences, Section for Clinical and Experimental Infection Medicine, Lund University, SE-22184 Lund, Sweden. Lisa.Pahlman@med.lu.se
authors.forename: Lisa I
authors.initials: LI
authors.lastname: Påhlman
authors.forename: Pauline F
authors.initials: PF
authors.lastname: Marx
authors.forename: Matthias
authors.initials: M
authors.lastname: Mörgelin
authors.forename: Slawomir
authors.initials: S
authors.lastname: Lukomski
authors.forename: Joost C M
authors.initials: JC
authors.lastname: Meijers
authors.forename: Heiko
authors.initials: H
authors.lastname: Herwald
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000378:metabolism / Q000502:physiology*; D025901:Carboxypeptidase B2 / Q000737:chemistry* / Q000378:metabolism; D002268:Carboxypeptidases / Q000737:chemistry; D003094:Collagen / Q000737:chemistry / Q000378:metabolism / Q000502:physiology; D005341:Fibrinolysin / Q000737:chemistry / Q000378:metabolism; D005342:Fibrinolysis; D046529:Microscopy, Electron, Transmission; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D011485:Protein Binding; D017422:Sequence Analysis, DNA; D013297:Streptococcus pyogenes / Q000378:metabolism*; D013917:Thrombin / Q000737:chemistry; D018180:Thrombomodulin / Q000737:chemistry; D013997:Time Factors
chemical_list: D001426:Bacterial Proteins; D018180:Thrombomodulin; D003094:Collagen; D002268:Carboxypeptidases; D025901:Carboxypeptidase B2; D013917:Thrombin; D005341:Fibrinolysin