Antimicrobial activity of fibrinogen and fibrinogen-derived peptides--a novel link between coagulation and innate immunity

• Published in: Thrombosis and haemostasis Vol. 109; no. 5; p. 930
• Main Authors: Påhlman, L I, Mörgelin, M, Kasetty, G, Olin, A I, Schmidtchen, A, Herwald, H
• Format: Journal Article
• Language: English
• Published: Germany 2013
• Subjects: Bacteria - growth & development; Bacteria - immunology; Bacteria - metabolism; Bacteria - ultrastructure; Blood Coagulation; Fibrin Fibrinogen Degradation Products - metabolism; Fibrinogen - metabolism; Humans; Immunity, Innate; Microbial Viability; Peptide Fragments - metabolism; Thrombin - metabolism; Time Factors
• ISSN: 0340-6245
• DOI: 10.1160/TH12-10-0739

Fibrinogen is a key player in the blood coagulation system, and is upon activation with thrombin converted into fibrin that subsequently forms a fibrin clot. In the present study, we investigated the role of fibrinogen in the early innate immune response. Here we show that the viability of fibrinogen-binding bacteria is affected in human plasma activated with thrombin. Moreover, we found that the peptide fragment GHR28 released from the β-chain of fibrinogen has antimicrobial activity against bacteria that bind fibrinogen to their surface, whereas non-binding strains are unaffected. Notably, bacterial killing was detected in Group A Streptococcus bacteria entrapped in a fibrin clot, suggesting that fibrinogen and coagulation is involved in the early innate immune system to quickly wall off and neutralise invading pathogens.