Binding of Efb from Staphylococcus aureus to fibrinogen blocks neutrophil adherence.
In addition to its pivotal role in hemostasis, fibrinogen (Fg) and provisional fibrin matrices play important roles in inflammation and regulate innate immune responses by interacting with leukocytes. Efb (the extracellular fibrinogen-binding protein) is a secreted Staphylococcus aureus protein that engages host Fg and complement C3. However, the molecular details underlying the Efb-Fg interaction and the biological relevance of this interaction have not been determined. In the present study, we characterize the interaction of Efb with Fg. We demonstrate that the Fg binding activity is located within the intrinsically disordered N-terminal half of Efb (Efb-N) and that the D fragment of Fg is the region that mediates Efb-N binding. More detailed studies of the Efb-N-Fg interactions using ELISA and surface plasmon resonance analyses revealed that Efb-N exhibits a much higher affinity for Fg than typically observed with Fg-binding MSCRAMMs (microbial surface components recognizing adhesive matrix molecules), and data obtained from ELISA analyses using truncated Efb-N constructs demonstrate that Efb-N contains two binding sites located within residues 30-67 and 68-98, respectively. Efb-N inhibits neutrophil adhesion to immobilized Fg by binding to Fg and blocking the interaction of the protein with the leukocyte integrin receptor, α(M)β(2). A motif in the Fg γ chain previously shown to be central to the α(M)β(2) interaction was shown to be functionally distinguishable from the Efb-N binding site, suggesting that the Fg-Efb interaction indirectly impedes Fg engagement by α(M)β(2). Taken together, these studies provide insights into how Efb interacts with Fg and suggest that Efb may support bacterial virulence at least in part by impeding Fg-driven leukocyte adhesion events.
Center for Infectious and Inflammatory Disease, Institute of Bioscience and Technology, Texas A&M Health Science Center, Houston, Texas 77030, USA.
Ya-Ping
YP
Ko
Xiaowen
X
Liang
C Wayne
CW
Smith
Jay L
JL
Degen
Magnus
M
Höök
D018829:Adhesins, Bacterial / Q000737:chemistry / Q000378:metabolism; D020816:Amino Acid Motifs; D001426:Bacterial Proteins / Q000737:chemistry / Q000378:metabolism*; D001665:Binding Sites; D002448:Cell Adhesion; D005340:Fibrinogen / Q000737:chemistry / Q000378:metabolism*; D057809:HEK293 Cells; D006801:Humans; D009504:Neutrophils / Q000737:chemistry / Q000378:metabolism*; D011485:Protein Binding; D013211:Staphylococcus aureus / Q000737:chemistry / Q000378:metabolism* / Q000472:pathogenicity
D018829:Adhesins, Bacterial; D001426:Bacterial Proteins; C114014:Efb protein, Staphylococcus aureus; C509820:MSCRAMM proteins, Staphylococcus; D005340:Fibrinogen
PLoS Pathog. 2010 Aug 05;6(8):e1001036
20700445
Thromb Haemost. 2004 Apr;91(4):779-89
15045140
J Clin Invest. 2007 Nov;117(11):3224-35
17932565
J Exp Med. 2004 Dec 6;200(11):1455-66
15583017
Clin Infect Dis. 2001 May 15;32 Suppl 2:S114-32
11320452
J Pathol. 2006 Nov;210(3):325-33
16981239
J Biol Chem. 1998 Aug 28;273(35):22519-27
9712878
J Clin Invest. 1979 Feb;63(2):221-9
372238
Mol Microbiol. 1994 May;12(4):599-606
7934883
J Biol Chem. 1998 May 22;273(21):13177-81
9582359
Int J Biochem Cell Biol. 1999 Jul;31(7):741-6
10467729
J Biol Chem. 2001 Aug 24;276(34):31691-7
11418620
Eur Respir J. 2008 Aug;32(2):405-12
18321926
J Biol Chem. 2005 Jan 14;280(2):1336-45
15485828
J Immunol. 2008 Dec 1;181(11):7463-7
19017934
Blood. 2001 Jun 15;97(12):3691-8
11389004
Thromb Haemost. 2007 Sep;98(3):503-11
17849038
J Exp Med. 2007 Oct 1;204(10):2461-71
17893203
J Exp Med. 2001 May 21;193(10):1123-33
11369784
Nat Immunol. 2005 Sep;6(9):920-7
16086019
J Infect Dis. 2004 Aug 1;190(3):571-9
15243934
J Infect Dis. 2001 Dec 15;184(12):1572-80
11740733
Anal Biochem. 1989 Oct;182(1):16-9
2604040
J Biol Chem. 2004 Dec 3;279(49):50710-6
15337748
J Immunol. 2001 Feb 1;166(3):2002-10
11160249
J Exp Med. 2007 Mar 19;204(3):571-82
17339406
N Engl J Med. 1998 Aug 20;339(8):520-32
9709046
J Clin Invest. 1989 Jun;83(6):2008-17
2566624
J Cell Sci. 2000 Jan;113 ( Pt 1):45-57
10591624
J Biol Chem. 2001 Jul 27;276(30):27799-805
11371571
Mol Microbiol. 2006 Jan;59(1):1-4
16359313
Thromb Haemost. 2005 May;93(5):927-31
15886811
J Clin Invest. 1988 Nov;82(5):1746-56
2903180
Cell Res. 1999 Sep;9(3):171-8
10520599
Trends Microbiol. 1998 Dec;6(12):484-8
10036727
J Immunol. 2001 Sep 1;167(5):2869-78
11509634
J Exp Med. 2004 Mar 1;199(5):687-95
14993252
Protein Sci. 1995 May;4(5):1013-6
7663337
Cell. 2004 Feb 6;116(3):367-79
15016372
Am J Physiol Cell Physiol. 2004 Nov;287(5):C1264-72
15229106
Infect Immun. 1996 Dec;64(12):5284-9
8945578
Proc Natl Acad Sci U S A. 2000 Aug 1;97(16):9026-31
10922058
Cell. 1993 Jul 2;73(7):1423-34
8100742
Thromb Haemost. 2005 Aug;94(2):278-85
16113816
Nat Immunol. 2007 Apr;8(4):430-7
17351618
EMBO J. 1996 Nov 1;15(21):5760-71
8918453
Eur J Immunol. 2003 May;33(5):1429-38
12731070
Nat Rev Microbiol. 2005 Dec;3(12):948-58
16322743
J Clin Invest. 2004 Jun;113(11):1596-606
15173886
Biochem Biophys Res Commun. 1998 Jul 30;248(3):690-5
9703988
J Biol Chem. 1993 Jan 25;268(3):1847-53
8093615
J Immunol. 2004 Jun 1;172(11):6994-7001
15153520