Thromb Haemost 2018; 118(07): 1230-1241
DOI: 10.1055/s-0038-1660435
Blood Cells, Inflammation and Infection
Georg Thieme Verlag KG Stuttgart · New York

Assessment of the Dual Role of Clumping Factor A in S. Aureus Adhesion to Endothelium in Absence and Presence of Plasma

Jorien Claes
1  Division of Cardiovascular Developmental Biology, Department of Cardiovascular Sciences, KU Leuven, Leuven, Belgium
2  Department of Cardiovascular Sciences, Center for Molecular and Vascular Biology, KU Leuven, Leuven, Belgium
,
Bartosz Ditkowski*
1  Division of Cardiovascular Developmental Biology, Department of Cardiovascular Sciences, KU Leuven, Leuven, Belgium
,
Laurens Liesenborghs
2  Department of Cardiovascular Sciences, Center for Molecular and Vascular Biology, KU Leuven, Leuven, Belgium
,
Tiago Rafael Veloso
1  Division of Cardiovascular Developmental Biology, Department of Cardiovascular Sciences, KU Leuven, Leuven, Belgium
,
Jose M. Entenza
3  Department of Fundamental Microbiology, University of Lausanne, Lausanne, Switzerland
,
Philippe Moreillon
3  Department of Fundamental Microbiology, University of Lausanne, Lausanne, Switzerland
,
Thomas Vanassche
2  Department of Cardiovascular Sciences, Center for Molecular and Vascular Biology, KU Leuven, Leuven, Belgium
,
Peter Verhamme
2  Department of Cardiovascular Sciences, Center for Molecular and Vascular Biology, KU Leuven, Leuven, Belgium
,
Marc F. Hoylaerts
2  Department of Cardiovascular Sciences, Center for Molecular and Vascular Biology, KU Leuven, Leuven, Belgium
,
Ruth Heying
1  Division of Cardiovascular Developmental Biology, Department of Cardiovascular Sciences, KU Leuven, Leuven, Belgium
› Author Affiliations
Funding This study was sponsored by a grant of the Research Fund KU Leuven (OT/14/097) and by the Programmafinanciering KU Leuven (PF/10/014). T.R.V. was a postdoctoral fellow of the FWO Research Foundation–Flanders (Belgium; Grant Number - 12K0916N) and R.H. is supported by the Clinical Research Fund of UZ Leuven.
Further Information

Publication History

15 December 2017

02 May 2018

Publication Date:
17 June 2018 (eFirst)

Abstract

Adhesion of Staphylococcus aureus to endothelial cells (ECs) is paramount in infective endocarditis. Bacterial proteins such as clumping factor A (ClfA) and fibronectin binding protein A (FnbpA) mediate adhesion to EC surface molecules and (sub)endothelial matrix proteins including fibrinogen (Fg), fibrin, fibronectin (Fn) and von Willebrand factor (vWF). We studied the influence of shear flow and plasma on the binding of ClfA and FnbpA (including its sub-domains A, A16+, ABC, CD) to coverslip-coated vWF, Fg/fibrin, Fn or confluent ECs, making use of Lactococcus lactis, expressing these adhesins heterologously. Global adherence profiles were similar in static and flow conditions. In the absence of plasma, L. lactis-clfA binding to Fg increased with shear forces, whereas binding to fibrin did not. The degree of adhesion of L. lactis-fnbpA to EC-bound Fn and of L. lactis-clfA to EC-bound Fg, furthermore, was similar to that of L. lactis-clfA to coated vWF domain A1, in the presence of vWF-binding protein (vWbp). Yet, in plasma, L. lactis-clfA adherence to activated EC-vWF/vWbp dropped over 10 minutes by 80% due to vWF-hydrolysis by a disintegrin and metalloproteinase with thrombospondin type 1 motif, member 13 and that of L. lactis-fnbpA likewise by > 70% compared to the adhesion in absence of plasma. In contrast, plasma Fg supported high L. lactis-clfA binding to resting and activated ECs. Or, in plasma S. aureus adhesion to active endothelium occurs mainly via two complementary pathways: a rapid but short-lived vWF/vWbp pathway and a stable integrin-coupled Fg-pathway. Hence, the pharmacological inhibition of ClfA-Fg interactions may constitute a valuable additive treatment in infective endocarditis.

Authors' Contributions

M.H., R.H., B.D., T.V., L.L., T.R.V. and P.V. designed the research. J.C. and B.D. performed the experiments and analysed the data. J.C., B.D., M.H. and R.H. wrote the manuscript. P.M. and J.M.E. designed the research and provided the L. lactis strains. B.D. performed all work of the revision.


* Bartosz Ditkowski performed all the experimental work during the revision and drafted the revised manuscript.


Supplementary Material