Open AccessEspP, an Extracellular Serine Protease from Enterohemorrhagic E. coli, Reduces Coagulation Factor Activities, Reduces Clot Strength, and Promotes Clot Lysis
Author(s) -
Kevin H.M. Kuo,
Shekeb Khan,
Margaret L. Rand,
Hira Mian,
Elena Brnjac,
Linda E. Sandercock,
Indira Akula,
Jean-Philippe Julien,
E.F. Pai,
Alden Chesney
Publication year - 2016
Publication title -
plos one
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.99
H-Index - 332
ISSN - 1932-6203
DOI - 10.1371/journal.pone.0149830
Subject(s) - serine protease , coagulation , tissue factor , partial thromboplastin time , lysis , whole blood , thromboplastin , thrombin , fibrinogen , microbiology and biotechnology , chemistry , biology , protease , biochemistry , enzyme , immunology , medicine , platelet
Background EspP ( E . coli secreted serine protease, large plasmid encoded) is an extracellular serine protease produced by enterohemorrhagic E . coli (EHEC) O157:H7, a causative agent of diarrhea-associated Hemolytic Uremic Syndrome (D+HUS). The mechanism by which EHEC induces D+HUS has not been fully elucidated. Objectives We investigated the effects of EspP on clot formation and lysis in human blood. Methods Human whole blood and plasma were incubated with EspP WT at various concentrations and sampled at various time points. Thrombin time (TT), prothrombin time (PT), and activated partial thromboplastin time (aPTT), coagulation factor activities, and thrombelastgraphy (TEG) were measured. Results and Conclusions Human whole blood or plasma incubated with EspP WT was found to have prolonged PT, aPTT, and TT. Furthermore, human whole blood or plasma incubated with EspP WT had reduced activities of coagulation factors V, VII, VIII, and XII, as well as prothrombin. EspP did not alter the activities of coagulation factors IX, X, or XI. When analyzed by whole blood TEG, EspP decreased the maximum amplitude of the clot, and increased the clot lysis. Our results indicate that EspP alters hemostasis in vitro by decreasing the activities of coagulation factors V, VII, VIII, and XII, and of prothrombin, by reducing the clot strength and accelerating fibrinolysis, and provide further evidence of a functional role for this protease in the virulence of EHEC and the development of D+HUS.