contribution of plasminogen activation towards the pathogenic potential of oral streptococci纤溶酶原激活物的贡献向口腔链球菌的致病潜力.pdf

Contribution of Plasminogen Activation towards the Pathogenic Potential of Oral Streptococci 1 1 1 2 2 Andreas Itzek , Christine M. Gillen , Marcus Fulde , Claudia Friedrichs , Arne C. Rodloff , Gursharan S. 1 1 Chhatwal , Daniel Patric Nitsche-Schmitz * 1 Department of Medical Microbiology, Helmholtz Centre for Infection Research, Braunschweig, Germany, 2 Institute for Medical Microbiology and Epidemiology of Infectious Diseases, University of Leipzig, Leipzig, Germany Abstract Oral streptococci are a heterogeneous group of human commensals, with a potential to cause serious infections. Activation of plasminogen has been shown to increase the virulence of typical human pathogenic streptococci such as S. pneumoniae. One important factor for plasminogen activation is the streptococcal a-enolase. Here we report that plasminogen activation is also common in oral streptococci species involved in clinical infection and that it depends on the action of human plasminogen activators. The ability to activate plasminogen did not require full conservation of the internal plasminogen binding sequence motif FYDKERKVY of a-enolase that was previously described as crucial for increased plasminogen binding, activation and virulence. Instead, experiments with recombinant a-enolase variants indicate that the naturally occurring variations do not impair plasminogen binding. In spite of these variations in the internal plasminogen binding motif oral streptococci showed similar activation of plasminogen. We conclude that the pathomechanism of plasminogen activation is conserved in oral streptococci that cause infections in human. This may