학술논문
Heterologous expression of Streptococcus mutans Cnm in Lactococcus lactis promotes intracellular invasion, adhesion to human cardiac tissues and virulence.
Document Type
Article
Author
Source
Subject
*STREPTOCOCCUS mutans
*VIRULENCE of bacteria
*LACTOCOCCUS lactis
*CELL adhesion
*HEART physiology
*GENE expression
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Language
ISSN
2150-5594
Abstract
InS. mutans, the expression of the surface glycoprotein Cnm mediates binding to extracellular matrix proteins, endothelial cell invasion and virulence in theGalleria mellonellainvertebrate model. To further characterize Cnm as a virulence factor, thecnmgene fromS. mutansstrain OMZ175 was expressed in the non-pathogenicLactococcus lactisNZ9800 using a nisin-inducible system. Despite the absence of the machinery necessary for Cnm glycosylation, Western blot and immunofluorescence microscopy analyses demonstrated that Cnm was effectively expressed and translocated to the cell wall ofL. lactis. Similar toS. mutans, expression of Cnm inL. lactisenabled robust binding to collagen and laminin, invasion of human coronary artery endothelial cells and increased virulence inG. mellonella. Using anex vivohuman heart tissue colonization model, we showed that Cnm-positive strains of eitherS. mutansorL. lactisoutcompete their Cnm-negative counterparts for tissue colonization. Finally, Cnm expression facilitatedL. lactisadhesion and colonization in a rabbit model of infective endocarditis. Collectively, our results provide unequivocal evidence that binding to extracellular matrices mediated by Cnm is an important virulence attribute ofS. mutansand confirm the usefulness of theL. lactisheterologous system for further characterization of bacterial virulence factors. [ABSTRACT FROM AUTHOR]