1. Bacillus anthracis protease InhA regulates BslA-mediated adhesion in human endothelial cells.
- Author
-
Tonry JH, McNichol BA, Ramarao N, Chertow DS, Kim KS, Stibitz S, Schneewind O, Kashanchi F, Bailey CL, Popov S, and Chung MC
- Subjects
- Animals, Bacillus anthracis genetics, Bacillus anthracis physiology, Bicarbonates chemistry, Brain blood supply, Culture Media chemistry, Gene Expression, Gene Expression Regulation, Bacterial, Gene Knockout Techniques, Host-Pathogen Interactions, Humans, Macrophages microbiology, Metalloproteases genetics, Mice, Microbial Viability, Microvessels cytology, Phenanthrolines pharmacology, Protease Inhibitors pharmacology, Proteolysis, Virulence Factors metabolism, Adhesins, Bacterial metabolism, Bacillus anthracis enzymology, Bacterial Adhesion, Endothelial Cells microbiology, Metalloproteases metabolism
- Abstract
To achieve widespread dissemination in the host, Bacillus anthracis cells regulate their attachment to host endothelium during infection. Previous studies identified BslA (Bacillus anthracis S-layer Protein A), a virulence factor of B. anthracis, as necessary and sufficient for adhesion of vegetative cells to human endothelial cells. While some factors have been identified, bacteria-specific contributions to BslA mediated adhesion remain unclear. Using the attenuated vaccine Sterne 7702 strain of B. anthracis, we tested the hypothesis that InhA (immune inhibitor A), a B. anthracis protease, regulates BslA levels affecting the bacteria's ability to bind to endothelium. To test this, a combination of inhA mutant and complementation analysis in adhesion and invasion assays, Western blot and InhA inhibitor assays were employed. Results show InhA downregulates BslA activity reducing B. anthracis adhesion and invasion in human brain endothelial cells. BslA protein levels in ΔinhA bacteria were significantly higher than wild-type and complemented strains showing InhA levels and BslA expression are inversely related. BslA was sensitive to purified InhA degradation in a concentration- and time-dependent manner. Taken together these data support the role of InhA regulation of BslA-mediated vegetative cell adhesion and invasion., (© 2012 Blackwell Publishing Ltd.)
- Published
- 2012
- Full Text
- View/download PDF