This Article Full Text Full Text (PDF) Other Versions of this Article: IAI.00434-07v1 75/9/4498    most recent Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Bozue, J. Articles by Hale, M. L. Search for Related Content PubMed PubMed Citation Articles by Bozue, J. Articles by Hale, M. L.

Bacillus anthracis Spores of the bclA Mutant Exhibit Increased Adherence to Epithelial Cells, Fibroblasts, and Endothelial Cells but Not to Macrophages

Bacteriology Division,¹ Integrated Toxicology Division,² Headquarters, U.S. Army Medical Research Institute of Infectious Diseases, 1425 Porter Street, Fort Detrick, Frederick, Maryland³

Received 26 March 2007/ Returned for modification 10 May 2007/ Accepted 15 June 2007

Bacillus anthracis is the causative agent of anthrax, and the spore form of the bacterium represents the infectious particle introduced into a host. The spore is surrounded by an exosporium, a loose-fitting membrane composed of proteins and carbohydrates from which hair-like projections extend. These projections are composed mainly of BclA (Bacillus-collagen-like protein of B. anthracis). To date, exact roles of the exosporium structure and BclA protein remain undetermined. We examined differences in spore binding of wild-type Ames and a bclA mutant of B. anthracis to bronchial epithelial cells as well as to the following other epithelial cells: A549, CHO, and Caco-2 cells; the IMR-90 fibroblast line; and human umbilical vein vascular endothelium cells. The binding of wild-type Ames spores to bronchial epithelial cells appeared to be a dose-dependent, receptor-ligand-mediated event. There were similar findings for the bclA mutant, with an additional nonspecific binding component likely leading to significantly more adherence to all nonprofessional phagocytic cell types. In contrast, we detected no difference in adherence and uptake of spores by macrophages for either the wild-type Ames or the bclA mutant strain. These results suggest that one potential role of the BclA fibers may be to inhibit nonspecific interactions between B. anthracis spores with nonprofessional phagocytic cells and thus direct the spores towards uptake by macrophages during initiation of infection in mammals.

Published ahead of print on 2 July 2007.

Editor: D. L. Burns

This article has been cited by other articles:

• Dong, S., McPherson, S. A., Tan, L., Chesnokova, O. N., Turnbough, C. L. Jr., Pritchard, D. G. (2008). Anthrose Biosynthetic Operon of Bacillus anthracis. J. Bacteriol. 190: 2350-2359 [Abstract] [Full Text]  
• Oliva, C. R., Swiecki, M. K., Griguer, C. E., Lisanby, M. W., Bullard, D. C., Turnbough, C. L. Jr., Kearney, J. F. (2008). The integrin Mac-1 (CR3) mediates internalization and directs Bacillus anthracis spores into professional phagocytes. Proc. Natl. Acad. Sci. USA 105: 1261-1266 [Abstract] [Full Text]  
• Brahmbhatt, T. N., Janes, B. K., Stibitz, E. S., Darnell, S. C., Sanz, P., Rasmussen, S. B., O'Brien, A. D. (2007). Bacillus anthracis Exosporium Protein BclA Affects Spore Germination, Interaction with Extracellular Matrix Proteins, and Hydrophobicity. Infect. Immun. 75: 5233-5239 [Abstract] [Full Text]