Vice President Academic and Provost, UBC
B.Sc., U.B.C. (1965); Ph.D., Illinois (1970)
Periodontal diseases are the result of bacterial infection in which there is destruction of the soft tissues and bone that surround and support the teeth. During infection, the gingival sulcus is populated by increased numbers of Gram-negative anaerobes, and there is good evidence to indicate their role as potential pathogens. Pathogenic bacteria may possess a number of different virulence determinants; among those thought to be important in oral infections are the ability to adhere to and damage host tissue, to adhere to other bacteria which may colonize host tissue, and to produce enzymes which degrade protein (proteases). Adherance ensures that the organism is located in an environment where it can exert its damage. Proteases degrade host defence proteins and break down other proteins required to maintain the structural integrity of host tissue. An understanding of these interactions will allow us to develop prophylactic and therapeutic procedures based on interference with the pathogenic reaction. Our current research focuses on two species of oral anaerobes, Treponema denticola and Porphyromomas gingivalis. We are identifying and characterizing proteins which are located in the bacterial outer membrane, and hence come into direct contact with soluble proteins and proteins on the host cells. The approach combines molecular, biochemical, and immunological techniques. Recently, the gene encoding a T. denticola major surface protein was cloned and sequenced. The protein has pore-forming activity, binds several components of the extracellular matrix of epithelial cells, and is cytotoxic. We are studying the function of both T. denticola and P. gingivalis membrane-bound proteins by constructing isogenic mutants.
- Fenno, J.C., G.W.K. Wong, P.M. Hannam, and B.C. McBride. 1998. Mutagenesis of outer membrane virulence determinants of the oral spirochete Treponema denticola. FEMS Microbial. Lett.163:209-215
- Lu, B., and B.C. McBride. 1998. Expression of the tpr protease gene of Porphyromonas gingivalis is regulated by peptide nutrients. Infect. Immun. 66:5147-5156.
- Fenno, J.C., P.M. Hannam, W.K. Leung, M. Tamura, V.-J. Uitto, and B.C. McBride. 1998. Cytopathic effects of the major surface protein and the chymotrypsinlike protease of Treponema denticola. Infect. Immun. 66:1869-1877.