ASSESSMENT OF THE RELATIVE CYTOTOXICITY OF PORPHYROMONAS GINGIVALIS CELLS,PRODUCTS, AND COMPONENTS ON HUMAN EPITHELIAL CELL LINES

Established human cell lines derived from a transitional cell carcinoma (J82), a squamous carcinoma (SCaBER), and a normal urothelium (HCV-29) were used to assess the relative cytotoxicity and tissue specificity of putative virulence determinants of P. gingivalis W83. Intact cells of W83 had no effect on any of the cell lines, whereas disrupted cells caused extensive cytotoxicity particularly to monolayers of HCV-29 and J82. The purified cysteine proteinase, gingivain, caused marked disruption of the basement membrane of the SCaBER monolayers but had no cytotoxic effects. Use of the thiol-inhibitor, 2,2′-dipyridyl disulphide revealed that the effects observed with the vesicles and the culture supernatant were due to the presence of the cysteine proteinase. The attachment of vesicles to the SCaBER cells was evident in electron micrographs. Shortchain volatile fatty acids added in concentrations equivalent to those present in the culture supernatant had no effect on any of the cell lines tested. Culture sup...