Cytopathic effects of Treponema denticola chymotrypsin-like proteinase on migrating and stratified epithelial cells

Abstract

The effects of Treponema denticola and its outer membrane-bound chymotrypsin-like proteinase on periodontal ligament epithelial cell cultures at different stages of maturity were studied. In sparse cultures with migrating epithelial cells, large intracellular vacuoles were formed rapidly following exposure to live T. denticola. Treponemes showing structural damage were seen occasionally inside membrane-bound vesicles. Intensive membrane blebbing occurred in infected cells and continued for up to 48 h before the cell died. Blebbing could also be induced by a purified chymotrypsin-like proteinase of T. denticola. Cortical actin and ␣-actinin of the bacterium-treated cells showed disorganization, and pericellular fibronectin was degraded by both whole T. denticola and the isolated proteinase. Epithelial cells with well-formed lateral cell contacts appeared to be more resistant to the effects of T. denticola than migrating isolated cells. In multilayer epithelial cultures, adhesion of T. denticola and membrane blebbing were observed infrequently. There was no evidence of invasion of T. denticola into epithelial multilayers. However, immunogold electron microscopy showed rapid transport of T. denticola chymotrypsin-like proteinase into newly formed large intracellular vacuoles within the epithelial layers. These vacuoles were lined by membranes studded with ribosomes. T. denticola-treated epithelial multilayers had loose cell contacts, collapsed intercellular spaces, and increased permeability. Through its capacity to cause these unique cytopathic effects, the chymotrypsin-like proteinase of T. denticola has the potential to contribute to the initiation of periodontal disease.

Treponema denticola chymotrypsin‐like proteinase is present in early‐stage mobile tongue squamous cell carcinoma and related to the clinicopathological features

“…This proteinase has been associated with promotion of Td attachment to epithelial cells, degradation of host proteins and protease inhibitors and activation of latent proMMPs, thus facilitating Td migration through the epithelium down to the basement membrane. 6,9 The role of Td and Td-CTLP in cancer may be related to its ability to cause structural damage to epithelial cells 6 and to activate mitogen-activated protein kinase (MAP kinase) signalling pathways controlling cell proliferation and survival, 17 as well as to immunomodulation. 9 The high prevalence and high immunopositivity of and to immortalise epithelial cells.…”

New insights into the emerging role of oral spirochaetes in periodontal disease

“…Periodontal tissue cells T. denticola cells and individual virulence factors are cytotoxic to epithelial cells [75,92]; they perturb cytoskeletal dynamics [93][94][95][96][97][98] and cell-cell junctions [99,100]. T. denticola can penetrate epithelium [96,101], whereas T. medium also invades epithelial cells [102]. Penetration of tissues by oral treponemes involves direct motility and proteolysis.…”

Infection and apoptosis associated with inflammation in periodontitis: An immunohistologic study

“…Although some apoptosis could occur in the clinically healthy gingiva, especially in the junctional epithelium, a phenomenon that may play a role in the regulation of mucosal inflammation for the maintenance of homoeostasis, increased apoptosis and reduced proliferation observed in the deepest sulcular pocket and most apical part of the pocket might be an essential factor in progression of periodontitis (Jarnbring, Somogyi, Dalton, Gustafsson, & Klinge, 2002;Tonetti, Cortellini, & Lang, 1998). Periodontopathogens are associated with cell apoptosis and necrosis with concomitant activation of the immune system (Kelk et al, 2011;Leung, Wu, Hannam, McBride, & Uitto, 2002;Uitto et al, 1995). The various inflammatory processes could also drive surrounding tissue cells, granulocytes, and macrophages to apoptosis and thus increase and maintain the inflammation (Haanen & Vermes, 1995).…”