Host-Bacteria Crosstalk at the Dentogingival Junction

Table 1

Virulence factors of periodontopathogenic bacteria, and their effects on host cells.

Bacterial virulence factor	Effect on host cells	References
Fimbriae, flagellae	Promote bacterial colonization, adherence and invasion of host cells	[37, 38]
	Modulate inflammatory response
Lipoteichoic acids (LTAs)	Mediate bacterial adhesion to human cells and teeth	[39–47]
	Arrest growth and decrease mitosis in epithelial cells
	Stimulate leukocytes, activate complement
	Increase cytokine and inflammatory mediator production
	Stimulate bone resorption
Lipopolysaccharides (LPSs)	Increase epithelial cell permeability, penetrate gingival epithelium	[39, 45, 48–58]
	Stimulate JE basal cell proliferation at high concentration (5000 μg/mL)
	Stimulate gingival fibroblast proliferation at low concentration (<10 μg) and suppress at high concentration
	Stimulate T-helper cell proliferation
	Increase cytokine and inflammatory mediator production
	Activate osteoclasts
Short chain fatty acids (SCFAs)	Raise inflammatory response	[59–63]
	Inhibit gingival epithelial cell and fibroblast proliferation
Proteinases	Activate host MMP:s, degrade extracellular matrix components, immunoglobulins and complement proteins
	Promote apoptosis in gingival fibroblasts	[64]
	Induce human β-defensin-2 expression in gingival epithelial cells in vitro
Heat shock proteins	Activate epithelial cells and osteoclasts at low concentrations and cause cell death at high concentrations	[65]
Cytolethal distending toxin	Upregulate RANKL expression in T cells	[66]
Leukotoxin	Cause apoptosis and necrosis of PMNs, T cells, natural killer cells	[48]
Capsule	Increase resistance to phagocytosis	[48]
Ammonium, hydrogen sulphide	Toxic to cells, cause cell vacuolization, inhibit collagen formation	[67, 68]