Table 1.

Effects of pathogens on gingival epithelial barrier function.

Pathogen	Factor	Direct/indirect effects on epithelial barrier function	Reference
P. gingivalis	whole bacteria (ATCC33277)	Degradation of adhesion junction proteins (E-cadherin) and tight junction protein [Occludin), decrease in TEER, increase in paracellular translocation of bacteria	10
		Increase in paracellular permeability of FITC-dextran, decrease the expression levels of tight junction proteins [ZO-1, Occludin], decrease in TEER	11
	gingipain	Degradation of E-cadherin protein [Kgp protease has more strong effect than RgpA and RgpB]	12
	LPS	Decreased expression level of E-cadherin mRNA and protein	13
		decrease mRNA level of Occludin and Claudin	14
	fimbriae	Increase adherence to oral epithelial cells	15
		degradation of cell-adhesive protein	16
A. actinomycetemcomitans	whole bacteria (Y4]	Decrease the expression level of gap junction [connexin) mRNA and protein	17
		decrease the protein level of E-cadherin	18,
	outer membrane protein	Decrease gap junctional intercellular communication, degradate gap junction protein [connexin]	19
	Cdt	Change cytosolic distribution of E-cadherin	20
T. denticola	whole bacteria [ATCC35405]	Disrupt desmosome structures, decrease in paracellular permeability	21,
	dentilisin	Degradation of ZO-1 protein, decrease in TEER	22