Vibrio parahaemolyticus Disruption of Epithelial Cell Tight Junctions Occurs Independently of Toxin...

Vibrio parahaemolyticus Disruption of Epithelial Cell Tight JunctionsOccurs Independently of Toxin Production

Tarah Lynch, Scott Livingstone, Enrico Buenaventura, Erika Lutter, Jason Fedwick,Andre G. Buret, David Graham, and Rebekah DeVinney

INFECTION AND IMMUNITY, Mar. 2005, p. 1275–1283

Background

• Vibrio parahaemolyticus

• Toxin production: TDH(thermostable direct hemolysin) & TRH(TDH-related hemolysin)

• Barrier function is maintained by tight junction

• Tight junction comprise of transmembrane proteins (ex: actin 、 occludin 、 ZO-1)

• Cytoskeletal components are anchored to tight junction

Background

• Latex agglutination test

Background

• Lactate dehydrogenase (LDH)

Background

• TER ( transepithelial resistance ) & paracellular permeability

Background

• Southern confirmation

-/+ +/- -/- +/+

PCR Southern confirmation

TLH

TRH

TDH

TDH / TRH

+/++/-

+/-

-/+

-/-

Purified TDH

Uninfected

Uninfected

TDH(-) / TRH(-)

toxigenic

nontoxigenic

-/++/-+/++/-

-/-

V. parahaemolyticus disrupts TER and that this disruption occurs independently of toxin production.

+/+

+/-

-/+

-/-

-/-

-/- -/-

TER ↓ paracellular permeability ↑

V. parahaemolyticus disrupts TER and that this disruption occurs independently of toxin production.

-/-

+/+

-/-

-/-

red/green red/green

V. parahaemolyticus disrupts TER and that this disruption occurs independently of toxin production.

+/+

+/- +/- -/+

-/-

-/--/-

-/-

White ： 3 hrBlack ： 6 hr

Disruption of epithelial barrier function does not correlate with cytotoxicity

V. parahaemolyticus disrupts TER and that this disruption occurs independently of toxin production.

Discussion

• 破壞上皮的 barrier function 產物 TDH & TRH 不是主要的腳色，可能有其他未知物質

TDH/TRH

TDH

TRH

+

+

+

TDH purify

TER ↓

TER ↓

TER ↓

TER ↓

TER ↓

Discussion

• 高濃度 TDH(> 5 HU/ml) 一樣會造成 TER↓，並增加 LDH release ，所以並不排除 TDH and/or TRH 的毒性，只是作用較晚

• 非 TDH and/or TRH 的毒素，影響上皮的 barrier function 作用較早 (1.5 ~ 3 hr postinfection)

Discussion

• 不同的 toxin genotypes 腸炎弧菌，在上皮的 barrier function 有相同的反應，說明可能是由其他物質造成的

• 當測 LDH release 指出破壞上皮的 barrier function 跟 cytotoxicity 無關， LDH release 測得於 cell lysis ，但不能決定 cell 開始 apoptosis

TDH/TRH

TDH

TRH

+

+

+

TDH purify

TER ↓

TER ↓

TER ↓

TER ↓

TER ↓

V. parahaemolyticus disrupts TER and that this disruption occurs independently of toxin production.

Summary

TER ↓ TDH purify LDH release

Disruption of epithelial barrier function does not correlate with cytotoxicity

Summary