Placental Trophoblast Responses to Porphyromonas gingivalis Mediated by Toll-like Receptor-2 and -4

Abstract

Trophoblast participates in preventing allorecognition and controlling pathogens that compromise fetal wellbeing. Toll-like receptors recognize conserved sequences on the pathogens surface and trigger effector cell functions. Porphyromonas gingivalis is thought to spread to the umbilical cord and cause fetal growth restriction. Objective: To characterize expression and function of TLR-2 and TLR-4 in trophoblast cells from Porphyromonas gingivalisinfected pregnant rats. Methods: Live Porphyromonas gingivalis were challenged into the maxillary first molar

subgi ngival sulcus of female r at s before a nd /or dur i ng pregnancy a nd sacr i fied on gest at ional d ay (GD) 14 a nd 20. Porphyromonas gingivalis was detected by API-ZYM system in the maternal blood of the retro-orbital venous plexus and the umbilical cord. TLR-2 and TLR-4 expressions in trophoblast cells was detected by immunohistochemistry. Results: Porphyromonas gingivalis was first detected in the maternal blood and finally spread to the umbilical cord. Syncytiotrophoblast, spongitrophoblast and trophoblastic giant cell in treated groups had significantly higher expr e s si on of T LR-2 a nd T LR- 4 t ha n c ont r ol g r oup ( p<0.05). Conclusion: Syncytiotrophoblast, spongitrophoblast and trophoblastic giant cell are able to recognize Porphyromonas gingivalis through TLR-2 and TLR-4 expression. The ligation of TLR-2 and TLR- 4 promoted cytokine production and induced trophoblast cell death. These findings strengthen links between periodontal disease and fetal growth restriction.