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

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 gingivalis infected pregnant rats. Methods: Live Porphyromonas gingivalis were challenged into the maxillary first molar subgingival sulcus of female rats before and/or during pregnancy and sacrified on gestational day (GD) 14 and 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 immunohisto chemistry. 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 expression of TLR-2 and TLR-4 than control group (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.