Cutting-Edge Report: TLR10 Plays a Role in Mediating Bacterial Peptidoglycan-Induced Trophoblast Apoptosis

Problem There is a strong correlation between intrauterine bacterial infection and preterm labor. While inflammation is a common mechanism, certain pathogens may trigger placental apoptosis. TLR2 activation by gram-positive bacterial peptidoglycan (PDG) induces first-trimester trophoblast apoptosis and decreased IL-6 secretion. This is dependent upon the presence of TLR1 and the absence of TLR6 and both TLR2 coreceptors. As TLR10 is also a TLR2 coreceptor, the objective of this study was to determine its expression and function in the trophoblast. Method of study First-and third-trimester human placental tissue and isolated trophoblast were evaluated for TLR10 expression. A first-trimester human trophoblast cell line stably transfected with a TLR10 dominant negative (TLR10-DN) or vector control was treated with or without PDG and analyzed for apoptosis and IL-6. Results TLR10 was expressed by trophoblasts during the first and third trimesters of pregnancy. PDG-induced trophoblast caspase-3 activity was inhibited by the presence of the TLR10-DN. The presence of the TLR10-DN had no effect on PDG reduction in trophoblast IL-6 secretion. Conclusion This study demonstrates that trophoblast TLR10 plays a role in promoting apoptosis triggered by gram-positive bacterial components and suggests that TLR10 may regulate the balance between trophoblast survival and cell death.