Effect of regulatory T cells on reducing the placental inflammatory response

To evaluate the effects of regulatory T cells (Tregs) on the placental inflammatory response in a lipopolysaccharide (LPS)-induced preterm birth mouse model. An LPS-induced preterm birth mouse model was established. Tregs were isolated from pregnant mice and injected into different pregnant mice before LPS treatment. The expression levels of fork head family transcription factor (Foxp3), leukemia inhibitory factor (LIF), heme oxygenase-1 (HO-1), transforming growth factor β1 (TGF-β1), and interleukin-6 (IL-6) in the placenta were examined by western blot and real-time reverse transcription polymerase chain reaction. The expression of Foxp3, HO-1, LIF, and TGF-β1 at both the mRNA and protein levels in the placentas from LPS-treated mice was significantly decreased compared with the controls, while the adoptive transfer of Tregs significantly abrogated the changes in the expression of the above factors after LPS treatment. Interestingly, the expression of IL-6 in the placentas was significantly increased after LPS treatment, and this effect was blocked by the adoptive transfer of Tregs. Maternal LPS exposure significantly induced preterm birth and affected the expression of Foxp3, HO-1, LIF, TGF-β1 and IL-6 in placental tissue. Moreover, the adoptive transfer of Tregs completely abrogated the changes in the expression of the above factors after LPS treatment.