Expression and immune effect of toll-like receptor 4 in human trophoblast cells

Summary  This study investigated the expression and immune effect of TLR4 in human trophoblast cells. The expression level of TLR4 mRNA in normal and LPS-stimulated human term trophoblast cells (1 mg/L LPS, 12 h) was detected by RT-PCR. In LPS-stimulated human term trophoblast cells of TLR4-blocked group and non-TLR4-blocked group, and normal term trophoblast cells of blank control group, apoptosis rate was measured by flow cytometry (FCM), and the level of TNF-α determined by using enzyme linked immunosorbent assay (ELISA) respectively. RT-PCR results showed that the expression level of TLR4 mRNA in LPS-stimulated human trophoblast cells was significantly higher than that in normal cells (P<0.01). FCM revealed that there was significant difference in apoptosis rate of LPS-stimulated human term trophoblast cells between TLR4-blocked group and non-TLR4-blocked group (P<0.05), or between TLR4 antibody-blocked group and blank control group. ELISA indicated that the level of TNF-α in LPS-stimulated human trophoblast cells also had statistical differences between TLR4 antibody-blocked group and non-TLR4 antibody-blocked group (P<0.05). Our results suggest that TLR4 plays an important role in the immunological mechanism of apoptosis and secretion of TNF-α of human term trophoblast cells stimulated by LPS.