Relationship between TLR9 expression in placenta and intrauterine infection of hepatitis B virus

Abstract：To understand the expression and distribution of TLR9 in HBsAg sero-positive placenta and explore the relationship between TLR9 and HBV intrauterine infection, we collected 22 full-term placental tissues of HBsAg sero-positive mothers and 6 samples of HBsAg sero-negative mothers. We tested neonatal HBsAg by Chemiluminescence, detected HBV serologic markers in mothers by ELJSA, as well as investigated HBsAg and TLR9 in the placental tissues by SABC immunohistochemical staining. Theses detection and analysis illustrated that HBV infection rate of placenta was 77.27% (17/22) and HBsAg was in the decidual cells (DC), tro-phoblastic cells (TC), villous mesenchymal cells (VMC), and villous capillary endothelial cells (VCMC); TLR9 was expressed in the TC of HBsAg sero-negative mothers and also in the TC, VMC and VCMC of HBsAg sero-positive mothers. Furthermore, TLR9 expression was stronger in HBsAg sero-positive mothers than that in sero-negative mothers (P<0.05). As for the placentas from HBsAg sero-positive mothers, TLR9 expression was statistical significance in HBsAg-negative placenta expressed higher TLR9 compared with HB-sAg-positive placenta (P<0.05). These data should be viewed as preliminary considering the expression of TLR9 has association with HBV intrauterine infection and TLR9 may effectively protect fetus from HBV intrauterine infection.