The role of TLR3 in HBV infection in placenta and newborns of HBsAg positive women

The Role of TLR3 in HBV Infection in Placenta and Newborns of HBsAg Positive Womem

 Objective: To explore the relationship of Toll-Like Receptor(TLR) 3 in term human placenta and hepatitis B virus(HBV) intrauterine infections.
Methods: Both semi-quantitative RT-PCR and quantitative Real-time RT-PCR were conducted to detect TLR3 mRNA in term human placenta from normal and HBsAg positive women. Immunohistochemistry ABC and double labeling immunofluorescent histochemistry assay were conducted to detect TLR3 in term placenta of  the normal and HBsAg positive women. HBV DNA were determined by fluorescence quantitative PCR (FQ-PCR).
Results: TLR3 mRNA in term placenta showed weaker expression in HBsAg positive women(116) than normal women(41) by both semi-quantitative RT-PCR and quantitative Real-time RT-PCR(t=3.003, P<0.01; t=4.698, P<0.01). The positive rate of TLR3 in normal and HBsAg positive pregnant women was 100%(41/41) and 73.0(85/116),respectively. There was significant difference in distribution of TLR3 between placentas of normal and HBsAg positive women (Fisher’s exact probability test P<0.01). TLR3 and HBsAg in 300 term placenta were detected by immunohistochemistry ABC and double labeling immunofluorescent histochemistry assay. TLR3 was mostly located in the cytoplasm, a part on the cell membrane and occasionally in the nuceus. The positive rate TLR3 gradually increased from the maternal side to the fetal side in the placental cell layers and the positive rate of HBsAg gradually decreased (trend χ² value 262.715,P<0.01; 109.809, P<0.01, respectively). The expression of TLR3 in term placenta(235/300) was showed a protective factor of HBV infection in placenta of HBsAg positive women (73/115 vs 162/185, χ² value 24.247, P<0.01,OR=0.247, 0.141~0.431). The multivariable analysis showed the expression of TLR3 in term placenta also was a protective factor of HBV intrauterine infection in newborns of HBsAg positive women (OR=0.438, 0.204~0.942).
Conclusion: It is suggested the TLR3 take the role against HBV infection in placenta and newborns of HBsAg positive women.