P-74: Variation in the Expression of TLR3 in Ectopic Pregnancy

Background: Toll-like receptors (TLRs) form the major family of pattern recognition receptors (PRRs) which are involved in the innate immunity. They recognize pathogen-associated molecular patterns (PAMPs) in bacteria, viruses, fungi and parasites. In human, 10 members of this family have been identified so far. Among these TLRs, TLR3, 7, 8 and 9 designed to recognize nucleic acids and expressed on endosomal membranes. TLR3 recognizes double-stranded RNA (ds-RNA) and is considered to mediate various antiviral responses. Constitutive expression of TLR3 has been reported in female genital tract. It is likely that pregnancy disorders associated with variation in TLR expression. Thus we investigate the role of TLR3 in an Ectopic Pregnancy (EP), a complication of pregnancy in which fertilized egg implants outside the uterus, most often in the Fallopian Tube (FT). Materials and Methods: Biopsies from Isthmus, Ampulla and Infundibulum of fallopian tube were obtained from women who underwent tubectomy for EP. As control group, human chorionic gonadotropin (HCG) was injected to women who undergoing abdominal hysterectomy for benign gynaecological conditions to produce a state of pseudo-pregnancy. RT-PCR was used to test the existence of TLR3 gene in these sections. Pseudo-pregnant and EP groups were compared with Q-RT PCR for TLR3 gene. Results: Using RT-PCR the presence of TLR3 gene has been shown in all regions of the FT in both pseudo-pregnant and EP groups. Q-PCR has confirmed relative TLR3 expression in Isthmus, Ampulla and Infundibulum of FTs carrying EP is lower than FTs in pseudo-pregnant women. Conclusion: The lower expression of TLR3 in Isthmus, Ampulla and Infundibulum of FTs carrying EP indicates that variation in TLR3 expression can be a risk factor for EP.