I-30: Separate and Combination Effect of SexHormones on TLRs Expression in FallopianTubes

Background: Implantation is characterized by the interaction of two immunologically and genetically distinct tissues. The embryo differs from the cells of the mother, and would be rejected as a parasite by the immune system of the mother if it didn’t secrete immunosuppressive agents. Thus, immunological rejection of the fetus due to recognition of paternal antigens by the maternal immune system, resulting in abnormal immune cells and cytokine production, is postulated to be one cause of unexplained pregnancy loss. Most of the recent investigations suggest differences in the expression of some immune factors in women with recurrent miscarriage. Toll Like Receptors (TLRs) are the main family of pattern recognition receptors and they recognise pathogen-associated molecular pattern and constitute a major part of the innate immune system. Reports from our laboratory and others have demonstrated the existence of TLRs in the female reproductive tract and also it’s known that they expressed highly during secretory phase of menstrual cycle in endometrium which is the time of implantation. However, little has been done to identify if TLR expression in the fallopian tubes is cycle dependent as well. In addition, it is not known if sex hormones can influence TLRs expression in fallopian tubes. The aims of this study were to test the existence of TLR1-6 genes in fallopian tube and also, combination and separate effects of sex hormones on the expression of these receptors in an immortalised human fallopian tube epithelial cell line (OE-E6/E7).Materials and Methods: RT-PCR was used to show the existence of TLR1-6 genes in fallopian tube tissue and OE-E6/E7 cell line. To compare relative quantities of TLR 1-6 genes expression in OE-E6/E7cell line, they were treated by different levels of estradiol and progesterone separately, they were divided into ten groups; control (without any additional treatment of sex hormone), E0.1 (0.1nM/ml estradiol), E1 (1nM/ml estradiol), E10 (10nM/ml estradiol), E100 (100nM/ml estradiol), P1(1nM/ml progesterone), P10(10nM/ml progesterone), P100 (100nM/ml progesterone) and P1000 (1000nM/ ml progesterone) respectively. In addition, The OE-E6/ E7cell line was treated by both estradiol and progesterone in combination and they were divided into four groups; control (without any additional treatment of sex hormone), Menstruation (1nM progesterone and 0.1nM estradiol), Pre-ovulation (6.5nM progesterone and1.5nM estradiol) and window of implantation (35nM progesterone and 1nM estradiol). Relative TLRs 1-6 expression quantities were compared between these groups using real time quantitative PCR.Results: TLR1-6 genes were expressed in human fallopian tube tissue and OE-E6/E7 cell line. Our data clearly showed that Estrogen had no effect on the expression of TLRs in OE-E6/E7 cells. In contrast, progesterone had an inhibitory effect on the expression of TLR1-4 genes in this cell line. How ever, the expression of TLRs 1-6 was altered in OE-E6/E7 with different concentrations of sex hormones in combination. The highest expression of all the TLR genes was in window of implantation group, compared to all other groups.Conclusion: It seems sex hormones alter the expression of some of the TLRs in human fallopian tube epithelial cells in vitro. Although increasing levels of sex hormones in combination enhanced TLR1-6 genes expression in OE-E6/E7 cells, further experiments are in progress to elucidate the regulatory mechanism behind this novel effect of sex hormones in modulating innate immunity in the human female reproductive tract. Therefore, Understanding the roles of local and systemic immune factors in fallopian tube and uterine for implantation is necessary to develop approaches to enhance reproductive health and fertility in humans.