Impact of Pathogens on Oviduct-Sperm Interactions
Professor Sabine Koelle and her research group investigate reproductive medicine with special emphasis on improving the results of assisted reproduction. Their research includes a study of the mechanisms of gameto-maternal interaction, embryo-maternal communication and early embryogenesis in both humans and animals.
A recent publication by O’Doherty, Di Fenza and Koelle in Nature’s Scientific Reports describe an ex vivo model to investigate the impact of sexually transmitted Chlamydia pathogens on sperm behaviour in the oviduct and associated immune responses.
The oviduct functions in the transportation of gametes to the site of fertilization (the ampulla) and is the site of early embryonic development. Alterations of this early developmental environment, such as the presence of sexually transmitted pathogens, may affect oviduct function leading to reduced fertilization rates and contribute to compromised embryonic development.
In the reported study, sperm interactions, particle transport speed (PTS) and cilia beat frequency (CBF) in the ampulla were investigated following exposure to lipopolysaccharide (LPS), a constituent of the sexually transmitted pathogens Chlamydia trachomatis and Chlamydia abortus. Three complementary experiments were performed to analyse; (1) bound sperm motility and cilia function (2) transport velocity in the oviduct and (3) the expression of genes related to immune function and inflammatory response (CASP3, CD14, MYD88, TLR4 and TRAF6). The motility of bound sperm was significantly lower in ampullae that were exposed to LPS. CBF and PTS significantly increased after treatment with LPS for 2 hours. Finally, gene expression analysis revealed that CASP3 and CD14 were significantly upregulated and TLR4 trended towards increased expression following treatment with LPS. These findings provide an insight on the impact of LPS on the oviduct sperm interaction, and have implications for both male and female fertility.
The Koelle group has established new criteria for functional sperm and oocyte assessment and is developing new methods for in vivo imaging of fertilization and early embryogenesis in the female genital tract. These tools, it is hoped, will provide improved understanding of fertility issues.
Lipopolysaccharide (LPS) disrupts particle transport, cilia function and sperm mobility in an ex vivo oviduct model
AM O'Doherty, M Di Fenza and S Koelle, Sci Rep. 2016 Apr 15;6:24583 [link]
Prof Sabine Koelle's Research Group