176. GDF-9, BMP-15 AND ACTIVIN A CONTRIBUTE TO SEMINAL FLUID SIGNALLING IN HUMAN CERVICAL EPITHELIAL CELLS

Abstract

We have previously shown that in women, as in animal species, introduction of seminal fluid at coitus induces cytokine expression and a local inflammatory-like response in the female reproductive tract. The response is characterised by induction of mRNAs encoding several pro-inflammatory cytokines including GM-CSF, IL-1α and IL-6, as well as chemokines IL-8, MIP-3α and MCP-1. Recent studies in our laboratory have focused on identifying active signalling agents present in human seminal plasma. To date we have shown that all three mammalian isoforms of TGFβ (TGFβ1, TGFβ2 and TGFβ3) and 19-hydroxy PGE are key regulators of this response. The current study aimed to determine whether other members of the TGFβ superfamily including GDF-9, BMP-15 and Activin A also contribute. To investigate this we utilised immortalised Ect1 ectocervical epithelial cells, which mimic the response of primary ectocervical epithelial cells. Ect1 cells were incubated with increasing doses (0.5, 5.0, 50 or 500 ng/ml) of rGDF-9, rBMP-15 or rActivin A and production of pro-inflammatory cytokines and chemokines was assessed in 24 hour post-treatment supernatants using Luminex microbead technology. BMP-15 was found to stimulate GM-CSF production (2-fold), while GDF-9 and Activin A both stimulated IL-6 production (2.4-fold and 80% increases respectively), all acting in a dose-dependent manner. In contrast, all three factors inhibited IL-8 production by Ect1 cells. These data demonstrate that GDF-9, BMP-15 and Activin A are new seminal fluid signalling agents capable of targeting female reproductive tract epithelial cells and inducing different response profiles compared with TGFβ and 19-hydroxy PGE. The relative bioavailability of these factors in seminal fluid would therefore influence the profile of inflammatory response in the female partner, regulating immune responses to male seminal antigens as well as sexually transmitted pathogens.