Oral Presentation ESA-SRB-ANZOS 2025 in conjunction with ENSA

Characterising the immune response driven by seminal extracellular vesicles in human primary cervical epithelial cells (128502)

Elizabeth Torres Arce 1 2 , David J Sharkey 3 , Shanmathi Parameswaran 1 2 , Sarah A Robertson 3 , Brett Nixon 1 2 , John E Schjenken 1 2
  1. Centre for Reproductive Science, School of Environmental and Life Sciences, College of Engineering, Science and Environment, University of Newcastle, Newcastle, NSW 2308, Australia
  2. Hunter Medical Research Institute, Infertility and Reproduction Research Program, New Lambton Heights, NSW 2305, Australia
  3. The Robinson Research Institute and School of Biomedicine, University of Adelaide, Adelaide, SA 5005, Australia

Introduction: Seminal plasma interacts with epithelial cells lining the female reproductive tract (FRT) to activate proinflammatory responses that facilitate pregnancy. Seminal extracellular vesicles (SEVs) are postulated to contribute to this process, although their signalling capacity is poorly understood.

Aims: To explore the immune-signalling capacity of SEVs in human primary cervical epithelial cells.

Methods: SEVs were isolated using an established density gradient ultracentrifugation protocol and EV concentration was characterised using nanoparticle tracking analysis. SEVs or matching seminal plasma from normozoospermic donors (n=14) was co-incubated with primary human cervical epithelial cells using media-treated cells as control. Intra-donor SEV signalling capacity was assessed by comparing normozoospermic (n=3) and non-normozoospermic (n=3) SEV samples from the same donor. Pro-inflammatory cytokines were quantified in cell culture supernatants by Luminex microbead assay.  

Results: Seminal plasma significantly increased secretion of chemokine (C-C motif) ligand (CCL5), interleukin (IL)1A, IL4, IL6, IL8, IL22, macrophage colony-stimulating factor (MCSF), vascular endothelial growth factor (VEGF)A and suppressed secretion of IL1B (all p<0.05 compared to control). IL8 and IL22 were induced to an equivalent extent by SEVs (p<0.05 compared to control), suggesting their secretion was driven by SEV exposure. Additionally, CXCL1 was significantly induced following SEV co-incubation (p<0.05 compared to control). Pearson’s correlation analysis of SEV-regulated cytokines showed SEV number was not associated with CXCL1 or IL22 secretion but was negatively correlated with IL8 (r=-0.48, p=0.051). SEVs from non-normozoospermic samples showed a reduced capacity to induce CXCL1, IL8, and IL22 compared to those from normozoospermic samples.

Conclusion: In addition to seminal plasma, SEVs elicit FRT cytokine induction in primary epithelial cervical cells, providing evidence for a physiological contribution during the peri-conception period. Our future studies are exploring SEV effects across different regions of the FRT, with preliminary data showing SEVs interact with vaginal (n=7), endometrial (n=5) and fallopian tube (n=7) epithelial cells.