Influence of co-culture with established human endometrial epithelial and stromal cell lines on sperm movement characteristics

The effects of co-culture of human spermatozoa with human immortalizedendometrial cells - epithelial or stromal - on sperm movementcharacteristics, including hyperactivation, were studied using computer-assisted sperm analysis (CASA). Epithelial and stromal cell types could beseparated following 8-10 days of culture of endometrial cells originatingfrom human biopsies. Both cell types were immortalized by the SV 40 large Tantigen. Co-incubation of sperm with epithelial and stromal monolayersenhanced the rate of hyperactivation: 24.9% (P <0.05) and 17.8% (P =0.05) versus 9.5% as control, respectively, whereas the majority ofmotility parameters remained unchanged. Conditioned media had no effectupon sperm parameters, including hyperactivation. Co-incubation with eithermonolayer was able to maintain sperm motility over a longer period thanincubation in control medium alone. In four patients whose spermatozoa didnot exhibit hyperactivation, co-incubation with epithelial cells, but notconditioned medium, allowed normal rates of hyperactivation (range: 6.9-15.6%).