Human sperm function after coculture with human fallopian tubal epithelial cell monolayers: In vitro model for studying cell interactions in early human conception

Abstract

It has been difficult to study the behavior of sperm in the tubal environment in vivo. Human tubal epithelial cells were therefore cultured in vitro to stimulate tubal conditions and human sperm function was assessed in the presence of such cells in vitro. Ampullary epithelial cell lines were established from fallopian tubes collected from premenopausal women undergoing hysterectomy. Approximately 1 x 10 5 cells/mL from monolayers of the third passage were seeded with 1 mL of culture medium into each well of 4-well plastic dishes. Sperm from 10 ejaculates of 10 different oligoasthenozoospermic men 30-41 years of age were recovered by the swim-up method and 200,000 sperm from each ejaculate were added into each well at the time of cell seeding. Control wells were treated the same but without cells. All dishes were incubated at 37°C in 5% CO 2, and sperm motility, acrosome reaction, and sperm-cell binding assessed at 1, 5, and 24 h. curvilinear velocity and mean amplitude of lateral head displacement were significantly different in ampullary cultures as compared with controls for all three time periods: 1 h (67 ± 5.2 vs 58 2+ 4.9 μm/s, p < 0.05; 4.48 ± 0.4 vs 3.29 ± 0.3 μm; p < 0.05), 5 h (75 ± 5.8 vs 64 ± 5.0 μm/s, p < 0.05; 4.92 ± 0.5 vs 3.68 ± 0.3 μm, p < 0.05), and 24 h (70 ± 4.8 vs 59 ± 4.2 μm/s, p < 0.05; 4.36 ± 0.4 vs 3.11 ± 0.3 μm, p < 0.05). The mean percentage of sperm undergoing the acrosome reaction was not significantly different between experimental and control samples at 1, 5, and 24 hours (4.9 ± 2.0% to 18.2 ± 4.2% vs 4.8 ± 2.1% to 17.0 ± 4.5%; p > 0.01). Approximately, 10 to 15% of sperm binding to epithelial cells was observed at 5 and 24 h. It would appear that the increase in sperm motility may help to improve fertilization rates in vitro fertilization.