Higher-quality human sperm in a sample selectively attach to oviduct (fallopian tube) epithelial cells in vitro.

OBJECTIVE: To determine if sperm attachment to oviduct epithelial cells (OEC) in vitro is selective for higher quality sperm and if the system requires homologous species OEC. DESIGN: Controlled prospective study with outcomes assayed by a technician blind to sperm treatment groups. SETTING: An academic research laboratory. PATIENT(S): Experiment 1: normospermic donors with children (4 donors, 7 ejaculates). Experiment 2: cryopreserved donor samples (4 donors). INTERVENTION(S): Semen collection by masturbation after 48 hours of abstinence. MAIN OUTCOME MEASURE(S): Experiment 1: sperm assays of motility, morphology, membrane integrity, and capacitation status. Experiment 2: sperm chromatin (DNA) integrity and condensation. RESULT(S): Experiment 1: sperm not attaching to OEC had lower motility, more membrane disruptions, and more acrosome reactions than did control sperm. This selectivity was equivalent for sperm in coculture with all OEC types. Experiment 2: sperm attached to OEC had fewer abnormalities in chromatin structure compared with sperm that were not attached. CONCLUSION(S): Selective attachment of functionally superior sperm to OEC is likely important during sperm reservoir formation in vivo and may be exploitable in vitro as a method to isolate high-quality sperm for clinical procedures. Such a system does not require human origin OEC.

Human sperm function in co-culture with human, macaque or bovine oviduct epithelial cell monolayers.

Human sperm function was compared in co-culture with monolayers of oviduct epithelial cells (OEC) from three species, human, macaque and bovine. For all species, freeze-thawed and passaged OEC from females in the periovulatory phase were used. OEC cultured on an extracellular matrix (Matrigel) formed a monolayer which supported human sperm attachment to OEC from all three species. Spermatozoa in co-culture with OEC from all three species showed prolonged survival and improved motility characteristics over those cultured in medium alone. This paper describes an efficient, repeatable co-culture system for human spermatozoa which supports sperm attachment to OEC and subsequently improves sperm function over that seen in control medium cultures. Because the improved sperm function in co-culture did not differ significantly between human and bovine OEC for those attributes studied, it is proposed that bovine OEC could be used as an alternative to human OEC in certain human sperm coculture studies. Follicular phase bovine OEC from reproductively normal donors are far more accessible than their human counterparts, thus making this co-culture system more widely available for the study of human spermatozoa-female tract interactions.

Coculture of human sperm with bovine oviduct epithelial cells decreases sperm chromatin structural changes seen during culture in media alone.

OBJECTIVE: To compare sperm chromatin structural changes seen in media only culture or in coculture with bovine oviduct epithelial cells. DESIGN: Three freshly ejaculated and three cryopreserved sperm samples in media culture or in oviduct epithelial cell coculture. Sperm in each treatment were evaluated by the sperm chromatin structure assay during a 72-hour time course. SETTING: An academic research laboratory. PATIENT(S): Normospermic donors with children. INTERVENTION(S): Semen collection through masturbation after 48 hours of abstinence. MAIN OUTCOME MEASURE(S): The sperm chromatin structure assay using flow cytometry to detect the susceptibility of sperm in either treatment to denaturation of DNA in situ. RESULT(S): The sperm chromatin structure assay data differed for sperm type (fresh or cryopreserved), over time, and between treatments within 6 hours of culture. In oviduct epithelial cell coculture, fresh sperm chromatin structure assay values for fresh sperm were stable, whereas in control medium higher chromatin degeneration levels were seen by 10 hours. For cryopreserved sperm, chromatin degeneration had increased by 1 hour postthaw in both treatments, although levels were higher in the control treatment thereafter. CONCLUSION(S): Sperm chromatin structural changes occur over time in culture. Such changes were observed within 2 hours for cryopreserved sperm. Coculture of sperm with oviduct epithelial cells results in a stabilizing effect for sperm against chromatin changes.