Components in seminal plasma regulating sperm transport and elimination

Area of Science:

• Reproductive biology
• Immunology
• Animal reproduction

Background:

• Seminal plasma influences sperm transport and inflammation in the female reproductive tract.
• Understanding seminal plasma's role is crucial for sperm survival and elimination processes.

Purpose of the Study:

• To investigate the role of seminal plasma components in sperm transport and elimination.
• To identify specific seminal plasma factors affecting sperm-immune cell interactions.

Main Methods:

• Hysteroscopic insemination with and without prostaglandin E (PGE).
• In vitro opsonization and phagocytosis assays with treated seminal plasma and sperm.
• Analysis of sperm-polymorphonuclear neutrophil (PMN) binding and phagocytosis with various seminal plasma protein fractions.

Main Results:

• Prostaglandin E (PGE) showed a potential role in sperm transport across the utero-tubal junction in mares.
• Whole seminal plasma suppressed sperm opsonization and phagocytosis by PMNs, an effect reduced by heat treatment.
• Seminal plasma proteins differentially affected viable and non-viable sperm interactions with PMNs, with distinct roles for protease activity.

Conclusions:

• Seminal plasma contains components vital for viable sperm transport and survival.
• Specific seminal plasma proteins modulate immune responses, facilitating the elimination of non-viable spermatozoa.
• Protease activity within seminal plasma influences its interaction with both viable and non-viable sperm and immune cells.