Importance of β-defensins in sperm function

Recent work in humans and mouse has confirmed the involvement of the host defence beta-defensin peptides in male fertility. We discuss here the work that has implicated beta-defensins in sperm function including the identification of the epididymis as the predominant site of expression of the peptides and the in vivo consequences of mutation and deletion. The potential dual role of these peptides in the regulation of infection and control of sperm maturation is compelling and may combine their antimicrobial activity with the ability of these molecules to interact with cell membrane receptors and modulate ion transport.