A recent collaborative research conducted by the Epithelial Cell Biology Research Centre and Shenzhen Second People's Hospital revealed that deficient human β-defensin-1 (DEFB1) underlies male infertility associated with poor sperm motility and genital tract infection.

Male infertility is attributed to multiple factors. Reduced sperm motility and seminal tract infection are two common causes. Interestingly, sperm with reduced motility is often associated with genital tract infection. However, the underlying cause and possible association between the two disorders remain largely unexplored.

The research led by Prof. Chan Hsiao-chang, director of the Epithelial Cell Biology Research Centre and Professor of Physiology, found that the amount of DEFB1 in sperm from infertile men exhibiting either genital tract infection or reduced sperm motility is much lower than that in normal fertile sperm. Interference with DEFB1 function also decreases both motility and bactericidal activity in normal sperm.

The study further demonstrates that treatment with recombinant DEFB1 markedly restores DEFB1 expression, bactericidal activity, sperm quality, and egg-penetrating ability in sperm from infertile patients exhibiting poor sperm motility and genital tract infection, suggesting a feasible therapeutic approach for related male infertility. The finding has recently been published in Science Translational Medicine.