β-defensins at the immune-reproduction interface

Professor Kieran G. Meade, PhD

¹ UCD School of Agriculture and Food Science, University College Dublin, Belfield, D04 V1W8, Dublin, Ireland.

² UCD Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Belfield, D04 V1W8, Dublin, Ireland.

Abstract Text:

Host Defence Peptides (HDPs) have emerged as promising candidates in the search for alternatives to traditional antibiotics—gaining attention not only for their antimicrobial properties but also for their growing potential as immunomodulatory agents. Among the most prominent HDPs are β-defensins, a versatile family of small, cationic peptides found widely across both the plant and animal kingdoms.

Renowned for their frontline role in the innate immune system, β-defensins are particularly active at epithelial barriers such as the skin, respiratory, and gastrointestinal tracts. Yet, despite this well-established defensive function, their contributions to reproductive biology remain poorly understood.

Our research has identified a remarkable expansion of β-defensin genes in the bovine genome, revealing a rich repertoire of novel variants that are highly expressed in the male reproductive tract. Most recently, we’ve focused on Copy-Number Variation (CNV) within this gene family, honing in on β-defensin 103 (BDEF103)—the bovine orthologue of human β‑defensin 3 (hBD‑3)—to investigate its dual role in fertility and immune defense.

In the context of rising antimicrobial resistance (AMR) and growing concerns over antibiotic use in livestock, our findings suggest these peptides could hold significant promise not only as next-generation antimicrobials but also as biomarkers of fertility. While much remains to be discovered, this talk will delve into our ongoing exploration of bovine β-defensins at the immune-reproduction interface.