Human beta-defensin (hBD) (hBD)

Human beta-defensins (hBDs) are a family of small, cationic, cysteine-rich peptides that serve as essential components of the human innate immune system. Primarily expressed by epithelial cells in the skin, respiratory tract, and gastrointestinal tract, these peptides exhibit broad-spectrum antimicrobial activity against bacteria, fungi, and enveloped viruses by disrupting microbial cell membranes (UniProt, 2023). Beyond their direct killing capabilities, hBDs act as potent immunomodulators, functioning as chemoattractants for CCR6-expressing cells such as memory T cells and immature dendritic cells, thereby bridging innate and adaptive immunity (PubMed, PMID: 10591210). In clinical contexts, the expression levels of hBDs are highly relevant; for instance, hBD-2 and hBD-3 are significantly upregulated in psoriatic lesions, contributing to the relative resistance of these patients to skin infections, whereas their deficiency in atopic dermatitis correlates with increased susceptibility to Staphylococcus aureus (NIH, 2021). Therapeutic strategies targeting hBD expression include the use of dietary factors like Vitamin D, isoleucine, and butyrate to induce endogenous production, which is being explored for treating infections and inflammatory bowel diseases (StatPearls, 2023). However, caution is required as chronic overexpression of certain hBDs has been linked to tumor progression and metastasis in specific cancers, highlighting the need for precise modulation (PubMed, PMID: 25151956).

Other names

Beta-defensinDEFBAntimicrobial peptideHost defense peptidehBD-1hBD-2hBD-3hBD-4Defensin beta

Induction of endogenous antimicrobial peptide production via transcriptional activation of pathways such as the Vitamin D Receptor (VDR), NF-kappaB, or AP-1; direct antimicrobial activity occurs through the disruption of microbial cell membranes via pore formation.