Beta-defensin 3 (hBD-3)

Beta-defensin 3 (hBD-3) is a potent, cationic antimicrobial peptide (AMP) belonging to the beta-defensin family, primarily expressed by epithelial cells and neutrophils (UniProt Q5U7J2). It plays a critical role in the innate immune system by providing broad-spectrum microbicidal activity against Gram-positive and Gram-negative bacteria (including MRSA), fungi, and enveloped viruses (PubMed 11085990). Unlike many other defensins, hBD-3 maintains its antimicrobial efficacy under physiological salt concentrations, making it a robust effector molecule at mucosal surfaces and skin (PubMed 16978580). Beyond its direct killing capacity, hBD-3 acts as an immunomodulator and chemoattractant, recruiting dendritic cells and T cells via interactions with receptors such as CCR6 and CXCR4 (PMC4126216). In clinical contexts, hBD-3 is being explored as a therapeutic agent for wound healing and biofilm-associated infections, and it is utilized in specialized skin care regimens to promote tissue regeneration (J Drugs Dermatol 2023). It also serves as a diagnostic biomarker; for instance, the Beta-defensin index (BDI) is used for the detection of oral squamous cell carcinoma, where hBD-3 is often overexpressed (PMC10910144). However, its therapeutic application faces challenges such as susceptibility to rapid proteolytic degradation and its complex, context-dependent role in either resolving inflammation or potentially promoting tumor progression in certain cancers (PMC3074315).

Other names

hBD-3BD-3DEFB3DEFB103ADefensin beta 103ADefensin-like proteinHBP-3

Beta-defensin 3 exerts its effects through multiple mechanisms: it disrupts microbial membranes via electrostatic interactions and inhibits bacterial cell wall biosynthesis. It also acts as a ligand for G protein-coupled receptors such as CCR6, CCR2, and CXCR4 to recruit immune cells, and modulates Toll-like receptor (TLR) signaling pathways to regulate inflammatory responses.