Human beta-defensin (HBD)

Human beta-defensins are a family of small cationic antimicrobial peptides primarily produced by epithelial cells as part of the innate immune system. They are characterized by a conserved six-cysteine motif forming three disulfide bonds that stabilize their structure. These peptides disrupt microbial membranes through pore formation and also act as chemoattractants for various immune cell types—bridging innate and adaptive immunity. Expression can be constitutive or inducible in response to infection or inflammatory stimuli. Multiple human beta-defensins exist (e.g., HBD1–HBD3), each with distinct expression patterns and regulatory mechanisms. Beyond direct antimicrobial action against bacteria and fungi—and some antiviral effects—they modulate immune responses by recruiting leukocytes to sites of infection or injury. Dysregulation has been implicated in chronic inflammation and certain diseases.

Other names

Beta-defensinβ-defensinHBD1HBD2HBD3DEFB1DEFB4ADEFB103A