Defensin alpha 3 (DEFA3)

Defensin alpha 3 (DEFA3) is an antimicrobial peptide found predominantly in the granules of neutrophils and plays a crucial role in the innate immune system, acting as an effector molecule with broad activity against bacteria, fungi, and viruses[1][3]. It exhibits direct antimicrobial effects by disrupting microbial membranes, neutralizes bacterial toxins, and can block viral entry by binding to viral envelope proteins[1][3]. DEFA3, grouped with other alpha-defensins such as HNP-1 to HNP-4, is rapidly expressed and deployed by neutrophils at sites of infection or inflammation and plays additional roles in chemotaxis and immune modulation[3]. The gene is highly similar to DEFA1, differing by only one amino acid[1]. Clinical associations include sialolithiasis and roles in both controlling infection and regulating inflammation; however, the high cationic and amphipathic nature of alpha-defensins means there could be cytotoxicity to host cells if regulation fails[3]. There are currently no known approved drugs directly targeting or mimicking DEFA3, but its mechanism provides a template for antimicrobial drug development[1][3][4].

Other names

Neutrophil defensin 3HNP-3DEF3HP-3Neutrophil-specific defensinDefensin, alpha 3Neutrophil peptide 3HNP3HP3Defensin 3

Disruption of microbial membranes (via pore formation or detergent-like action), Neutralization of bacterial toxins, Inhibition of viral entry