Defensin HNP-1 (human) (trifluoroacetate salt)

Defensin HNP-1 is a peptide secreted by polymorphonuclear leukocytes (PMNs) that has antimicrobial properties. It induces lysis of mammalian cells when used at concentrations of 25 and 100 μg/ml, respectively. It also completely inhibits secretion of the exotoxin superantigen TSS toxin-1 (TSST-1) from S. aureus when used at a concentration of 50 ng/ml and inhibits anthrax lethal toxin (IC50 = 148 nM). HNP-1 binds to recombinant HIV-1 envelope glycoprotein (gp120) and human CD4 (Kds = 23.2 and 12.9 nM, respectively). It induces lysis and leakage from liposomes composed of dipalmitoyl phosphatidylcholine and dioleyl phosphatidylserine (DOPS). In vivo, HNP-1 (5 μg) increases interferon α (IFN-α) production by human plasmacytoid dendritic cells (pDCs) injected into nude mice.