Human beta-defensin-2 peptide

Human beta-defensin-2 (hBD-2), also known as skin-antimicrobial peptide 1 (SAP1) is a cysteine-rich cationic antimicrobial peptide of 41 amino acids. It was originally isolated from skin cells of psoriasis patients. hBD-2, which belongs to the defensin family, is implicated in the innate immunity thanks to its antimicrobial activity. Thus, β-defensins can play a role at the cutaneous level by limiting the use of antibiotics in severe burns and disease like psoriasis. Moreover, at the pulmonary level, defensins might be involved in the resorption of the infection in cases of cystic fibrosis. hBD-2 is produced after stimulation of epithelial cells following their contact with some organisms like Gram-negative bacteria and Candida Albicans, fungus or cytokines such as TNF-alpha and IL-1 beta. This antimicrobial activity was shown to be microbicidal at concentrations greater than 1 µM and was lethal for E.Coli and pseudomonas (LD90 : 10 mg/mL) and Candida Albicans (LD90 : 25 mg/mL). Besides its antimicrobial activity, hBD-2 also exhibits proinflammatory properties as chemoattractants for memory T-cells, immature dendritic cells, mast cells and neutrophils. hBD-2 has also demonstrated inhibitory activity of the voltage-gated potassium channel Kv1.3 at picomolar concentration. Kv1.3 are overexpressed by T-cells in case of autoimmune disorders.