Therapeutic Potentials of Antimicrobial Peptides

Volume 5 • Issue 3 • 2013 Antimicrobial peptides (AMPs) are small proteins (<100 amino acids) which include alpha-defensins, beta-defensins and the cathelicidin LL-37 in humans [1]. Alpha-defensins are expressed in neutrophils as part of their non-oxidative antimicrobial mechanismsand are also found in Paneth cells in the intestine [2,3]. They are synthesized as precursors that are proteolytically activated and released during inflammation [4]. The human beta-defensins (hBDs) are cationic antimicrobial peptides made primarily by epithelial cells and expressed in all human epithelia tested to date [5]. The defensins are secreted in biological fluids, including urine, bronchial fluids, nasal secretions, saliva and gingival crevicular fluid [5-7]. hBD-1 is expressed constitutively in epithelial tissues, whereas hBD-2 and hBD-3 are expressed when epithelia are stimulated with bacteria, Candida albicans, IL-1, or TNF-α [8,9]. LL-37 is an amphipathic cationic peptide expressed in various epithelial cell types, including inflam206-543-4339 ed epidermal keratinocytes and in human tongue, buccal mucosa and saliva following inflammatory stimulation [10,11].