title: α-Defensins in human innate immunity.
abstract: Defensins are small, multifunctional cationic peptides. They typically contain six conserved cysteines whose three intramolecular disulfides stabilize a largely β-sheet structure. This review of human α-defensins begins by describing their evolution, including their likely relationship to the Big Defensins of invertebrates, and their kinship to the β-defensin peptides of many if not all vertebrates, and the θ-defensins found in certain non-human primates. We provide a short history of the search for leukocyte-derived microbicidal molecules, emphasizing the roles played by luck (good), preconceived notions (mostly bad), and proper timing (essential). The antimicrobial, antiviral, antitoxic, and binding properties of human α-defensins are summarized. The structural features of α-defensins are described extensively and their functional contributions are assessed. The properties of HD6, an enigmatic Paneth cell α-defensin, are contrasted with those of the four myeloid α-defensins (HNP1-4) and of HD5, the other α-defensin of human Paneth cells. The review ends with a decalogue that may assist researchers or students interested in α-defensins and related aspects of neutrophil function.
authors.affiliation: Department of Medicine and Molecular Biology Institute, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095-1688, USA. rlehrer@mednet.ucla.edu
authors.forename: Robert I
authors.initials: RI
authors.lastname: Lehrer
authors.forename: Wuyuan
authors.initials: W
authors.lastname: Lu
mesh_terms: D000818:Animals; D000890:Anti-Infective Agents / Q000737:chemistry / Q000276:immunology*; D005075:Biological Evolution; D019295:Computational Biology; D006801:Humans; D007113:Immunity, Innate; D018928:Immunity, Mucosal; D009504:Neutrophils / Q000276:immunology; D019879:Paneth Cells / Q000276:immunology*; D011487:Protein Conformation; D023084:alpha-Defensins / Q000737:chemistry / Q000235:genetics / Q000276:immunology*
chemical_list: D000890:Anti-Infective Agents; D023084:alpha-Defensins