title: Functional synergism of Human Defensin 5 and Human Defensin 6.
abstract: The gut epithelium is critically involved in maintaining intestinal immune homeostasis. Acting as a physical barrier, it separates the intestinal microflora from cells of the immune system. In addition to its barrier function, the intestinal epithelium expresses defensins, natural, endogenous antimicrobial peptides. In humans, specialized epithelial cells, termed Paneth cells, located primarily in the small intestine express two defensins, Human Defensin-5 (HD-5) and Human Defensin-6 (HD-6). Previously, we have shown that HD-5 potently kills bacteria and induces secretion of interleukin-8 by intestinal epithelial cells. We show that HD-6 specifically and synergistically enhances the HD-5-induced IL-8 secretion, but does not alter its anti-bacterial activity. Further, we find that HD-5 decreases the trans-epithelial electrical resistance of intestinal epithelial cells and that HD-6 negates this effect of HD-5.
authors.affiliation: Department of Radiation Oncology, University of Maryland Baltimore School of Medicine, 620 West Lexington Street, Baltimore, MD 21201, USA.
authors.forename: Aiping
authors.initials: A
authors.lastname: Zhao
authors.affiliation: Institute of Human Virology and Department of Molecular Biology & Biochemistry of the University of Maryland Baltimore School of Medicine, 725 West Lombard Street, Baltimore, MD 21201, USA.
authors.forename: Wuyuan
authors.initials: W
authors.lastname: Lu
authors.affiliation: Institute of Human Virology and Department of Molecular Biology & Biochemistry of the University of Maryland Baltimore School of Medicine, 725 West Lombard Street, Baltimore, MD 21201, USA. Electronic address: edeleeuw@som.umaryland.edu.
authors.forename: Erik
authors.initials: E
authors.lastname: de Leeuw
mesh_terms: D023082:Defensins / Q000502:physiology*; D006801:Humans; D016209:Interleukin-8 / Q000096:biosynthesis; D007413:Intestinal Mucosa / Q000502:physiology
chemical_list: D023082:Defensins; D016209:Interleukin-8
keywords: Human defensin 5; Human defensin 6; Interleukin 8; Intestinal epithelium