title: Distinct defensin profiles in Neisseria gonorrhoeae and Chlamydia trachomatis urethritis reveal novel epithelial cell-neutrophil interactions.
abstract: Defensins are key participants in mucosal innate defense. The varied antimicrobial activity and differential distribution of defensins at mucosal sites indicate that peptide repertoires are tailored to site-specific innate defense requirements. Nonetheless, few studies have investigated changes in peptide profiles and function after in vivo pathogen challenge. Here, we determined defensin profiles in urethral secretions of healthy men and men with Chlamydia trachomatis- and Neisseria gonorrhoeae-mediated urethritis by immunoblotting for the epithelial defensins HBD1, HBD2, and HD5 and the neutrophil defensins HNP1 to -3 (HNP1-3). HBD1 was not detectable in secretions, and HBD2 was only induced in a small proportion of the urethritis patients; however, HD5 and HNP1-3 were increased in C. trachomatis infection and significantly elevated in N. gonorrhoeae infection. When HNP1-3 levels were low, HD5 appeared mostly as the propeptide; however, when HNP1-3 levels were >10 microg/ml, HD5 was proteolytically processed, suggesting neutrophil proteases might contribute to HD5 processing. HD5 and HNP1-3 were bactericidal against C. trachomatis and N. gonorrhoeae, but HD5 activity was dependent upon N-terminal processing of the peptide. In vitro proteolysis of proHD5 by neutrophil proteases and analysis of urethral secretions by surface-enhanced laser desorption ionization substantiated that neutrophils contribute the key convertases for proHD5 in the urethra during these infections. This contrasts with the small intestine, where Paneth cells secrete both proHD5 and its processing enzyme, trypsin. In conclusion, we describe a unique defensin expression repertoire in response to inflammatory sexually transmitted infections and a novel host defense mechanism wherein epithelial cells collaborate with neutrophils to establish an antimicrobial barrier during infection.
authors.affiliation: Department of Biological Sciences, California State University, Los Angeles, 5151 State University Drive, Los Angeles, CA 90032, USA. eporter@calstatela.edu
authors.forename: Edith
authors.initials: E
authors.lastname: Porter
authors.forename: Huixia
authors.initials: H
authors.lastname: Yang
authors.forename: Sujata
authors.initials: S
authors.lastname: Yavagal
authors.forename: Gloria C
authors.initials: GC
authors.lastname: Preza
authors.forename: Omar
authors.initials: O
authors.lastname: Murillo
authors.forename: Heriberto
authors.initials: H
authors.lastname: Lima
authors.forename: Sheila
authors.initials: S
authors.lastname: Greene
authors.forename: Laily
authors.initials: L
authors.lastname: Mahoozi
authors.forename: Marcia
authors.initials: M
authors.lastname: Klein-Patel
authors.forename: Gill
authors.initials: G
authors.lastname: Diamond
authors.forename: Sunita
authors.initials: S
authors.lastname: Gulati
authors.forename: Tomas
authors.initials: T
authors.lastname: Ganz
authors.forename: Peter A
authors.initials: PA
authors.lastname: Rice
authors.forename: Alison J
authors.initials: AJ
authors.lastname: Quayle
mesh_terms: D002690:Chlamydia Infections / Q000378:metabolism*; D002692:Chlamydia trachomatis; D023082:Defensins / Q000378:metabolism*; D004847:Epithelial Cells / Q000378:metabolism*; D006069:Gonorrhea / Q000378:metabolism*; D006801:Humans; D015151:Immunoblotting; D008297:Male; D009344:Neisseria gonorrhoeae; D009504:Neutrophils / Q000201:enzymology / Q000378:metabolism*; D010447:Peptide Hydrolases / Q000378:metabolism; D014521:Urethra / Q000378:metabolism; D014526:Urethritis / Q000378:metabolism*
chemical_list: D023082:Defensins; D010447:Peptide Hydrolases