title: Expression of beta-defensins pBD-1 and pBD-2 along the small intestinal tract of the pig: lack of upregulation in vivo upon Salmonella typhimurium infection.
abstract: Defensins are antimicrobial peptides that play an important role in the innate immune response in the intestine. Up to date, only one beta-defensin (pBD-1), has been described in pig, which was found to be expressed at low levels in the intestine. We set-up a quantitative PCR method to detect the gene expression of pBD-1 and a newly discovered porcine beta-defensin, pBD-2. Expression of pBD-1 mRNA increased from the proximal to the distal part of the intestine whereas pBD-2 expression decreased. The main gene expression sites for pBD-2 were kidney and liver, whereas pBD-1 was mainly expressed in tongue. The porcine small intestinal segment perfusion (SISP) technique was used to investigate effects of Salmonella typhimurium DT104 on intestinal morphology and pBD-1 and pBD-2 mRNA levels in vivo. The early responses were studied 2, 4 and 8 h post-infection in four separate jejunal and ileal segments. Immunohistochemistry showed invasion of the mucosa by Salmonella and changes in intestinal morphology. However, no concomitant changes in expression of either pBD-1 or pBD-2 were observed. We conclude that at least two defensins are differentially expressed in the intestine of pigs, and that expression of both defensins is not altered by S. typhimurium under these conditions.
authors.affiliation: Department of Infectious Diseases & Immunology, Faculty of Veterinary Medicine, Utrecht University, P.O. Box 80.175, Utrecht, The Netherlands. E.Veldhuizen@vet.uu.nl
authors.forename: Edwin J A
authors.initials: EJ
authors.lastname: Veldhuizen
authors.forename: Albert
authors.initials: A
authors.lastname: van Dijk
authors.forename: Monique H G
authors.initials: MH
authors.lastname: Tersteeg
authors.forename: Stefanie I C
authors.initials: SI
authors.lastname: Kalkhove
authors.forename: Jan
authors.initials: J
authors.lastname: van der Meulen
authors.forename: Theo A
authors.initials: TA
authors.lastname: Niewold
authors.forename: Henk P
authors.initials: HP
authors.lastname: Haagsman
mesh_terms: D000818:Animals; D005786:Gene Expression Regulation; D066298:In Vitro Techniques; D007421:Intestine, Small / Q000378:metabolism* / Q000382:microbiology / Q000473:pathology; D009928:Organ Specificity; D012333:RNA, Messenger / Q000032:analysis; D012480:Salmonella Infections / Q000378:metabolism* / Q000473:pathology; D012486:Salmonella typhimurium; D013552:Swine; D023083:beta-Defensins / Q000096:biosynthesis* / Q000235:genetics
chemical_list: D012333:RNA, Messenger; D023083:beta-Defensins