Salmonella Research Today is a free monthly online journal that collates and summarizes the latest research about Salmonella, including details on salmonella typhimurium, food poisoning, infection, treatment.

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.

Veldhuizen EJ, van Dijk A, Tersteeg MH, Kalkhove SI, van der Meulen J, Niewold TA, Haagsman HP

Department of Infectious Diseases & Immunology, Faculty of Veterinary Medicine, Utrecht University, P.O. Box 80.175, Utrecht, The Netherlands. E.Veldhuizen@vet.uu.nl

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.

Published 29 August 2006 in Mol Immunol, 44(4): 276-83.
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