Expression of Toll-like receptor 2 in duodenal biopsies from dogs with inflammatory bowel disease is associated with severity of disease

• Published in: Veterinary immunology and immunopathology Vol. 135; no. 1-2; pp. 158 - 163
• Main Authors: McMahon, L.A., House, A.K., Catchpole, B., Elson-Riggins, J., Riddle, A., Smith, K., Werling, D., Burgener, I.A., Allenspach, K.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 15-05-2010; Amsterdam: Elsevier
• Subjects: Animals; biopsy; Biopsy - veterinary; disease resistance; disease severity; Dog; dog diseases; Dog Diseases - immunology; Dogs; duodenum; Duodenum - chemistry; Duodenum - immunology; Duodenum - pathology; enteropathogens; etiology; Female; gene expression; Gene Expression - genetics; Gene Expression - immunology; histopathology; immune response; immunologic factors; Inflammatory bowel disease; Inflammatory Bowel Diseases - immunology; Inflammatory Bowel Diseases - pathology; Inflammatory Bowel Diseases - veterinary; intestinal microorganisms; Male; messenger RNA; microbial colonization; pathogenesis; pathophysiology; receptors; Reverse Transcriptase Polymerase Chain Reaction - veterinary; Severity of Illness Index; Toll-Like Receptor 2 - analysis; Toll-Like Receptor 2 - biosynthesis; Toll-Like Receptor 2 - immunology; Toll-like receptors; Inflammatory bowel disease; Toll-like receptors; Dog
• ISSN: 0165-2427; 1873-2534
• DOI: 10.1016/j.vetimm.2009.11.012

There is growing evidence that aberrant innate immune responses towards the bacterial flora of the gut play a role in the pathogenesis of canine inflammatory bowel disease (IBD). Toll-like receptors (TLR) play an important role as primary sensors of invading pathogens and have gained significant attention in human IBD as differential expression and polymorphisms of certain TLR have been shown to occur in ulcerative colitis (UC) and Crohn's disease (CD).
The aim of the current study was to evaluate the expression of two TLR important for recognition of commensals in the gut. TLR2 and TLR4 mRNA expression in duodenal biopsies from dogs with IBD was measured and correlated with clinical and histological disease severity. Endoscopic duodenal biopsies from 20 clinical cases and 7 healthy control dogs were used to extract mRNA. TLR2 and TLR4 mRNA expression was assessed using quantitative real-time PCR. TLR2 mRNA expression was significantly increased in the IBD dogs compared to controls, whereas TLR4 mRNA expression was similar in IBD and control cases. In addition, TLR2 mRNA expression was mildly correlated with clinical severity of disease, however, there was no correlation between TLR2 expression and histological severity of disease.