Increased expression of Toll-like receptor (TLR) 2 and TLR4 in the colonic mucosa of children with inflammatory bowel disease

• Published in: Clinical and experimental immunology Vol. 151; no. 1; pp. 34 - 41
• Main Authors: Szebeni, B, Veres, G, Dezsõfi, A, Rusai, K, Vannay, Á, Mraz, M, Majorova, E, Arató, A
• Format: Journal Article
• Language: English
• Published: Oxford, UK Oxford, UK : Blackwell Publishing Ltd 01-01-2008; Blackwell Publishing Ltd; Blackwell; Blackwell Science Inc
• Subjects: Adolescent; Analytical, structural and metabolic biochemistry; Biological and medical sciences; Blotting, Western - methods; Case-Control Studies; Child; children; Colon; colon biopsy samples; Disease Susceptibility; expression pattern; Female; Fundamental and applied biological sciences. Psychology; Gastroenterology. Liver. Pancreas. Abdomen; Humans; Immunity, Innate; inflammatory bowel disease; Inflammatory Bowel Diseases - immunology; Inflammatory Bowel Diseases - metabolism; Intestinal Mucosa - immunology; Intestinal Mucosa - metabolism; Male; Medical sciences; Other diseases. Semiology; Recurrence; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger - analysis; Statistics, Nonparametric; Stomach. Duodenum. Small intestine. Colon. Rectum. Anus; Toll-Like Receptor 2 - analysis; Toll-Like Receptor 2 - genetics; Toll-Like Receptor 2 - metabolism; Toll-Like Receptor 3 - analysis; Toll-Like Receptor 3 - genetics; Toll-Like Receptor 3 - metabolism; Toll-Like Receptor 4 - analysis; Toll-Like Receptor 4 - genetics; Toll-Like Receptor 4 - metabolism; Toll-like receptors; Translational Studies; Human; expression pattern; Digestive system; Mucosa; Gut; Toll like receptor; Biochemistry; inflammatory bowel disease; Inflammatory disease; Crohn disease; Biopsy; children; Toll-like receptors; colon biopsy samples; Digestive diseases; Intestinal disease; Colon; Child; Ulcerative colitis
• ISSN: 0009-9104; 1365-2249
• DOI: 10.1111/j.1365-2249.2007.03531.x

Inflammatory bowel disease (IBD) may result from exaggerated stimulation of the mucosal immune system by luminal bacterial flora. Bacterial products are recognized by pattern recognition receptors such as Toll-like receptors (TLRs), which are key regulators of the innate immune system. Therefore, the expression of TLR2, TLR3 and TLR4 in colonic biopsy samples taken from children with active IBD were studied and compared to controls. Colonic biopsy samples were collected from macroscopically inflamed and non-inflamed regions of the mucosa of 12 children with freshly diagnosed IBD (fdIBD) and 23 children with relapsed IBD (rIBD). Specimens were also obtained from eight controls. TLR2, TLR3 and TLR4 mRNA expression and protein levels were determined by real-time reverse transcription polymerase chain reaction (RT-PCR) and Western blot. We found higher TLR2 and TLR4 mRNA and protein levels in the inflamed colonic mucosa of children with fdIBD and rIBD compared to controls. In the non-inflamed colonic mucosa of children with fdIBD and rIBD, TLR2 and TLR4 mRNA and protein levels were similar to controls. TLR2 and TLR4 mRNA and protein levels also did not differ between children with fdIBD or rIBD in either inflamed or non-inflamed colonic mucosa. TLR3 mRNA expression and protein levels were similar in all groups studied. Our results of increased levels of TLR2 and TLR4 in the inflamed colonic mucosa of children with IBD confirm the hypothesis that innate immunity has an important role in the pathogenesis of this disease.