Effect of experimental ileitis on expression of tlr-2 in lymphfocytes of small intestine

Abstract

Introduction Crohn’s disease and ulcerative colitis are the main clinical phenotypes of inflammatory bowel disease (IBD). Both forms of IBD can increase the incidence of gastrointestinal and colon cancers, and both ones are associated with significant morbidity and mortality worldwide. In addition, they can begin early in life and persist for long periods. The pathogenesis of IBD is complex and multifactorial. Differential alteration of Toll-like receptor (TLR) expression in inflammatory bowel disease was first described 15 years ago. Studies have led to the current concept that TLRs represent key mediators of innate host defense in the intestine, and they are involved in mucosa maintaining as well as commensal homeostasis. Recent findings in diverse murine models of ileitis have helped to reveal the importance of TLR dysfunction mechanisms in IBD pathogenesis. The aim of research The aim of this study was to investigate the effect of acute ileitis on expression intensity of TLR-2 in lymphocytes of small intestine. Materials and methods Male Wistar rats with weight 200–250 g were housed in standard wire-mesh bottom cages at constant temperature of 25°C and 12/12 h light/dark cycles. The rats were given water and standard laboratory diet with no restriction prior to indomethacin injection. A total number of 20 rats were examined, including control group (n = 10). For induction of acute ileitis, rats received one subcutaneous dose of indomethacin (Sigma, 15 mg/kg). Tissue was examined on the fifth day. For histological examination sections were colored with haematoxylin and eosin. The TLR-2+cells were determined using a direct immunofluorescence technique with using monoclonal rat anti-TLR-2 antibodies. Images were taken by using a fluorescence microscope PrimoStar (ZEISS, Germany) with a computer-assisted video system AxioCam 5c (ZEISS, Germany) including the NIH-Image software (NIH Image version 1·46). All statistical analyses were performed using EXCEL MS Office 2010 (Microsoft Corp., USA), STATISTICA 6.0 (Stat-Soft, 2001) software. Results are expressed as mean values ± SEM. Differences were considered statistically significant if the p value was <0.05. Results In our study the significant increase of TLR-2+ lymphocytes during the acute intestinal inflammation over a short time-course suggests that TLR-2+ lymphocytes are involved in the inflammatory process and therefore it might be one of the factors that support the progression of IBD. Conclusions We established that development of ileitis was accompanied with the increase of amount of TLR-2+ lymphocytes and their density on cytoplasmic membrane.

Keywords

• ileitis
• small intestine
• TLR