[doi: 10.5505/2017ichc.PP-92]Expression of TLR2 in Sheep Ileum during Prenatal DevelopmentMehmet Özbek1, Emel Ergün2, Feyzullah Beyaz3, Levent Ergün2, Nuh Yıldırım2, Özge Özgenç2, Füsun Erhan22Ankara University, Faculty of Veterinary Medicine, Department of Histology and Embryology, Ankara, Turkey 3Erciyes University, Faculty of Veterinary Medicine, Department of Histology and Embryology, Kayseri, Turkey Introduction The intestines are the biggest defense barrier of our bodies. More than 60% of immune cells are found in the intestinal mucosa and are ready to identify and control the presence of potential aggressors and prevent uncurbed inflammatory reactions. Toll like receptors (TLR), which are family of pattern recognition receptors, make a big contribution in repressing the activation of the inflammatory cascade to continue the stabilize of intestinal homeostasis and in promoting inflammatory responses to pathogens. This study was conducted to examine the localization and expression of TLR2 in the prenatal period in the sheep ileum. Materials & Methods In this study, the distal ileums from ten sheep fetuses with gestational ages varying between 63 and 147 days were used as a material. Distal ileal tissue samples were fixed in Bouin’s solution and passed through the standart histological procedures, and then embedded in paraffin. Immunohistochemical staining was performed with the primary antibody to TLR2 by using StreptAvidin Biotin (Strep-ABC) method. Results In the early stages of the prenatal period TLR2 expression was intensively observed on apical surfaces of intestinal epithelial cells. It was noted that this immunological reaction in intestinal epithelial cells diminished towards the end of the prenatal period. Cells with a strong cytoplasmic positive reaction were found among the intestinal epithelial cells. It was observed that the number of these cells increased towards the end of the prenatal period. Immunological reaction were observed the smooth muscle cells forming tunica muscularis and lamina muscularis at all period. Conclusion The appearance of TLR2 expression in sheep during the fetal period suggests that the innate immun system before birth is well prepared against bacterial invasion in the neonatal period. Strong positively responsive cells between the intestinal epithelial cells resemble enteroendocrine cells when literature reviews and cell morphology are taken into consideration. |