Figure 5.

Immunohistochemical detection of TLR on paraffin sections of human small intestine. Small intestine biopsies from healthy individuals were stained for various Toll-like receptors (TLRs). No expression of TLR-1, -2, -3, -4 and -9 were found. However, the following TLRs were found to be expressed in the SI sections. TLR-5: weak positive staining is observed along the entire epithelial layer. TLR-6: epithelial layer showed moderate staining while intense reaction observed in the lamina propria cells and granules of paneth cells. TLR-7: both villus and crypt epithelial cells showed granular-positive reaction. TLR-8: diffuse positive staining of moderate intensity is observed along the whole epithelial layer. Many cells in the lamina propria also showed positive reaction. In two samples, intense positive reaction for TLR-8 is observed at the luminal side of epithelial layer; in these samples, few lamina propria cells showed positive reaction. TLR-10: intense positive reaction is observed in epithelial cells along the entire crypt–villus axis. Intense brown reaction was observed in the granules of paneth cells and also many lamina propria cells are intensely stained. Magnification 40×.