Figure 3. Expression of TLR2, TLR4, NOD1, and NOD2 on human oral epithelial cells. (a) Human oral epithelial HSC-2, HO-1-u-1, KB cells, and primary gingival epithelial cells were cultured until confluent at 37°C. After incubation, the total RNA was extracted, and the mRNA expression of TLR2, TLR4, NOD1, and NOD2 was analyzed by PCR. (b) Human oral epithelial cells were cultured until confluent at 37°C. The expression of TLR2, TLR4, NOD1, and NOD2 was assessed by flow cytometry. Thin lines represent the isotype Ab control. The results presented are representative of 4 different experiments demonstrating similar results. (c) Human oral epithelial HSC-2 cells were cultured until confluent at 37°C. After fixation, cells were treated with anti-TLR2 antibody or anti-TLR4 antibody and then visualized with Alexa Fluor 488 (green). Nuclei were visualized by being stained with propidium iodide (red). For NOD staining, cells were treated with anti-NOD1 antibody (brown) or anti-NOD2 antibody (brown). The results are representative of 3 different experiments with similar results. Scale bars: 20 µm.