Mannan-Binding Lectin Inhibits Candida albicans-Induced Cellular Responses in PMA-Activated THP-1 Cells through Toll-Like Receptor 2 and Toll-Like Receptor 4
Figure 8
Inhibition of binding of MBL to PMA-activated THP-1 cells by anti-TLR2 mAb and anti-TLR4 mAb.
(A) MBL binds to PMA-activated THP-1 cells in a Ca2+-dependent manner. PMA-activated THP-1 cells were incubated with biotinylated MBL in Tris-buffered saline solution containing various concentration of calcium ion. (a) Tris-buffered saline with 1.3 mM CaCl2; (b) Tris-buffered saline with 5 mM CaCl2; (c) Tris-buffered saline with 5 mM EDTA. Each solution of THP-1 cells was incubated for 30 min at 37°C, binding of MBL to the cells was analyzed by FCM, as shown in the representative histograms. Black lines, biotinylated MBL binding. Dotted lines, negative controls (the cells only). (B) Anti-TLR2 mAb attenuates the binding of MBL to PMA-activated THP-1 cells. PMA-activated THP-1 cells were incubated with anti-TLR2 mAb or control mouse isotype IgG1, for 10 min before the addition of biotinylated MBL, and the binding of MBL was revealed by ExtrAvidin-FITC. Shaded curves, cells only, black solid line, with anti-TLR2 mAb, dotted line, without anti-TLR2 mAb. Data shown are representatives of four independent experiments. (C) Anti-TLR4 mAb attenuates the binding of MBL to PMA-activated THP-1 cells. PMA-activated THP-1 cells were incubated with anti-TLR4 mAb or control mouse isotype IgG2, for 10 min before the addition of biotinylated MBL, and the binding of MBL was revealed by ExtrAvidin-FITC. Shaded curves, cells only, black solid line, with anti-TLR4 mAb, dotted line, without anti-TLR4 mAb. Data shown are representative of four independent experiments.