Neutralization of p40 by mAb stimulates the internalization of IL-12Rβ1 in TRAMP-C2 cells. (A) Cells were treated with p40 (20 ng/mL), p402 (20 ng/mL), p70 (20 ng/mL), p40 mAb (0.5 µg/mL), and mouse IgG (0.5 µg/mL) for 2 h in serum-free conditions followed by FACS analyses of IL-12Rβ1 in control cells (i) and cells treated with p70 (ii), p40 (iii), p402 (iv), p40 mAb (v), and IgG (vi). Immunoblot analyses of membrane-bound IL-12Rβ1 (B), pan-cadherin (pCAD) (C), and total IL-12Rβ1 (D) in p40-, p402-, p70-, p40 mAb-, and IgG-treated TRAMP cells. Immunoblot analyses of membrane-bound IL-12Rβ1 (E), pCAD (F), and total IL-12Rβ1 (G) in p40 cytokine- and p40 mAb-treated TRAMP cells. Results represent three independent experiments. Immunoblot analyses of IL-12Rβ1 (H) in the membrane fraction of p40 mAb-treated TRAMP cells pretreated with 5 µM filipin or 2 µM cpm for 2 h. Immunoblot results were normalized with pCAD immunoblot (Bottom). (I) Relative density of immunoblot analyses normalized with pCAD. Results are mean ± SD of three different experiments (*P < 0.001 vs. p40 mAb). Immunocytochemical analyses of IL-12 Rβ1 (red) and caveoiln-1 (Cav-1; green) in (J) control, (K) p40 mAb-, and (L) p40 mAb plus filipin-treated TRAMP cells. Nuclei were stained with DAPI. (M) Schematic presentation by which neutralization of p40 induces cell-mediated immunity in TRAMP cells.