Detection of interleukin 17 (IL-17) receptors (R) IL-17R A and IL-17R B on mouse Schwann cells (SCs), using immunocytochemistry and rtPCR analysis. (A-C) immunocytochemistry for IL-17R A, IL-17R B with mainly membrane-bound expression (D-F). (G-I) Real-time PCR results of IL-17R mRNA expression of mouse dorsal root ganglia (DRG) co-cultures. Cultures were treated with IL-17 for 21 days at the indicated concentrations. Stimulation gave rise to a strong decrease in IL-17R A expression at the mRNA level under stimulation with 0.5 and 50 mg/mL IL-17, with a remaining expression of 30% (***P ≤0.001). A dose-dependent decrease was detected for IL-17R B and IL-17R C. The remaining expression of IL-17R B was 58% with 0.5 ng/mL IL-17 (**P ≤0.01) and 14% with 50 ng/mL IL-17 (***P ≤0.001). Similarly, the expression of IL-17R C was significantly reduced at the mRNA level to 78% for 0.5 ng/mL IL-17 (*P ≤0.05) and 33% for 50 ng/mL IL-17 (***P ≤0.001). For all three receptors and the concentrations applied, an analysis of variance between the three independent experiments revealed no significant difference. AU, arbitrary unit; DAPI, diamidino-2-phenylindole.