Insulin-Like Growth Factor-I as an Effector Element of the Cytokine IL-4 in the Development of a Leishmania major Infection

Figure 5

The effects of IGF-I siRNA transfection on the L-arginine metabolic pathway. The quantification of (a) Arg1 mRNA, (b) Larg mRNA, (c) Cat-2B mRNA, (d) arginase activity, (e) Nos2 mRNA, and (f) NO production in L. major-infected RAW 264.7 cells following transfection with IGF-I siRNA and cytokine stimulation is shown. Promastigote-infected cells transfected with or without IGF-I siRNA were stimulated with IFN-γ (200 U/mL), IL-4 (2 ng/mL), and IL-13 (5 ng/mL) for 48 hours. One representative experiment from three independent assays is shown. (ANOVA and Tukey’s tests) compared to the respective control without siRNA.

(a)

(b)

(c)

(d)

(e)

(f)