Tocilizumab does not block interleukin-6 (IL-6) signaling in murine cells
Fig 4
Tocilizumab blocks IL-6 signaling in human, but not murine cells with endogenous IL-6R expression.
(A) Human U-937 cells were pretreated with tocilizumab as indicated for 30 min and then stimulated with 10 ng/ml hIL-6 for 15 min. Phosphorylation of STAT3 was determined by western blot. Quantification of three independent experiments and one representative western blot are shown. (B-D) The experiments were performed as described under (A) but with murine RAW264.7 cells and mIL-6 (B), with human HepG2 cells and hIL-6 (C) and with murine AML-12 cells and mIL-6 (D). Statistical significance was analyzed with one-way ANOVA followed by Dunnett's multiple comparisons test (**: p<0.01; ***: p < 0.001; ns: not significant).
