Fig. 5.

Effect of soluble IL-6 receptor (sIL-6R) or soluble gp130 (sgp130) on interleukin (IL)-6-induced proliferation of murine hybridoma cell line B9. (a) The B9 cells were cultured with various concentrations of sIL-6R in the absence or presence of IL-6 for 4 days, and the cellular proliferation was determined by a colorimetric method using MTT dye as described in Materials and methods. (b) The B9 cells were cultured with various combinations of sIL-6R and sgp130 in the presence of IL-6 for 4 days, and the cellular proliferation was determined by a colorimetric method using MTT dye. Values represent the mean ± s.d. of triplicate cultures. The experiment was repeated three times and yielded comparable results.