Figure 5.
The regulatory effects of interleukin-10 (IL-10) on B-cell proliferation and IL-10 gene expression in B cells. (a) Purified B cells were stimulated with lipopolysaccharide (LPS; 10 μg/ml) in the presence (5 μg/ml) of monoclonal antibody anti-IL-10, anti-IL-10R or anti-IL-6, and cell proliferation was determined by [3H]thymidine added to the cultures for the last 6 hr of the 72-hr incubation period. (b) Purified B cells were stimulated for 72 hr with LPS (10 μg/ml) in the presence of the indicated concentrations of exogenous IL-10 and the expression of the IL-10 gene was determined by real-time PCR. Each bar represents the mean ± SD from three or four independent determinations. Values with asterisks are significantly (*P < 0·05, **P < 0·01) different from the control (the cells stimulated in the absence of added cytokines).