Figure 3.

Effect of LPS pretreatment on CD40L-induced cytokine secretion. Monocytes were cultured and stimulated as described in the legend to Fig. 2(b). Cytokine release in supernatants was assessed by ELISA. No intracellular sequestration of cytokines was detected by ELISA testing of cells lysed by repeated cycles of freezing and thawing (data not shown). Shown is the amount of the different cytokines as the mean of three experiments, with three different donors, each carried out in triplicate. The error bars represent the standard errors. The asterisk indicates P < 0·05.