Figure 1.

The effects of adenosine on the expression of ICAM-1 on monocytes. (a and b) The effect of adenosine at concentrations ranging from 0.01 to 100 μM (Con, no adenosine) on the expression of ICAM-1 in the absence (a) or presence (b) of 100 ng ml⁻¹ IL-18. PBMC were treated with adenosine or IL-18, and the expression of ICAM-1 on monocytes was examined by multi color flow cytometry using a combination of anti-CD14 antibody with anti-ICAM-1 antibody. The values shown as IgG₁ represent the IgG1 isotype-matched control. Results are expressed as the means±s.e.m. of triplicate determinations from five donors. ^##P< 0.01 compared with the value for IL-18 alone. When an error bar was within a symbol, the bar was omitted. (c) The dot plots of ICAM-1 are shown. The cells were treated with adenosine at 100 μM in the presence or absence of IL-18 at 100 ng ml⁻¹ and then incubated for 24 h.