Figure 1.

Increase of Treg population by the stimulation of A2AR. Mixed lymphocyte culture (MLC) was set up in the presence of A2AR agonist, CGS21680 (1 μM), or NECA (1 μM). After 5 days, the cultured cells were restimulated with the same allogenic stimulator cells for 2 more days in the same condition. A2AR stimulation inhibited CD25 expression in CD8⁺ cells (top row), whereas the population of CD4⁺ CD25⁺ cells was rather increased in the same culture (middle row). The change in CD4⁺ CD25⁺ cells correlated well with an increase of FoxP3-expressing CD4⁺ cells (bottom row). The addition of A2AR antagonist ZM241385 (1 μM) reversed the changes. Numbers in the panels represent percentages in each quadrant. The data shown here represent four separate experiments with similar results.