Figure 2.
cAMP augments GATA-3–mediated Th2 cytokine induction in committed Th1 cells and a Th1 clone as well as developing Th1 cells. GFP+ Th1 cells from day 22 of infection and HDK1 cells infected with either R-EGFP or R-GATA-3-EGFP as in Fig. 1 were stimulated with either PMA/ionomycin (filled bars) or PMA/ionomycin/cAMP (open bars) for 48 h as indicated, and the level of cytokines in supernatants was determined by immunoassay. (B) GFP HDK1 cells were stimulated with either PMA/ionomycin or cAMP as indicated for 6 h, and intracellular cytokine production was analyzed by flow cytometry as previously described 9. The data in A and B are representative of greater than three experiments with similar results.