Fig. 1

Determination of the appropriate G. spinigerum ESA concentration for PBMC culture; 2 million PBMC (CD27⁻) were cultured in RPMI 1640 supplemented with 10 % of inactivated FBS alone or plus IL-2 (10 ng/ml) or ESA (0.1, 0.5, and 1 μg/ml). After incubation for 12 or 24 h, the cultured PBMC were stained with PI. The intensity of PI-positive staining was then analyzed by FACSCalibur flow cytometer and CellQuest software (Becton Dickinson, San Jose, CA, USA). a Histograms compare the amount of dead cells (PI-positive staining cells) among PBMC treated with different conditions for 12 h. b Percentages of total dead cells in PBMC cultures compared among in medium alone, or each condition at 12 and 24 h of incubation. Each data element represents mean ± SEM from three independent experiments using three buffy coats. Significant differences among groups are indicated; NS not significant. The phenotype of PBMC treated with ESA (0.1 μg/ml) was similar to those in medium alone or plus IL-2 for 24 h. Therefore, the ESA at the dose of 0.1 μg/ml was the optimal condition for PBMC culture in this study