Flow cytometry immunophenotyping of DEP-treated T lymphocytes. Flow cytometry analysis of T cell activation markers (A) and cytokine expression at the single cell level (B) carried out in CD4+ and CD8+ T lymphocytes from 15 healthy donors after treatment with 30 μg/ml of E4 or E5 particles for 48 h (activation markers) or 72 h (cytokine production). For CD4+ and CD8+ T lymphocyte subsets, data were expressed as the percentage of each subset within the CD4+ or CD8+ population considered as 100%. Data are represented as box plots displaying medians, 25th and 75th percentiles as boxes, and 10th and 90th percentiles as whiskers. *p < 0.05 versus untreated cells.