Th1, Th2 and Th17 polarized T cell lines have distinct cytokine profiles and differ in expression of co-stimulatory molecules. (A) Th1 (gray bar), Th2 (black bar) and Th17 (white bar) polarized cultures show the expected phenotype (note that, as described by others, Th17 lines can produce IFNγ). Data are shown for five independent Th1 (n = 5), Th2 (n = 5) and Th17 (n = 5) lines. This experiment was repeated on more than three separate occasions. (B-F) Highly polarized T cell lines derived from the same CFA/peptide immunizations were maintained in culture for one passage of re-stimulation (10 days) and then analyzed for expression of the indicated co-stimulatory molecules expressed on CD4-co-stained cells. This experiment was repeated on three separate occasions. Statistically significant differences are indicated (unpaired T test).