Cytokine profile of Th1- and Th2-polarized CD4⁺ T cells. Purified CD4⁺ T cells were stimulated on day 0 with bead-adsorbed anti-CD3 and anti-CD28 mAb under Th1- or Th2-polarizing conditions. On day 12 cells were harvested and restimulated for 24 hours with mAb-coated beads under neutral conditions, and culture supernatants were assayed by cytokine ELISA. The mean ± SE of 16 donors are shown.