TRP-1 cells expanded in vitro under polarizing conditions show highly different cytokine secretion patterns. (A) Release of INF-γ by Th0, Th1, and Th17 TRP-1 cells as measured by ELISA. Polarized TRP-1–specific TCR transgenic T cells were restimulated overnight with TRP-1_106-130 peptide–pulsed splenocytes at escalating concentrations or gp100 control peptide (at a concentration of 10⁻⁵ mg/mL; left panel) or were incubated overnight with B16 and B16/CIITA melanoma cell lines. Tumor cell lines lacking the relevant antigen, MCA205 and EL-4, were used as specificity control (right panel). (B) Release of IL-17A by Th0, Th1, and Th17 TRP-1 cells upon stimulation with escalating concentrations of TRP-1_106-130 peptide (left) or B16 and B16/CIITA melanoma cell lines (right). MCA205 and EL-4 were used as a negative control. (C) Secretion of TNF-α, IL-2, IL-6, IL-10, IL-17, IL-21, and CCL20 was measured by ELISA after overnight stimulation with TRP-1_106-130 peptide–pulsed splenocytes (left panels) or B16 and B16/CIITA melanoma cells (right panels). Splenocytes pulsed with gp-100 peptide and MCA205 and EL-4 tumor cells were used as specificity control.