Figure 2.

The subsets of IL-21-producing CD8⁺ T cells. (A) PBMCs from HCs were stimulated with CD3/28 beads for 72 h. Production of IL-21, IFN-γ and granzyme B in naïve (CD45RA⁺CCR7⁺), memory (CD45RA^-) and terminal effector (CD45RA⁺CCR7^-) cells was analyzed by intracellular staining (added PMA and Ionomycin for the last 6 h). Left panels are representative data and right graphs summarize the results (N=3). (B) PBMCs from HCs were stimulated under the same condition as (A), and then analyzed by flow cytometry. The panel shows four fractions of CD8⁺ T cells (CD45RA⁺, CD45RA^-PD-1^-/low, CD45RA^-PD-1^int and CD45RA^-PD-1^hi). The panels show IL-21 production from four populations including CD45RA⁺, CD45RA^-PD-1^-/low, CD45RA^-PD-1^int and CD45RA^-PD-1^hi CD8⁺ T cells by intracellular staining. *P < 0.05.