Figure 4. CD4⁺PD-1^hi T cells preferentially produce IL-21 as compared to IFNγ after mitogenic stiumulation.

(a) Representative dot plots and b) relative proportions of LN CD4⁺PD-1^– and CD4⁺PD-1^hi T cells capable of producing IL-21 and IFNγ following short-term in vitro stimulation with PMA and ionomycin in the presence of Brefeldin-A. c) The ratio of IL-21:IFNγ in LN CD4⁺PD-1^hi and CD4⁺PD-1^– T cells.