FIGURE 5.

CD28 but not TNFR costimulation is required for optimal induction of Il2 transcription in resting, Pre-Ac CD4⁺ T cells. (A) IL-2-GFP expression in naïve or Pre-Ac IL-2-GFP^KI/WT CD4⁺ T cells following stimulation with α-TCR-β alone (-α -CD28) or α-TCR-β + α-CD28 for the times indicated; cells are gated on 7-AAD⁻Vβ3⁺ for analyses. (B) Pre-Ac WT (●) or TNFR^Δ/Δ (○) CD4⁺ T cells were re-challenged with α-TCR-β or α-TCR-β + α-CD28; IL-2 production is reported as the frequency of CD4⁺ T cells producing IL-2 at 6 h Data from (A) and (B) are representative of two separate experiments. (C) Naïve or Pre-Ac WT CD4⁺ T cells were stimulated with α-TCR-β + α-CD28 for 24 h or 6 h, respectively and gated on CD4 for analyses. Unstimulated lymph node CD4⁺ T cells from TNFR^Δ/Δ mice are also gated for negative controls. The MFI ± SEM for three separate experiments of TNFRI and TNFRII are shown. Data shown is from one of three representative experiments