Figure 1. Increased Foxo3 expression in CD4⁺ T cells after TCR engagement.

(A) Foxo3 expression by naive CD62L⁺, CD44⁻ (white bars) and activated CD62L⁻, CD44⁺ (dark grey bars) WT CD4⁺ T cells (n=7 mice per genotype). (B) Foxo3 expression by naive WT CD4⁺ T cells stimulated in vitro with the indicated dose of anti-CD3 mAbs (n=4 mice per genotype). (C) Foxo3 expression by naive WT CD4⁺ T cells stimulated with anti-CD3 mAbs (2μg/mL) for 18, 36 or 72 hours (n=4 mice per genotype). Mean and SEM of the relative MFI of Foxo3 expression was calculated by subtracting the WT MFI from the Foxo3^−/− MFI. (D) Immunofluorescence staining of Foxo3 in naive CD4⁺ T cell from WT or Foxo3^−/− mice stimulated in vitro with the indicated dose of anti-CD3 mAbs for 48 hours (Scale bar, 10μm). (E) Immunoblot analysis of Foxo3, PLC-γ and TFIID expression in nuclear and cytoplasmic fractions of naive CD4⁺ T cells from WT or Foxo3^−/− mice stimulated in vitro as in D. Data are representative of three independent experiments. Error bars, SEM.; P values (Mann–Whitney U test). See also Figure S1