FIGURE 2.

T cell-specific TTP conditional knockout mice have increased IL-17–producing effector T cells. (A) Single spleen cells of wild-type (WT) and CD4^CreTTP^f/f mice aged 6–8 months were labeled with CFSE and cultured with anti-CD3 (1 μg/mL) Ab for 4 days before the proliferation was assessed by flow cytometry. Percentages of CFSE^low CD4⁺ T cells were summarized from three to four independent experiments. (B) Wild-type and CD4^CreTTP^f/f splenocytes were stained for CD44 and CD62L gated on CD4⁺ cells. Percentages of CD62L^– CD44⁺ (effector) and CD62L⁺CD44^– (naive) CD4⁺ T cells from four independent experiments were summarized and compared by t-test. (C) WT and CD4^CreTTP^f/f splenocytes were stimulated by PMA and ionomycin for 4 h and then analyzed by flow cytometry for intracellular cytokine gated on CD4⁺ T cells. Fluorescence-activated cell sorting images represent one of five similar results. Percentages of IL-17⁺ and IFN⁺ CD4 T cells from four independent experiments were summarized and compared by t-test. (D) Cells from spleens (SP) of WT and CD4^CreTTP^f/f mice were stimulated with anti-CD3 Ab (1 μg/mL) for 3 days. Supernatants were collected and filtered for detection of IL-17A by ELISA. Data represent means ± SD from three to four mice in each group. (E) IL-17A in serum of WT and CD4^CreTTP^f/f mice aged between 6 and 30 weeks old was determined by ELISA. Data in E and F are expressed as means ± SD, with four to five mice per group. *p < 0.05, **p < 0.01, and ***p < 0.001 between groups.