Figure 5. Mutant T cells have increased ER stress, decreased survival, and impaired function.

(A–D) mRNA expression of ER stress response genes (A), numbers of viable T cells (B, left) and percentage of FVD^–Annexin⁺ apoptotic cells among CD3⁺ T cells (B, right), representative histograms of CTV (C) and IFN-γ secretion (D) after 3 days of T cell stimulation with αCD3+αCD28. (E–G) Effect of TUDCA addition on sXbp1 and Ddit3 mRNA expression (E) cell viability and apoptosis (F), and IFN-γ secretion (G) on αCD3+αCD28 stimulated T cells. (H and I) Numbers of viable CD3⁺ T cells (H, left), percentage of FVD^–Annexin⁺ apoptotic cells among CD3⁺ T cells (H, right), and IFN-γ secretion (I) after 3 days of ex vivo stimulation of splenocytes from OVA-immunized mutant mice and controls with OVA in the presence or absence of TUDCA. n = 4 independent experiments, 5 mice per group. (J) T cell allocytotoxicity in mutant and WT C57BL/6 (H2^b) mice. Splenocytes were stimulated with mitomycin C–treated BALB/C (H2^d) splenocytes for 5 days, and cytotoxicity was measured in a 4-hour assay with P815 (H2^d) and EL4 (H2^b) cells. n = 2 independent experiments each with 3 mice per group. (K) NK cell cytotoxicity in mutant and WT splenocytes. Mice were treated with either Poly(I:C) i.p. or PBS 18 hours prior to harvest. Cytotoxicity of WT and mutant splenic NK cells was measured in a 4-hour assay against ⁵¹Cr-labeled YAC-1 cells. n = 2 experiments each with 3 mice per group. Similar results were obtained in 3 independent experiments each with 3 mice per group for A–G. Columns and bars represent mean and SEM. *P ≤ 0.05; **P ≤ 0.01; ***P ≤ 0.001, 2-tailed Student’s t test (A–D); Holm-Šídák test to control for multiple comparisons (E–I); 2-way ANOVA (J); Mann-Whitney U test (K).