Th-POK regulates CD4 and CD8 expression in Vα14i NKT cells. (A) Staining of thymocytes and electronically gated B220⁻ splenocytes and liver mononuclear cells from hd/hd and +/+ littermates with αGalcer-CD1d tetramers and anti–TCR-β. The percentages of Vα14i NKT cells are indicated next to the gates. Data are representative of at least five individual experiments. (B) Scatter plots depicting the numbers of Vα14i NKT cells observed in the thymus (n = 6), spleen (n = 4), and liver (n = 3) of 6–10-wk-old hd/hd and hd/+ littermates. Different symbols are used to represent separate littermate pairs. Paired Student's t test p-values are shown, with significant differences indicated by asterisks (*, 0.05 > P < 0.01). Error bars show SD and horizontal bars show the arithmetic mean of the samples in each column. (C) CD4 and CD8 expression in T cells from mice carrying the hd mutation in the Th-POK gene. Liver mononuclear cells from WT (+/+, left) and hd/hd mice (right) were stained with αGalCer-CD1d tetramers together with antibodies against CD4, CD8α, and TCR-β. Plots shown depict the CD8 and CD4 expression in Vα14i NKT and conventional T cell populations (Conv T cells). Data are representative of at least six independent experiments.