Effect of Th-POK deficiency on cytokine gene transcription in Vα14i NKT cells. (A and B) RNA analyzed was obtained from either liver mononuclear cells from the indicated mice that had been injected with 2 µg αGalCer (A) or mock-injected (not depicted) or from liver mononuclear cells from unstimulated mice from the same strains that had been highly enriched for Vα14i NKT cells by magnetic selection (B). cDNA was amplified with primers specific for the Il4 and Ifng loci using a real-time thermocycler. Relative transcript quantities were normalized to L32 and the fraction of Vα14i NKT cells in each preparation, as determined by flow cytometry. The bar graphs show data normalized to the amount from WT samples. Error bars indicate variation between duplicate or triplicate samples in one experiment. Data are representative of at least two experiments testing independently collected samples. Injection of αGalCer resulted in a >100-fold increase in Il4 and Ifng transcripts (not depicted).