Figure 4.

SOX4 is a T cell–intrinsic factor required for iNKT cell development from DP thymocytes. (A) Volcano plot shows genes that are expressed at higher (red) or lower (blue) in CKO DP thymocytes relative to WT counterparts. Genes whose expression was different by at least twofold on average with indicated P values are shown (FC, fold change). Expression values were determined using microarrays of three sorted DP thymocyte replicates for each genotype. Cd1d, Cd24, and Mir181a/b were all decreased in expression, but are not denoted on the plot as they were decreased 1.7–1.9-fold on average in transcript amounts as detected using microarrays. (B) Impaired iNKT cell development from Sox4-deficient precursors cannot be rescued in trans by codifferentiating WT T cells in the thymus. Flow cytometric analysis of thymocytes from Rag1^−/− mice that were reconstituted with an ∼1:1 mix of WT:WT or WT:CKO BM cells ∼8–10 wk prior. Partner WT cells were from congenic C57BL/6 (Ly5.1) mice for tracking purposes. Shown are contributions from partner precursors (top panels; range for CKO reconstitution: 38–76% relative to partner WT cells, with no correlation between the extent of defective iNKT cell generation and relative reconstitution frequencies), iNKT cell frequencies (middle), and iNKT cell maturation profiles (bottom). Representative plots from two independent experiments with a minimum of five mixed BM chimeras/group.