Figure 6.

SAP-dependent activating SFR signaling regulates NKT cell selection partially by activating the CBM complex. (A) CD4 T cells isolated from WT and CARMA1-deficient (KO) mice were stimulated with anti-CD3 plus anti-CD28 and then restimulated with anti-CD3 plus anti-CD28 or different concentrations of anti-SLAM antibody for 1 h. Nuclear extracts were prepared from these cells and then subjected to electrophoretic mobility shift assays using a ³²P-labeled NF-κB probe and Oct-1 as a control probe. Unstimulated (unst) cell extracts were used as a control. (B–D) WT or CARMA1 KO (B), Bcl10 KO (C), or IKKβ KO (D) CD4 T cells activated by IL-6 and anti-CD3 plus anti-CD28 were restimulated with anti-CD3 plus anti-CD28 or an anti-SLAM antibody for 5 h. Nuclear extracts were prepared from these cells and then subjected to electrophoretic mobility shift assays using a ³²P-labeled c-Maf probe and an Oct-1 probe as a control. Unstimulated cell extracts were used as a control. (E) Representative flow cytometry plots (left) and percentages and absolute numbers (right) of the CD3⁺CD1d-Tet⁺ NKT cell population or the CD3⁺NK1.1⁺ NKT cell population in the thymus, spleen, and liver from WT and CARD9-deficient mice. Data represent the mean ± SEM of three to four mice per group. **, P < 0.01.