Figure 6.

Activating receptor signaling on NK cell control the differentiation of Th1 cells. Naive CD4⁺ T cells (5 × 10⁴ cells/well) were cultured with purified splenic NK cells (2.5 × 10⁴ cells/well) and irradiated T cell depleted syngeneic splenocytes (5 × 10⁴ cells/well) along with purified recombinant IL-2 (20 ng/mL) and anti-mouse CD3ε mAb (5 μg/mL) in the presence or absence of anti-NKG2D, anti-Ly49H, anti-Ly49D, anti-NKG2A, or isotype control antibody (10 μg/mL) at 37°C in U-bottomed 96 well plates for 4 d. (A) Expression of T-bet in the CD4⁺ T cells was analyzed after gating on CD4⁺ cells using flow cytometry (left). The bar graph represent the percentage of CD25⁺T-bet⁺ cells gated on total CD4⁺ T cells (right). Mean ± SEM shown, n = 3–4 independent experiments (Student's t-test, *p < 0.05; NS, not significant). (B) Culture supernatants were harvested from the above experiment and secretion of IFNγ was analyzed by ELISA. Mean ± SD of duplicate wells are shown and data are representative of one of the two independent experiments.