Figure 3.

Paracrine and autocrine production responsiveness to IL-2 promote IL-9 production. (A) Th9 cells were cultured as before and stimulated at 10⁶, 10⁵ and 10⁴ cells per ml for 5.5 hours with PI in the presence or absence of IL-2/CD25 blocking antibodies or rhIL-2 (50U/ml) and Il9, Il2, and Tnf mRNA levels were assessed by RT-PCR. (B) Th9 cells were cultured from WT mice (CD45.1⁺) or Il2-/- mice (CD45.2⁺) for 5 days. Differentiated Th9 cells from WT and Il2-/- mice were cultured alone or mixed at a 1:1 ratio. (C) Cells were subsequently stimulated for 5.5 hours with PI in the presence or absence of IL-2/CD25 blocking antibodies or rhIL-2. Representative contour plots of intracellular IL-9 and IL-10 staining are shown for each condition. The frequency of IL-9⁺ (D) and IL-10⁺ (E) cells was determined based off of plots shown in panel C. * p<0.05, significantly decreased in comparison to Nil-treated cells. # p<0.05, significantly increased as compared to Nil-treated cells. These data represent 2 individual experiments with cultures being derived from 3 individual mice per experiment.