Role of Ikaros in the transcriptional signature of Th17 cells

We found that CD4+ T cells require Ikaros to promote IL-17 production when cultured in Th17 conditions. To understand why Ikaros null T cells do not produce IL-17, we analyzed the transcriptome of WT vs. Ikaros null naive CD4+ T cells both resting (day 0) or activated with anti-CD3 plus anti-CD28 antibodies, IL-6, TGFb1 and neutralizing anti-IFNg and anti-IL-4 antibodies (Th17 condition) for 1 or 2 days. Samples from 3 independent experiments were analyzed. 3 independent experiments were performed Purified naive CD4+ T cells (CD4+CD8-CD44loCD62L+CD25-) from spleen of Ikarosf/f (WT) or Ikarosf/f x CD4-Cre (TKO) mice (6-7 weeks-old) were activated on a plate, pretreated with Goat anti-Hamster IgG and coated with anti-CD3 (2C11; 1 µg/ml) and anti-CD28 (37.51; 0.25µg/ml) Abs, in the presence of mIL-6 (20 ng/ml), hTGFb1 (1 ng/ml) and neutralizing anti-IL-4 and anti-IFNg Abs (2 µg/ml each). RNA from cells cultured for 1 and 2 days as well as with naive CD4+ T cells (day 0) was extracted and used for a transcriptome analysis using GeneChip® Mouse Gene 2.0ST arrays (Affymetrix).