Figure 1. IL-4+TGF-β in presence of pbCD3/sCD28 activation induce generation of CD4⁺IL-9⁺ T cells.

A) CD4⁺CD25⁻ T cells (1.0×10⁶/ml in 24 well plates) were activated with plate bound-anti-CD3 mAb (pbCD3)/soluble-anti-CD28 mAb (sCD28) in presence or absence of IL-4 or TGF-β or IL-4+TGF-β for 96hrs and analyzed by flow cytometry for IL-9 expression. IL-4+TGF-β in combination induced significantly higher percentage of CD4⁺ T cells positive for IL-9, as compared to IL-4, TGF-β, or neither (n = 14). Data is expressed as the mean±SD. B) CD4⁺CD25⁻ T cells, CD4⁺CD25⁻CD45RA⁺ T cells (naïve T cells), CD4⁺CD25⁻CD45RO⁺ T cells (resting memory T cells) (2.0×10⁵/ml in 96 well plates) were activated with pbCD3/sCD28 in presence of IL-4+TGF-β in a 96 well plate for 96hrs. Cells were surface stained for CD4 PerCP-Cy5.5 and intracellular stained for IL-9 PE. IL-4+TGF-β in combination induced IL-9 expression by both naïve and memory T cells, but memory T cells expressed high levels of IL-9. Data are representative of six independent experiments (six different donors).