ELISA for active and total TGF-β
in the media (A, B). At day 22, the concentration of active and total TGF-β2 in the media of IL-13 pre-treated NHBE at 1 and 10 ng/ml is significantly higher as compared to untreated NHBE (0 ng/ml of IL-13) media; * p < 0.01. At day 22 and day 28, the concentration of active TGF-β2 in the IL-13 pre-treated NHBE at 10 ng/ml is elevated compared to pre-treated NHBE at 1 ng/ml; # p < 0.01. At day 28 active and total TGF-β2 in IL-13 pre-treated NHBE at 10 ng/ml is increased compared to untreated NHBE; * p < 0.01. (C, D) At day 25, the NHBE pre-treated with IL-13 at 10 ng/ml, has higher levels of active and total TGF-β2 in the media as compared to untreated and pre-treated NHBE at 1 ng/ml co-cultured with NHLF (*, # p < 0.01 compared to 0 and 1 ng/ml IL-13 pre-treated NHBE co-cultured with NHLF, respectively). At day 31, there is no significant difference in the levels of active and total TGF-β2 between treatment conditions. NHLF represents levels of active and total TGF-β2 in media of fibroblasts in a collagen gel without NHBE co-culture. All experiments were performed using 3 donors, grown in duplicate, with 3–6 wells per condition.