IECs from DSS mice induce IL-17A response via CD80/CD86 and CD40 dependent costimulation.

<p>(a) IECs from DSS mice were co-cultured with CD4⁺ T cells from control mice in the presence of anti-CD3 antibody. In the indicated groups, IECs were pretreated with CD80 or CD86 blocking antibodies, and CD4⁺ T cells were pretreated with CD40L blocking antibody before co-culturing. The data are representative of two experiments. Results are expressed as means ± standard error (n = 4). ^**<i>p</i><0.01 versus CD4⁺ T cells alone (CD4⁺T); ^##<i>p</i><0.01 versus co-culture of CD4⁺ T cells and IECs from DSS-treated mice (DSS-IEC). (b) IECs were cultured in the absence (gray bars) and presence (black bars) of CD40 agonist antibody for 24 h. IL-6 concentration in the supernatant was measured by ELISA. The data are representative of three experiments. (c) CD4⁺ T cells were cultured for 3 days in fresh medium or supernatant from IECs (IECs sup) cultured as described in (b) in the presence of anti-CD3/CD28 antibodies. The IL-17A concentration in the supernatant was measured by ELISA. The data are representative of two experiments. Results are expressed as means ± standard error (n = 4). ^**<i>p</i><0.01 versus the supernatant from IECs stimulated with CD40 agonist antibody (CD40 agonist Ab). (d) CD4⁺ T cells were cultured with fresh medium or supernatant from CD40-stumulated IEC of DSS mice (DSS-IEC sup) as described in (c) in the presence of IL-6-neutralizing antibody (anti-IL-6) or IgG control antibody (isotype). The IL-17A concentration in the supernatant was measured by ELISA. Results are expressed as means ± standard error (n = 6). ^**<i>p</i><0.01 versus fresh medium; ^#<i>p</i><0.05 versus the supernatant from CD40-stumulated IEC of DSS mice (DSS-IEC sup).