Figure 3.

Eosinophils inhibit dendritic cell-induced activation of CD3^-CD4⁺ T cells in vitro. Purified CD3^-CD4⁺ T cells were cultured in presence of LPS-matured dendritic cells from healthy subjects for 5 days, in absence or in presence of IgA/anti-IgA-activated eosinophils. Proliferation was assessed on the basis of H³-thymidine incorporation (3a), IL-5 was measured in culture supernatants by ELISA (3b), and expression of activation markers CD25 and HLA-DR was assessed by flow cytometry (3c). Histograms represent mean proliferation (cpm) (3a, n=8) and IL-5 concentrations (pg/ml) (3b, n=6), and bars show the standard error of the mean for each condition. For cytometry studies (3c), histograms show CD25 and HLA-DR expression on CD3^-CD4⁺ T cells cultured alone (continuous fine line), with dendritic cells (dashed bold line), and with both dendritic cells and eosinophils (continuous bold line); results are representative of 3 independent experiments.