The effect of γ-chain cytokines on IFN-γ production by T cells.

<p><b>A.</b> IFN-γ levels were measured in supernatants of T cells cultured in the presence of IL-2, IL-4, IL-7, IL-15 and IL-21 for five days. <b>B.</b> The same supernatants were tested for the ability to trigger CD95 upregulation on B lymphocytes. Representative data out of 3 independent experiments are shown. <b>C.</b> Purified B cells were cultured in the presence of IL-2 or IL-15 treated T cell supernatants for 3 days and then CD95 expression was analyzed by flow cytometry. IFN-γ was neutralized in the supernatants using 10 µg/ml anti-IFN-γ antibodies (black lines). Histograms with grey line represent samples containing isotype control antibody, the grey filled histograms represent samples without antibodies added and the dotted histograms represent stainings with isotype control antibody.