Fig 3. Human IL-39 does not activate immune cells and does not activate STAT3.

(A) Human neutrophils were incubated with IL-39 containing concentrated supernatants or with recombinant human IL-39 fusion or IgG1-Fc control protein (both at 1 μg/ml). After 24 hrs, the reported IL-39-controlled target BAFF and other neutrophil mediator genes were quantified by quantitative RT-PCR. Gene expression was normalized to β-glucoronidase levels and expressed as arbitrary units. Graphs are representative from two experiments containing three technical replicates each. Error bars represent the SD. (B and C) PBMCs were stimulated with CD3+CD28 Abs in the presence of IL-39 IgG1-Fc fusion or IgG1-Fc control protein (3 μg/ml). After 72 hrs of incubation, IFNγ and IL-17A concentrations present in the supernatants were determined by ELISAs. Data represent triplicate measurements of three independent experiments.