Binding of 125I-G-CSF to K pneumoniaeB5055. (A) Binding curve of 125I-G-CSF after 40 minutes at 4°C with K pneumoniae B5055 or K pneumoniae F201. Results are representative of at least three independent experiments. (B) Competition of G-CSF with 125I-G-CSF for binding toK pneumoniae B5055. 125I-G-CSF (50 ng) was incubated (4°C, 40 minutes) with K pneumoniae, along with various concentrations of unlabeled G-CSF. The results, plotted as specific binding relative to results of an assay with no added competitor, are from four independent experiments, each done in duplicate and are shown as mean ± standard deviation. (C) Competition of IL-1α with 125I-G-CSF for binding to K pneumoniae B5055. 125I-G-CSF (50 ng) was incubated (4°C, 40 minutes) with K pneumoniae, along with various concentrations of unlabeled IL-1α. The results, plotted as specific binding, are from four independent experiments, each performed in duplicate, and are shown as mean ± standard deviation.