On page 3536 of the 15 May 1999 article, Figure 5A and 5B were noted to have duplications between histograms for isotype control staining. The authors believe that these errors were made inadvertently because of very similar histograms showing no isotype binding under any condition. The authors have attempted to retrieve the primary flow cytometric data from these experiments; however, the records had been discarded 10 years following completion of the experiments, as permitted by institutional and governmental regulations. The pages at the time of disposal were no longer readable, having faded significantly. To verify the validity of the conclusions originally reported in the article, the experiment was repeated. The original anti–IL-15 M112 antibody (Genzyme) and IL-15 IgG2b fusion protein are no longer commercially available; therefore, the authors substituted a rabbit anti-human IL-15 polyclonal antibody produced by Peprotech. The IL-15:Fc fusion protein was obtained from Chimerigen. The new figure and legend are shown below.
Cell surface IL-15 is not associated with its own receptor. (A) MONO-MAC-6 were treated with IFN-γ (500 U/mL) for 24 hours. Cells were then washed and incubated in PBS, acetate buffer (pH 4.4), or trypsin as described in Materials and Methods. All groups were stained with rabbit anti–human IL-15 polyclonal antibodies (Peprotech) and analyzed on FACSCalibur. Fluorescence intensity is represented by open histograms; solid histograms refer to background staining of isotype control. (B) MONO-MAC-6 treated with IFN-γ as described above were incubated with PBS (left panel) or trypsin (right panel). Cells were then incubated with biotinylated human IL-15:Fc fusion protein (Chimerigen; open histogram) or with equal amount of control fusion protein (solid histogram) followed by FITC streptavidin (BD Biosciences). In the central panel, cells were incubated with the biotinylated IL-15:Fc fusion protein and then with acetate buffer, pH 4.4. The x-axis represents the intensity of green fluorescence expressed in a log scale as mean channel, and the y-axis represents the number of cells per channel.
Cell surface IL-15 is not associated with its own receptor. (A) MONO-MAC-6 were treated with IFN-γ (500 U/mL) for 24 hours. Cells were then washed and incubated in PBS, acetate buffer (pH 4.4), or trypsin as described in Materials and Methods. All groups were stained with rabbit anti–human IL-15 polyclonal antibodies (Peprotech) and analyzed on FACSCalibur. Fluorescence intensity is represented by open histograms; solid histograms refer to background staining of isotype control. (B) MONO-MAC-6 treated with IFN-γ as described above were incubated with PBS (left panel) or trypsin (right panel). Cells were then incubated with biotinylated human IL-15:Fc fusion protein (Chimerigen; open histogram) or with equal amount of control fusion protein (solid histogram) followed by FITC streptavidin (BD Biosciences). In the central panel, cells were incubated with the biotinylated IL-15:Fc fusion protein and then with acetate buffer, pH 4.4. The x-axis represents the intensity of green fluorescence expressed in a log scale as mean channel, and the y-axis represents the number of cells per channel.
This feature is available to Subscribers Only
Sign In or Create an Account Close Modal