Fig. 2. PRL induces the IL-2R chain on PRL-R W53 transfected cells. Expression of B-lineage markers was analyzed by flow cytometry in BaF-3 cells and in W53 cells grown in PRL-enriched medium during 4 days. Cells (5 x 105) were incubated with biotin-conjugated PC61 mAb and then revealed with streptavidin-PE. Expression of IL-2R chain in BaF-3 cells growth in IL-3-enriched medium (upper histogram) and in W53 cells grown in IL-3 or with titrated doses of PRL (··· 0.3, 3, 30 ng/ml; bottom histograms) are shown. The background signals, provided by isotype-matched irrelevant mAb in both BaF-3 and W53 cells, were adjusted during cell acquisition, and they are displayed in the shaded histograms for both cell lines. The percentages of IL-2R chain+ cells are shown at the upper right corner of the histograms. This is one representative experiment of four independent analyses.