Fig. 2.

IL-5Rs colocalize with CTB-positive vesicles (lipid rafts). (A) Cytokine-starved TF1 cells were serum-starved for 60 min before the addition of cold cholera toxin-B (CTB)-488 (10 μg/ml, green) and unlabeled IL-5 (10 ng/ml) to chilled cells on ice for 30 min. The remaining procedure is exactly the same as in Fig. 1. Percentage of cells counted showing βc/CTB colocalization was 13%; 17% between 5Rα/CTB, and 45% between Cy3-IL-5/CTB. Raw cell counts are listed in Table 1. Scale bar = 5 μm. (B) Cy3-IL-5 and CTB-488 (lipid raft-positive) colocalize in human eosinophils. The procedure is exactly the same as in Fig. 1B, except cells were labeled with CTB-488 and Cy3-IL-5. Again, these results are representative of 4 independent experiments and reflect a minimum of 80-100 cells, which were analyzed.