Surface expression of IL-9R on human peripheral blood eosinophils.

(A) Highly purified peripheral blood eosinophils and (B) eosinophil-differentiated HL-60 cell lines were analyzed with a mouse affinity purified mAb antihuman IL-9R–α chain (5 μg/mL isotype IgG1) (solid line) followed by a FITC-conjugated goat antimouse IgG (dilution 1:200). Mouse IgG1 (5 μg/mL clone MOPC-1) was used as an isotype-matched control antibody (broken line). (C) The surface expression of IL-9R–α showed no significant difference between asthmatics and normal (nonasthmatic) controls using flow cytometry analysis (P > .05). Flow cytometry analysis was performed as described in “Materials and methods.” +ve, positive; FL1, fluorescence 1.