Figure 5.
Inhibition of IgE-induced serotonin release in ILT2-transfected RBL cells. Transfected and control cells were stimulated with purified mouse IgE (20 μg/ml) alone and in combination with either HP-F1 [20 μg/ml of whole antibody or F(ab′)2 fragments] or with the isotype-matched antibody HP-1F7 [20 μg/ml of whole antibody or F(ab′)2 fragments] immobilized on plastic. The percentage of serotonin release, as compared to total and spontaneous release, was determined after 1 h at 37°C. The expression of ILT2 on transfected RBL cells was assessed by indirect immunofluorescence with HP-F1 mAb (not shown).