FIGURE 2. Recombinant Api m 1 binds basophils from BV-allergic patients in a dose-dependent manner and induces basophil activation. A)Representative staining of basophils from blood of a BV-allergic patient stimulated with [Api m 1]4-APC (red) or streptavidin-APC (blue) - left plot. Median fluorescence intensity (MFI) of basophils from controls (blue; middle) and BV-allergic subjects (red; right) following incubation with 1 µg/ml streptavidin-APC (“0”) or 0.01, 0.1 and 1 µg/ml [Api m 1]4-APC. B)Representative histogram of CD63 staining on basophils (left), and frequencies of basophils from controls (middle) and BV-allergic patients (right) expressing CD63 following stimulation with streptavidin-APC or increasing concentrations of [Api m 1]4-APC.C) Representative histogram of CD63 staining on basophils (left), and frequencies of basophils from controls (middle) and BV-allergic patients (right) expressing CD63 following stimulation with increasing concentrations of BV extract.