Basophil depletion by anti-Thy1.2 mAb administration and basophil sensitization by serum transfer. (A) Dot plot of blood samples from 4get/rag^−/− mice before (left) or 2 days after (right) anti-Thy1.2 treatment. Plots are gated on total autofluorescence⁻IL-4/eGFP⁺ cells and display eosinophils (Siglec-F⁺FcϵRI⁻) and basophils (Siglec-F⁻FcϵRI⁺). (B) Kinetics of basophil depletion after administration of 0.5 mg or 1 mg anti-Thy1.2 mAb. Results show the mean of 2 mice per time point and condition. (C) Frequency of eosinophils in the peripheral blood of 2 individual basophil-depleted (anti-Thy1.2) or control mice on day 2 after mAb administration. Each dot represents 1 mouse. (D) Dot plots of blood samples from 4get/rag^−/− mice before (control) or 1 day after (serum transfer) transfer of serum from N brasiliensis–infected wild-type mice. Plots are gated on autofluorescence⁻IL-4/eGFP⁺ cells and display eosinophils (Siglec-F⁺) and basophils (Siglec-F⁻). For panels A and D, the numbers in quadrants indicate the frequency of each population. (E) Kinetics of IgE clearance. Indicated amounts of serum from N brasiliensis–infected mice were transferred to 4get/rag^−/− mice, and the mean fluorescence staining intensity (MFI) of IgE bound to the cell surface of basophils was determined on days 1, 5, and 8 after transfer.