Siglec-F^−/− mice show elevated eosinophilic inflammation in lung, peripheral blood, and bone morrow in an OVA-induced lung allergy model. WT or Siglec-F^−/− mice were either OVA sensitized and challenged (OVA) or OVA sensitized and PBS challenged (No OVA). All groups were compared for numbers of eosinophils in airway (A,B), blood (C), and bone marrow (D) (n = 6 mice/group, data shown is representative of 3 experiments). (A) WT and Siglec-F^−/− OVA lung sections were stained for MBP. Dark red–stained peribronchial MBP⁺ cells were counted as eosinophils, and 8 to 10 bronchi/slide were counted. A 20×/0.40 DPlan dry objective lens was used to visualize images, and an Olympus BH2 camera was used to capture them. (B) Quantitative result derived from panel A, expressed as the number of eosinophils per bronchus. (C) Peripheral-blood leukocytes and (D) bone marrow cells were stained with Wright-Giemsa and differential cell counts taken under a light microscope. (B-D) *P < .05; **P < .01; ***P < .001. Each error bar represents the SEM.