Figure 1. Plcb3^−/− Mice Spontaneously Develop AD-like Skin Lesions in a Mast Cell-Dependent Manner.

(A) Kaplan-Meier plots for dermatitis development in Plcb3^−/− mice (n = 21).

(B) Note the eczematous skin lesions and hair loss in periocular areas, cheeks, ears, neck, and flanks in a 10-month-old Plcb3^−/− mouse.

(C) Histology of healthy (WT) and skin lesions (Plcb3^−/−) in ear. Scale bar, 100 µm.

(D) Graphic representation of histological analysis of ear skin lesions of 8- to 10-month-old WT and Plcb3^−/− mice. Neutrophils (Neut), eosinophils (Eos), and mast cells (MC) were enumerated in H&E-, Congo-red- and Toluidine-blue-stained preparations, respectively. Immunofluorescence staining was performed to detect CD4⁺, CD8⁺, and F4/80⁺ (Mϕ) cells. Data represent mean ± SEM. *p < 0.05, **p < 0.01, ***p < 0.001 versus WT mice by Student’s t test. Similar results were obtained in lesional skin in cheeks and neck (data not shown). HPF, high-power field.

(E) Serum IgE levels were increased in 8- to 10-month-old Plcb3^−/− mice. Data represent mean ± SEM.

(F) Correlation between serum IgE levels and numbers of body parts with skin lesions (see the legend for B for eczematous body parts). r² = 0.78, p < 0.0001, Pearson’s correlation.

(G) Incidence of skin lesions in Plcb3^−/− (KO), Plcb3^−/−;Kit^W-sh/W-sh (KO;W^sh), Plcb3^−/−;TCRb^−/− (KO;TCRb⁻) and Plcb3^−/−;µMT/µMT (KO;µMT) mice for 12 months.

Results in (E) and (F) are representative of two independent experiments using three to six mice per group. See also Figure S1.