Figure 4

PI-PLC enhances epidermal thickening, immune cell infiltration, and ZO-1 mislocalization in Staphylococcus aureus-infected skin in a mouse model of AD. (a,d) Staining of skin specimens with hematoxylin and eosin (top panels) or with antibodies against CD45 (red), Gr-1 (red), CD4 (red), ZO-1 (green), and Hoechst (blue) at 4 days after epicutaneous infection by wild-type (a), Δplc (a), Δplc :: plc (d), and Δplc :: plc-MT (d) strains. Staining was also performed on non-infected skin (non) (a). Scale bar = 50 µm. For ZO-1 staining, a magnified view of the indicated area (surrounded by square) is also shown. Scale bar = 20 µm. Images of wild-type- and Δplc mutant-infected skin in (a) or Δplc :: plc- and Δplc :: plc-MT-infected skin in (d) were from the right and left flanks of the same mice, respectively. (b,c,e,f) Epidermal thickness (b,e) and number of CD4⁺ cells (c,f) at 4 days after epicutaneous infection by wild-type (b,c), Δplc (b,c), Δplc :: plc (e,f), and Δplc :: plc-MT (e,f) strains. N = 5 in wild-type and Δplc strains. N = 7 in Δplc :: plc and Δplc :: plc-MT strains. The data from the right and left flanks of the same mice were linked with lines. Data are presented as the means ± SEM. Individual data value are represented by a single symbol on the bar graphs. Statistical significance was assessed using the paired t test. *p < 0.05. **p < 0.01. Results are representative of two trials (a–f).