TLR2 on mast cell–dependent skin inflammation upon application of PGN. Reconstitution of skin mast cells of W/W^v mice by TLR2^–/–, TLR4^–/–, or wild-type BMMCs was done as described in Methods. Wild-type mice (a) or indicated mice (b) were intravenously injected with 0.5% Evans blue 5 minutes before intradermal application and 20 μl of PGN (100 μg/ml) or LPS (100 ng/ml) into the left ear or saline into the right ear. The mice were sacrificed 15 minutes after PGN or LPS injection, and dye contents in the tissues were measured as described in Methods. Data shown are mean ± SD of three mice. (c) Reconstitution of skin mast cells of W/W^v mice by TLR2^–/–, TLR4^–/–, or wild-type BMMCs was histologically confirmed by Alcian blue and Safranin staining (AS; without any treatment; upper panels) and Toluidine blue staining (TB; saline-injected; lower panels). (d) Mice were intradermally injected with PGN (upper four rows) or LPS (bottom row) as described above. Mice were sacrificed 15 minutes (left and middle columns) or 4 hours later (right column), and ear sections from W/W^v (first row), W/W^v/wild-type (W/W^v/WT; second row), W/W^v/TLR4^–/– (third row), or W/W^v/TLR2^–/– mice (fourth row) were stained with H&E (middle and right columns) or Toluidine blue (TB; left column) for histological evaluations. All magnification is ×600, except the figures at 4 hours after PGN application from W/W^v/WT and W/W^v/TLR4^–/– and at 4 hours after LPS application (all ×200).