Toll-like receptor 4 (TLR4) activation induces inflammation and cellular infiltration. (A-D) Representative figure of H&E-stained cross-section of skin from C57Bl6/wild-type (WT) mouse after treatment with PBS or lipopolysaccharide (LPS) with subcutaneous pumps for 1 week (WT-PBS-1w or WT-LPS-1w: A, B) or 4 weeks (WT-PBS-4w or WT-LPS-4w: C, D). (E-L) Relative expression of mRNA by nanostring in 1-week, LPS-treated (n = 13, solid circles) compared to PBS-treated (n = 6, open circles) WT mice, and 4-week, LPS-treated (n = 5, solid triangles) compared to PBS-treated (n = 7, open triangles) WT mice, **P <0.01, ****P <0.0001. In the dot plot, each data point represents a single sample. Increased gene expression of proinflammatory markers in LPS- compared to PBS-treated mice at 1 week and 4 weeks: (E) IL-1β: 1 week, P <0.0001; 4 weeks, P <0.01. (F) IL-6: 1 week, P <0.001; 4 weeks, P <0.01. (G) TNF-α: 1 week, P <0.0001; 4 weeks, P <0.01. (H) CD14: 1 week, P <0.0001; 4 weeks, P <0.01. (I) F4/80: 1 week, P <0.0001; 4 weeks, P <0.01. (J) CD11b: 1 week, P <0.0001; 4 weeks, P <0.001. (K) Flow cytometry: representative plots of CD11b+ high-scatter (CD11b+SSChi) and low-scatter (CD11b+SSClo) cells, isolated from skin of WT mice treated with PBS or LPS for 1 week. (L-N) Percentage of cells, CD11b+(L), CD11b+SSChi(M), and CD11b+SSClo(N) cells in LPS-treated WT mice (n = 3) compared with PBS-treated WT mice (n = 3), for 1 week. Each bar represents the mean ± standard error of the mean.