Figure 7. Immune damage and loss of eLC opens the epidermal compartment.

Male mice received BMT with or without T cells. A. Graph shows the number ± SD of total CD11b⁺Langerin⁺ LC in mice receiving BMT alone (triangles) or BMT with T cells (circles). Data are pooled from 2 independent experiments (n=5–13). The white square and dotted line shows LC numbers ± SD in untreated controls (n=5). B-C. Epidermal sheets were stained with anti-Langerin and anti-CD45.2, and confocal images processed and quantified using the Definiens Developer software: eLC (cyan) are Langerin⁺CD45.2⁺; DETC (red) Langerin^negCD45.2⁺; and mLC (yellow) are Langerin⁺CD45.2^neg. B. shows example images from mice receiving BMT + T cells, and the graph in C. is the volume of mLC compared to eLC from BMT controls. Data are from 1 transplant experiment with 3 BMT (20 fields of view analyzed) and 2 BMT+T cell recipients (14 fields of view analyzed) (n= 162 cells from BMT mice and 356 LC from BMT+ T cell recipients). D-F. Topical FITC was painted on the ear skin of control un-transplanted mice (No Tx), or BMT and BMT + T cell recipients 10 weeks post-transplant. 3 days later uptake of FITC was analyzed within MHCII^highEpCAM⁺Langerin⁺ LC in draining LN. D. Bar graph showing the frequency ± SD of FITC⁺ cells within LC. E. Representative contour plots show FITC uptake in gated LC. F. Bar graph showing the FITC median fluorescent intensity ± SD within FITC⁺ LC. Data are pooled from 2 independent experiments (n=4–7), significance was analyzed using a 1-way ANOVA, ***P<0.001. G. BMT + T cell recipients received a second round of irradiation and BMT alone 8 weeks later. The schematic illustrate the experimental set-up. H. Flow plots show the outcome in the epidermis of independent mice, who have received the 1st transplant only (Tx 1), the 2nd transplant only (Tx 2) or both transplants (Tx 1 and 2). Contour plots are pre-gated on EpCAM⁺Langerin(PE-labelled)⁺ LC.