Infiltration of human IL-17A-producing T cells and CD4+ Foxp3-expressing T cells in the inflamed human skin in the SCID/skin allograft mouse model.

<p><b>A.</b> Immunohistochemistry of human CD4 (brown, top) and CD8 (brown, bottom) expression in human skin grafts from SCID beige mice 21 days after infusion or huPBMC. Photographs show representative examples. 20× magnification. <b>B.</b> Summarized data of figure A. showing mean±SEM CD4 (top) or CD8 (bottom) positive cells/mm² of n = 4 and 10 upon PBS and huPBMC infusion resp in the epidermis (white bars) and dermis (black bars). <b>C.</b> Immunohistochemistry of human IL-17A expression in human skin grafts from SCID beige mice 21 days after infusion of PBS (left) or huPBMC (right). Photographs show representative examples of n = 6 (huPBMCs) n = 3 (controls). 20× magnification. Graph shows summarized data of IL-17A positive cells/mm² following PBS or huPBMC infusion in the human skin biopsies (mean±SEM, of n = 4 and 10). <b>D.</b> Immunohistochemistry of coexpression of human CD4 (blue) and IL-17A (red, top) and CD8 (blue) and IL-17A (red, bottom) in human skin grafts from SCID beige mice 21 days after infusion of huPBMC (20× magnification). Inserts show a higher magnification (40×) of single CD4/CD8 and IL-17A staining and CD4/IL-17A or CD8/IL-17A co-staining. . Photographs show representative examples of n = 6. <b>E.</b> Immunohistochemistry of IL-17A (red) in human mastcell tryptase (brown) and granulocyte elastase (brown) in human skin biopsies from SCID beige mice 21 days after infusion of PBS (left) or huPBMC (right). Photographs show representative examples of n = 6 (huPBMCs) n = 3 (controls). 20× magnification. <b>F.</b> Immunohistochemistry of co-expression of human Foxp3 (brown) and CD4 (blue) in human skin grafts from SCID beige mice 21 days after infusion of PBS (left) or huPBMC (right) (40× magnification). Inserts show a higher magnification (63×) of single Foxp3 and CD4+ staining and Foxp3/CD4 co-staining. Photographs show representative examples of n = 6 (huPBMCs) n = 3 (controls).