PMC

A schema of the results. LC, Langerhans cell; T, T cell.

B7–1 expression (brown) in the dermis of inflamed skin (hematoxylin counterstaining). B7–1⁺ cells (arrow) were selectively observed in the lumen of thin-walled vessels (arrowheads). Original magnification, ×100.

Double staining for CD1a (red) and CD4 (blue) in the dermis of inflamed skin (no counterstaining). Dermal CD1a⁺ cells are admixed with CD4⁺ T cells. Original magnification, ×132.

B7–2 expression (brown) in inflamed skin (methyl green counterstaining). Note an abundance of B7–2⁺ cells in the inflamed dermis and an absence of B7–2⁺ cells in the epidermis. E, epidermis; D, dermis. Original magnification, ×50.

Double staining for CD4 (brown) and Ki-67 (black) in the dermis of inflamed skin (hematoxylin counterstaining). The arrow indicates a Ki-67⁺/CD4⁺ T cell. Note Ki-67 expression on keratinocytes as a control (arrowheads). Original magnification, ×330.

Double immunofluorescence for Lag (green) and CD1a (red) in inflamed dermis. Lag⁺/CD1a⁺ cells (yellow, arrowheads) constitute a part of CD1a⁺ cells (red) in the inflamed dermis. Note an absence of Lag⁺ cells without CD1a expression (green). Original magnification, ×100.

Double immunofluorescence for B7–2 (green) and CD1a (red) in inflamed skin. Yellow cells are double positive for B7–2/CD1a. Most CD1a⁺ cells in the dermis coexpress B7–2, whereas CD1a⁺ cells in the epidermis do not express B7–2 (inset). Original magnification, ×100.

Double staining for B7–2 (black) and VEGFR-3 (blue) in inflamed skin (no counterstaining). B7–2⁺ Langerhans cells are aggregated within VEGFR-3⁺ lymphatic vessels (arrows). Note B7–2⁺ dermal Langerhans cells (asterisks) as well as Langerhans cells within the lymphatic vessels. Original magnification, ×50.

Double immunofluorescence for CD45RO (green) and CD4 (red) in the dermis of inflamed skin. An abundance of yellow cells indicates that almost all CD4⁺ T cells infiltrating the dermis are CD45RO⁺, a memory phenotype. Original magnification, ×100.

Double staining for Lag (red, asterisks) and B7–2 (black, arrowheads) in the dermis of inflamed skin (hematoxylin counterstaining). The Lag⁺/B7–2⁺ dermal Langerhans cell is in close contact with lymphocytes. Note the presence of B7–2⁺ cell processes holding lymphocytes. Original magnification, ×500.

Double immunofluorescence for factor XIIIa (green) and CD4 (red) in the dermis of inflamed skin. Factor XIIIa⁺ dermal dendrocytes (arrows) are located at the periphery of the cluster of CD4⁺ T cells (asterisks) and are not in contact with them. Original magnification, ×50.

Immunohistochemistry for CD1a (brown) in inflamed skin autotransplanted to the oral cavity (methyl green counterstaining). Note an abundance of dermal CD1a⁺ cells (asterisks) in the area of lymphocytic infiltrate (arrowheads), contrasted by a decrease in epidermal CD1a⁺ cells (arrow). E, epidermis; D, dermis. Original magnification, ×50.

Immunoelectron microscopy for B7–2 in the dermis of inflamed skin. Black represents the immunoreactivity for B7–2. The B7–2⁺ dermal Langerhans cell (LC) is in cell-to-cell contact with a lymphocyte (L). Note numerous cytoplasmic processes positive for B7–2 (arrows). The lymphocyte possesses a large nucleolus (arrowheads), another finding of activation. CD83⁺ dermal Langerhans cells showed the same features (not shown). Original magnification, ×5000.