Figure 2

A) Dendritic cell (DC) precursors secrete HLA-DR among parabasal cells (arrows) and differentiate into mature DC (arrowheads). B) T cells migrate through pb layer (arrow) to pb/im interface and show fragmentation after entering im layer (arrowheads). C) Transformation of DC precursors into mature DC at the top of pb layer is associated with CD68 expression (arrow). Mature DC (black arrowheads) secrete CD68 material in im layer accompanying mature and aged epithelial cells (white arrowheads). D) CD1a is expressed by DC precursors (arrows) and mature DC (black arrowheads). Mature DC (Langerhans' cells) undergo fragmentation in mid im layer (white arrowheads). E) Strong IgM binding (arrowheads) in upper parabasal (1), upper intermediate (2) and upper superficial layers (3). F) IgG binds to the entire s layer. For abbreviations see Fig. 1.