Figure 3

Dual color IHC (HLA-DR peroxidase/CD8 FITC) viewed in dark field visible light (A) and dark field fluorescence (B). A) HLA-DR cells associate with (open white arrow) and migrate through the basement membrane (arrowhead). White arrows indicate DC precursors among parabasal cells, which differentiate into mature DC (yellow arrow) at the pb/im interface (dashed line). Open yellow arrows show activated T cells (see B). B) T cells migrate through (yellow arrowheads) and accumulate above the basement membrane. With the assistance of MDC (white arrows), the T cells enter pb layer and migrate toward pb/im interface. At the interface, they accompany differentiation of DC (solid yellow arrow) and show temporary activation with HLA-DR expression (short open yellow arrows). The T cells entering im layers show diminution in size (long open yellow arrow).