ABSTRACT

Conclusion:

These observations support the concept that Langerhans cells de-liver antigen peptides to regional lymph nodes/thymus and spleen, to the former via lymph vessels and to the latter via arterial circulation, and CD1a, S-100, and HLA-DR were suitable markers for the detection of Langerhans cells in diffe-rent lymphoid tissues except langerin.

Results:

We noted CD1a-, S-100-, and HLA-DR-positive LCs in the epidermis and S-100/HLA-DR-positive LCs in the dermis and around its vessels. These were shaped like dendritic cells. We also saw these S-100/HLA-DR immunore-active cells in the LNs, spleen, and thymus by discriminating them from the L1-positive macrophages. These positive cells were very close to the blood vessels.

Materials and Methods:

Migrated LCs from the epidermis were measured as a function of the frequency of CD1a/HLA-DR and S100 positive LCs were fo-und in epidermal sheets prepared frompunch biopsies of the normal skin sites of healthy humans. For this purpose, we investigated 6 healthy tissue samples of each lymphoid organ biopsy with these antigens. Moreover, we used L1 MoAb to distinguish macrophages from LCs or their derivatives. We examined normal samples from subjects who pre-sented at the Pathology Department of Gazi University Medical Hospital, Tur-key. Standard immunohistochemical methods were used to detect the presence of antigens in formalin fixed tissue specimens. The intensity of the immunope-roxidase reaction was classified under a light microscope (Leica DM 4000B).

Purpose:

Migration from sites of antigen uptake to lymphoid organs is crucial for the generation of immune responses by dendritic cells. We investigated the human epidermal Langerhans cells in their migratory pathway, from the epi-dermis to the draining lymph nodes (LNs) and/or other secondary lymphoid or-gans, by immunohistochemical methods, presenting the intensity of immunore-active cells with Langerhans cells (LCs) specific antibodies.