T-CELL RECEPTOR GAMMA-DELTA-BEARING CELLS IN NORMAL HUMAN-SKIN

T-cell antigen receptors (TCR) are divided into common αβ and less common γδ types. In the murine skin, TCR γδ+ cells have been reported to form the great majority of epidermal T lymphocytes. We have examined the relative contribution of TCR αβ+ and TCR γδ+ cells to the T-cell population in normal human skin. Serial sections of freshly frozen skin specimens were acetone fixed, incubated with anti-CD3, βF 1 (anti-TCR αβ), anti-TCR γδ-1 and anti-TCR δ1 (anti-TCR γδ) monoclonal antibodies (MoAb), and stained with a highly sensitive method. Over 90% of the T cells of normal human skin are localized around the postcapillary venules of the dermis, while less than 5% are present within the epidermis. In papillary dermis, TCR γδ+ cells formed on average 7% (anti-TCR γδ-1) or 9% (anti-TCR δ1) of the total number of CD3+ cells, while TCR αβ+ cells constituted up to 80%. In epidermis, these percentages were 18% and 29% for TCR γβ+ cells, and up to 60% for TCR αβ+ cells. It is concluded that there is no preferential immigration or in situ expansion of TCR γδ+ T cells in normal human skin, because the relative percentages found for the TCR αβ+ and TCR γδ+ populations in skin are comparable to those found in lymphoid organs and peripheral blood. However, the percentage of TCR γδ+ cells in epidermis seemed on average higher than in papillary dermis. Therefore, there may still be a difference in migration patterns of TCR γδ+ v TCR αβ+ cells, but this does not result in their preferential localization in human epidermis. The hypothesis that TCR γδ+ T cells have a specialized function in immunosurveillance of epithelia may thus not be valid for human epidermis. © 1990.