Epithelial defence by gamma delta T cells

gamma delta T cells constitute a separate lineage of T lymphocytes which differ from conventional alpha beta T cells with regard to T cell receptor (TCR) repertoire and tissue localization. In murine skin, gamma delta T cells expressing a canonical V gamma 5 TCR are abundant and contribute as so-called dendritic epidermal T cells to local immune surveillance. In humans, major subsets of gamma delta T cells are recognized on the basis of their TCR V delta usage. While V delta 2 cells dominate in the peripheral blood, V delta 1 cells are preferentially localized in mucosal tissue including the intestinal epithelia. In this article we summarize basic features of intraepithelial gamma delta T cells and discuss their possible role in epithelial defence. Copyright (C) 2005 S. Karger AG, Basel.