Regulation of Cutaneous Malignancy by γδ T Cells

摘要

The localization of γδ T Cells within epithelia suggests that these cells may contribute tot he down-regulation of epithelial malignancies. We report that mice lacking γδ cells are highly susceptible to multiple regimens of cutaneous carcinogenesis. After exposure to carcinogens, skin cells expressed Rae-1 and H60, major histocompatibility complex-related molecules structurally resem- Bling human MICA. Each of these is a ligand for NKG2d, a receptor expressed By cytolytic t cells and natural killer (NK) cells. In vitro, skin-associated NKG2d+ γδ cells killed skin carcinoma cells by a mechanism that was sensitive to blocking NKG2d engagement. Thus, local T cells may use evolutionarily con- served proteins to negatively regulate malignancy.