Infiltrating lymphocytes in benign and malignant naevomelanocytic lesions.

Cutaneous melanocytic tumors include benign (naevi) and malignant (melanoma), potentially metastatic lesions. In this report, we show that infiltrating lymphocytes from benign tumors may be expanded in vitro as TIL from melanoma in the presence of autologous tumoral cells and recombinant IL2. Moreover it seems that TIL from primary cutaneous benign or malignant lesions more frequently express the T-cell receptor gamma delta than TIL from metastatic melanoma. Otherwise, a gamma delta + line and a gamma delta + clone extracted from a primary cutaneous melanoma exhibit a specific non MHC-restricted cytotoxic activity against autologous tumor cells. This is the first report of a TCR gamma delta + T lymphocyte cytotoxic activity against a human solid cutaneous tumor.