Activated lymphocyte killer cells derived from melanoma tissue or peripheral blood

Lymphoid cells infiltrating metastatic melanomas were grown directly from cell suspensions of tumour tissue by the addition of T cell growth factor. Lymphoid cells grew out at the expense of tumour cells in six of seven freshly excised tumours, and cells from two cultures were expanded for in vitro testing of cytolytic function against different target cells. Early in culture the tumour derived lymphocytes killed fresh autologous melanoma cells and, particularly later in culture, were highly and non-specifically cytolytic for cultured melanoma and non-melanoma cells. Cultured peripheral blood lymphocytes from patients with melanoma, and from normal subjects, were cytolytic to the same degree as tumour derived lymphocytes, and also resembled cells grown from tumour tissue in possessing acid phosphatase activity which was resistant to tartrate. Cultured lymphoblasts from both tumour and peripheral blood had a T cell phenotype when analysed with monoclonal antibodies. An in vitro co-culture system was employed to study the kinetics and the precursors of these non-specific killer cells among blood mononuclear cells. Blood mononuclear cells cultured with irradiated B lymphoblasts led to the generation of non-specific cytolytic cells, referred to as activated lymphocyte killer (ALK) cells, after 7-10 days of culture and the progenitors of these ALK cells were demonstrated to be distinct from those of specific cytolytic T cells.