Autocrine growth stimulation of a human T-cell lymphoma line by interleukin 2.

The ability of tumor cells to produce and to respond to their own growth factor (autocrine secretion) may be of importance for their growth. We describe a human tumor cell line regulated by an autocrine secretion of the growth factor interleukin 2 (IL-2). This T-lymphocyte cell line, IARC 301, was established from a patient with a T-cell lymphoma in the absence of any added specific growth factor. It constitutively expresses biologically functional high-affinity cell-surface receptors for IL-2 as shown by the binding of both radiolabeled purified IL-2 and monoclonal antibodies to IL-2 receptors. In addition, it synthesizes IL-2, which is bound to cell surface receptors. Monoclonal antibodies directed against either IL-2 or the IL-2 receptor block IARC 301 cell growth. These findings demonstrate that the proliferation of this tumor cell line is mediated by an autocrine pathway involving endogenous IL-2 production and its binding to cell surface receptors.