Lymphocyte-activating and growth-inhibitory activities for several sources of native and recombinant interleukin 1.

Several native and recombinant forms of human interleukin-1 (IL-1) and recombinant murine IL-1 were assayed for their ability to inhibit the growth of cell lines established from malignant and nonmalignant human sources. The amount of growth-inhibitory activity was compared to the units of half-maximal [3H]thymidine incorporation in mouse thymocyte cultures exposed to IL-1. Three malignant human mammary cell lines (MCF-7, T47D, and MDA-MB-415) were growth inhibited in the presence of both native and the alpha and beta forms of recombinant human IL-1. MDA-MB-415 was most sensitive. Although most sources of IL-1 showed good correlation between units of activity and percentage of growth inhibition, native IL-1 from Genzyme Corporation induced a cytotoxic effect. Murine IL-1 was less growth inhibitory than the human forms of the monokine. Human embryonic lung (HEL), adult fibroblast (CRL 1445), and transformed milk (HBL-100) lines were not growth inhibited when tested against any IL-1 source. A lung carcinoma (CALU-1) and a colon carcinoma (SW-48) were not inhibited by either the alpha or beta forms of human recombinant IL-1.