Thymoma production of T cell growth factor (Interleukin 2).

Phorbol-12-myristate-13-acetate stimulates a subline of mouse EL-4 thymoma cells to produce, in vitro, in very high titer, T cell growth factor (Interleukin 2, IL 2). The EL-4-derived IL 2 has the same m.w. (30,000) and isoelectric point heterogeneity (pI 3.8-4.4) as the IL 2 produced by Con A-stimulated spleen cells. In addition, the thymoma-derived IL 2 exhibits the same spectrum of biologic activities as has been reported for spleen cell-derived IL 2.