RETROVIRAL INTERLEUKIN-4 GENE-TRANSFER INTO AN INTERLEUKIN-4-DEPENDENT CELL-LINE RESULTS IN AUTOCRINE GROWTH BUT NOT IN TUMORIGENICITY

A retroviral vector has been constructed containing the mouse interleukin 4 (IL 4) gene under the transcriptional control of the thymidine kinase promoter. Infection of the IL 4‐dependent T cell line CT4S by the thymidine kinase IL 4 construct resulted in factor‐independent growth. The infected cells grow as a consequence of continous consumption of the endogenously produced IL 4. Clones were established secreting different amounts of IL 4 but none of them was capable of growing in vivo. The lack of correlation between factor‐independent growth and tumorigenicity distinguishes IL 4 from other growth factors and could reflect the recently reported activity of IL 4 to suppress tumor growth in vivo. Copyright © 1990 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim