Generation of an autocrine leukaemia using a retroviral expression vector carrying the interleukin-3 gene.

The growth factor-dependent, non-leukemogenic cell line FDC-P1, was converted to an interleukin-3 (IL-3) producing leukemogenic cell line using a retroviral expression vector carrying the IL-3 gene. The new cell line, FDC-P1-IL3 proliferated independently of exogenous IL-3 and its proliferation was inhibited by anti IL-3 antisera. This inhibition could be overcome by addition of GM-CSF to the cultures. The data indicate that insertion of the retroviral expression vector into the genome of FDC-P1 cells has established an autocrine loop involving constitutive secretion of IL-3 and that such a loop can play an important role in leukemogenesis.