CONSTITUTIVE EXPRESSION OF IMMUNOSUPPRESSION-ASSOCIATED CYTOKINE GENES IN A PANEL OF HUMAN T-LEUKEMIA-CELL LINES - HIGH-INCIDENCE OF TRANSFORMING GROWTH-FACTOR-BETA GENE-EXPRESSION

The expression of RNA for interleukin (IL) -9, -10 and -12, interferon gamma (IFN-gamma), transforming growth factor beta one (TGF-beta1), m acrophage inflammatory protein one alpha (MIP-1alpha) and granulocyte- macrophage colony-stimulating factor (GM-CSF) in a panel of human T le ukemia cell lines at various stages of differentiation, and normal thy mocytes was examined using reverse transcriptase-polymerase chain reac tion (RT-PCR). Fourteen of 16 T cell lines expressed the gene for TGF- beta1 and 12 of the cell lines also expressed the gene for GM-CSF. Non e of the 5 normal thymocyte samples constitutively expressed RNA for T GF-beta1 or GM-CSF. One cell line established from a patient with adul t T cell leukemia (ATL), ED-S-, expressed the genes for TGF-beta1, GM- CSF, IL-10, IL-12, IFN-gamma and MIP-1alpha. IL-9 was not expressed by any cell line, IL-10 was expressed by only three cell lines and IL-12 was expressed by only two cell lines. The production of immunosuppres sive factors such as TGF-beta1 by T leukemic cells is a possible mecha nism for the clinical progression of this disease.