Targeted disruption of Stat6 DNA binding activity by an oligonucleotide decoy blocks IL-4-driven TH2 cell response

The transcription factor, signal transducer and activator of transcription (Stat) 6, regulates T(H)2-lymphocyte activity by controlling the expression and responsiveness to interleukin (IL)-4, which plays a key role in numerous allergic maladies. Therefore, we sought to use a phosphorothiolate cis-element decoy to target disruption of Stat6 transcriptional activity. Here we showed that the State decoy potently ablated the messenger RNA expression and production of IL-4, but not of several other cytokines. The Stat6 decoy functionally disrupted IL-4-inducible cell proliferation of murine T(H)2 cells and primary human CD4(+) T lymphocytes, Specificity of the decoy was demonstrated by its ability to directly block State binding to a cis-element probe and transactivation, but not affect Stat6 tyrosine phosphorylation or expression of the IL-4 receptor chains, Moreover the decoy failed to inhibit non-Stat6-dependent signaling pathways since IL-2 was competent to induce cell proliferation and activation of Stats 1, 3, and 5a/b, With the use of laser scanning confocal microscopy, fluorescently tagged Stats decoy was detectable in the cytoplasm and nucleus; however, greater levels of oligonucleotide were present in the latter following IL-4 treatment. Taken together, these data suggest that IL-4-driven T(H)2 cell activity can be preferentially restricted via targeted disruption of Stat6 by a novel and specific decoy strategy that may possess gene therapeutic potential, (Blood, 2000;95: 1249-1257) (C) 2000 by The American Society of Hematology.