title: Oligonucleotide fishing for STAT6: cross-talk between IL-4 and chemokines.
abstract: Signal transducer and activator of transcription 6 (STAT6) is essential for the biological activities of interleukin-4 (IL-4) and the development of allergic responses in mice. Here we report on a sensitive and specific assay for STAT6 activation in response to IL-4. We took advantage of double-stranded oligonucleotide probes containing a STAT6-binding gene-sequence from the promotor of the immunoglobulin heavy chain germline epsilon transcript to study the IL-4-induced DNA binding of STAT6. Using these probes, we show that repeated adjacent STAT6-binding sites result in enhanced STAT6-DNA binding. Moreover, the distance between the binding sites is critical for STAT-DNA binding, i.e. STAT6 binding is decreased at distances above 20 nucleotides between neighbouring binding sites. Using this assay to study cross-talk between IL-4 and chemokines, we provide evidence that MIP-1beta and MIG inhibit IL-4-induced STAT6 activation, whereas other chemokines and cytokines do not. In conclusion, our data show that oligonucleotide fishing is a supplementary tool for studying cytokine cross-talk at a genomic level.
authors.affiliation: Institute of Medical Microbiology and Immunology, University of Copenhagen, Copenhagen, Denmark.
authors.forename: K W
authors.initials: KW
authors.lastname: Eriksen
authors.forename: M
authors.initials: M
authors.lastname: Nielsen
authors.forename: K
authors.initials: K
authors.lastname: Kaltoft
authors.forename: A
authors.initials: A
authors.lastname: Svejgaard
authors.forename: M H
authors.initials: MH
authors.lastname: Nissen
authors.forename: C
authors.initials: C
authors.lastname: Röpke
authors.forename: N
authors.initials: N
authors.lastname: Ødum
mesh_terms: D000818:Animals; D001483:Base Sequence; D001665:Binding Sites / Q000235:genetics; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology / Q000378:metabolism; D002460:Cell Line; D018925:Chemokines / Q000378:metabolism*; D016207:Cytokines / Q000378:metabolism; D004247:DNA / Q000235:genetics / Q000378:metabolism; D006801:Humans; D015847:Interleukin-4 / Q000378:metabolism* / Q000494:pharmacology; D051379:Mice; D008969:Molecular Sequence Data; D015345:Oligonucleotide Probes; D010766:Phosphorylation; D050800:STAT6 Transcription Factor; D015534:Trans-Activators / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D014443:Tyrosine / Q000378:metabolism
chemical_list: D018925:Chemokines; D016207:Cytokines; D015345:Oligonucleotide Probes; D050800:STAT6 Transcription Factor; C494101:STAT6 protein, human; C494100:Stat6 protein, mouse; D015534:Trans-Activators; D015847:Interleukin-4; D014443:Tyrosine; D004247:DNA