Nuclear factor of activated T cells is associated with a mast cell interleukin 4 transcription complex.
Interleukin 4 (IL-4), an immunoregulatory cytokine, is produced only by a subset of activated T cells and cells of the mast cell-basophil lineage. The production of IL-4 by mast cells likely represents a significant source of this protein in local immune-inflammatory responses in the skin, brain, gastrointestinal, and respiratory tracts, in which mast cells are prevalent. In the present study, the cis- and trans-acting elements that control inducible mast cell IL-4 gene transcription were examined and compared with those that function in T cells. We demonstrate that, as in T cells, sequences between bp -87 and -70 are critical for protein association and activation-dependent gene transcription and that this region (termed the activation-responsive element region) is the target of an inducible, cyclosporin A-sensitive, DNA-protein interaction. When assessed by electrophoretic mobility shift assays and UV cross-linking analyses, multiple proteins in both T- and mast cell nuclear extracts associate with the activation-responsive element in vitro, and some of these appear identical. However, distinct proteins are associated with each of the complexes as well. AP-1 family members are unique to the T-cell-stimulation-dependent complex, whereas mast cell complexes contain factors that are reactive with anti-nuclear factor of activated T cells p (NF-ATp) and anti-NF-ATc antibodies but have distinct molecular masses compared with those of T-cell-derived NF-AT. Furthermore, an anti-NF-ATp-reactive factor with a molecular mass of approximately 41 kDa is present in the nuclei of unstimulated cells and binds independently of cell activation, unlike the previously described NF-AT family members. These data support the idea that there are uniquely regulated, cell lineage-specific transcription factors related to T-cell-derived NF-AT that mediate inducible IL-4 transcription in mast cells. These differences likely reflect the distinct cell surface signaling requirements for IL-4 production in T and mast cells.
Department of Medicine, Oregon Health Sciences University, Portland 97201, USA.
D L
DL
Weiss
J
J
Hural
D
D
Tara
L A
LA
Timmerman
G
G
Henkel
M A
MA
Brown
D000818:Animals; D001483:Base Sequence; D015500:Chloramphenicol O-Acetyltransferase / Q000235:genetics; D016572:Cyclosporine / Q000494:pharmacology; D004247:DNA / Q000235:genetics; D004268:DNA-Binding Proteins / Q000378:metabolism*; D017930:Genes, Reporter; D015847:Interleukin-4 / Q000235:genetics* / Q000378:metabolism*; D008407:Mast Cells / Q000187:drug effects / Q000276:immunology* / Q000378:metabolism*; D051379:Mice; D008969:Molecular Sequence Data; D009154:Mutation; D050778:NFATC Transcription Factors; D009687:Nuclear Proteins; D013601:T-Lymphocytes / Q000276:immunology* / Q000378:metabolism*; D014157:Transcription Factors / Q000378:metabolism*; D014158:Transcription, Genetic / Q000187:drug effects
D004268:DNA-Binding Proteins; D050778:NFATC Transcription Factors; D009687:Nuclear Proteins; D014157:Transcription Factors; D015847:Interleukin-4; D016572:Cyclosporine; D004247:DNA; D015500:Chloramphenicol O-Acetyltransferase