NF45 and NF90 regulate HS4-dependent interleukin-13 transcription in T cells.
Expression of the cytokine interleukin-13 (IL13) is critical for Th2 immune responses and Th2-mediated allergic diseases. Activation of human IL13 expression involves chromatin remodeling and formation of multiple DNase I-hypersensitive sites throughout the locus. Among these, HS4 is detected in the distal IL13 promoter in both naive and polarized CD4(+) T cells. We show herein that HS4 acts as a position-independent, orientation-dependent positive regulator of IL13 proximal promoter activity in transiently transfected, activated human CD4(+) Jurkat T cells and primary murine Th2 cells. The 3'-half of HS4 (HS4-3') was responsible for IL13 up-regulation and bound nuclear factor (NF) 90 and NF45, as demonstrated by DNA affinity chromatography coupled with tandem mass spectrometry, chromatin immunoprecipitation, and gel shift analysis. Notably, the CTGTT NF45/NF90-binding motif within HS4-3' was critical for HS4-dependent up-regulation of IL13 expression. Moreover, transfection of HS4-IL13 reporter vectors into primary, in vitro differentiated Th2 cells from wild-type, NF45(+/-), or NF90(+/-) mice showed that HS4 activity was exquisitely dependent on the levels of endogenous NF45 (and to a lesser degree NF90), because HS4-dependent IL13 expression was virtually abrogated in NF45(+/-) cells and reduced in NF90(+/-) cells. Collectively, our results identify NF45 and NF90 as novel regulators of HS4-dependent human IL13 transcription in response to T cell activation.
Kiesler
Patricia
P
Functional Genomics Laboratory, Arizona Respiratory Center, University of Arizona, Tucson, Arizona 85719, USA.
Haynes
Paul A
PA
Shi
Lingfang
L
Kao
Peter N
PN
Wysocki
Vicki H
VH
Vercelli
Donata
D
D000818:Animals; D001483:Base Sequence; D015870:Gene Expression / Q000276:immunology; D005816:Genetic Complementation Test; D006801:Humans; D018793:Interleukin-13 / Q000235:genetics*; D019169:Jurkat Cells; D008213:Lymphocyte Activation / Q000235:genetics*; D051379:Mice; D008810:Mice, Inbred C57BL; D008817:Mice, Mutant Strains; D008969:Molecular Sequence Data; D051903:Nuclear Factor 45 Protein / Q000378:metabolism*; D050779:Nuclear Factor 90 Proteins / Q000378:metabolism*; D010766:Phosphorylation / Q000276:immunology; D011401:Promoter Regions, Genetic / Q000276:immunology; D018418:Th2 Cells / Q000502:physiology*; D014158:Transcription, Genetic / Q000276:immunology; D015854:Up-Regulation / Q000276:immunology
C494013:ILF2 protein, human; C429643:ILF3 protein, human; C494014:Ilf2 protein, mouse; D018793:Interleukin-13; D051903:Nuclear Factor 45 Protein; D050779:Nuclear Factor 90 Proteins