Characterization of a novel PMA-inducible pathway of interleukin-13 gene expression in T cells.
Although interleukin 13 (IL-13) is an important mediator of asthma and allergic diseases, the molecular mechanisms regulating IL-13 gene expression are not well understood. This study was designed to define the molecular mechanisms governing IL-13 gene expression in T cells. IL-13 expression was examined in human peripheral blood T cells and in the EL-4 T-cell line by enzyme-linked immunosorbent assay and reverse-transcription polymerase chain reaction. An IL-13 promoter deletion analysis was performed using luciferase-based reporter plasmids transiently transfected into EL-4 cells by electroporation. DNA binding factors were investigated using electrophoretic mobility shift assays. In contrast to IL-4 expression, which required concomitant activation of calcium- and protein kinase C- (PKC-) dependent signalling pathways, PKC activation alone was sufficient for IL-13 protein secretion in mitogen-primed (but not resting) peripheral blood T cells, and for IL-13 mRNA expression and promoter activity in EL-4 T cells. Promoter deletion analysis localized a phorbol 12-myristate 13-acetate (PMA)-sensitive element to a proximal promoter region between -109 and -79 base pairs upstream from the IL-13 transcription start site. This promoter region supported the binding of both constitutive and PMA-inducible nuclear factors in gel shift assays.
Keen
Judith C
JC
Department of Environmental Health Sciences, Johns Hopkins University School of Medicine, Balitmore, MD 21224, USA.
Cianferoni
Antonella
A
Florio
Giovanni
G
Guo
Jia
J
Chen
Rongbing
R
Roman
Jessica
J
Wills-Karp
Marsha
M
Casolaro
Vincenzo
V
Georas
Steve N
SN
D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D002478:Cells, Cultured; D005786:Gene Expression Regulation / Q000276:immunology; D006801:Humans; D018793:Interleukin-13 / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D051379:Mice; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D011493:Protein Kinase C / Q000276:immunology; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D015398:Signal Transduction / Q000276:immunology; D013045:Species Specificity; D013601:T-Lymphocytes / Q000276:immunology*; D013755:Tetradecanoylphorbol Acetate / Q000276:immunology*; D014158:Transcription, Genetic / Q000276:immunology
D018793:Interleukin-13; D011493:Protein Kinase C; D013755:Tetradecanoylphorbol Acetate