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Inhibition of interleukin‐13 gene expression by triptolide in activated T lymphocytes
Author(s) -
Dai Shanlin,
Yin Kaisheng,
Yao Xin,
Zhou Lin
Publication year - 2013
Publication title -
respirology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.857
H-Index - 85
eISSN - 1440-1843
pISSN - 1323-7799
DOI - 10.1111/resp.12145
Subject(s) - triptolide , medicine , gene expression , interleukin , interleukin 4 , immunology , interleukin 2 , gene , cancer research , microbiology and biotechnology , cytokine , genetics , apoptosis , biology
Background and objective Triptolide, a type of diterpenoid, is the active compound of T ripterygium wilfordii ; it plays roles in anti‐inflammatory and immune response regulation. Our objective was to investigate the mechanism of the inhibitory effect of triptolide on interleukin‐13 ( IL ‐13) gene expression in activated T lymphocytes. Understanding the molecular mechanism by which triptolide exerts a therapeutic function may be useful in developing a pharmaceutical treatment for asthma. Methods Peripheral blood mononuclear cells ( PBMC ) and H ut‐78 cells were stimulated with anti‐ CD3 / CD28 with or without co‐incubation with triptolide. The alteration of IL ‐13 messenger RNA ( mRNA ), expression and protein level were analysed using real‐time reverse transcription polymerase chain reaction ( PCR ) and enzyme‐linked immunosorbent assay, respectively. The intracellular distribution profile of transcription factor GATA3 and nuclear factor of activated T cells ( NFAT1 ) were analysed by W estern blotting. The binding rates of GATA3 and NFAT1 to the promoter sequence of IL ‐13 were analysed by chromatin immunoprecipitation ( ChIP ) PCR . Results In PBMC , the release of IL ‐13 was dependent on anti‐ CD3 / CD28 stimulation. Its release could be inhibited by triptolide at the concentration of 500 nmol. In H ut‐78 cells, IL ‐13 mRNA and protein expression were increased with anti‐ CD3 / CD28 stimulation and significantly inhibited by incubation with 28 nmol triptolide. This concentration of triptolide also significantly inhibited the nuclear translocation of GATA3 and NFAT1 reducing the binding rate to the IL ‐13 gene promoter. Conclusions Triptolide inhibits IL ‐13 gene transcription and protein expression by inhibiting GATA3 and NFAT1 nuclear translocation and their binding rates to the IL ‐13 gene promoter region.