A cell-based bioluminescence assay reveals dose-dependent and contextual repression of AP-1-driven gene expression by BACH2.


Type
Article
Change log
Authors
Vardaka, Panagiota 
Lozano, Teresa 
Bot, Christopher 
Ellery, Jonathan 
Whiteside, Sarah K 
Abstract

Whereas effector CD4+ and CD8+ T cells promote immune activation and can drive clearance of infections and cancer, CD4+ regulatory T (Treg) cells suppress their function, contributing to both immune homeostasis and cancer immunosuppression. The transcription factor BACH2 functions as a pervasive regulator of T cell differentiation, promoting development of CD4+ Treg cells and suppressing the effector functions of multiple effector T cell (Teff) lineages. Here, we report the development of a stable cell-based bioluminescence assay of the transcription factor activity of BACH2. Tetracycline-inducible BACH2 expression resulted in suppression of phorbol 12-myristate 13-acetate (PMA)/ionomycin-driven activation of a luciferase reporter containing BACH2/AP-1 target sequences from the mouse Ifng + 18k enhancer. BACH2 expression repressed the luciferase signal in a dose-dependent manner but this activity was abolished at high levels of AP-1 signalling, suggesting contextual regulation of AP-1 driven gene expression by BACH2. Finally, using the reporter assay developed, we find that the histone deacetylase 3 (HDAC3)-selective inhibitor, RGFP966, inhibits BACH2-mediated repression of signal-driven luciferase expression. In addition to enabling mechanistic studies, this cell-based reporter may enable identification of small molecule agonists or antagonists of BACH2 function for drug development.

Description
Keywords
Acrylamides, Animals, Basic-Leucine Zipper Transcription Factors, Cell Differentiation, Dose-Response Relationship, Drug, Gene Expression Regulation, Humans, Jurkat Cells, Luciferases, Luminescent Measurements, Mice, Phenylenediamines, Tetracycline, Tetradecanoylphorbol Acetate, Transcription Factor AP-1
Journal Title
Sci Rep
Conference Name
Journal ISSN
2045-2322
2045-2322
Volume Title
10
Publisher
Springer Science and Business Media LLC
Rights
All rights reserved
Sponsorship
MRC (MR/S024468/2)
Wellcome Trust (105663/Z/14/Z)
MRC (1947452)