Dose-responsive gene expression in suberoylanilide hydroxamic acid-treated resting CD4+ T cells

B Reardon, N Beliakova-Bethell, CA Spina… - AIDS, 2015 - journals.lww.com
B Reardon, N Beliakova-Bethell, CA Spina, A Singhania, DM Margolis, DR Richman…
AIDS, 2015journals.lww.com
Design: Persistent latently infected CD4+ T cells represent a major obstacle to HIV
eradication. Histone deacetylase inhibitors (HDACis) are a proposed activation therapy.
However, off-target effects on gene expression in host immune cells are poorly understood.
We hypothesized that HDACi-modulated genes would be best identified with a dose–
response analysis. Methods: Resting primary CD4+ T cells were treated with 0.34, 1, 3, or 10
μmol/l of the HDACi, suberoylanilide hydroxamic acid (SAHA), for 24 h and subjected to …
Abstract
Design:
Persistent latently infected CD4+ T cells represent a major obstacle to HIV eradication. Histone deacetylase inhibitors (HDACis) are a proposed activation therapy. However, off-target effects on gene expression in host immune cells are poorly understood. We hypothesized that HDACi-modulated genes would be best identified with a dose–response analysis.
Methods:
Resting primary CD4+ T cells were treated with 0.34, 1, 3, or 10 μmol/l of the HDACi, suberoylanilide hydroxamic acid (SAHA), for 24 h and subjected to microarray gene expression analysis. Genes with dose-correlated expression were filtered to identify a subset with consistent up or downregulation at each SAHA dose. Histone modifications were characterized in six SAHA dose-responsive genes by chromatin immunoprecipitation (ChIP-RT-qPCR).
Results:
A large number of genes were shown to be upregulated (N= 657) or downregulated (N= 725) by SAHA in a dose-responsive manner (FDR-corrected P-value≤ 0.5, fold change≥| 2|). Several genes (eg CINNAL1, DPEP2, H1F0, IRGM, PHF15, and SELL) are potential in-vivo biomarkers of SAHA activity. SAHA dose-responsive genes included transcription factors, HIV restriction factors, histone methyltransferases, and host proteins that interact with HIV. Pathway analysis suggested net downregulation of T-cell activation with increasing SAHA dose. Histone acetylation was not correlated with host gene expression, but plausible alternative mechanisms for SAHA-modulated gene expression were identified.
Conclusion:
Numerous genes in CD4+ T cells are modulated by SAHA in a dose-responsive manner, including genes that may negatively influence HIV activation from latency. Our study suggests that SAHA influences gene expression through a confluence of several mechanisms, including histone modification, and altered expression and activity of transcription factors.
Lippincott Williams & Wilkins