The histone deacetylase inhibitor trichostatin A upregulates regulatory T cells and modulates autoimmunity in NZB/W F1 mice Christopher M. Reilly a, b, * , Megan Thomas a , Robert Gogal Jr. a, b , Selen Olgun b , Arben Santo b , Renna Sodhi f , Eileen T. Samy c , Stanford L. Peng d , Gary S. Gilkeson e , Nilamadhab Mishra f a Department of Biomedical Sciences and Pathobiology, Virginia-Maryland Regional College of Veterinary Medicine, Virginia Polytechnic Institute and State University, VA, USA b Edward Via Virginia College of Osteopathic Medicine, 2265 Kraft Drive, Blacksburg, VA 24060, USA c Inflammation Discovery, Roche Palo Alto, Palo Alto, CA 94304, USA d Clinical Research and Exploratory Development, Roche Palo Alto, CA 94304, USA e Medical University of South Carolina, Charleston, SC 29425, USA f Section on Rheumatology and Clinical Immunology, Department of Internal Medicine, Wake Forest University School of Medicine, Winston-Salem, NC 27157, USA article info Article history: Received 17 March 2008 Received in revised form 14 April 2008 Accepted 15 April 2008 Keywords: Autoimmunity Lupus nephritis Mouse model NZB/NZW Treg cell abstract We sought to determine if the histone deacetylase inhibitor (HDI), trichostatin A (TSA), would alter systemic lupus erythematosus (SLE) in NZB/W mice. Fourteen to sixteen-week-old female NZB/W F1 mice were given TSA (1.0 mg/kg body weight (BW)) intraperitonealy (i.p.) daily, TSA (1.0 mg/kg BW) i.p. þ anti-CD25 (250 mg/mouse) i.p. every third day, only anti-CD25 (250 mg/mouse) i.p., DMSO or isotype IgG. Disease progression was assessed as they aged. Mice were sacrificed at 26 or 38 weeks of age, tissues collected and evaluated. At 36 weeks, TSA-treated animals had decreased anti-double stranded DNA (dsDNA) autoantibodies and decreased protein excretion compared to controls. Spleen size and the percentage of CD4 þ CD69 þ cells were decreased, with an increase in CD4 þ CD25 þ T cells in the TSA- treated mice. Real-time reverse transcription-polymerase chain reaction (RT-PCR) analysis of T cells showed a decrease in IL-6 production but an increase in TGF-b1 and Foxp3 in the TSA-treated animals. Kidney analysis showed a decrease in IgG and C3 deposition, decrease in pathologic glomerular disease and renal MCP-1, MMP-9, and IL-6 mRNA expression. Anti-CD25-treated mice euthanized at 26 weeks of age showed decreased Foxp3 þ CD4 þ CD25 þ T cells compared to TSA-treated mice. These data suggest TSA administration modulates lupus-like disease, in part, by increasing T regulatory cells. Ó 2008 Elsevier Ltd. All rights reserved. 1. Introduction The equilibrium between opposing activities of histone acety- lase transferases and histone deacetylase enzymes determines global cellular acetylation status. The acetylation status of lysine residues in nuclear core histones is an important factor in allowing the chromatin superstructure to be accessed by transcriptional factors to initiate gene activation [1]. Histone deacetylase inhibitors (HDIs) are grouped into three classes; TSA is a potent and specific inhibitor for class I and class II HDIs and has been shown to have efficacy at low nanomolar concentrations. TSA given i.p. to mice is rapidly absorbed and detectable in the plasma within 2 min and has a half-life of 10 min [2]. TSA has a potent broad spectrum anti- tumor activity against virally transformed cells in culture without apparent toxicity in preclinical studies and inhibits tumor cell growth in vitro [3–6]. We have previously shown that the histone deacetylase inhibitor (SAHA) can modulate renal disease in MRL/lpr mice and TSA can decrease renal disease in MRL/lpr mice [7–9]. TSA has been shown to inhibit the stimulation of toll-like receptors (TLRs) [10] and has been proposed to be used as therapy in auto- immune disorders [11]. CD4 þ CD25 þ regulatory T cells (Treg), constitute 5–10% of pe- ripheral CD4 þ T cells in normal naive mice and humans. Deletion of Treg from healthy animals can break self-tolerance, leading to the development of autoimmune disease, whereas repopulation of these cells can re-establish self-tolerance and prevents autoim- mune diseases [12–14]. This observation indicates that Treg play a critical role in the maintenance of self-tolerance and the * Corresponding author. Edward Via Virginia College of Osteopathic Medicine, 2265 Kraft Drive, Blacksburg, VA 24060, USA. Tel.: þ1 540 231 5345; fax: þ1 540 231 5252. E-mail address: chreilly@vcom.vt.edu (C.M. Reilly). Contents lists available at ScienceDirect Journal of Autoimmunity journal homepage: www.elsevier.com/locate/jautimm 0896-8411/$ – see front matter Ó 2008 Elsevier Ltd. All rights reserved. doi:10.1016/j.jaut.2008.04.020 Journal of Autoimmunity 31 (2008) 123–130