Antigen presenting cells (APCs) play a critical role in the induction of graft-versus-host (GVHD)/ leukemia (GVL) responses after allogeneic bone marrow transplantation (BMT). Therefore agents that regulate the functions of dendritic cells (DCs), the most potent APCs, might have therapeutic potential in GVH processes. Protein lysine deacetylases, traditionally referred to as histone deacetylases (HDAC) play a pivotal role many biological processes. HDAC inhibitors (HDACi) have been developed as anti-tumor agents and they appear to be well tolerated in human clinical trials;but their immuno-modulatory effects have heretofore been largely unrecognized. Data generated by us demonstrate that HDACi regulate experimental acute GVHD partly through induction of the immuno-suppressive enzyme indoleamine 2, 3 dioxygenase (IDO) in host DCs. These exciting pre-clinical experimental data formed the rationale for the development of a proof of concept clinical trial at our institution (IRB Approval # 2001.0234), which will test the effects of HDAC inhibition in prevention of acute GVHD. However, the precise molecular mechanisms remain unknown. Preliminary data demonstrate that acetylation of non-histone immuno-regulatory protein, STAT-3, in DCs is critical for the DC suppressive effects of HDACi. Data also show that HDAC-1 enzyme interacts with STAT-3 in DCs. In this proposal we will build on our exciting published and unpublished observations from both murine models and cells from healthy human donors. We will test the central hypothesis that acetylation of the non-histone protein, STAT-3, is critical for the negative regulation of DCs and experimental GVHD after treatment with HDACi.
The specific aims (SA) are as follows:
Specific Aim (SA) 1: To determine the specific HDAC enzyme critical for acetylation of STAT-3 and regulation of DC function by the HDACi. In this specific aim we will test the hypothesis that HDAC enzyme 1 is critical for STAT-3 acetylation and regulation of the innate and allo-stimulatory functions of DCs.
Specific Aim (SA) 2: To elucidate the critical role of STAT-3 in regulation of DCs and GVHD by HDACi. In this specific aim we will explore the hypothesis that acetylation of STAT-3 by HDACi is critical for suppression of DCs and experimental GVHD.
Allogeneic hematopoietic stem cell transplantation is potentially curative therapy for many malignant diseases whose applicability has been impeded by the development of its most serious complication, GVHD. Strategies that mitigate GVHD will allow for better harnessing of this effective therapeutic modality to treat many patients with hematological cancers.
|Sun, Yaping; Iyer, Matthew; McEachin, Richard et al. (2017) Genome-Wide STAT3 Binding Analysis after Histone Deacetylase Inhibition Reveals Novel Target Genes in Dendritic Cells. J Innate Immun 9:126-144|
|Wu, Shin-Rong; Reddy, Pavan (2017) Regulating Damage from Sterile Inflammation: A Tale of Two Tolerances. Trends Immunol 38:231-235|
|Toubai, Tomomi; Mathewson, Nathan; Oravecz-Wilson, Katherine et al. (2015) Host CD8?+ dendritic cells may be a key factor for separating graft-versus-host disease from graft-versus-leukemia. Biol Blood Marrow Transplant 21:775-6|
|Sun, Yaping; Oravecz-Wilson, Katherine; Mathewson, Nathan et al. (2015) Mature T cell responses are controlled by microRNA-142. J Clin Invest 125:2825-40|
|Choi, Sung Won; Gatza, Erin; Hou, Guoqing et al. (2015) Histone deacetylase inhibition regulates inflammation and enhances Tregs after allogeneic hematopoietic cell transplantation in humans. Blood 125:815-9|
|Sun, Yaping; Wang, Ying; Toubai, Tomomi et al. (2015) BET bromodomain inhibition suppresses graft-versus-host disease after allogeneic bone marrow transplantation in mice. Blood 125:2724-8|
|Choi, Sung Won; Braun, Thomas; Chang, Lawrence et al. (2014) Vorinostat plus tacrolimus and mycophenolate to prevent graft-versus-host disease after related-donor reduced-intensity conditioning allogeneic haemopoietic stem-cell transplantation: a phase 1/2 trial. Lancet Oncol 15:87-95|
|Toubai, Tomomi; Hou, Guoqing; Mathewson, Nathan et al. (2014) Siglec-G-CD24 axis controls the severity of graft-versus-host disease in mice. Blood 123:3512-23|
|Tawara, Isao; Liu, Chen; Tamaki, Hiroya et al. (2013) Influence of donor microbiota on the severity of experimental graft-versus-host-disease. Biol Blood Marrow Transplant 19:164-8|
|MacDonald, Kelli P; Shlomchik, Warren D; Reddy, Pavan (2013) Biology of graft-versus-host responses: recent insights. Biol Blood Marrow Transplant 19:S10-4|
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