scholarly journals Polycomb Repressor Complex 2 Regulates HOXA9 and HOXA10, Activating ID2 in NK/T-Cell Lines.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 1281-1281
Author(s):  
Stefan Nagel ◽  
Letizia Venturini ◽  
Marquez E. Victor ◽  
Corinna Meyer ◽  
Maren Kaufmann ◽  
...  

Abstract Abstract 1281 Poster Board I-303 Many oncogenes code for transcription factors involved in regulation of developmental pathways. The activity of these pathways is tissue specific and restricted to certain developmental stages. Here, we searched for T-cell acute lymphoblastic leukemia (T-ALL) oncogenes which physiologically regulate differentiation of natural killer (NK) cells. NK- and T-cells are closely related lymphocytes, sharing the same early progenitors which can differentiate into either lineage. We compared expression profiles of malignant NK- and T-cell lines to identify aberrantly expressed genes in T-ALL. This analysis revealed high expression of HOXA9, HOXA10 and ID2 in NK-cell lines and in one T-ALL line, LOUCY, suggesting leukemic deregulation therein. Subsequently, we analyzed mechanisms underlying their regulation. Overexpression and chromatin immuno-precipitation experiments demonstrated that HOXA9 and HOXA10 directly activate ID2 expression. Analysis of other ALL and acute myeloid leukemia cell lines with and without mixed lineage leukemia (MLL) gene translocations demonstrated a correlated expression of HOXA9/10 and ID2, highlighting ID2 as an indirect target of MLL fusion proteins which deregulate HOXA genes. Furthermore, profiling data of genes coding for chromatin regulators of homeobox genes, including the components EZH2 and HOP of polycomb repressor complex 2 (PRC2), showed downregulation of EZH2 in LOUCY and limited expression of HOP to NK-cell lines. Subsequent treatment of T-ALL cell lines JURKAT and LOUCY with DZNep, an inhibitor of EZH2/PRC2, resulted in elevated and unchanged HOXA9/10 expression levels, respectively, confirming repressive activity of EZH2 in T-cells. Additionally, profiling data and overexpression analysis indicated that reduced expression of E2F cofactor TFDP1 contributed to the lack of EZH2 in LOUCY. Forced expression of HOP in JURKAT cells resulted in reduced HOXA10 and ID2 expression levels, suggesting enhancement of PRC2 repression. Taken together, our results show that major differentiation factors of the NK-cell lineage, including HOXA9, HOXA10 and ID2, were (de)regulated via PRC2 and may contribute to T-cell leukemogenesis. Disclosures No relevant conflicts of interest to declare.

Blood ◽  
1999 ◽  
Vol 94 (10) ◽  
pp. 3531-3540 ◽  
Author(s):  
Angelo A. Cardoso ◽  
J. Pedro Veiga ◽  
Paolo Ghia ◽  
Hernani M. Afonso ◽  
W. Nicholas Haining ◽  
...  

We have previously shown that leukemia-specific cytotoxic T cells (CTL) can be generated from the bone marrow of most patients with B-cell precursor acute leukemias. If these antileukemia CTL are to be used for adoptive immunotherapy, they must have the capability to circulate, migrate through endothelium, home to the bone marrow, and, most importantly, lyse the leukemic cells in a leukemia-permissive bone marrow microenvironment. We demonstrate here that such antileukemia T-cell lines are overwhelmingly CD8+ and exhibit an activated phenotype. Using a transendothelial chemotaxis assay with human endothelial cells, we observed that these T cells can be recruited and transmigrate through vascular and bone marrow endothelium and that these transmigrated cells preserve their capacity to lyse leukemic cells. Additionally, these antileukemia T-cell lines are capable of adhering to autologous stromal cell layers. Finally, autologous antileukemia CTL specifically lyse leukemic cells even in the presence of autologous marrow stroma. Importantly, these antileukemia T-cell lines do not lyse autologous stromal cells. Thus, the capacity to generate anti–leukemia-specific T-cell lines coupled with the present findings that such cells can migrate, adhere, and function in the presence of the marrow microenvironment enable the development of clinical studies of adoptive transfer of antileukemia CTL for the treatment of ALL.


Blood ◽  
2004 ◽  
Vol 103 (4) ◽  
pp. 1438-1444 ◽  
Author(s):  
Tjadine M. Holling ◽  
Erik Schooten ◽  
Anton W. Langerak ◽  
Peter J. van den Elsen

Abstract Expression of major histocompatibility complex (MHC) class II molecules in human activated T cells is under normal circumstances regulated exclusively by the CIITA-PIII subtype of the class II transactivator (CIITA). In this study, we show that the absence of MHC class II expression in leukemic T cells was due to a lack of expression of CIITA, whereas in T-lymphoma cells, expression of CIITA correlated with expression of MHC class II. Interestingly, activation of a CIITA-promoter (P)III–reporter construct was not affected in leukemic T cells. This revealed that the absence of endogenous CIITA expression was not caused by a lack of transcription factors critical for CIITA-PIII activation but suggests the involvement of an epigenetic silencing mechanism. Subsequent analysis showed that the lack of human leukocyte antigen–DR (HLA-DR) expression correlated with hypermethylation of CIITA-PIII in leukemic T-cell lines and in primary T-cell acute lymphoblastic leukemia (T-ALL) and a T-cell prolymphocytic leukemia (T-PLL). Treatment of leukemic T-cell lines with a demethylation agent showed re-expression of CIITA-PIII and HLA-DRA. Furthermore, in vitro methylation of CIITA-PIII and subsequent assessment of CIITA-PIII activity in Jurkat leukemic T cells resulted in reduction of constitutive and CREB-1 (cyclic adenosine monophosphate [cAMP]–response element binding protein 1)–induced promoter activity. Together, these results argue for an important role of DNA hyper-methylation in the control of CIITA expression in leukemic T cells.


2008 ◽  
Vol 82 (8) ◽  
pp. 3843-3852 ◽  
Author(s):  
Masanori Baba ◽  
Mika Okamoto ◽  
Takayuki Hamasaki ◽  
Sawako Horai ◽  
Xin Wang ◽  
...  

ABSTRACT Human T-lymphotropic virus type 1 (HTLV-1) is the etiologic agent of adult T-cell leukemia (ATL). In Japan, the number of HTLV-1 carriers is estimated to be 1.2 million and more than 700 cases of ATL have been diagnosed every year. Considering the poor prognosis and lack of curative therapy of ATL, it seems mandatory to establish an effective strategy for the treatment of ATL. In this study, we attempted to identify the cell surface molecules that will become suitable targets of antibodies for anti-ATL therapy. The expression levels of approximately 40,000 host genes of three human T-cell lines carrying HTLV-1 genomes were analyzed by oligonucleotide microarray and compared with the expression levels of the genes in an HTLV-1-negative T-cell line. The HTLV-1-carrying T-cell lines used for experiments had totally different expression patterns of viral genome. Among the genes evaluated, the expression levels of 108 genes were found to be enhanced more than 10-fold in all of the T-cell lines examined and 11 of the 108 genes were considered to generate the proteins expressed on the cell surface. In particular, the CD70 gene was upregulated more than 1,000-fold and the enhanced expression of the CD70 molecule was confirmed by laser flow cytometry for various HTLV-1-carrying T-cell lines and primary CD4+ T cells isolated from acute-type ATL patients. Such expression was not observed for primary CD4+ T cells isolated from healthy donors. Since CD70 expression is strictly restricted in normal tissues, such as highly activated T and B cells, CD70 appears to be a potential target for effective antibody therapy against ATL.


2005 ◽  
Vol 12 (3) ◽  
pp. 203-209 ◽  
Author(s):  
Mathilda Mandel ◽  
Michael Gurevich ◽  
Gad Lavie ◽  
Irun R. Cohen ◽  
Anat Achiron

Multiple sclerosis (MS) is an autoimmune disease where T-cells activated against myelin antigens are involved in myelin destruction. Yet, healthy subjects also harbor T-cells responsive to myelin antigens, suggesting that MS patient-derived autoimmune T-cells might bear functional differences from T-cells derived from healthy individuals. We addressed this issue by analyzing gene expression patterns of myelin oligodendrocytic glycoprotein (MOG) responsive T-cell lines generated from MS patients and healthy subjects. We identified 150 transcripts that were differentially expressed between MS patients and healthy controls. The most informative 43 genes exhibited >1.5-fold change in expression level. Eighteen genes were up-regulated including BCL2, lifeguard, IGFBP3 and VEGF. Twenty five genes were down-regulated, including apoptotic activators like TNF and heat shock protein genes. This gene expression pattern was unique to MOG specific T-cell lines and was not expressed in T-cell lines reactive to tetanus toxin (TTX). Our results indicate that activation in MS that promotes T-cell survival and expansion, has its own state and that the unique gene expression pattern that characterize autoreactive T-cells in MS represent a constellation of factors in which the chronicity, timing and accumulation of damage make the difference between health and disease.


Blood ◽  
2006 ◽  
Vol 109 (8) ◽  
pp. 3325-3332 ◽  
Author(s):  
Anders Woetmann ◽  
Paola Lovato ◽  
Karsten W. Eriksen ◽  
Thorbjørn Krejsgaard ◽  
Tord Labuda ◽  
...  

AbstractBacterial toxins including staphylococcal enterotoxins (SEs) have been implicated in the pathogenesis of cutaneous T-cell lymphomas (CTCLs). Here, we investigate SE-mediated interactions between nonmalignant T cells and malignant T-cell lines established from skin and blood of CTCL patients. The malignant CTCL cells express MHC class II molecules that are high-affinity receptors for SE. Although treatment with SE has no direct effect on the growth of the malignant CTCL cells, the SE-treated CTCL cells induce vigorous proliferation of the SE-responsive nonmalignant T cells. In turn, the nonmalignant T cells enhance proliferation of the malignant cells in an SE- and MHC class II–dependent manner. Furthermore, SE and, in addition, alloantigen presentation by malignant CTCL cells to irradiated nonmalignant CD4+ T-cell lines also enhance proliferation of the malignant cells. The growth-promoting effect depends on direct cell-cell contact and soluble factors such as interleukin-2. In conclusion, we demonstrate that SE triggers a bidirectional cross talk between nonmalignant T cells and malignant CTCL cells that promotes growth of the malignant cells. This represents a novel mechanism by which infections with SE-producing bacteria may contribute to pathogenesis of CTCL.


2004 ◽  
Vol 26 (5) ◽  
pp. 243-246 ◽  
Author(s):  
W. Tuo ◽  
W. C. Davis ◽  
R. Fetterer ◽  
M. Jenkins ◽  
P. C. Boyd ◽  
...  

Blood ◽  
2003 ◽  
Vol 102 (12) ◽  
pp. 4130-4136 ◽  
Author(s):  
Hye-Kyung Chung ◽  
Howard A. Young ◽  
Peter K. C. Goon ◽  
Gisela Heidecker ◽  
Gerald L. Princler ◽  
...  

Abstract Human T-cell leukemia virus type 1 (HTLV-1) infection profoundly alters T-cell gene expression, and the dysregulated synthesis of cytokines could influence the course and pathologic consequences of infection. In the process of screening T-cell lines for T helper 1 (Th1) and Th2 cytokine mRNAs, we observed that interleukin-13 (IL-13) mRNA was highly expressed in HTLV-1-infected, IL-2-dependent T-cell lines. IL-9 and interferon gamma (IFN-γ) mRNAs were also expressed at high levels in chronically infected cell lines. IL-5 mRNA was detected in 60% of the HTLV-1-infected cell lines, but mRNAs for IL-4, IL-10, IL-2, and IL-15 were either below detection limits or did not correlate with HTLV-1 infection. Transcriptional activation of the IL-13 promoter by the HTLV-1 Tax trans-regulatory protein was demonstrated in Jurkat T cells transiently transfected with an IL-13 promoter-reporter plasmid. The clinical relevance of these observations was demonstrated by immunofluorescent staining and flow cytometry of lymphocytes obtained from HTLV-1-infected patients. These studies revealed that IL-13 production was directly related to the level of Tax expression in the infected CD4+ T cells soon after in vitro culture. As IL-13 plays key roles in tumor immunosurveillance, asthma, and central nervous system inflammation, it may contribute to the pathophysiology of HTLV-1-associated diseases. (Blood. 2003;102:4130-4136)


2012 ◽  
Vol 93 (11) ◽  
pp. 2399-2407 ◽  
Author(s):  
Mohammed A. Sarhan ◽  
Annie Y. Chen ◽  
Rodney S. Russell ◽  
Tomasz I. Michalak

Hepatitis C virus (HCV) is a hepatotropic virus that also infects cells of the immune system. HCV clones cultivated in human hepatoma Huh-7.5 cells have significantly advanced our understanding of HCV replication and candidate hepatocyte receptors. However, naturally occurring patient-derived HCV, in contrast to the HCV JFH-1 clone, is unable to infect Huh-7.5 cells, while it can replicate in human primary T-cells and selected T-cell lines. To better understand this incongruity, we examined the susceptibility of primary T-cells, PBMCs and T-cell lines to infection with patient-derived HCV, the classical HCV JFH-1 and a cell culture-adapted JFH1T known to be highly infectious to Huh-7.5 cells. We also tested whether Huh-7.5 cells are prone to virus readily infecting T-lymphocytes. The results revealed that while primary T-cells and Molt4 and Jurkat T-cell lines were susceptible to patient-derived HCV, they were resistant to infection with either JFH1T or JFH-1. However, the JFH1T clone interacted more firmly, although non-productively, with the cells than JFH-1. Further, Huh-7.5 cells robustly supported replication of JFH1T but not patient-derived, wild-type virus, despite using highly sensitive detection assays. In conclusion, JFH-1 and JFH1T clones were unable to establish productive infection in human primary T-cells, PBMCs and T-cell lines known to be prone to infection by patient-derived HCV, while Huh-7.5 cells were resistant to infection with naturally occurring virus infecting immune cells. The data showed that the ability to infect lymphocytes is a characteristic of native virus but not laboratory HCV clones.


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