scholarly journals Stage-specific action of Runx1 and GATA3 controls silencing of PU.1 expression in mouse pro–T cells

2021 ◽  
Vol 218 (8) ◽  
Author(s):  
Hiroyuki Hosokawa ◽  
Maria Koizumi ◽  
Kaori Masuhara ◽  
Maile Romero-Wolf ◽  
Tomoaki Tanaka ◽  
...  
Keyword(s):  
T Cells ◽  
Transcription Factor ◽  
Transcription Factors ◽  
T Cell ◽  
Cell Line ◽  
Functional Site ◽  
Lineage Commitment ◽  
Factor Binding ◽  
Ets Family ◽  
Intron 2

PU.1 (encoded by Spi1), an ETS-family transcription factor with many hematopoietic roles, is highly expressed in the earliest intrathymic T cell progenitors but must be down-regulated during T lineage commitment. The transcription factors Runx1 and GATA3 have been implicated in this Spi1 repression, but the basis of the timing was unknown. We show that increasing Runx1 and/or GATA3 down-regulates Spi1 expression in pro–T cells, while deletion of these factors after Spi1 down-regulation reactivates its expression. Leveraging the stage specificities of repression and transcription factor binding revealed an unconventional but functional site in Spi1 intron 2. Acute Cas9-mediated deletion or disruption of the Runx and GATA motifs in this element reactivates silenced Spi1 expression in a pro–T cell line, substantially more than disruption of other candidate elements, and counteracts the repression of Spi1 in primary pro–T cells during commitment. Thus, Runx1 and GATA3 work stage specifically through an intronic silencing element in mouse Spi1 to control strength and maintenance of Spi1 repression during T lineage commitment.

scholarly journals Precise developmental regulation of Ets family transcription factors during specification and commitment to the T cell lineage

Development ◽  
1999 ◽  
Vol 126 (14) ◽  
pp. 3131-3148 ◽  
Author(s):  
M.K. Anderson ◽  
G. Hernandez-Hoyos ◽  
R.A. Diamond ◽  
E.V. Rothenberg
Keyword(s):  
Transcription Factors ◽  
T Cell ◽  
B Cell ◽  
Developmental Stages ◽  
Developmental Regulation ◽  
Hematopoietic Cells ◽  
Cell Lineage ◽  
Lineage Commitment ◽  
Lineage Specification ◽  
Ets Family

Ets family transcription factors control the expression of a large number of genes in hematopoietic cells. Here we show strikingly precise differential expression of a subset of these genes marking critical, early stages of mouse lymphocyte cell-type specification. Initially, the Ets family member factor Erg was identified during an arrayed cDNA library screen for genes encoding transcription factors expressed specifically during T cell lineage commitment. Multiparameter fluorescence-activated cell sorting for over a dozen cell surface markers was used to isolate 18 distinct primary-cell populations representing discrete T cell and B cell developmental stages, pluripotent lymphoid precursors, immature NK-like cells and myeloid hematopoietic cells. These populations were monitored for mRNA expression of the Erg, Ets-1, Ets-2, Fli-1, Tel, Elf-1, GABPalpha, PU.1 and Spi-B genes. The earliest stages in T cell differentiation show particularly dynamic Ets family gene regulation, with sharp transitions in expression correlating with specification and commitment events. Ets, Spi-B and PU.1 are expressed in these stages but not by later T-lineage cells. Erg is induced during T-lineage specification and then silenced permanently, after commitment, at the beta-selection checkpoint. Spi-B is transiently upregulated during commitment and then silenced at the same stage as Erg. T-lineage commitment itself is marked by repression of PU.1, a factor that regulates B-cell and myeloid genes. These results show that the set of Ets factors mobilized during T-lineage specification and commitment is different from the set that maintains T cell gene expression during thymocyte repertoire selection and in all classes of mature T cells.

scholarly journals Histone Deacetylase 11 (HDAC11) Interaction with Ikaros Represent a Novel Mechanism of Regulation of Essential Transcriptional Factors in CD4+ T Cells

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 864-864
Author(s):  
Jie Chen ◽  
Fengdong Cheng ◽  
David Michael Woods ◽  
Edward Seto ◽  
Alejandro Villagra ◽  
...  
Keyword(s):  
T Cells ◽  
Transcription Factor ◽  
Transcription Factors ◽  
T Cell ◽  
Histone Deacetylase ◽  
Transcriptional Activity ◽  
Gene Promoter ◽  
Epigenetic Mechanism ◽  
Gene Promoters ◽  
H3 Acetylation

Abstract Histone deacetylase 11 (HDAC11), the most recently identified histone deacetylase, is the sole member of class IV HDACs [1]. Since its discovery, no biological function was assigned to this HDAC until we demonstrated its central role in negatively regulating IL-10 production in antigen presenting cells (APCs) [2]. More recently, we have found that disruption of HDAC11 in T cells is associated with an enhanced pro-inflammatory cytokine profile and effector molecule production. Furthermore, T-cells lacking HDAC11 were less susceptible to regulatory T-cell (Treg) suppression in vitro, were refractory to tolerance induction in vivo and displayed enhanced allo-reactivity and anti-tumor responses in murine models. Of note, T-cells lacking HDAC11 expressed higher levels of the transcription factors Eomes and Tbet. Conversely, overexpression of HDAC11 in T-cells decreased the expression of both transcription factors. The molecular mechanism(s) by which HDAC11 regulates the expression of these transcription factors have remained unknown. By using chromatin immunoprecipitation (ChIP) assay we found that in resting T-cells HDAC11 is present at the Eomes and Tbet gene promoters where it maintains histone deacetylation, a compacted chromatin and gene repression. Following T-cell stimulation, HDAC11 was largely absent from both promoters, which resulted in increased histone 3 (H3) acetylation and gene transcriptional activity. These findings were confirmed in T-cells isolated from HDAC11 knock out (KO) mice which also displayed an increase in H3 acetylation at the Tbet and Eomes gene promoter regions. Conversely, H3 acetylation was decreased in both gene promoters in T-cells overexpressing HDAC11 as compared to empty-vector transfected cells. Given that HDACs do not bind to DNA, we asked next which transcription factor(s) HDAC11 might be associated with, in order to regulate Tbet and Eomes gene transcriptional activity. In prior studies we have found that HDAC11 form a molecular complex with another member of the HDAC family, HDAC6, which physically interacts with the transcription factor, STAT3 in both the cytoplasmic and nuclear compartments. However, in T-cells no direct interaction of HDAC11 with STAT3 was detected in either compartment. In contrast, we found for the first time that HDAC11 physically associates with Ikaros (Ikzf1), a member of the Ikaros zinc finger transcription factor family that has been previously implicated in the regulation of T-bet gene expression and IFN-g production in T-cells [3-5]. The protein complex HDAC11-Ikaros was mainly detected in the nuclear compartment and both proteins were present at the T-bet gene promoter. Collectively, these results point to the HDAC11-Ikaros complex as a novel epigenetic mechanism of regulation of Tbet and Eomes, transcription factors that are essential for T cell development and function. Disclosures Woods: BMS: Other: Stock; HDAC11: Patents & Royalties: Patent for targeting HDAC11; Lion Biotech: Other: Stock.

scholarly journals CBF, Myb, and Ets Binding Sites Are Important for Activity of the Core I Element of the Murine Retrovirus SL3-3 in T Lymphocytes

1998 ◽  
Vol 72 (4) ◽  
pp. 3129-3137 ◽  
Author(s):  
Ari L. Zaiman ◽  
Angel Nieves ◽  
Jack Lenz
Keyword(s):  
T Cells ◽  
Transcription Factor ◽  
Transcription Factors ◽  
T Lymphocytes ◽  
Binding Site ◽  
Binding Sites ◽  
Transcriptional Activity ◽  
Long Terminal Repeats ◽  
The Core ◽  
Ets Family

ABSTRACT Transcriptional enhancers within the long terminal repeats of murine leukemia viruses are major determinants of the pathogenic properties of these viruses. Mutations were introduced into the adjacent binding sites for three transcription factors within the enhancer of the T-cell-lymphomagenic virus SL3-3. The sites that were tested were, in 5′-to-3′ order, a binding site for core binding factor (CBF) called core II, a binding site for c-Myb, a site that binds members of the Ets family of factors, and a second CBF binding site called core I. Mutation of each site individually reduced transcriptional activity in T lymphocytes. However, mutation of the Myb and core I binding sites had larger effects than mutation of the Ets or core II site. The relative effects on transcription in T cells paralleled the effects of the same mutations on viral lymphomagenicity, consistent with the idea that the role of these sequences in viral lymphomagenicity is indeed to regulate transcription in T cells. Mutations were also introduced simultaneously into multiple sites in the SL3-3 enhancer. The inhibitory effects of these mutations indicated that the transcription factor in T cells that recognizes the core I element of SL3-3, presumably CBF, needed to synergize with one or more factors bound at the upstream sites to function. This was tested further by generating a multimer construct that contained five tandem core I elements linked to a basal long terminal repeat promoter. This construct was inactive in T cells. However, transcriptional activity was detected with a multimer construct in which the transcription factor binding sites upstream of the core were also present. These results are consistent with the hypothesis that CBF requires heterologous transcription factors bound at nearby sites to function in T cells.

183 Overcoming immunotherapy resistance in T cell-inflamed lung cancer

2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A197-A197
Author(s):  
Brendan Horton ◽  
Brendan Horton ◽  
Duncan Morgan ◽  
Noor Momin ◽  
Vidit Bhandarkar ◽  
...  
Keyword(s):  
Lung Cancer ◽  
T Cells ◽  
T Cell ◽  
Cell Line ◽  
Cancer Patients ◽  
Rna Sequencing ◽  
Mechanistic Study ◽  
Nsclc Cell Line ◽  
Effector Molecule ◽  
Effector Molecules

BackgroundTumor infiltrating T cells (TIL) are highly correlated with response to checkpoint blockade immunotherapy (CBT) in melanoma. However, in non-small cell lung cancer (NSCLC), 61% of patients have TIL, but only 32% respond to CBT. It is unknown how these T cell-inflamed tumors are resistant to CBT. Understanding and overcoming this resistance would greatly increase the number of cancer patients who benefit from CBT.MethodsTo understand lung-specific anti-tumor immune responses, a NSCLC cell line derived from an autochthonous murine lung cancer (KP cell line) was transplanted into syngeneic C57BL/6 mice subcutaneously or intravenously. To study antigen-specific responses, the KP cell line was engineered with SIY and 2C TCR transgenic T cells, which are specific for SIY, were adoptively transferred into tumor-bearing animals.ResultsSubcutaneous KP tumors responded to CBT (aCTLA-4 and aPD-L1) with significant tumor regression while lung KP tumors were CBT resistant. Immunohistochemistry found that this was not due to lack of T cell infiltration, as lung tumors contained 10-fold higher numbers of CD8+ TIL than subcutaneous tumors. Single cell RNA sequencing of TIL uncovered that CD8+ TIL in lung lesions had blunted effector molecule expression that correlated with a lack of IL-2 signaling. Adoptive transfer of naïve, tumor-reactive 2C T cells resulted in equally robust T cell proliferation in both the inguinal and mediastinal lymph nodes (LNs). However, RNA sequencing of adoptively transferred 2C T cells isolated 3-days after transfer from draining LNs identified that T cells activated in the mediastinal LN had reduced levels of IL-2 signaling and blunted effector functions early during priming. Flow cytometry confirmed that T cells primed in the mediastinal LNs did not express CD25, GZMB, or IFN-g, while T cells in inguinal LNs upregulated all three of these effector molecules. Delivery of IL-2 and IL-12 during priming was sufficient to restore effector molecule expression on 2C T cells in mediastinal LNs. Analysis of published patient data identified that a subset of lung cancer patients showed a sizable population of CD8+ TIL with low IL-2 signaling and low expression of effector molecules, including common targets of CBT.ConclusionsImmunotherapy resistance in T cell-inflamed tumors is due to defective CD8+ T cell effector differentiation. IL-2-based therapies could enhance differentiation of functional CD8+ effector T cells and could turn immunotherapy resistant tumors to immunotherapy sensitive tumors. This is the first mechanistic study providing evidence for a distinct type of T cell dysfunction resistant to current CBT.Ethics ApprovalThis study was approved by MIT’s Committee on Animal Care, protocol number 0220-006-23.

scholarly journals Evidence for the divergence of innate and adaptive T-cell precursors before commitment to the αβ and γδ lineages

Blood ◽  
2011 ◽  
Vol 118 (25) ◽  
pp. 6591-6600 ◽  
Author(s):  
Jan Kisielow ◽  
Luigi Tortola ◽  
Jacqueline Weber ◽  
Klaus Karjalainen ◽  
Manfred Kopf
Keyword(s):  
T Cells ◽  
T Cell ◽  
Natural Killer ◽  
Negative Selection ◽  
Intraepithelial Lymphocytes ◽  
Lineage Commitment ◽  
Γδt Cells ◽  
Cell Lineages ◽  
Innate T Cells ◽  
Tcr Signals

Abstract In addition to adaptive T cells, the thymus supports the development of unconventional T cells such as natural killer T (NKT) and CD8αα intraepithelial lymphocytes (IELs), which have innate functional properties, particular antigenic specificities, and tissue localization. Both conventional and innate T cells are believed to develop from common precursors undergoing instructive, TCR-mediated lineage fate decisions, but innate T cells are proposed to undergo positive instead of negative selection in response to agonistic TCR signals. In the present study, we show that, in contrast to conventional αβT cells, innate αβT cells are not selected against functional TCRγ rearrangements and express TCRγ mRNA. Likewise, in contrast to the majority of γδT cells, thymic innate γδT cells are not efficiently selected against functional TCRβ chains. In precursors of conventional T cells, autonomous TCR signals emanating from the pre-TCR or γδTCR in the absence of ligand mediate selection against the TCR of the opposite isotype and αβ/γδ lineage commitment. Our data suggest that developing innate T cells ignore such signals and rely solely on agonistic TCR interactions. Consistently, most innate T cells reacted strongly against autologous thymocytes. These results suggest that innate and adaptive T-cell lineages do not develop from the same pool of precursors and potentially diverge before αβ/γδ lineage commitment.

scholarly journals Structure and specificity of T cell receptor gamma/delta on major histocompatibility complex antigen-specific CD3+, CD4-, CD8- T lymphocytes.

1988 ◽  
Vol 168 (5) ◽  
pp. 1899-1916 ◽  
Author(s):  
J A Bluestone ◽  
R Q Cron ◽  
M Cotterman ◽  
B A Houlden ◽  
L A Matis
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Line ◽  
Gene Segment ◽  
Cell Receptor ◽  
Gamma Delta ◽  
Human T Cells ◽  
T Cell Lines ◽  
Gamma Delta T Cell ◽  
Delta Cells

Analyses of TCR-bearing murine and human T cells have defined a unique subpopulation of T cells that express the TCR-gamma/delta proteins. The specificity of TCR-gamma/delta T cells and their role in the immune response have not yet been elucidated. Here we examine alloreactive TCR-gamma/delta T cell lines and clones that recognize MHC-encoded antigens. A BALB/c nu/nu (H-2d)-derived H-2k specific T cell line and derived clones were both cytolytic and released lymphokines after recognition of a non-classical H-2 antigen encoded in the TL region of the MHC. These cells expressed the V gamma 2/C gamma 1 protein in association with a TCR-delta gene product encoded by a Va gene segment rearranged to two D delta and one J delta variable elements. A second MHC-specific B10 nu/nu (H-2b) TCR-gamma/delta T cell line appeared to recognize a classical H-2D-encoded MHC molecule and expressed a distinct V gamma/C gamma 4-encoded protein. These data suggest that many TCR-gamma/delta-expressing T cells may recognize MHC-linked antigens encoded within distinct subregions of the MHC. The role of MHC-specific TCR-gamma/delta cells in immune responses and their immunological significance are discussed.

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