scholarly journals Stepwise progression of β-selection during T cell development as revealed by histone deacetylation inhibition

2021 ◽  
Author(s):  
Anchi S Chann ◽  
Mirren Charnley ◽  
Lucas Newton ◽  
Andrea Newbold ◽  
Patrick O O Humbert ◽  
...  
Keyword(s):  
T Cell ◽  
Genetic Recombination ◽  
T Cell Development ◽  
Cell Receptor ◽  
Cell Development ◽  
Histone Deacetylation ◽  
Histone Deacetylase 6 ◽  
Functional Connection ◽  
The Impact ◽  
Tcr Signalling

During T cell development, the first step in creating a unique T Cell Receptor (TCR) is the genetic recombination of the TCRβ chain. The quality of this newly recombined gene is assessed at the β-selection checkpoint, and most cells fail this checkpoint and are removed. The coordination of the complex events that combine to control fate at the β-selection checkpoint is not yet understood. We assessed the impact on T cell development of a selective inhibitor to histone deacetylase 6, ACY1215, currently in clinical use. ACY1215 led to bypass of the β-selection checkpoint such that cells in the DN4 stage often lacked expression of TCRβ, and failed to progress to the DP stage. Characterisation of the molecular basis for this bypass revealed a new, pivotal stage in β-selection, the beginning and end of which were defined by the upregulation of the TCR co-receptors, CD28 and CD2 respectively. Within this stage, termed DN3bPre, CD5 and Lef1 are upregulated to reflect pre-TCR signalling. We propose that the progressive expression of CD28, CD5 then CD2 reports and modulates the pre-TCR signal to orchestrate passage through the β-selection checkpoint. By disrupting the functional connection between CD5 and pre-TCR, ACY1215 allows cells to inappropriately bypass the β-selection checkpoint. These findings implicate a refined model of β-selection in which a coordinated increase in expression of pre-TCR, CD5 and Lef1 provides for an escalating test of TCR signalling strength, and culminates in the expression of CD2 to enable exit from the β-selection checkpoint.

scholarly journals Deletion of the mouse T-cell receptor beta gene enhancer blocks alphabeta T-cell development.

1996 ◽  
Vol 93 (15) ◽  
pp. 7877-7881 ◽  
Author(s):  
G. Bouvier ◽  
F. Watrin ◽  
M. Naspetti ◽  
C. Verthuy ◽  
P. Naquet ◽  
...  
Keyword(s):  
T Cell ◽  
T Cell Receptor ◽  
T Cell Development ◽  
Cell Receptor ◽  
Cell Development ◽  
Gene Enhancer ◽  
T Cell Receptor Beta ◽  
Beta Gene ◽  
Receptor Beta

Loss of Function of the Homeobox Gene Hoxa-9 Perturbs Early T-Cell Development and Induces Apoptosis in Primitive Thymocytes

Blood ◽  
1998 ◽  
Vol 92 (2) ◽  
pp. 383-393 ◽  
Author(s):  
David J. Izon ◽  
Sofia Rozenfeld ◽  
Stephen T. Fong ◽  
László Kömüves ◽  
Corey Largman ◽  
...  
Keyword(s):  
T Cell ◽  
Hox Genes ◽  
Apoptotic Cell ◽  
T Cell Development ◽  
Interleukin 2 ◽  
Homeobox Gene ◽  
Cell Receptor ◽  
Cell Development ◽  
Loss Of Function ◽  
Double Positive

Abstract Hox homeobox genes play a crucial role in specifying the embryonic body pattern. However, a role for Hox genes in T-cell development has not been explored. The Hoxa-9 gene is expressed in normal adult and fetal thymuses. Fetal thymuses of mice homozygous for an interruption of the Hoxa-9 gene are one eighth normal size and have a 25-fold decrease in the number of primitive thymocytes expressing the interleukin-2 receptor (IL-2R, CD25). Progression to the double positive (CD4+CD8+) stage is dramatically retarded in fetal thymic organ cultures. This aberrant development is associated with decreased amounts of intracellular CD3 and T-cell receptor β (TCRβ) and reduced surface expression of IL-7R and E-cadherin. Mutant thymocytes show a significant increase in apoptotic cell death and premature downregulation of bcl-2 expression. A similar phenotype is seen in primitive thymocytes from adult Hoxa-9−/− mice and from mice transplanted with Hoxa-9−/−marrow. Hoxa-9 appears to play a previously unsuspected role in T-cell ontogeny by modulating cell survival of early thymocytes and by regulating their subsequent differentiation.

scholarly journals Development of a diverse human T-cell repertoire despite stringent restriction of hematopoietic clonality in the thymus

2015 ◽  
Vol 112 (44) ◽  
pp. E6020-E6027 ◽  
Author(s):  
Martijn H. Brugman ◽  
Anna-Sophia Wiekmeijer ◽  
Marja van Eggermond ◽  
Ingrid Wolvers-Tettero ◽  
Anton W. Langerak ◽  
...  
Keyword(s):  
T Cell ◽  
T Cell Development ◽  
Xenograft Model ◽  
Subsequent Development ◽  
Cell Receptor ◽  
Cell Development ◽  
Cell Repertoire ◽  
Hematopoietic Stem ◽  
Human T Cell ◽  
Hsc Transplantation

The fate and numbers of hematopoietic stem cells (HSC) and their progeny that seed the thymus constitute a fundamental question with important clinical implications. HSC transplantation is often complicated by limited T-cell reconstitution, especially when HSC from umbilical cord blood are used. Attempts to improve immune reconstitution have until now been unsuccessful, underscoring the need for better insight into thymic reconstitution. Here we made use of the NOD-SCID-IL-2Rγ−/− xenograft model and lentiviral cellular barcoding of human HSCs to study T-cell development in the thymus at a clonal level. Barcoded HSCs showed robust (>80% human chimerism) and reproducible myeloid and lymphoid engraftment, with T cells arising 12 wk after transplantation. A very limited number of HSC clones (<10) repopulated the xenografted thymus, with further restriction of the number of clones during subsequent development. Nevertheless, T-cell receptor rearrangements were polyclonal and showed a diverse repertoire, demonstrating that a multitude of T-lymphocyte clones can develop from a single HSC clone. Our data imply that intrathymic clonal fitness is important during T-cell development. As a consequence, immune incompetence after HSC transplantation is not related to the transplantation of limited numbers of HSC but to intrathymic events.

scholarly journals Inactivation of c-Cbl Reverses Neonatal Lethality and T Cell Developmental Arrest of SLP-76–deficient Mice

2004 ◽  
Vol 200 (1) ◽  
pp. 25-34 ◽  
Author(s):  
Y. Jeffrey Chiang ◽  
Connie L. Sommers ◽  
Martha S. Jordan ◽  
Hua Gu ◽  
Lawrence E. Samelson ◽  
...  
Keyword(s):  
Signal Transduction ◽  
T Cells ◽  
T Cell ◽  
T Cell Development ◽  
Adaptor Protein ◽  
Premature Death ◽  
Cell Receptor ◽  
Cell Development ◽  
Neonatal Lethality ◽  
Deficient Mice

c-Cbl is an adaptor protein that negatively regulates signal transduction events involved in thymic-positive selection. To further characterize the function of c-Cbl in T cell development, we analyzed the effect of c-Cbl inactivation in mice deficient in the scaffolding molecule SLP-76. SLP-76–deficient mice show a high frequency of neonatal lethality; and in surviving mice, T cell development is blocked at the DN3 stage. Inactivation of c-cbl completely reversed the neonatal lethality seen in SLP-76–deficient mice and partially reversed the T cell development arrest in these mice. SLP-76−/− Cbl−/− mice exhibited marked expansion of polarized T helper type (Th)1 and Th2 cell peripheral CD4+ T cells, lymphoid infiltrates of parenchymal organs, and premature death. This rescue of T cell development is T cell receptor dependent because it does not occur in recombination activating gene 2−/− SLP-76−/− Cbl−/− triple knockout mice. Analysis of the signal transduction properties of SLP-76−/− Cbl−/− T cells reveals a novel SLP-76– and linker for activation of T cells–independent pathway of extracellular signal–regulated kinase activation, which is normally down-regulated by c-Cbl.

scholarly journals Signal-Transducing Adaptor Molecules STAM1 and STAM2 Are Required for T-Cell Development and Survival

2002 ◽  
Vol 22 (24) ◽  
pp. 8648-8658 ◽  
Author(s):  
Mitsuhiro Yamada ◽  
Naoto Ishii ◽  
Hironobu Asao ◽  
Kazuko Murata ◽  
Chieko Kanazawa ◽  
...  
Keyword(s):  
T Cell ◽  
Protein Kinase ◽  
Double Mutant ◽  
T Cell Development ◽  
Interleukin 2 ◽  
Cell Receptor ◽  
Cell Development ◽  
Mitogen Activated Protein Kinase ◽  
Calcium Flux ◽  
Mitogen Activated Protein

ABSTRACT We previously reported that the STAM family members STAM1 and STAM2 are phosphorylated on tyrosine upon stimulation with cytokines through the γc-Jak3 signaling pathway, which is essential for T-cell development. Mice with targeted mutations in either STAM1 or STAM2 show no abnormality in T-cell development, and mice with double mutations for STAM1 and STAM2 are embryonically lethal; therefore, here we generated mice with T-cell-specific double mutations for STAM1 and STAM2 using the Cre/loxP system. These STAM1−/− STAM2−/− mice showed a significant reduction in thymocytes and a profound reduction in peripheral mature T cells. In proliferation assays, thymocytes derived from the double mutant mice showed a defective response to T-cell-receptor (TCR) stimulation by antibodies and/or cytokines, interleukin-2 (IL-2) and IL-7. However, signaling events downstream of receptors for IL-2 and IL-7, such as activations of STAT5, extracellular signal-regulated kinase (ERK), and protein kinase B (PKB)/Akt, and c-myc induction, were normal in the double mutant thymocytes. Upon TCR-mediated stimulation, prolonged activations of p38 mitogen-activated protein kinase and Jun N-terminal protein kinase were seen, but activations of ERK, PKB/Akt, and intracellular calcium flux were normal in the double mutant thymocytes. When the cell viability of cultured thymocytes was assessed, the double mutant thymocytes died more quickly than controls. These results demonstrate that the STAMs are indispensably involved in T-cell development and survival in the thymus through the prevention of apoptosis but are dispensable for the proximal signaling of TCR and cytokine receptors.

T cell development and repertoire of mice expressing a single T cell receptor α chain

1995 ◽  
Vol 25 (9) ◽  
pp. 2650-2655 ◽  
Author(s):  
Daniel Brändle ◽  
Karin Brduscha-Riem ◽  
Adrian C. Hayday ◽  
Michael J. Owen ◽  
Hans Hengartner ◽  
...  
Keyword(s):  
T Cell ◽  
T Cell Receptor ◽  
T Cell Development ◽  
Cell Receptor ◽  
Cell Development ◽  
Α Chain

scholarly journals Functions of E2A-HEB Heterodimers in T-Cell Development Revealed by a Dominant Negative Mutation of HEB

2000 ◽  
Vol 20 (18) ◽  
pp. 6677-6685 ◽  
Author(s):  
Robert J. Barndt ◽  
Meifang Dai ◽  
Yuan Zhuang
Keyword(s):  
T Cell ◽  
Target Genes ◽  
T Cell Development ◽  
Cell Lineage ◽  
Cell Receptor ◽  
Cell Development ◽  
Dominant Negative ◽  
Helix Loop Helix ◽  
Dominant Negative Mutation ◽  
Bhlh Proteins

ABSTRACT Lymphocyte development and differentiation are regulated by the basic helix-loop-helix (bHLH) transcription factors encoded by theE2A and HEB genes. These bHLH proteins bind to E-box enhancers in the form of homodimers or heterodimers and, consequently, activate transcription of the target genes. E2A homodimers are the predominant bHLH proteins present in B-lineage cells and are shown genetically to play critical roles in B-cell development. E2A-HEB heterodimers, the major bHLH dimers found in thymocyte extracts, are thought to play a similar role in T-cell development. However, disruption of either the E2A or HEBgene led to only partial blocks in T-cell development. The exact role of E2A-HEB heterodimers and possibly the E2A and HEB homodimers in T-cell development cannot be distinguished in simple disruption analysis due to a functional compensation from the residual bHLH homodimers. To further define the function of E2A-HEB heterodimers, we generated and analyzed a dominant negative allele of HEB, which produces a physiological amount of HEB proteins capable of forming nonfunctional heterodimers with E2A proteins. Mice carrying this mutation show a stronger and earlier block in T-cell development than HEB complete knockout mice. The developmental block is specific to the α/β T-cell lineage at a stage before the completion of V(D)J recombination at the TCRβ gene locus. This defect is intrinsic to the T-cell lineage and cannot be rescued by expression of a functional T-cell receptor transgene. These results indicate that E2A-HEB heterodimers play obligatory roles both before and after TCRβ gene rearrangement during the α/β lineage T-cell development.

scholarly journals Rearrangement of T-cell receptor beta-chain genes during T-cell development.

1985 ◽  
Vol 82 (9) ◽  
pp. 2925-2929 ◽  
Author(s):  
W. Born ◽  
J. Yague ◽  
E. Palmer ◽  
J. Kappler ◽  
P. Marrack
Keyword(s):  
T Cell ◽  
T Cell Receptor ◽  
T Cell Development ◽  
Cell Receptor ◽  
Cell Development ◽  
Beta Chain ◽  
T Cell Receptor Beta ◽  
Beta Chain Genes ◽  
Receptor Beta

Prognostic Significance of Molecular-Cytogenetic Abnormalities in Pediatric T-ALL Is Not Explained by Immunophenotypic Differences.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 4220-4220
Author(s):  
Martine van Grotel ◽  
Anton W. Langerak ◽  
H. Berna Beverloo ◽  
Jessica G.C.A.M. Buijs-Gladdines ◽  
Nicole B. Burger ◽  
...  
Keyword(s):  
T Cell ◽  
T Cell Receptor ◽  
T Cell Development ◽  
Prognostic Significance ◽  
Cell Receptor ◽  
Cell Development ◽  
Cytogenetic Abnormalities ◽  
Molecular Cytogenetic ◽  
Poor Outcome ◽  
Notch1 Mutations

Abstract Pediatric T-cell acute lymphoblastic leukemia (T-ALL) is characterized by recurrent chromosomal rearrangements that may have prognostic significance. T-ALL cases with specific aberrations may arrest at specific T-cell development stages. Two classification systems were developed to classify T-ALL into developmental subgroups, i.e. the European Group for the Immunological Characterization of Leukemias (EGIL) and the T-cell receptor (TCR) classification system. In this study, we investigated the relationship between molecular-cytogenetic abnormalities and T-cell development stage. We investigated whether arrest at specific T-cell stages explains the prognostic significance of molecular-cytogenetic abnormalities. To this aim, we extensively studied 72 pediatric T-ALL cases by FISH and RQ-PCR for the presence of genetic abnormalities and expression of transcription factors, by PCR and sequencing for NOTCH1 mutations and by flow-cytometry to determine the T-cell receptor status as well as CD marker expression. The median clinical follow-up was 5 years. HOX11 rearranged cases were CD1 positive consistent with a cortical stage, but as 4 out of 5 cases lacked cytoplasmatic-beta expression, developmental arrest may precede beta-selection. HOX11L2 was especially confined to immature and pre-AB developmental stages, but 3 out of 17 HOX11L2 mature cases were restricted to the γδ-lineage. TAL1 rearrangements were restricted to the αβ-lineage with most cases being TCRαβ positive. NOTCH1 mutations were present in all molecular-cytogenetic subgroups without restriction to a specific developmental stage. The CALM-AF10 translocation as detected in 3 T-ALL patients was significantly associated with early relapse. TAL1 or HOX11L2 rearrangements were associated with trends to good and poor outcome, respectively. Cases with high TAL1 expression levels also demonstrated a trend towards good outcome, whereas cases with the lowest TAL1 levels had a poor outcome and were mostly HOX11L2 or CALM-AF10 positive. NOTCH1 mutations did not predict for poor outcome. Classification into T-cell developmental subgroups did not predict for outcome. In conclusion, the present study shows that differences in outcome for various molecular-cytogenetic subgroups cannot be attributed to differences in T-cell maturation stage.

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