scholarly journals Delta-like 4 is the essential, nonredundant ligand for Notch1 during thymic T cell lineage commitment

2008 ◽  
Vol 205 (11) ◽  
pp. 2515-2523 ◽  
Author(s):  
Ute Koch ◽  
Emma Fiorini ◽  
Rui Benedito ◽  
Valerie Besseyrias ◽  
Karin Schuster-Gossler ◽  
...  
Keyword(s):  
T Cell ◽  
B Cells ◽  
T Cell Development ◽  
Cell Lineage ◽  
Cell Development ◽  
Lineage Commitment ◽  
Thymic Epithelial Cells ◽  
Hematopoietic Progenitors ◽  
Immature B Cells

Thymic T cell lineage commitment is dependent on Notch1 (N1) receptor–mediated signaling. Although the physiological ligands that interact with N1 expressed on thymic precursors are currently unknown, in vitro culture systems point to Delta-like 1 (DL1) and DL4 as prime candidates. Using DL1- and DL4-lacZ reporter knock-in mice and novel monoclonal antibodies to DL1 and DL4, we show that DL4 is expressed on thymic epithelial cells (TECs), whereas DL1 is not detected. The function of DL4 was further explored in vivo by generating mice in which DL4 could be specifically inactivated in TECs or in hematopoietic progenitors. Although loss of DL4 in hematopoietic progenitors did not perturb thymus development, inactivation of DL4 in TECs led to a complete block in T cell development coupled with the ectopic appearance of immature B cells in the thymus. These immature B cells were phenotypically indistinguishable from those developing in the thymus of conditional N1 mutant mice. Collectively, our results demonstrate that DL4 is the essential and nonredundant N1 ligand responsible for T cell lineage commitment. Moreover, they strongly suggest that N1-expressing thymic progenitors interact with DL4-expressing TECs to suppress B lineage potential and to induce the first steps of intrathymic T cell development.

scholarly journals Hierarchy of Notch–Delta interactions promoting T cell lineage commitment and maturation

2007 ◽  
Vol 204 (2) ◽  
pp. 331-343 ◽  
Author(s):  
Valerie Besseyrias ◽  
Emma Fiorini ◽  
Lothar J. Strobl ◽  
Ursula Zimber-Strobl ◽  
Alexis Dumortier ◽  
...  
Keyword(s):  
T Cell ◽  
T Cell Development ◽  
Cell Lineage ◽  
Cell Development ◽  
Lineage Commitment ◽  
Binding Studies ◽  
Maturation In Vitro ◽  
Cell Commitment

Notch1 (N1) receptor signaling is essential and sufficient for T cell development, and recently developed in vitro culture systems point to members of the Delta family as being the physiological N1 ligands. We explored the ability of Delta1 (DL1) and DL4 to induce T cell lineage commitment and/or maturation in vitro and in vivo from bone marrow (BM) precursors conditionally gene targeted for N1 and/or N2. In vitro DL1 can trigger T cell lineage commitment via either N1 or N2. N1- or N2-mediated T cell lineage commitment can also occur in the spleen after short-term BM transplantation. However, N2–DL1–mediated signaling does not allow further T cell maturation beyond the CD25+ stage due to a lack of T cell receptor β expression. In contrast to DL1, DL4 induces and supports T cell commitment and maturation in vitro and in vivo exclusively via specific interaction with N1. Moreover, comparative binding studies show preferential interaction of DL4 with N1, whereas binding of DL1 to N1 is weak. Interestingly, preferential N1–DL4 binding reflects reduced dependence of this interaction on Lunatic fringe, a glycosyl transferase that generally enhances the avidity of Notch receptors for Delta ligands. Collectively, our results establish a hierarchy of Notch–Delta interactions in which N1–DL4 exhibits the greatest capacity to induce and support T cell development.

scholarly journals Delta-like 4 is indispensable in thymic environment specific for T cell development

2008 ◽  
Vol 205 (11) ◽  
pp. 2507-2513 ◽  
Author(s):  
Katsuto Hozumi ◽  
Carolina Mailhos ◽  
Naoko Negishi ◽  
Ken-ichi Hirano ◽  
Takashi Yahata ◽  
...  
Keyword(s):  
T Cell ◽  
Notch Signaling ◽  
Cell Fate ◽  
T Cell Development ◽  
Cell Development ◽  
Thymic Epithelial Cells ◽  
Hematopoietic Progenitors ◽  
Double Positive

The thymic microenvironment is required for T cell development in vivo. However, in vitro studies have shown that when hematopoietic progenitors acquire Notch signaling via Delta-like (Dll)1 or Dll4, they differentiate into the T cell lineage in the absence of a thymic microenvironment. It is not clear, however, whether the thymus supports T cell development specifically by providing Notch signaling. To address this issue, we generated mice with a loxP-flanked allele of Dll4 and induced gene deletion specifically in thymic epithelial cells (TECs). In the thymus of mutant mice, the expression of Dll4 was abrogated on the epithelium, and the proportion of hematopoietic cells bearing the intracellular fragment of Notch1 (ICN1) was markedly decreased. Corresponding to this, CD4 CD8 double-positive or single-positive T cells were not detected in the thymus. Further analysis showed that the double-negative cell fraction was lacking T cell progenitors. The enforced expression of ICN1 in hematopoietic progenitors restored thymic T cell differentiation, even when the TECs were deficient in Dll4. These results indicate that the thymus-specific environment for determining T cell fate indispensably requires Dll4 expression to induce Notch signaling in the thymic immigrant cells.

scholarly journals T-Cell Development: T-cell lineage commitment revisited

1995 ◽  
Vol 5 (8) ◽  
pp. 829-831 ◽  
Author(s):  
Richard Boismenu ◽  
Wendy L. Havran
Keyword(s):  
T Cell ◽  
T Cell Development ◽  
Cell Lineage ◽  
Cell Development ◽  
Lineage Commitment

Driving T Cell Development in the Thymus.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 3860-3860
Author(s):  
Cristina M. Joao ◽  
Brenda M. Ogle ◽  
Marilia Cascalho ◽  
Jeffrey L. Platt
Keyword(s):  
T Cell ◽  
B Cells ◽  
B Cell ◽  
T Cell Development ◽  
Cell Development ◽  
Thymic Epithelial Cells ◽  
P Value ◽  
Tcr Repertoire ◽  
Repertoire Diversity ◽  
Deficient Mice

Abstract Background: Classic reports on lymphocyte development hold that B and T cells develop independently. This concept derives in part from the observation that patients with pure B cell immunodeficiency and hypogammaglobulinemia have a normal thymus and T cell numbers. Our recent findings however challenge this concept. We found that T cell development depends not only on the interaction of T cell precursors with thymic epithelial cells but also on other cells. Here we report that those other cells are B cells. Aims: The purpose of this study was to determine whether B cells drive T cell development and TCR diversification in the thymus. Methods: We compared the number of sub-populations of thymocytes and TCR repertoire diversity in B-cell deficient and B-cell proficient mice and in B cell deficient mice following immunoglobulin (Ig) injections. Total leucocytes numbers were determined with a Coulter counter and numbers of thymocytes sub-populations were calculated by flow cytometry analysis. TCR repertoire diversity was measured by a novel method based on hybridization of TCR Vβ specific cRNA on a gene chip platform. Results: In B-cell deficient mice the number of thymocytes was four times reduced and TCR Vβ chain diversity was up to one million times lower compared with wild type mice. Numbers and diversity were restored by treatment of the mice with gamma globulin (see table). Conclusions: T cell development and diversification is driven by B cells. Mice Number of total thymocytes (mean ± standard deviation) p Value β V TCR diversity of thymocytes (median; min.-max.) p Value C57BL/6 (wild mice) 1.3 x 108 ± 5.1 x 107N=7 4.7 x 106; 1.0 x 105 − 1.1 x 108N=5 JH−/− (B cell immunodeficient mice) 3.1 x 107 ± 1.7 x107N=7 0.002 5.9 x 102; 3.6 x 102 − 1.1 x 103N=5 0.0002 JH−/− treated with Ig 3.9 x 107 ± 1.4 x106N=2 0.20 1.1 x 105; 2.7 x 100 − 7.7 x 105N=4 0.08

CBFB Is Required for Early T Cell Development in the Thymus.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 648-648
Author(s):  
Ling Zhao ◽  
Jennifer L. Cannons ◽  
Stacie Anderson ◽  
Martha R. Kirby ◽  
Liping Xu ◽  
...  
Keyword(s):  
T Cell ◽  
Bone Formation ◽  
Fusion Gene ◽  
T Cell Development ◽  
Cell Lineage ◽  
Cell Development ◽  
Dominant Negative ◽  
Compound Heterozygous ◽  
Thymocyte Development

Abstract Runx1 and Runx3 play important roles in early T cell development. Runx1 is required in the development of double negative cells. Runx1 is also required to repress CD4 expression in DN cells while Runx 3 is essential for epigenetic silencing of CD4 expression in CD8 cells. Both Runx1 and Runx3 are required for CD8 cell development. Because Cbfβ heterodimerizes with both Runx1 and Runx3, we hypothesized that Cbfb is also important in T cell development. To address this issue we analyzed transgenic mouse models with three Cbfb alleles. The first is a null allele for Cbfb and embryos homozygous for this allele die in midgestation due to failure of definitive hematopoiesis and hemorrhage. The second one is a GFP knockin. This Cbfb-GFP allele is a hypomorphic one in that the fusion protein Cbfβ-GFP produced from the allele behaves similarly as the wildtype Cbfβ protein but RNA and protein production from the allele is lower than that of the wildtype allele. Interestingly, AGM hematopoiesis is relatively normal and there is no hemorrhage in the CbfbGFP/GFP embryos, which die at birth due to bone formation defects. The third model is our knock-in mouse model expressing Cbfb-MYH11, the fusion gene found in human AML MeEo with inv (16)(p13; q22). Heterozygous knock-in mice had a phenotype identical to that of the Cbfb and Runx1 null mice, suggesting that the fusion gene Cbfb-MYH11 functions in a dominant-negative manner. We conditionally expressed the Cbfb-MYH11 fusion gene in T cells by using Cre-lox recombination with a floxed Cbfb-MYH11 allele and a Lck-Cre transgene, which starts to express the Cre enzyme at the DN2 stage. By analyzing embryos compound-heterozygous for the null and the hypomorphic GFP knockin alleles (Cbfb−/GFP), we found that CD4 expression was derepressed and thymocyte development was blocked at DN1 and DN2 stages in E17.5 Cbfb−/GFP embryos, which also had much smaller thymi with reduced cellularity compared to their litter mate controls. Further studies on cell proliferation and apoptosis indicated that increased cell death might account for the reduced cellularity. The compound heterozygous Cbfb−/GFP mice died at birth with severe bone formation defects. The Tg(Lck-Cre)/conditional Cbfb-MYH11 mice were viable. In adult thymus, Cbfb-MYH11 expression led to a 10-fold reduction in thymocyte numbers, resulting from both impaired survival of CD4+CD8+ thymocytes (similar as in Cbfb−/GFP embryos) and a differentiation block at DN3 stage. The reduced cellularity could be rescued by over expression of Bcl2 through crossing with Tg(Lck-hBcl2) mice. Cbfb-MYH11 did not derepress CD4 expression in the thymus even though it did so in reporter assays in vitro, which could be due to incomplete Cre-lox reaction, or that Cbfb-MYH11 acts more than just a pure dominant negative. Our data suggest that Cbfβ is critical for several stages of T cell development and may help to explain why CBFB-MYH11+ cells cannot be detected in the T cell lineage in AML patients with this fusion gene.

scholarly journals Dynamic Repositioning of CD4 and CD8 Genes during T Cell Development

2004 ◽  
Vol 200 (11) ◽  
pp. 1427-1435 ◽  
Author(s):  
Stephanie Delaire ◽  
Yina Hsing Huang ◽  
Shaio Wei Chan ◽  
Ellen A. Robey
Keyword(s):  
T Cell ◽  
Current Knowledge ◽  
T Cell Development ◽  
Cell Lineage ◽  
Early Response ◽  
Cell Development ◽  
Gene Repression ◽  
Lineage Commitment ◽  
Stable Gene ◽  
Central Feature

Although stable repression of CD4 and CD8 genes is a central feature of T cell lineage commitment, we lack detailed information about the timing and mechanism of this repression. Stable gene repression has been linked to the position of genes within the nucleus. Therefore, information about the nuclear position of CD4 and CD8 genes during T cell development could provide insights into both the mechanism of regulation of CD4 and CD8 genes, and the process of lineage commitment. Here, we report that lineage-specific repression of CD4 and CD8 genes is associated with the repositioning of alleles close to heterochromatin. We also provide evidence that the relocalization of CD4 and CD8 genes to heterochromatin can occur as an early response to positive selection signals. We discuss our results in terms of our current knowledge of CD4 and CD8 gene regulation and CD4 versus CD8 lineage commitment.

scholarly journals Single-cell perturbation dissects transcription factor control of progression speed and trajectory choice in early T-cell development

2021 ◽  
Author(s):  
Wen Zhou ◽  
Fan Gao ◽  
Maile Romero-Wolf ◽  
Suin Jo ◽  
Ellen V. Rothenberg
Keyword(s):  
T Cell ◽  
Single Cell ◽  
Single Cells ◽  
T Cell Development ◽  
Cell Development ◽  
Lineage Commitment ◽  
Functional Roles ◽  
Two Stages ◽  
Developmental Block

In early T-cell development, single cells dynamically shift expression of multiple transcription factors (TFs) during transition from multipotentiality to T-lineage commitment, but the functional roles of many TFs have been obscure. Here, synchronized in vitro differentiation systems, scRNA-seq with batch indexing, and controlled gene-disruption strategies have unraveled single-cell impacts of perturbing individual TFs at two stages in early T-cell development. Single-cell CRISPR perturbation revealed that early-acting TFs Bcl11a, Erg, Spi1 (PU.1), Gata3, and Tcf7 (TCF1) each play individualized roles promoting or retarding T-lineage progression and suppressing alternative trajectories, collectively determining population dynamics and path topologies. Later, during T-lineage commitment, cells prevented from expressing TF Bcl11b "realized" this abnormality not with a developmental block, but by shifting into a divergent path via bZIP and Sox TF activation as well as E protein antagonism, finally exiting the T-lineage trajectory. These TFs thus exert a network of impacts to control progression kinetics, trajectories, and differentiation outcomes of early pro-T cells.

scholarly journals T Cell Development in TCRβ Enhancer-Deleted Mice: Implications for αβ T Cell Lineage Commitment and Differentiation

2000 ◽  
Vol 165 (3) ◽  
pp. 1364-1373 ◽  
Author(s):  
Isabelle Leduc ◽  
William M. Hempel ◽  
Noëlle Mathieu ◽  
Christophe Verthuy ◽  
Gaëlle Bouvier ◽  
...  
Keyword(s):  
T Cell ◽  
T Cell Development ◽  
Cell Lineage ◽  
Cell Development ◽  
Lineage Commitment

scholarly journals CD45-null transgenic mice reveal a positive regulatory role for CD45 in early thymocyte development, in the selection of CD4+CD8+ thymocytes, and B cell maturation.

1996 ◽  
Vol 183 (4) ◽  
pp. 1707-1718 ◽  
Author(s):  
K F Byth ◽  
L A Conroy ◽  
S Howlett ◽  
A J Smith ◽  
J May ◽  
...  
Keyword(s):  
Signal Transduction ◽  
T Cell ◽  
B Cells ◽  
Transgenic Mice ◽  
B Cell ◽  
T Cell Development ◽  
Cell Development ◽  
Cross Linking ◽  
Thymocyte Development ◽  
Double Positive

The CD45 transmembrane glycoprotein has been shown to be a protein phosphotyrosine phosphatase and to be important in signal transduction in T and B lymphocytes. We have employed gene targeting to create a strain of transgenic mice that completely lacks expression of all isoforms of CD45. The spleens from CD45-null mice contain approximately twice the number of B cells and one fifth the number of T cells found in normal controls. The increase in B cell numbers is due to the specific expansion of two B cell subpopulations that express high levels of immunoglobulin (IgM) staining. T cell development is significantly inhibited in CD45-null animals at two distinct stages. The efficiency of the development of CD4-CD8- thymocytes into CD4+ CD8+ thymocytes is reduced by twofold, subsequently the frequency of successful maturation of the double positive population into mature, single positive thymocytes is reduced by a further four- to fivefold. In addition, we demonstrate that CD45-null thymocytes are severely impaired in their apoptotic response to cross-linking signals via T cell receptor (TCR) in fetal thymic organ culture. In contrast, apoptosis can be induced normally in CD45-null thymocytes by non-TCR-mediated signals. Since both positive and negative selection require signals through the TCR complex, these findings suggest that CD45 is an important regulator of signal transduction via the TCR complex at multiple stages of T cell development. CD45 is absolutely required for the transmission of mitogenic signals via IgM and IgD. By contrast, CD45-null B cells proliferate as well as wild-type cells to CD40-mediated signals. The proliferation of B cells in response to CD38 cross-linking is significantly reduced but not abolished by the CD45-null mutation. We conclude that CD45 is not required at any stage during the generation of mature peripheral B cells, however its loss reveals a previously unrecognized role for CD45 in the regulation of certain subpopulations of B cells.

Sign in / Sign up

Export Citation Format

Share Document