scholarly journals Synergy between the pre–T cell receptor and Notch: cementing the αβ lineage choice

2006 ◽  
Vol 203 (10) ◽  
pp. 2233-2237 ◽  
Author(s):  
Cynthia J. Guidos

Notch1 signaling suppresses B cell development and promotes T lineage commitment in thymus-seeding hematopoietic progenitors. Notch1 is also activated in early T cell progenitors, but the functions of these later Notch signals have not been clearly defined. Recent studies reveal that Notch signaling is not essential for pre–T cell receptor (TCR) expression or γδ lineage choice. Rather, pre-TCR signaling enhances progenitor competitiveness for limiting Notch ligands, leading to preferential expansion of TCRβ-bearing progenitors.

2008 ◽  
Vol 205 (5) ◽  
pp. 1173-1186 ◽  
Author(s):  
Taras Kreslavsky ◽  
Annette I. Garbe ◽  
Andreas Krueger ◽  
Harald von Boehmer

αβ and γδ T cell lineages develop in the thymus from a common precursor. It is unclear at which stage of development commitment to these lineages takes place and in which way T cell receptor signaling contributes to the process. Recently, it was demonstrated that strong TCR signals favor γδ lineage development, whereas weaker TCR signals promote αβ lineage fate. Two models have been proposed to explain these results. The first model suggests that commitment occurs after TCR expression and TCR signaling directly instructs lymphocytes to adopt one or the other lineage fate. The second model suggests that commitment occurs before TCR expression and that TCR signaling merely confirms the lineage choice. By tracing the fate of single T cell precursors, this study shows that there is no commitment to either the αβ or γδ lineage before TCR expression and that modulation of TCR signaling in progeny of a single TCR-expressing cell changes lineage commitment.


Cancers ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 340
Author(s):  
Ming Liang Oon ◽  
Jing Quan Lim ◽  
Bernett Lee ◽  
Sai Mun Leong ◽  
Gwyneth Shook-Ting Soon ◽  
...  

T-cell lymphomas arise from a single neoplastic clone and exhibit identical patterns of deletions in T-cell receptor (TCR) genes. Whole genome sequencing (WGS) data represent a treasure trove of information for the development of novel clinical applications. However, the use of WGS to identify clonal T-cell proliferations has not been systematically studied. In this study, based on WGS data, we identified monoclonal rearrangements (MRs) of T-cell receptors (TCR) genes using a novel segmentation algorithm and copy number computation. We evaluated the feasibility of this technique as a marker of T-cell clonality using T-cell lymphomas (TCL, n = 44) and extranodal NK/T-cell lymphomas (ENKTLs, n = 20), and identified 98% of TCLs with one or more TCR gene MRs, against 91% detected using PCR. TCR MRs were absent in all ENKTLs and NK cell lines. Sensitivity-wise, this platform is sufficiently competent, with MRs detected in the majority of samples with tumor content under 25% and it can also distinguish monoallelic from biallelic MRs. Understanding the copy number landscape of TCR using WGS data may engender new diagnostic applications in hematolymphoid pathology, which can be readily adapted to the analysis of B-cell receptor loci for B-cell clonality determination.


1996 ◽  
Vol 183 (5) ◽  
pp. 2109-2117 ◽  
Author(s):  
B Combadière ◽  
M Freedman ◽  
L Chen ◽  
E W Shores ◽  
P Love ◽  
...  

Engagement of the T cell receptor (TCR) of mature T lymphocytes can lead either to activation/proliferation responses or programmed cell death. To understand the molecular regulation of these two fundamentally different outcomes of TCR signaling, we investigated the participation of various components of the TCR-CD3 complex. We found that the TCR-zeta chain, while not absolutely required, was especially effective at promoting mature T cell apoptosis compared with the CD3 epsilon, gamma, or delta chains. We also carried out mutagenesis to address the role of the immunoreceptor tyrosine-based activation motifs (ITAMs) that are the principal signaling components found three times in the TCR-zeta chain and once in each of the CD3 epsilon, gamma, or delta chains. We found that the ability of the TCR-zeta chain to promote apoptosis results both from a quantitative effect of the presence of multiple ITAMs as well as qualitatively different contributions made by individual ITAMs. Apoptosis induced by single chain chimeras revealed that the first zeta ITAM stimulated greater apoptosis than the third zeta ITAM, and the second zeta ITAM was unable to trigger apoptosis. Because microheterogeneity in the amino acid sequence of the various ITAM motifs found in the TCR-zeta and CD3 chains predicts interactions with distinct src-homology-2-domain signaling proteins, our results suggest the possibility that individual ITAM motifs might play unique roles in TCR responses by engaging specific signaling pathways.


PROTEOMICS ◽  
2009 ◽  
Vol 9 (13) ◽  
pp. 3549-3563 ◽  
Author(s):  
Masaki Matsumoto ◽  
Koji Oyamada ◽  
Hidehisa Takahashi ◽  
Takamichi Sato ◽  
Shigetsugu Hatakeyama ◽  
...  

1994 ◽  
Vol 14 (2) ◽  
pp. 1095-1103
Author(s):  
A L Burkhardt ◽  
T Costa ◽  
Z Misulovin ◽  
B Stealy ◽  
J B Bolen ◽  
...  

Signal transduction by antigen receptors and some Fc receptors requires the activation of a family of receptor-associated transmembrane accessory proteins. One common feature of the cytoplasmic domains of these accessory molecules is the presence is at least two YXXA repeats that are potential sites for interaction with Src homology 2 domain-containing proteins. However, the degree of similarity between the different receptor-associated proteins varies from that of T-cell receptor (TCR) zeta and Fc receptor RIIIA gamma chains, which are homologous, to the distantly related Ig alpha and Ig beta proteins of the B-cell antigen receptor. To determine whether T- and B-cell antigen receptors are in fact functionally homologous, we have studied signal transduction by chimeric immunoglobulins bearing the Ig alpha or Ig beta cytoplasmic domain. We found that Ig alpha and Ig beta cytoplasmic domains were able to activate Ca2+ flux, interleukin-2 secretion, and phosphorylation of the same group of cellular substrates as the TCR in transfected T cells. Chimeric proteins were then used to examine the minimal requirements for activation of the Fyn, Lck, and ZAP kinases in T cells. Both Ig alpha and Ig beta were able to trigger Fyn, Lck, and ZAP directly without involvement of TCR components. Cytoplasmic tyrosine residues in Ig beta were required for recruitment and activation of ZAP-70, but these amino acids were not essential for the activation of Fyn and Lck. We conclude that Fyn and Lck are able to recognize a clustered nonphosphorylated immune recognition receptor, but activation of these kinases is not sufficient to induce cellular responses such as Ca2+ flux and interleukin-2 secretion. In addition, the molecular structures involved in antigen receptor signaling pathways are conserved between T and B cells.


2016 ◽  
Vol 113 (6) ◽  
pp. E705-E714 ◽  
Author(s):  
Akhee S. Jahan ◽  
Maxime Lestra ◽  
Lee Kim Swee ◽  
Ying Fan ◽  
Mart M. Lamers ◽  
...  

Posttranslational modifications are central to the spatial and temporal regulation of protein function. Among others, phosphorylation and ubiquitylation are known to regulate proximal T-cell receptor (TCR) signaling. Here we used a systematic and unbiased approach to uncover deubiquitylating enzymes (DUBs) that participate during TCR signaling in primary mouse T lymphocytes. Using a C-terminally modified vinyl methyl ester variant of ubiquitin (HA-Ub-VME), we captured DUBs that are differentially recruited to the cytosol on TCR activation. We identified ubiquitin-specific peptidase (Usp) 12 and Usp46, which had not been previously described in this pathway. Stimulation with anti-CD3 resulted in phosphorylation and time-dependent translocation of Usp12 from the nucleus to the cytosol. Usp12−/− Jurkat cells displayed defective NFκB, NFAT, and MAPK activities owing to attenuated surface expression of TCR, which were rescued on reconstitution of wild type Usp12. Proximity-based labeling with BirA-Usp12 revealed several TCR adaptor proteins acting as interactors in stimulated cells, of which LAT and Trat1 displayed reduced expression in Usp12−/− cells. We demonstrate that Usp12 deubiquitylates and prevents lysosomal degradation of LAT and Trat1 to maintain the proximal TCR complex for the duration of signaling. Our approach benefits from the use of activity-based probes in primary cells without any previous genome modification, and underscores the importance of ubiquitin-mediated regulation to refine signaling cascades.


1998 ◽  
Vol 165 (1) ◽  
pp. 111-119 ◽  
Author(s):  
Harald Boehmer ◽  
Iannis Aifantis ◽  
Orly Azogui ◽  
Jacqueline Feinberg ◽  
Claude Saint-Ruf ◽  
...  

2017 ◽  
Vol 64 (4) ◽  
pp. 476-481 ◽  
Author(s):  
Jerome Bouquet ◽  
Jennifer L. Gardy ◽  
Scott Brown ◽  
Jacob Pfeil ◽  
Ruth R. Miller ◽  
...  

2006 ◽  
Vol 203 (11) ◽  
pp. 2509-2518 ◽  
Author(s):  
Shen Dong ◽  
Béatrice Corre ◽  
Eliane Foulon ◽  
Evelyne Dufour ◽  
André Veillette ◽  
...  

Adaptor proteins positively or negatively regulate the T cell receptor for antigen (TCR) signaling cascade. We report that after TCR stimulation, the inhibitory adaptor downstream of kinase (Dok)-2 and its homologue Dok-1 are involved in a multimolecular complex including the lipid phosphatase Src homology 2 domain–containing inositol polyphosphate 5′-phosphatase (SHIP)-1 and Grb-2 which interacts with the membrane signaling scaffold linker for activation of T cells (LAT). Knockdown of LAT and SHIP-1 expression indicated that SHIP-1 favored recruitment of Dok-2 to LAT. Knockdown of Dok-2 and Dok-1 revealed their negative control on Akt and, unexpectedly, on Zap-70 activation. Our findings support the view that Dok-1 and -2 are critical elements of a LAT-dependent negative feedback loop that attenuates early TCR signal. Dok-1 and -2 may therefore exert a critical role in shaping the immune response and as gatekeepers for T cell tolerance.


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