scholarly journals Cytokine signal transduction is suppressed in preselection double-positive thymocytes and restored by positive selection

2006 ◽  
Vol 203 (1) ◽  
pp. 165-175 ◽  
Author(s):  
Qing Yu ◽  
Jung-Hyun Park ◽  
Loretta L. Doan ◽  
Batu Erman ◽  
Lionel Feigenbaum ◽  
...  
Keyword(s):  
Signal Transduction ◽  
Positive Selection ◽  
T Cell Receptor ◽  
High Surface ◽  
Cell Receptor ◽  
Surface Expression ◽  
Small Cell ◽  
Cytokine Signaling ◽  
Suppressor Of Cytokine Signaling ◽  
Double Positive

Death by neglect requires that CD4+8+ double-positive (DP) thymocytes avoid cytokine-mediated survival signals, which is presumably why DP thymocytes normally extinguish IL-7R gene expression. We report that DP thymocytes before positive selection (preselection DP thymocytes) fail to transduce IL-7 signals even when they express high levels of transgenic IL-7R on their surface, because IL-7R signal transduction is actively suppressed in preselection DP thymocytes by suppressor of cytokine signaling (SOCS)–1. SOCS-1 is highly expressed in preselection DP thymocytes, but it is down-regulated by T cell receptor–mediated positive selection signals. Interestingly, we found that the uniquely small cell volume of DP thymocytes is largely the result of absent IL-7 signaling in preselection DP thymocytes. We also report that, contrary to current concepts, preselection DP thymocytes express high levels of endogenously encoded IL-4Rs. However, their ability to transduce cytokine signals is similarly suppressed by SOCS-1. Thus, despite high surface expression of transgenic or endogenous cytokine receptors, cytokine signal transduction is actively suppressed in preselection DP thymocytes until it is restored by positive selection.

scholarly journals Regulation of thymocyte development through CD3. II. Expression of T cell receptor beta CD3 epsilon and maturation to the CD4+8+ stage are highly correlated in individual thymocytes.

1993 ◽  
Vol 178 (6) ◽  
pp. 1867-1875 ◽  
Author(s):  
C N Levelt ◽  
R Carsetti ◽  
K Eichmann
Keyword(s):  
Signal Transduction ◽  
T Cell ◽  
T Cell Receptor ◽  
Alternative Hypothesis ◽  
Cell Receptor ◽  
Surface Expression ◽  
Beta Chain ◽  
Thymocyte Development ◽  
Double Positive ◽  
Highly Correlated

Recent studies have shown that maturation of CD4-8- double negative (DN) thymocytes to the CD4+8+ double positive (DP) stage is dependent on expression of the T cell receptor (TCR)-beta polypeptide. The exact mechanism by which the TCR-beta chain regulates this maturation step remains unknown. Previous experiments had suggested that in the presence of some TCR+ thymocytes, additional DN thymocytes not expressing a TCR-beta chain may be recruited to mature to the DP stage. The recent demonstration of an immature TCR-beta-CD3 complex on early thymocytes lead to the alternative hypothesis that signal transduction through an immature TCR-CD3 complex may induce maturation to the DP stage. In the latter case, maturation to the DP stage would depend on the expression of TCR-beta-CD3 in the same cell. We examined these two hypotheses by studying the expression of the intra- and extracellular CD3 epsilon, CD3 zeta, and TCR-beta polypeptides in intrathymic subpopulations during embryogenesis. CD3 epsilon and CD3 zeta were expressed intracellularly 2 and 1 d, respectively, before intracellular expression of the TCR-beta chain, potentially allowing immediate surface expression of an immature TCR-beta-CD3 complex as soon as functional rearrangement of a TCR-beta gene locus has been accomplished. Calcium mobilization could be induced by stimulation with anti-CD3 epsilon mAb as soon as intracellular TCR-beta was detectable, suggesting that a functional TCR-beta-CD3 complex is indeed expressed on the surface of early thymocytes. From day 17 on, most cells were in the DP stage, and over 95% of the DP cells expressed on the TCR-beta chain intracellularly. At day 19 of gestation, extremely low concentrations of TCR-beta chain and CD3 epsilon were detectable on the cell surface of nearly all thymocytes previously thought to be TCR-CD3 negative. These findings strongly support the hypothesis that maturation to the DP stage depends on surface expression of and subsequent signal transduction through an immature TCR-beta-CD3 complex and suggest that maturation to the DP stage by recruitment, if it occurs at all, is of minor relevance.

scholarly journals Fc gamma RII/III and CD2 expression mark distinct subpopulations of immature CD4-CD8- murine thymocytes: in vivo developmental kinetics and T cell receptor beta chain rearrangement status.

1993 ◽  
Vol 177 (4) ◽  
pp. 1079-1092 ◽  
Author(s):  
H R Rodewald ◽  
K Awad ◽  
P Moingeon ◽  
L D'Adamio ◽  
D Rabinowitz ◽  
...  
Keyword(s):  
T Cell ◽  
T Cell Receptor ◽  
Fetal Development ◽  
Cell Receptor ◽  
Surface Expression ◽  
Cell Surface Expression ◽  
Immunoglobulin Gene ◽  
Beta Chain ◽  
Double Positive ◽  
Alpha Beta

We have recently identified a dominant wave of CD4-CD8- (double-negative [DN]) thymocytes in early murine fetal development that express low affinity Fc gamma receptors (Fc gamma RII/III) and contain precursors for Ti alpha/beta lineage T cells. Here we show that Fc gamma RII/III is expressed in very immature CD4low single-positive (SP) thymocytes and that Fc gamma RII/III expression is downregulated within the DN subpopulation and before the CD3-CD8low SP stage in T cell receptor (TCR)-alpha/beta lineage-committed thymocytes. DN Fc gamma RII/III+ thymocytes also contain a small fraction of TCR-gamma/delta lineage cells in addition to TCR-alpha/beta progenitors. Fetal day 15.5 DN TCR-alpha/beta lineage progenitors can be subdivided into three major subpopulations as characterized by cell surface expression of Fc gamma RII/III vs. CD2 (Fc gamma RII/III+CD2-, Fc gamma RII/III+CD2+, Fc gamma RII/III-CD2+). Phenotypic analysis during fetal development as well as adoptive transfer of isolated fetal thymocyte subpopulations derived from C57B1/6 (Ly5.1) mice into normal, nonirradiated Ly5.2 congenic recipient mice identifies one early differentiation sequence (Fc gamma RII/III+CD2(-)-->Fc gamma RII/III+CD2(+)-->Fc gamma RII/III-CD2+) that precedes the entry of DN thymocytes into the CD4+CD8+ double-positive (DP) TCRlow/- stage. Unseparated day 15.5 fetal thymocytes develop into DP thymocytes within 2.5 d and remain at the DP stage for > 48 h before being selected into either CD4+ or CD8+ SP thymocytes. In contrast, Fc gamma RII/III+CD2- DN thymocytes follow this same developmental pathway but are delayed by approximately 24 h before entering the DP compartment, while Fc gamma RII/III-CD2+ display accelerated development by approximately 24 h compared with total day 15.5 thymocytes. Fc gamma RII/III-CD2+ are also more developmentally advanced than Fc gamma RII/III+CD2- fetal thymocytes with respect to their TCR beta chain V(D)J rearrangement. At day 15.5 in gestation, beta chain V(D)J rearrangement is mostly, if not entirely, restricted to the Fc gamma RII/III-CD2+ subset of DN fetal thymocytes. Consistent with this analysis in fetal thymocytes, > 90% of adult thymocytes derived from mice carrying a disrupting mutation at the recombination-activating gene 2 locus (RAG-2-/-) on both alleles are developmentally arrested at the DN CD2- stage. In addition, there is a fivefold increase in the relative percentage of thymocytes expressing Fc gamma RII/III in TCR and immunoglobulin gene rearrangement-incompetent homozygous RAG-2-/- mice (15% Fc gamma RII/III+) versus rearrangement-competent heterozygous RAG-2+/- mice (< 3% Fc gamma RII/III+). Thus, Fc gamma RII/III expression defines an early DN stage preceding V beta(D beta)I beta rearrangement, which in turn is followed by surface expression of CD2. Loss of Fc gamma RII/III and acquisition of CD2 expression characterize a late DN stage immediately before the conversion into DP thymocytes.

Overexpression of suppressor of cytokine signaling-1 impairs pre-T-cell receptor–induced proliferation but not differentiation of immature thymocytes

Blood ◽  
2001 ◽  
Vol 97 (8) ◽  
pp. 2269-2277 ◽  
Author(s):  
Sébastien Trop ◽  
Paulo De Sepulveda ◽  
Juan Carlos Zúñiga-Pflücker ◽  
Robert Rottapel
Keyword(s):  
T Cell ◽  
T Cell Receptor ◽  
T Cell Development ◽  
Constitutive Expression ◽  
Cell Receptor ◽  
Cell Development ◽  
Negative Regulator ◽  
Cytokine Signaling ◽  
Suppressor Of Cytokine Signaling ◽  
Immature Thymocytes

Abstract Cytokines play an essential role during early T-cell development. However, the mechanisms controlling cytokine signaling in developing thymocytes have not been elucidated. Cytokine receptor signaling can be modulated by suppressor of cytokine signaling-1 (SOCS-1), which acts as a negative regulator of Janus kinases. SOCS-1 is normally expressed throughout thymocyte development; however, retroviral-mediated overexpression of SOCS-1 in fetal liver–derived hematopoietic progenitors prevented their progression beyond the earliest stage of T-cell development. Further analysis revealed that SOCS-1 expression is transiently suppressed following pre-T-cell receptor (TCR) signaling. Moreover, constitutive expression of SOCS-1 abrogated pre-TCR– mediated expansion of immature thymocytes but did not interfere with differentiation. These findings reveal that SOCS-1 serves to regulate cytokine signaling at critical checkpoints during early T-cell development.

scholarly journals Commitment of Immature CD4+8+ Thymocytes to the CD4 Lineage Requires CD3 Signaling but Does Not Require Expression of Clonotypic T Cell Receptor (TCR) Chains

1997 ◽  
Vol 186 (1) ◽  
pp. 17-23 ◽  
Author(s):  
Harumi Suzuki ◽  
Yoichi Shinkai ◽  
Lawrence G. Granger ◽  
Frederick W. Alt ◽  
Paul E. Love ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Positive Selection ◽  
T Cell Receptor ◽  
Cd8 T Cells ◽  
Cd8 T Cell ◽  
Cell Receptor ◽  
The Other ◽  
Double Positive ◽  
Cell Lineages

As a consequence of positive selection in the thymus, immature CD4+8+ double-positive, [DP] thymocytes selectively terminate synthesis of one coreceptor molecule and, as a result, differentiate into either CD4+ or CD8+ T cells. The decision by individual DP thymocytes to terminate synthesis of one or the other coreceptor molecule is referred to as lineage commitment. Previously, we reported that the intrathymic signals that induced commitment to the CD4 versus CD8 T cell lineages were markedly asymmetric. Notably, CD8 commitment appeared to require lineage-specific signals, whereas CD4 commitment appeared to occur in the absence of lineage-specific signals by default. Consequently, it was unclear whether CD4 commitment, as revealed by selective termination of CD8 coreceptor synthesis, occurred in all DP thymocytes, or whether CD4 commitment occurred only in T cell receptor (TCR)–CD3-signaled DP thymocytes. Here, we report that selective termination of CD8 coreceptor synthesis does not occur in DP thymocytes spontaneously. Rather, CD4 commitment in DP thymocytes requires signals transduced by either CD3 or ζ chains, which can signal CD4 commitment even in the absence of clonotypic TCR chains.

scholarly journals Contributions of the T Cell Receptor–associated CD3γ–ITAM to Thymocyte Selection

2002 ◽  
Vol 196 (1) ◽  
pp. 1-13 ◽  
Author(s):  
Mariëlle C. Haks ◽  
Elsa Pépin ◽  
Jeroen H.N. van den Brakel ◽  
Sigrid A.A. Smeele ◽  
Stanley M. Belkowski ◽  
...  
Keyword(s):  
T Cell ◽  
Positive Selection ◽  
T Cell Receptor ◽  
Dissociation Constants ◽  
Cell Receptor ◽  
Double Positive ◽  
Mutant Receptors

The immunoreceptor tyrosine-based activation motifs (ITAMs) in the CD3 chains associated with the T cell receptor (TCR) are crucial for TCR signaling. To probe the role of the CD3γ–ITAM in T cell development, we created knock-in mice in which the CD3γ chain of the TCR complex is replaced by a mutant signaling-deficient CD3γ chain, lacking the CD3γ–ITAM. This mutation results in considerable impairment in positive selection in the polyclonal TCR repertoire. When CD3γ–ΔITAM mice are crossed to mice expressing transgenic F5 TCRs, their thymocytes are completely unable to perform positive selection in vivo in response to intrathymic ligands. Also, the in vitro positive selection response of double-positive (DP) thymocytes with F5–CD3γ–ΔITAM mutant receptors to their agonist ligand and many of its variants is severely impaired or abrogated. Yet, the binding and dissociation constants of agonist ligands for the F5 receptor are not affected by the CD3γ–ΔITAM mutation. Furthermore, DP thymocytes with mutant receptors can respond to agonist ligand with normal antigen sensitivity and to normal levels, as shown by their ability to induce CD69 up-regulation, TCR down-regulation, negative selection, and ZAP70 and c-Jun NH2-terminal kinase activation. In sharp contrast, induction of extracellular signal-regulated kinase (ERK) activation and linker for activation of T cells (LAT) phosphorylation are severely impaired in these cells. Together, these findings underscore that intrinsic properties of the TCR–CD3 complex regulate selection at the DP checkpoint. More importantly, this analysis provides the first direct genetic evidence for a role of the CD3γ–ITAM in TCR-driven thymocyte selection.

Ig alpha and Ig beta are functionally homologous to the signaling proteins of the T-cell receptor

1994 ◽  
Vol 14 (2) ◽  
pp. 1095-1103
Author(s):  
A L Burkhardt ◽  
T Costa ◽  
Z Misulovin ◽  
B Stealy ◽  
J B Bolen ◽  
...  
Keyword(s):  
Signal Transduction ◽  
T Cells ◽  
T Cell ◽  
B Cell ◽  
T Cell Receptor ◽  
Interleukin 2 ◽  
Antigen Receptor ◽  
Cell Receptor ◽  
Antigen Receptors ◽  
Cell Antigen

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.

scholarly journals Usp12 stabilizes the T-cell receptor complex at the cell surface during signaling

2016 ◽  
Vol 113 (6) ◽  
pp. E705-E714 ◽  
Author(s):  
Akhee S. Jahan ◽  
Maxime Lestra ◽  
Lee Kim Swee ◽  
Ying Fan ◽  
Mart M. Lamers ◽  
...  
Keyword(s):  
T Cell ◽  
T Cell Receptor ◽  
Posttranslational Modifications ◽  
Protein Function ◽  
Adaptor Proteins ◽  
Cell Receptor ◽  
Surface Expression ◽  
Jurkat Cells ◽  
Tcr Signaling ◽  
Primary Mouse

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.

Defective T-cell receptor signalling and positive selection of Vav-deficient CD4+CDS+thymocytes

Nature ◽  
1995 ◽  
Vol 374 (6521) ◽  
pp. 474-476 ◽  
Author(s):  
Klaus-Dieter Fischer ◽  
Antanina Zmuidzinas ◽  
Sandra Gardner ◽  
Mariano Barbacid ◽  
Alan Bernstein ◽  
...  
Keyword(s):  
T Cell ◽  
Positive Selection ◽  
T Cell Receptor ◽  
Cell Receptor ◽  
Receptor Signalling ◽  
Selection Of
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