scholarly journals LAT-mediated signaling in CD4+CD25+ regulatory T cell development

2005 ◽  
Vol 203 (1) ◽  
pp. 119-129 ◽  
Author(s):  
Surapong Koonpaew ◽  
Shudan Shen ◽  
Lawrence Flowers ◽  
Weiguo Zhang
Keyword(s):  
T Cells ◽  
T Cell ◽  
Bone Marrow Cells ◽  
Critical Role ◽  
T Cell Development ◽  
Ectopic Expression ◽  
Adaptor Protein ◽  
Foxp3 Expression ◽  
Cell Receptor ◽  
Cell Development

Engagement of the T cell receptor for antigen (TCR) induces formation of signaling complexes mediated through the transmembrane adaptor protein, the linker for activation of T cells (LAT). LAT plays an important role in T cell development, activation, and homeostasis. A knock-in mutation at Tyr136, which is the phospholipase C (PLC)-γ1–binding site in LAT, leads to a severe autoimmune disease in mice. In this study, we show that CD4+CD25+ T reg cells that expressed Foxp3 transcription factor were nearly absent in both thymus and peripheral lymphoid organs of LATY136F mice. This defect was not a result of the autoimmune environment as LATY136F T reg cells also failed to develop in healthy LAT−/− mice that received mixed wild-type and LATY136F bone marrow cells. Moreover, adoptive transfer of normal CD4+CD25+ T reg cells protected neonatal LATY136F mice from developing this disease. These T reg cells effectively controlled expansion of CD4+ T cells in LATY136F mice likely via granzymes and/or TGF-β–mediated suppression. Furthermore, ectopic expression of Foxp3 conferred a suppressive function in LATY136F T cells. Our data indicate that the LAT–PLC-γ1 interaction plays a critical role in Foxp3 expression and the development of CD4+CD25+ T reg cells

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 The Effects of TLR Activation on T-Cell Development and Differentiation

2012 ◽  
Vol 2012 ◽  
pp. 1-32 ◽  
Author(s):  
Bo Jin ◽  
Tao Sun ◽  
Xiao-Hong Yu ◽  
Ying-Xiang Yang ◽  
Anthony E. T. Yeo
Keyword(s):  
T Cells ◽  
T Cell ◽  
Regulatory T Cells ◽  
T Cell Development ◽  
Cell Receptor ◽  
Treg Cells ◽  
Cell Development ◽  
T Cell Subsets ◽  
Follicular Helper ◽  
Development And Differentiation

Invading pathogens have unique molecular signatures that are recognized by Toll-like receptors (TLRs) resulting in either activation of antigen-presenting cells (APCs) and/or costimulation of T cells inducing both innate and adaptive immunity. TLRs are also involved in T-cell development and can reprogram Treg cells to become helper cells. T cells consist of various subsets, that is, Th1, Th2, Th17, T follicular helper (Tfh), cytotoxic T lymphocytes (CTLs), regulatory T cells (Treg) and these originate from thymic progenitor thymocytes. T-cell receptor (TCR) activation in distinct T-cell subsets with different TLRs results in differing outcomes, for example, activation of TLR4 expressed in T cells promotes suppressive function of regulatory T cells (Treg), while activation of TLR6 expressed in T cells abrogates Treg function. The current state of knowledge of regarding TLR-mediated T-cell development and differentiation is reviewed.

scholarly journals Separation of Notch1 Promoted Lineage Commitment and Expansion/Transformation in Developing T Cells

2001 ◽  
Vol 194 (1) ◽  
pp. 99-106 ◽  
Author(s):  
David Allman ◽  
Fredrick G. Karnell ◽  
Jennifer A. Punt ◽  
Sonia Bakkour ◽  
Lanwei Xu ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Development ◽  
Cell Receptor ◽  
Cell Development ◽  
Surface Proteins ◽  
Lineage Commitment ◽  
Double Positive ◽  
Hematopoietic Stem ◽  
Multipotent Progenitor Cells

Notch1 signaling is required for T cell development. We have previously demonstrated that expression of a dominant active Notch1 (ICN1) transgene in hematopoietic stem cells (HSCs) leads to thymic-independent development of CD4+CD8+ double-positive (DP) T cells in the bone marrow (BM). To understand the function of Notch1 in early stages of T cell development, we assessed the ability of ICN1 to induce extrathymic T lineage commitment in BM progenitors from mice that varied in their capacity to form a functional pre-T cell receptor (TCR). Whereas mice repopulated with ICN1 transduced HSCs from either recombinase deficient (Rag-2−/−) or Src homology 2 domain–containing leukocyte protein of 76 kD (SLP-76)−/− mice failed to develop DP BM cells, recipients of ICN1-transduced Rag-2−/− progenitors contained two novel BM cell populations indicative of pre-DP T cell development. These novel BM populations are characterized by their expression of CD3ε and pre-Tα mRNA and the surface proteins CD44 and CD25. In contrast, complementation of Rag-2−/− mice with a TCRβ transgene restored ICN1-induced DP development in the BM within 3 wk after BM transfer (BMT). At later time points, this population selectively and consistently gave rise to T cell leukemia. These findings demonstrate that Notch signaling directs T lineage commitment from multipotent progenitor cells; however, both expansion and leukemic transformation of this population are dependent on T cell–specific signals associated with development of DP thymocytes.

A Hypomorphic Cbfb Allele Reveals a Critical Dosage-Sensitive Function of Core Binding Factors at the Earliest Stages of T Cell Development.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 124-124
Author(s):  
Ivan Maillard ◽  
Laleh Talebian ◽  
Zhe Li ◽  
Yalin Guo ◽  
Daisuke Sugiyama ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Dna Binding ◽  
B Cell ◽  
Bone Marrow Cells ◽  
T Cell Development ◽  
Cell Development ◽  
B Cell Development ◽  
Hematopoietic Stem

Abstract The family of core binding factors includes the DNA-binding subunits Runx1-3 and the common non-DNA binding partner CBFβ. Runx1 and CBFβ are essential for the emergence of hematopoietic stem cells during fetal development, but not for stem cell maintenance during later ontogeny. Runx1 is also required for megakaryocyte differentiation, B cell development, and for the DN2 to DN3 transition in thymocyte development. Runx2/CBFβ are critical for normal osteogenesis, and Runx3 for CD4 silencing in CD8+ T cells, but their contribution to other steps of hematopoietic development is unknown. To examine the collective role of core binding factors in hematopoiesis, we generated a hypomorphic Cbfb allele (Cbfbrss). CBFβ protein levels were reduced by approximately 2–3 fold in fetuses homozygous for the Cbfbrss allele (Cbfbrss/rss), and 3–4 fold in fetuses carrying one hypomorphic and one knockout allele (Cbfbrss/−). Cbfbrss/rss and Cbfbrss/− fetuses had normal erythroid and B cell development, and relatively mild abnormalities in megakaryocyte and granulocyte differentiation. In contrast, T cell development was very sensitive to an incremental reduction of CBFβ levels: mature thymocytes were decreased in Cbfbrss/rss fetuses, and virtually absent in Cbfbrss/−fetuses. We next assessed the development of Cbfbrss/rss and Cbfbrss/− fetal liver progenitors after transplantation to irradiated adult recipients, in competition with wild-type (wt) bone marrow cells. Wt, Cbfbrss/rss and Cbfbrss/− fetal progenitors replenished the erythroid, myeloid and B cell compartments equally well. The overall development of Cbfbrss/rss T cells was preserved, although CD4 expression was derepressed in double negative thymocytes. In Cbfbrss/− chimeras, mature thymocytes were entirely derived from competitor cells. Furthermore, the developmental block in Cbfbrss/− progenitors was present at the earliest stages of T cell development within the DN1 (ETP) and DN2 subsets. Our data define a critical CBFβ threshold for normal T cell development, and they situate an essential role of core binding factors during the earliest stages of T cell development. In addition, early thymopoiesis appeared more severely affected by reduced CBFβ dosage than by the lack of Runx1 (Ichikawa et al., Nat Med 2004; Growney et al., Blood 2005), suggesting that Runx2/3 may contribute to core binding factor activity in the T cell lineage.

scholarly journals Phospholipase Cγ1 is essential for T cell development, activation, and tolerance

2010 ◽  
Vol 207 (2) ◽  
pp. 309-318 ◽  
Author(s):  
Guoping Fu ◽  
Yuhong Chen ◽  
Mei Yu ◽  
Andy Podd ◽  
James Schuman ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Biology ◽  
T Cell Development ◽  
Cell Receptor ◽  
Cell Development ◽  
Phospholipase Cγ1 ◽  
T Cell Biology ◽  
Single Positive ◽  
And Function

Phospholipase Cγ1 (PLCγ1) is an important signaling effector of T cell receptor (TCR). To investigate the role of PLCγ1 in T cell biology, we generated and examined mice with T cell–specific deletion of PLCγ1. We demonstrate that PLCγ1 deficiency affects positive and negative selection, significantly reduces single-positive thymocytes and peripheral T cells, and impairs TCR-induced proliferation and cytokine production, and the activation of ERK, JNK, AP-1, NFAT, and NF-κB. Importantly, PLCγ1 deficiency impairs the development and function of FoxP3+ regulatory T cells, causing inflammatory/autoimmune symptoms. Therefore, PLCγ1 is essential for T cell development, activation, and tolerance.

scholarly journals Requirement of dendritic cells and B cells in the clonal deletion of Mls-reactive T cells in the thymus.

1991 ◽  
Vol 173 (3) ◽  
pp. 539-547 ◽  
Author(s):  
O Mazda ◽  
Y Watanabe ◽  
J Gyotoku ◽  
Y Katsura
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
T Cell ◽  
B Cells ◽  
T Cell Development ◽  
Cell Receptor ◽  
Cell Development ◽  
Clonal Deletion ◽  
Fetal Thymus ◽  
Effector Cells

The present study was performed to identify cells responsible for the elimination of T cells reactive with minor lymphocyte-stimulating (Mls) antigens during T cell development. Experiments were carried out in a fetal thymus organ culture (FTOC) system. To examine the tolerance-inducing activity, various populations of cells from adult CBA/J (Mls-1a) mice were injected into deoxyguanosine (dGuo)-treated FTOC of C3H/He (Mls-1b) mice with a microinjector, and 2 d later, the thymus lobes were injected with fetal thymus cells from C3H/He mice as T cell precursors. After 14 d of cultivation, cells were harvested and assayed for the expression of the T cell receptor V beta 6 element. The absence or marked reduction of T cells expressing V beta 6 at high levels (V beta 6high) was regarded as indicating the deletion of Mls-1a-reactive T cells. T cell-depleted populations of thymic as well as splenic cells from CBA/J mice were able to induce clonal deletion. Further characterization of the effector cells was carried out by fractionating the spleen cells before injecting them into dGuo-FTOC. None of the dish-adherent population, dish-nonadherent population, or purified B cells alone were able to induce clonal deletion, whereas the addition of purified B cells to adherent cells restored tolerance inducibility. It was further shown that a combination of CBA/J B cells and C3H/He dendritic cells was effective in eliminating Mls-reactive clones. These results indicate that for the deletion of clones reactive with Mls antigens during T cell development in the thymus, both DC and B cells are required.

scholarly journals Deletion of the mitochondria-shaping protein Opa1 during early thymocyte maturation impacts mature memory T cell metabolism

2021 ◽  
Author(s):  
Mauro Corrado ◽  
Dijana Samardžić ◽  
Marta Giacomello ◽  
Nisha Rana ◽  
Erika L. Pearce ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Function ◽  
T Cell Development ◽  
Cell Receptor ◽  
Cell Development ◽  
Effector Memory ◽  
Long Term Memory ◽  
Memory T Cell ◽  
T Cell Function

AbstractOptic atrophy 1 (OPA1), a mitochondria-shaping protein controlling cristae biogenesis and respiration, is required for memory T cell function, but whether it affects intrathymic T cell development is unknown. Here we show that OPA1 is necessary for thymocyte maturation at the double negative (DN)3 stage when rearrangement of the T cell receptor β (Tcrβ) locus occurs. By profiling mitochondrial function at different stages of thymocyte maturation, we find that DN3 cells rely on oxidative phosphorylation. Consistently, Opa1 deletion during early T cell development impairs respiration of DN3 cells and reduces their number. Opa1-deficient DN3 cells indeed display stronger TCR signaling and are more prone to cell death. The surviving Opa1−/− thymocytes that reach the periphery as mature T cells display an effector memory phenotype even in the absence of antigenic stimulation but are unable to generate metabolically fit long-term memory T cells. Thus, mitochondrial defects early during T cell development affect mature T cell function.

scholarly journals Extracellular adenosine regulates naive T cell development and peripheral maintenance

2013 ◽  
Vol 210 (12) ◽  
pp. 2693-2706 ◽  
Author(s):  
Caglar Cekic ◽  
Duygu Sag ◽  
Yuan-Ji Day ◽  
Joel Linden
Keyword(s):  
T Cells ◽  
T Cell ◽  
Bone Marrow Cells ◽  
T Cell Development ◽  
Cell Development ◽  
Quiescent State ◽  
Naive T Cells ◽  
Naïve T Cells ◽  
Naïve T Cell ◽  
Naive T Cell

Adenosine produced as a byproduct of metabolic activity is present in all tissues and produces dose-dependent suppression of TCR signaling. Naive T cell maintenance depends on inhibition of TCR signals by environmental sensors, which are yet to be fully defined. We produced mice with a floxed adenosine A2A receptor (A2AR) gene, Adora2a, and show that either global A2AR deletion or cre-mediated T cell deletion elicits a decline in the number of naive but not memory T cells. A2AR signaling maintains naive T cells in a quiescent state by inhibiting TCR-induced activation of the phosphatidylinositide 3-kinase (PI3K)–AKT pathway, thereby reducing IL-7Rα down-regulation and naive T cell apoptosis. Patterns of IL-7Rα expression on T cells in chimeric mice reconstituted with Adora2a+/+ and Adora2a−/− bone marrow cells suggest that decreased IL-7Rα in naive T cells is a cell-intrinsic consequence of Adora2a deletion. In addition, A2AR expression increases in early thymic T cell development and contributes to progression of double-negative thymic precursors to single-positive thymocytes with increased IL-7Rα expression. Therefore, A2AR signaling regulates T cell development and maintenance to sustain normal numbers of naive T cells in the periphery.

Sign in / Sign up

Export Citation Format

Share Document