scholarly journals Pim1 Reconstitutes Thymus Cellularity in Interleukin 7–And Common γ Chain–Mutant Mice and Permits Thymocyte Maturation in Rag- but Not Cd3γ-Deficient Mice

1999 ◽  
Vol 190 (8) ◽  
pp. 1059-1068 ◽  
Author(s):  
Heinz Jacobs ◽  
Paul Krimpenfort ◽  
Mariëlle Haks ◽  
John Allen ◽  
Bianca Blom ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Leukemia Virus ◽  
T Cell Development ◽  
Cell Receptor ◽  
Cell Development ◽  
Interleukin 7 ◽  
Tcr Signal Transduction ◽  
Slow Expansion ◽  
Deficient Mice

The majority of lymphomas induced in Rag-deficient mice by Moloney murine leukemia virus (MoMuLV) infection express the CD4 and/or CD8 markers, indicating that proviral insertions cause activation of genes affecting the development from CD4−8− pro-T cells into CD4+8+ pre-T cells. Similar to MoMuLV wild-type tumors, 50% of CD4+8+ Rag-deficient tumors carry a provirus near the Pim1 protooncogene. To study the function of PIM proteins in T cell development in a more controlled setting, a Pim1 transgene was crossed into mice deficient in either cytokine or T cell receptor (TCR) signal transduction pathways. Pim1 reconstitutes thymic cellularity in interleukin (IL)-7– and common γ chain–deficient mice. In Pim1-transgenic Rag-deficient mice but notably not in CD3γ-deficient mice, we observed slow expansion of the CD4+8+ thymic compartment to almost normal size. Based on these results, we propose that PIM1 functions as an efficient effector of the IL-7 pathway, thereby enabling Rag-deficient pro-T cells to bypass the pre-TCR–controlled checkpoint in T cell development.

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.

CD4+CD25+ T-cell development is regulated by at least 2 distinct mechanisms

Blood ◽  
2002 ◽  
Vol 99 (2) ◽  
pp. 555-560 ◽  
Author(s):  
Akira Suto ◽  
Hiroshi Nakajima ◽  
Kei Ikeda ◽  
Shuichi Kubo ◽  
Toshinori Nakayama ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Transgenic Mice ◽  
T Cell Development ◽  
Cell Receptor ◽  
Cell Development ◽  
Histocompatibility Complex ◽  
Organ Specific ◽  
Immunoregulatory T Cells ◽  
Deficient Mice

Abstract It has recently been shown that CD4+CD25+ T cells are immunoregulatory T cells that prevent CD4+ T-cell–mediated organ-specific autoimmune diseases. In this study, the regulatory mechanism of CD4+CD25+ T-cell development were investigated using T-cell receptor (TCR) transgenic mice. It was found that CD4+CD25+ T cells preferentially expressed the endogenous TCRα chain in DO10+ TCR transgenic mice compared with CD4+CD25− T cells. Moreover, it was found that CD4+CD25+ thymocytes were severely decreased in DO10+ TCR-α−/− mice in positively selecting and negatively selecting backgrounds, whereas CD4+CD25− thymocytes efficiently developed by transgenic TCR in DO10+ TCR-α−/− mice in positively selecting backgrounds, indicating that the appropriate affinity of TCR to major histocompatibility complex (MHC) for the development of CD4+CD25+ thymocytes is different from that of CD4+CD25− thymocytes and that a certain TCR–MHC affinity is required for the development of CD4+CD25+ thymocytes. Finally, it was found that, in contrast to thymus, CD4+CD25+ T cells were readily detected in spleen of DO10+TCR-α−/− mice in positively selecting backgrounds and that splenic CD4+CD25+ T cells, but not CD4+CD25+ thymocytes, were significantly decreased in B-cell–deficient mice, suggesting that B cells may control the peripheral pool of CD4+CD25+ T cells. Together, these results indicate that the development of CD4+CD25+ T cells in thymus and the homeostasis of CD4+CD25+ T cells in periphery are regulated by distinct mechanisms.

scholarly journals Different composition of the human and the mouse γδ T cell receptor explains different phenotypes of CD3γ and CD3δ immunodeficiencies

2007 ◽  
Vol 204 (11) ◽  
pp. 2537-2544 ◽  
Author(s):  
Gabrielle M. Siegers ◽  
Mahima Swamy ◽  
Edgar Fernández-Malavé ◽  
Susana Minguet ◽  
Sylvia Rathmann ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Receptor ◽  
T Cell Development ◽  
Γδ T Cells ◽  
Cell Receptor ◽  
Cell Development ◽  
Γδ T Cell ◽  
Deficient Mice ◽  
Γδ T Cell Receptor

The γδ T cell receptor for antigen (TCR) comprises the clonotypic TCRγδ, the CD3 (CD3γε and/or CD3δε), and the ζζ dimers. γδ T cells do not develop in CD3γ-deficient mice, whereas human patients lacking CD3γ have abundant peripheral blood γδ T cells expressing high γδ TCR levels. In an attempt to identify the molecular basis for these discordant phenotypes, we determined the stoichiometries of mouse and human γδ TCRs using blue native polyacrylamide gel electrophoresis and anti-TCR–specific antibodies. The γδ TCR isolated in digitonin from primary and cultured human γδ T cells includes CD3δ, with a TCRγδCD3ε2δγζ2 stoichiometry. In CD3γ-deficient patients, this may allow substitution of CD3γ by the CD3δ chain and thereby support γδ T cell development. In contrast, the mouse γδ TCR does not incorporate CD3δ and has a TCRγδCD3ε2γ2ζ2 stoichiometry. CD3γ-deficient mice exhibit a block in γδ T cell development. A human, but not a mouse, CD3δ transgene rescues γδ T cell development in mice lacking both mouse CD3δ and CD3γ chains. This suggests important structural and/or functional differences between human and mouse CD3δ chains during γδ T cell development. Collectively, our results indicate that the different γδ T cell phenotypes between CD3γ-deficient humans and mice can be explained by differences in their γδ TCR composition.

scholarly journals Defective Development of γ/δ T Cells in Interleukin 7 Receptor–Deficient Mice Is Due to Impaired Expression of T Cell Receptor γ Genes

1999 ◽  
Vol 190 (7) ◽  
pp. 973-982 ◽  
Author(s):  
Joonsoo Kang ◽  
Mark Coles ◽  
David H. Raulet
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Receptor ◽  
T Cell Development ◽  
Cell Receptor ◽  
Cell Development ◽  
Special Role ◽  
Interleukin 7 ◽  
Reduced Rate

Mice lacking the interleukin 7 receptor (IL-7R) generate α/β T cells at a detectable but greatly reduced rate, but γ/δ T cells are completely absent. The special role of IL-7R signaling in γ/δ T cell development has remained unclear. IL-7Rα−/− mice exhibit a paucity of γ gene rearrangements. This striking observation can be explained by a defect in T cell receptor (TCR)-γ gene rearrangement, a defect in TCR-γ gene transcription leading to death of γ/δ lineage cells, and/or a requirement for IL-7R in commitment of cells to the γ/δ lineage. To determine the role of IL-7R signaling in γ/δ T cell development, we examined transcription of a prerearranged TCR-γ transgene in IL-7Rα−/− mice, as well as the effects of IL-7 on transcription of endogenous, rearranged TCR-γ genes in α/β lineage cells. The results demonstrate that IL-7R–mediated signals are necessary for the normal expression of rearranged TCR-γ genes. Equally significant, the results show that the poor expression of TCR-γ genes in IL-7Rα−/− mice is responsible for the selective deficit in γ/δ cells in these mice, since a high copy TCR-γ transgene exhibited sufficient residual expression in IL-7Rα−/− mice to drive γ/δ cell development. The results indicate that the absence of γ/δ T cells in IL-7Rα−/− mice is due to insufficient TCR-γ gene expression.

scholarly journals Interleukin-7 Regulates Bim Proapoptotic Activity in Peripheral T-Cell Survival

2009 ◽  
Vol 30 (3) ◽  
pp. 590-600 ◽  
Author(s):  
Wen Qing Li ◽  
Tad Guszczynski ◽  
Julie A. Hixon ◽  
Scott K. Durum
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Survival ◽  
T Cell Development ◽  
Cell Development ◽  
Effector Memory ◽  
Intracellular Location ◽  
Interleukin 7 ◽  
Peripheral T Cells ◽  
T Cell Survival

ABSTRACT Interleukin-7 (IL-7) is critical for T-cell development and peripheral T-cell homeostasis. The survival of pro-T cells and mature T cells requires IL-7. The survival function of IL-7 is accomplished partly through induction of the antiapoptotic protein Bcl-2 and inhibition of proapoptotic proteins Bax and Bad. We show here that the proapoptotic protein Bim, a BH3-only protein belonging to the Bcl-2 family, also plays a role in peripheral T-cell survival. Deletion of Bim partially protected an IL-7-dependent T-cell line and peripheral T cells, especially cells with an effector memory phenotype, from IL-7 deprivation. However, T-cell development in the thymus was not restored in IL-7−/− Rag2−/− mice reconstituted with Bim−/− bone marrow. IL-7 withdrawal altered neither the intracellular location of Bim, which was constitutively mitochondrial, nor its association with Bcl-2; however, a reduction in its association with the prosurvival protein Mcl-1 was observed. IL-7 withdrawal did not increase Bim mRNA or protein expression but did induce changes in the isoelectric point of BimEL and its reactivity with an antiphosphoserine antibody. Our findings suggest that the maintenance of peripheral T cells by IL-7 occurs partly through inhibition of Bim activity at the posttranslational level.

scholarly journals Cbp Deficiency Alters Csk Localization in Lipid Rafts but Does Not Affect T-Cell Development

2005 ◽  
Vol 25 (19) ◽  
pp. 8486-8495 ◽  
Author(s):  
Shengli Xu ◽  
Jianxin Huo ◽  
Joy En-Lin Tan ◽  
Kong-Peng Lam
Keyword(s):  
T Cell ◽  
Lipid Rafts ◽  
Tyrosine Kinases ◽  
Germ Line ◽  
T Cell Development ◽  
Cell Receptor ◽  
Cell Development ◽  
Calcium Flux ◽  
Functional Defect ◽  
Deficient Mice

ABSTRACT The ubiquitously expressed transmembrane adaptor Csk-binding protein (Cbp) recruits Csk to lipid rafts, where the latter exerts its negative regulatory effect on the Src family of protein tyrosine kinases. We have inactivated Cbp in the mouse germ line. In contrast to Csk gene inactivation, which leads to embryonic lethality and impaired T-cell development, Cbp-deficient mice were viable and exhibited normal T-cell development but with an increased thymocyte population. In the absence of Cbp, the amount of Csk that localizes to the lipid rafts was greatly reduced. Interestingly, this altered lipid raft localization of Csk did not lead to any detectable biochemical or functional defect in T cells. The T-cell receptor-induced intracellular calcium flux, cell proliferation, and cytokine secretion were not affected by the absence of Cbp. Peripheral T-cell tolerance to superantigen SEB was also largely intact in Cbp-deficient mice. Thus, Cbp is dispensable for T-cell development and activation.

scholarly journals Normal peripheral T-cell function in c-Fos-deficient mice.

1994 ◽  
Vol 14 (3) ◽  
pp. 1566-1574 ◽  
Author(s):  
J Jain ◽  
E A Nalefski ◽  
P G McCaffrey ◽  
R S Johnson ◽  
B M Spiegelman ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Development ◽  
Interleukin 2 ◽  
Family Members ◽  
Cell Receptor ◽  
Thymocyte Development ◽  
Activated T Cells ◽  
Peripheral T Cells ◽  
Deficient Mice

The ubiquitous transcription factors Fos and Jun are rapidly induced in T cells stimulated through the T-cell antigen receptor and regulate transcription of cytokines, including interleukin 2, in activated T cells. Since positive and negative selection of thymocytes during T-cell development also depends on activation through the T-cell receptor, Fos and Jun may play a role in thymocyte development as well. Fos and Jun act at several regulatory elements in the interleukin 2 promoter, including the AP-1 and NFAT sites. Using antisera specific to individual Fos and Jun family members, we show that c-Fos as well as other Fos family members are present in the inducible AP-1 and NFAT complexes of activated murine T cells. Nevertheless, c-Fos is not absolutely required for the development or function of peripheral T cells, as shown by using mice in which both copies of the c-fos gene were disrupted by targeted mutagenesis. c-Fos-deficient mice were comparable to wild-type mice in their patterns of thymocyte development and in the ability of their peripheral T cells to proliferate and produce several cytokines in response to T-cell receptor stimulation. Our results suggest that other Fos family members may be capable of substituting functionally for c-Fos during T-cell development and cytokine gene transcription in activated T cells.

scholarly journals Interleukin-7 is a critical growth factor in early human T-cell development

Blood ◽  
1996 ◽  
Vol 88 (11) ◽  
pp. 4239-4245 ◽  
Author(s):  
J Plum ◽  
M De Smedt ◽  
G Leclercq ◽  
B Verhasselt ◽  
B Vandekerckhove
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Development ◽  
Cell Development ◽  
Molecular Defect ◽  
Gamma Chain ◽  
Alpha Chain ◽  
Interleukin 7 ◽  
Human T Cell ◽  
Early Human

Highly purified human CD34+ fetal liver stem cells differentiate to mature T cells when seeded in vitro into isolated fetal thymic lobes of severe combined immunodeficient (SCID) mice followed by fetal thymus organ culture (FTOC). Here, this chimeric human-mouse FTOC was used to address the role of interleukin-7 (IL-7) and of the alpha chain of the IL-7 receptor (IL-7R alpha) in early human T-cell development. We report that addition of either the monoclonal antibody (MoAb) M25, which neutralizes both human and mouse IL-7, or the MoAb M21, which recognizes and blocks exclusively the human high-affinity alpha-chain of the IL-7R, results in a profound reduction in human thymic cellularity. Analysis of lymphoid subpopulations indicates that a highly reduced number of cells undergo maturation from CD34+ precursor cells toward CD4+CD3-CD1+ progenitor cells and subsequently toward CD4+CD8+ thymocytes. Our results reveal a critical role for IL-7 during early human thymocyte development, and may explain the absence or highly reduced levels of T cells in patients with X-linked SCID. The molecular defect in these patients has been shown to be a mutation in the gamma chain of the IL-2R. Although this gamma chain is not only present in the IL-2R, but also forms an essential part of other cytokine receptors, including IL-4, IL-7, IL-9, IL-13, and IL-15, the T- cell defect in these patients can be explained by the fact that IL-7 is not able to transduce its signal by the molecular defect of the common gamma (gamma c) chain and that IL-7 is indispensable for T-cell development.

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.

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