scholarly journals Role of Different T Cell Receptors in the Development of Pre–T Cells

1997 ◽  
Vol 185 (9) ◽  
pp. 1541-1548 ◽  
Author(s):  
Jan Buer ◽  
Iannis Aifantis ◽  
James P. DiSanto ◽  
Hans Joerg Fehling ◽  
Harald von Boehmer
Keyword(s):  
T Cells ◽  
Cell Death ◽  
T Cell ◽  
Programmed Cell Death ◽  
T Cell Receptor ◽  
T Cell Receptors ◽  
Cell Receptor ◽  
Double Function ◽  
Αβ T Cells

The development of pre–T cells with productive TCR-β rearrangements can be mediated by each the pre–T cell receptor (pre-TCR), the TCR-αβ as well as the TCR-γδ, albeit by distinct mechanisms. Although the TCR-γδ affects CD4−8− precursor cells irrespective of their rearrangement status by TCR-β mechanisms not involving TCR-β selection, both the preTCR and the TCR-αβ select only cells with productive TCR-β genes for expansion and maturation. The TCR-αβ appears to be much less effective than the pre-TCR because of the paucity of TCR-α proteins in TCR-β–positive precursors since an early expressed transgenic TCR-αβ can largely substitute for the pre-TCR. Thus, the TCR-αβ can assume a role not only in the rescue from programmed cell death of CD4+8+ but also of CD4−8− thymocytes. In evolution this double function of the TCR-αβ may have been responsible for the maturation of αβ T cells before the advent of the pre–TCR-α chain.

scholarly journals Donor γδ T Lymphocytes Promote Allogeneic Engraftment Across the Major Histocompatibility Barrier in Mice

Blood ◽  
1997 ◽  
Vol 89 (3) ◽  
pp. 1100-1109 ◽  
Author(s):  
William R. Drobyski ◽  
David Majewski
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Receptor ◽  
Γδ T Cells ◽  
Cell Receptor ◽  
Marrow Graft ◽  
Hematopoietic Reconstitution ◽  
Donor T Cells ◽  
Αβ T Cells

Abstract T cells that express the αβ T-cell receptor are thought to be the T-cell population primarily responsible for facilitating alloengraftment. The role of γδ+ T cells that comprise only a minority of mature T cells in promoting allogeneic engraftment, however, has not been extensively studied. The purpose of this study was to determine whether γδ T cells were capable of facilitating alloengraftment in murine recipients of major histocompatibility complex-mismatched marrow grafts. We developed a model where engraftment of C57BL/6 × 129/F2 (H-2b) marrow in sublethally irradiated (800 cGy) recipients (AKR/J, H-2k) is dependent on the presence of mature donor T cells in the marrow graft. In this model, donor T-cell engraftment was significantly augmented by as few as 1 × 105 αβ T cells. The role of γδ T cells was then investigated using transgenic donors (C57BL/6 × 129 background) in which a portion of the T-cell receptor–β chain gene was deleted by gene targeting so that these mice lack αβ T cells. Addition of 10 × 106 naive γδ T cells to T-cell depleted marrow grafts was required to significantly increase alloengraftment, although donor T cells averaged <50% of total splenic T cells. To determine whether higher doses of γδ T cells would improve donor engraftment and eradicate residual host T cells, γδ T cells were ex vivo expanded with a γδ T-cell–specific monoclonal antibody and interleukin-2 and then transplanted into irradiated recipients. Transplantation of ≥ 160 × 106 activated γδ T cells was necessary to consistently and significantly augment donor cell chimerism and enhance hematopoietic reconstitution when compared to control mice, but host T cells persisted in these chimeras. Addition of 2.5 × 104 mature αβ T cells, which alone were incapable of facilitating engraftment, to T-cell depleted marrow grafts containing 160 × 106 activated γδ T cells resulted in long-term (<100 day) complete donor engraftment, indicating that limiting numbers of αβ T cells were required in the marrow graft for the eradication of residual host T cells. Using serial weight curves and B-cell reconstitution as end points, clinically significant graft-versus-host disease was not observed in these chimeras under these experimental conditions. These data show that, whereas less potent than αβ T cells, γδ T cells are able to promote engraftment and enhance hematopoietic reconstitution in allogeneic marrow transplant recipients.

scholarly journals The Distinct Contributions of Murine T Cell Receptor (TCR)γδ+ and TCRαβ+ T Cells to Different Stages of Chemically Induced Skin Cancer

2003 ◽  
Vol 198 (5) ◽  
pp. 747-755 ◽  
Author(s):  
Michael Girardi ◽  
Earl Glusac ◽  
Renata B. Filler ◽  
Scott J. Roberts ◽  
Iva Propperova ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Receptor ◽  
Cell Receptor ◽  
Intraepithelial Lymphocytes ◽  
Tumor Promoter ◽  
Cell Type ◽  
Chemically Induced ◽  
Αβ T Cells

Epithelial tissues in which carcinomas develop often contain systemically derived T cell receptor (TCR)αβ+ cells and resident intraepithelial lymphocytes that are commonly enriched in TCRγδ+ cells. Recent studies have demonstrated that γδ cells protect the host against chemically induced cutaneous malignancy, but the role of αβ T cells has been enigmatic, with both protective and tumor-enhancing contributions being reported in different systems. This study aims to clarify the contributions of each T cell type to the regulation of squamous cell carcinoma induced in FVB mice by a two-stage regimen of 7,12-dimethylbenz[a]anthracene initiation followed by repetitive application of the tumor promoter 12-O-tetradecanoylphorbol 13-acetate. This protocol permits one to monitor the induction of papillomas and the progression of those papillomas to carcinomas. The results show that whereas γδ cells are strongly protective, the nonredundant contributions of αβ T cells to the host's protection against papillomas are more modest. Furthermore, at both high and low doses of carcinogens, αβ T cells can contribute to rather than inhibit the progression of papillomas to carcinomas. As is likely to be the case in humans, this study also shows that the contribution of T cells to tumor immunosurveillance is regulated by modifier genes.

scholarly journals Protease inhibitors selectively block T cell receptor-triggered programmed cell death in a murine T cell hybridoma and activated peripheral T cells.

1993 ◽  
Vol 178 (5) ◽  
pp. 1693-1700 ◽  
Author(s):  
A Sarin ◽  
D H Adams ◽  
P A Henkart
Keyword(s):  
T Cells ◽  
Cell Death ◽  
T Cell ◽  
Programmed Cell Death ◽  
Serine Protease ◽  
Protease Inhibitors ◽  
T Cell Receptor ◽  
Cell Receptor ◽  
Cross Linking ◽  
Serine Protease Inhibitors

The hypothesis that cytoplasmic proteases play a functional role in programmed cell death was tested by examining the effect of protease inhibitors on the T cell receptor-mediated death of the 2B4 murine T cell hybridoma and activated T cells. The cysteine protease inhibitors trans-epoxysuccininyl-L-leucylamido-(4-guanidino) butane (E-64) and leupeptin, the calpain selective inhibitor acetyl-leucyl-leucyl-normethional, and the serine protease inhibitors diisopropyl fluorophosphate and phenylmethylsulfonyl fluoride, all showed dose-dependent blocking of the 2B4 death response triggered by the T cell receptor complex and by anti-Thy-1. These protease inhibitors enhanced rather than inhibited IL-2 secretion triggered by T cell receptor cross-linking, showing that they did not act by preventing signal transduction. Growth inhibition induced by cross-linking the 2B4 T cell receptor, measured by inhibition of thymidine incorporation, was not generally blocked by these protease inhibitors. All five of these protease inhibitors enhanced rather than blocked 2B4 cell death triggered by dexamethasone, an agent previously shown to have a death pathway antagonistic with that of the TCR. 2B4 cytolysis by the cytotoxic agents staphylococcal alpha-toxin and dodecyl imidazole, and that caused by hypotonic conditions, was not significantly affected by the five protease inhibitors tested. The selected protease inhibitors blocked both the apoptotic nuclear morphology changes and DNA fragmentation induced by T cell receptor cross-linking, and enhanced both these properties induced by dexamethasone in 2B4 cells. The T cell receptor-induced death of activated murine lymph node T cells and human peripheral blood CD4+ T cells was blocked by both cysteine and serine protease inhibitors, showing that the protease-dependent death pathway also operates in these systems.

Distinct Regulation of T-Cell Death by CD28 Depending on Both Its Aggregation and T-Cell Receptor Triggering: A Role for Fas-FasL

Blood ◽  
1998 ◽  
Vol 92 (4) ◽  
pp. 1350-1363 ◽  
Author(s):  
Y. Collette ◽  
A. Benziane ◽  
D. Razanajaona ◽  
D. Olive
Keyword(s):  
T Cells ◽  
Cell Death ◽  
T Cell ◽  
T Cell Receptor ◽  
Cell Clone ◽  
Cell Receptor ◽  
Fasl Expression ◽  
T Cell Clone ◽  
Induced Apoptosis

CD28 is a major coreceptor that regulates cell proliferation, anergy, and viability of T cells. The negative selection by T-cell receptor (TCR)-induced cell death of immature thymocytes as well as of activated human antigen-specific T-cell clone, requires a costimulatory signal that can be provided by CD28. Conversely, CD28-mediated signals increase expression of Bcl-XL, a survival gene, and promote survival of naive T cells cultured in the absence of antigen or costimulation. Because CD28 appears to both protect from, or induce T-cell death, one important question is to define the activation and cellular parameters that dictate the differential role of CD28 in T-cell apoptosis. Here, we compared different CD28 ligands for their ability to regulate TCR-induced cell death of a murine T-cell hybridoma. In these cells, TCR triggering induced expression of Fas and FasL, and cell death was prevented by anti-Fas blocking monoclonal antibody (MoAb). When provided as a costimulus, both CD28 MoAb and the B7.1 and B7.2 counter receptors downregulated, yet did not completely abolish T-cell receptor–induced apoptosis. This CD28 cosignal resulted in both upregulation of Bcl-XL and prevention of FasL expression. In marked contrast, when given as a single signal, CD28 MoAb or B7.1 and B7.2 induced FasL expression and resulted in T-cell death by apoptosis, which was dependent on the level of CD28 ligation. Furthermore, triggering of CD28 upregulated FasL and induced a marked T-cell death of previously activated normal peripheral T cells. Our results identify Fas and FasL as crucial targets of CD28 in T-cell death regulation and show that within the same cell population, depending on its engagement as a single signal or as a costimulus together with the TCR, CD28 can either induce a dose-dependent death signal or protect from cell death, respectively. These data provide important insights into the role of CD28 in T-cell homeostasis and its possible implication in neoplastic disorders. © 1998 by The American Society of Hematology.

Distinct Regulation of T-Cell Death by CD28 Depending on Both Its Aggregation and T-Cell Receptor Triggering: A Role for Fas-FasL

Blood ◽  
1998 ◽  
Vol 92 (4) ◽  
pp. 1350-1363 ◽  
Author(s):  
Y. Collette ◽  
A. Benziane ◽  
D. Razanajaona ◽  
D. Olive
Keyword(s):  
T Cells ◽  
Cell Death ◽  
T Cell ◽  
T Cell Receptor ◽  
Cell Clone ◽  
Cell Receptor ◽  
Fasl Expression ◽  
T Cell Clone ◽  
Induced Apoptosis

Abstract CD28 is a major coreceptor that regulates cell proliferation, anergy, and viability of T cells. The negative selection by T-cell receptor (TCR)-induced cell death of immature thymocytes as well as of activated human antigen-specific T-cell clone, requires a costimulatory signal that can be provided by CD28. Conversely, CD28-mediated signals increase expression of Bcl-XL, a survival gene, and promote survival of naive T cells cultured in the absence of antigen or costimulation. Because CD28 appears to both protect from, or induce T-cell death, one important question is to define the activation and cellular parameters that dictate the differential role of CD28 in T-cell apoptosis. Here, we compared different CD28 ligands for their ability to regulate TCR-induced cell death of a murine T-cell hybridoma. In these cells, TCR triggering induced expression of Fas and FasL, and cell death was prevented by anti-Fas blocking monoclonal antibody (MoAb). When provided as a costimulus, both CD28 MoAb and the B7.1 and B7.2 counter receptors downregulated, yet did not completely abolish T-cell receptor–induced apoptosis. This CD28 cosignal resulted in both upregulation of Bcl-XL and prevention of FasL expression. In marked contrast, when given as a single signal, CD28 MoAb or B7.1 and B7.2 induced FasL expression and resulted in T-cell death by apoptosis, which was dependent on the level of CD28 ligation. Furthermore, triggering of CD28 upregulated FasL and induced a marked T-cell death of previously activated normal peripheral T cells. Our results identify Fas and FasL as crucial targets of CD28 in T-cell death regulation and show that within the same cell population, depending on its engagement as a single signal or as a costimulus together with the TCR, CD28 can either induce a dose-dependent death signal or protect from cell death, respectively. These data provide important insights into the role of CD28 in T-cell homeostasis and its possible implication in neoplastic disorders. © 1998 by The American Society of Hematology.

scholarly journals Ceramide Synthase 2 Null Mice Are Protected from Ovalbumin-Induced Asthma with Higher T Cell Receptor Signal Strength in CD4+ T Cells

2021 ◽  
Vol 22 (5) ◽  
pp. 2713
Author(s):  
Sun-Hye Shin ◽  
Kyung-Ah Cho ◽  
Hee-Soo Yoon ◽  
So-Yeon Kim ◽  
Hee-Yeon Kim ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Receptor ◽  
Cd4 T Cells ◽  
Acyl Chain ◽  
Signal Strength ◽  
Cell Receptor ◽  
Ceramide Synthase ◽  
Asthmatic Patients

(1) Background: six mammalian ceramide synthases (CerS1–6) determine the acyl chain length of sphingolipids (SLs). Although ceramide levels are increased in murine allergic asthma models and in asthmatic patients, the precise role of SLs with specific chain lengths is still unclear. The role of CerS2, which mainly synthesizes C22–C24 ceramides, was investigated in immune responses elicited by airway inflammation using CerS2 null mice. (2) Methods: asthma was induced in wild type (WT) and CerS2 null mice with ovalbumin (OVA), and inflammatory cytokines and CD4 (cluster of differentiation 4)+ T helper (Th) cell profiles were analyzed. We also compared the functional capacity of CD4+ T cells isolated from WT and CerS2 null mice. (3) Results: CerS2 null mice exhibited milder symptoms and lower Th2 responses than WT mice after OVA exposure. CerS2 null CD4+ T cells showed impaired Th2 and increased Th17 responses with concomitant higher T cell receptor (TCR) signal strength after TCR stimulation. Notably, increased Th17 responses of CerS2 null CD4+ T cells appeared only in TCR-mediated, but not in TCR-independent, treatment. (4) Conclusions: altered Th2/Th17 immune response with higher TCR signal strength was observed in CerS2 null CD4+ T cells upon TCR stimulation. CerS2 and very-long chain SLs may be therapeutic targets for Th2-related diseases such as asthma.

An obligate role for T-cell receptor αβ+ T cells but not T-cell receptor γδ+ T cells, B cells, or CD40/CD40L interactions in a mouse model of atopic dermatitis

2001 ◽  
Vol 107 (2) ◽  
pp. 359-366 ◽  
Author(s):  
Amy L. Woodward ◽  
Jonathan M. Spergel ◽  
Harri Alenius ◽  
Emiko Mizoguchi ◽  
Atul K. Bhan ◽  
...  
Keyword(s):  
T Cells ◽  
Atopic Dermatitis ◽  
T Cell ◽  
B Cells ◽  
Mouse Model ◽  
T Cell Receptor ◽  
Γδ T Cells ◽  
Cell Receptor ◽  
Αβ T Cells
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