scholarly journals Mechanisms of tolerance induction in major histocompatibility complex class II-restricted T cells specific for a blood-borne self-antigen.

1994 ◽  
Vol 180 (6) ◽  
pp. 2089-2099 ◽  
Author(s):  
T Zal ◽  
A Volkmann ◽  
B Stockinger
Keyword(s):  
T Cell ◽  
Transgenic Mice ◽  
T Cell Receptor ◽  
Tolerance Induction ◽  
Cell Receptor ◽  
Double Positive ◽  
Single Positive ◽  
Self Antigen

Transgenic mice expressing a major histocompatibility complex class II-restricted T cell receptor with specificity for a natural self-antigen, the fifth component of complement, were generated to analyze the mechanism of tolerance induction to a blood-borne self-protein. In the absence of C5 protein thymocytes from T cell receptor transgenic mice develop into mature CD4 single positive cells which emigrate into the periphery and mount C5-specific T cell responses upon immunization with C5. In the presence of circulating C5 protein, CD4 single positive thymocytes do not develop. Negative selection occurs late in thymic ontogeny leaving the bulk of CD4+8+ thymocytes unaffected. This phenotype may be due to a delay in contact with self-antigen presentation which, under physiological conditions, is inefficient in the cortex of C5+ mice, and therefore does not affect most immature double positive thymocytes. In contrast, in vitro exposure to C5(-)-presenting dendritic cells or in vivo injection of C5 peptide results in deletion of double positive thymocytes. C5+ transgenic mice are tolerant in vivo, but contain T cells in spleen and lymph nodes that secrete interleukin 2 and interferon gamma in response to C5 activation in vitro. When crossed onto a Rag1-/- background to prevent endogenous T cell receptor rearrangements, these peripheral potentially autoreactive cells do not appear. This indicates that endogenous T cell receptor rearrangements possibly leading to the expression of two receptors might be a prerequisite for their survival and export into the periphery.

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.

scholarly journals Ig-specific T cell receptor-transgenic T cells are not deleted in the thymus and are functional in vivo.

1996 ◽  
Vol 183 (1) ◽  
pp. 203-213 ◽  
Author(s):  
F Granucci ◽  
M Rescigno ◽  
G Marconi ◽  
M Foti ◽  
P Ricciardi-Castagnoli
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cells ◽  
Transgenic Mice ◽  
Transgenic Mouse ◽  
T Cell Receptor ◽  
Cell Receptor ◽  
Cell Receptor Transgenic Mouse

The mechanisms that induce T cell tolerance to circulating self-proteins are still controversial, and both the deletion and selection of autoreactive T cells have been observed in the thymus of transgenic mouse models. To address the question of the induction of tolerance to circulating self-constituents, a T cell receptor-transgenic mouse specific for the serum protein immunoglobulin (Ig) gamma and (IgG2ab) was generated. The choice of an allotype-specific T cell also allowed the generation of transgenic control mice not expressing the self-antigen. It was found that the transgenic T cells were not deleted in the thymus, did not become tolerant in the periphery, and regulated the function of gamma 2ab-positive B cells as shown by the lack of IgG2ab protein in the serum of the transgenic mice. In spite of this activity in vivo, the transgenic T cells did not proliferate in vitro in response to the allotype-specific peptide. Interestingly, antigen-specific T cell proliferation could be restored if the transgenic mice were previously challenged to induce IgG2ab responses. After this challenge, IgG2ab protein in the serum of the transgenic mice could be partially restored, although still remaining much lower than in control mice. In addition, there was a dramatic increase in serum IgE levels, suggesting that newly generated gamma 2ab-secreting B cells can be induced to switch to IgE in the presence of allotype-specific T cells. These results indicate that Ig-specific T cells may represent a late-acting form of T cell help for the regulation of the IgG2a-to-IgE class switch.

scholarly journals B cells solicit their own help from T cells.

1996 ◽  
Vol 183 (3) ◽  
pp. 891-899 ◽  
Author(s):  
B Stockinger ◽  
T Zal ◽  
A Zal ◽  
D Gray
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cells ◽  
Transgenic Mice ◽  
Cell Receptor ◽  
Type Contact ◽  
Antigen Presenting ◽  
Self Antigen

We have made use of T cell receptor (TCR)-transgenic mice with CD4+ T cells expressing a receptor specific for the self-antigen C5 (fifth component of complement) to study the role of different antigen-presenting cells in the determination of CD4+ T cell effector type. Contact of T cells from C5 TCR-transgenic mice with C5 protein or C5 peptide in vivo or in vitro induces biased T helper cell (Th) 1 type responses resulting in exclusive production of high levels of interferon gamma and interleukin (IL) 2. Transgenic mice, in contrast to nontransgenic littermates, do not generate an antibody response to C5. We show in this paper that B cell presentation in vitro induces a switch to the Th2 subset indicated by production of IL-4, and targetting C5 to B cells in vivo results in the generation of C5-specific antibodies.

scholarly journals CD4+ T Cells from Glutamic Acid Decarboxylase (GAD)65-specific T Cell Receptor Transgenic Mice Are Not Diabetogenic and Can Delay Diabetes Transfer

2002 ◽  
Vol 196 (4) ◽  
pp. 481-492 ◽  
Author(s):  
Kristin V. Tarbell ◽  
Mark Lee ◽  
Erik Ranheim ◽  
Cheng Chi Chao ◽  
Maija Sanna ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Transgenic Mice ◽  
T Cell Receptor ◽  
Glutamic Acid Decarboxylase ◽  
Cd4 T Cells ◽  
Cell Receptor ◽  
Acid Decarboxylase ◽  
Gad 65

Glutamic acid decarboxylase (GAD)65 is an early and important antigen in both human diabetes mellitus and the nonobese diabetic (NOD) mouse. However, the exact role of GAD65-specific T cells in diabetes pathogenesis is unclear. T cell responses to GAD65 occur early in diabetes pathogenesis, yet only one GAD65-specific T cell clone of many identified can transfer diabetes. We have generated transgenic mice on the NOD background expressing a T cell receptor (TCR)-specific for peptide epitope 286–300 (p286) of GAD65. These mice have GAD65-specific CD4+ T cells, as shown by staining with an I-Ag7(p286) tetramer reagent. Lymphocytes from these TCR transgenic mice proliferate and make interferon γ, interleukin (IL)-2, tumor necrosis factor (TNF)-α, and IL-10 when stimulated in vitro with GAD65 peptide 286–300, yet these TCR transgenic animals do not spontaneously develop diabetes, and insulitis is virtually undetectable. Furthermore, in vitro activated CD4 T cells from GAD 286 TCR transgenic mice express higher levels of CTL-associated antigen (CTLA)-4 than nontransgenic littermates. CD4+ T cells, or p286-tetramer+CD4+ Tcells, from GAD65 286–300-specific TCR transgenic mice delay diabetes induced in NOD.scid mice by diabetic NOD spleen cells. This data suggests that GAD65 peptide 286–300-specific T cells have disease protective capacity and are not pathogenic.

scholarly journals 173 Expression of a membrane-tethered IL-15/IL-15 receptor fusion protein enhances the persistence of MSLN-targeted TRuC-T cells

2021 ◽  
Vol 9 (Suppl 3) ◽  
pp. A185-A185
Author(s):  
Michelle Fleury ◽  
Derrick McCarthy ◽  
Holly Horton ◽  
Courtney Anderson ◽  
Amy Watt ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Fusion Protein ◽  
T Cell Receptor ◽  
Cytokine Production ◽  
Cell Receptor ◽  
Great Promise ◽  
And Function

BackgroundAdoptive cell therapies have shown great promise in hematological malignancies but have yielded little progress in the context of solid tumors. We have developed T cell receptor fusion construct (TRuC®) T cells, which are equipped with an engineered T cell receptor that utilizes the full complement of TCR signaling subunits and recognizes tumor-associated antigens independent of HLA. In clinical trials, mesothelin (MSLN)-targeting TRuC-T cells (TC-210 or gavo-cel) have shown unprecedented results in patients suffering from advanced mesothelioma and ovarian cancer. To potentially increase the depth of response, we evaluated strategies that can promote intra-tumoral T cell persistence and function. Among the common ??-chain cytokines, IL-15 uniquely supports the differentiation and maintenance of memory T cell subsets by limiting terminal differentiation and conferring resistance to IL-2 mediated activation-induced cell death (AICD). In the studies described here, we evaluated the potential of IL-15 as an enhancement to TRuC-T cell phenotype, persistence and function against MSLN+ targets.MethodsPrimary human T cells were activated and transduced with a lentiviral vector encoding an anti-MSLN binder fused to CD3ε alone or co-expressed with a membrane-tethered IL-15rα/IL-15 fusion protein (IL-15fu). Transduced T cells were expanded for 9 days and characterized for expression of the TRuC, IL-15rα and memory phenotype before subjecting them to in vitro functional assays to evaluate cytotoxicity, cytokine production, and persistence. In vivo efficacy was evaluated in MHC class I/II deficient NSG mice bearing human mesothelioma xenografts.ResultsIn vitro, co-expression of the IL-15fu led to similar cytotoxicity and cytokine production as TC-210, but notably enhanced T-cell expansion and persistence upon repeated stimulation with MSLN+ cell lines. Furthermore, the IL-15fu-enhanced TRuC-T cells sustained a significantly higher TCF-1+ population and retained a stem-like phenotype following activation. Moreover, the IL-15fu-enhanced TRuCs demonstrated robust in vivo expansion and intra-tumoral accumulation as measured by ex vivo analysis of TRuC+ cells in the tumor and blood, with a preferential expansion of CD8+ T cells. Finally, IL-15fu-enhanced TRuC-T cells could be observed in the blood long after the tumors were cleared.ConclusionsThese pre-clinical studies suggest that the IL-15fu can synergize with TC-210 to increase the potency and durability of response in patients with MSLN+ tumors.Ethics ApprovalAll animal studies were approved by the respective Institutional Animal Care and Use Committees.

scholarly journals A Novel Approach for the Treatment of T Cell Malignancies: Targeting T Cell Receptor Vβ Families

Vaccines ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 631
Author(s):  
Jie Wang ◽  
Katarzyna Urbanska ◽  
Prannda Sharma ◽  
Reza Nejati ◽  
Lauren Shaw ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
T Cells ◽  
T Cell ◽  
T Cell Receptor ◽  
Cell Receptor ◽  
T Cell Lymphomas ◽  
Novel Approach ◽  
T Cell Malignancies

Peripheral T cell lymphomas (PTCLs) are generally chemotherapy resistant and have a poor prognosis. The lack of targeted immunotherapeutic approaches for T cell malignancies results in part from potential risks associated with targeting broadly expressed T cell markers, namely T cell depletion and clinically significant immune compromise. The knowledge that the T cell receptor (TCR) β chain in human α/β TCRs are grouped into Vβ families that can each be targeted by a monoclonal antibody can therefore be exploited for therapeutic purposes. Here, we develop a flexible approach for targeting TCR Vβ families by engineering T cells to express a chimeric CD64 protein that acts as a high affinity immune receptor (IR). We found that CD64 IR-modified T cells can be redirected with precision to T cell targets expressing selected Vβ families by combining CD64 IR-modified T cells with a monoclonal antibody directed toward a specific TCR Vβ family in vitro and in vivo. These findings provide proof of concept that TCR Vβ-family-specific T cell lysis can be achieved using this novel combination cell–antibody platform and illuminates a path toward high precision targeting of T cell malignancies without substantial immune compromise.

scholarly journals Evidence for in vivo clonal proliferation of unique population of blood CD4-/CD8- T cells bearing T-cell receptor alpha and beta chains in two normal men

Blood ◽  
1992 ◽  
Vol 79 (11) ◽  
pp. 2965-2972 ◽  
Author(s):  
Y Kusunoki ◽  
Y Hirai ◽  
S Kyoizumi ◽  
M Akiyama
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Receptor ◽  
Nk Cell ◽  
Cell Receptor ◽  
Cell Markers ◽  
Clonal Proliferation ◽  
Alpha Beta

Abstract Rare T lymphocytes bearing CD3 surface antigen and T-cell receptor (TCR) alpha and beta chains, but lacking both CD4 and CD8 antigens, viz, TCR alpha beta+CD4–8- cells, appear at a frequency of 0.1% to 2% in peripheral blood TCR alpha beta+ cells of normal donors. Here we report two unusual cases, found among 100 healthy individuals studied, who showed an abnormally elevated frequency of these T cells, ie, 5% to 10% and 14% to 19%. Southern blot analyses of the TCR alpha beta+CD4–8- clones all showed the identical rearrangement patterns for each individual, demonstrating that these are derivatives of a single T cell. The same rearrangement patterns were also observed for the freshly isolated lymphocytes of TCR alpha beta+CD4-CD8- fraction, which excludes the possible bias in the processes of in vitro cloning. These TCR alpha beta+CD4–8- T cells were found to express other mature T-cell markers such as CD2, CD3, and CD5 antigens, as well as natural killer (NK) cell markers (CD11b, CD16, CD56, and CD57 antigens) for both individuals. Further, although lectin-dependent or redirected antibody- dependent cell-mediated cytotoxicities were observed for both freshly sorted lymphocytes of TCR alpha beta+CD4–8- fraction and in vitro established clones, NK-like activity was not detected.

scholarly journals The Caspase 8 Inhibitor c-FLIPL Modulates T-Cell Receptor-Induced Proliferation but Not Activation-Induced Cell Death of Lymphocytes

2002 ◽  
Vol 22 (15) ◽  
pp. 5419-5433 ◽  
Author(s):  
Susanne M. A. Lens ◽  
Takao Kataoka ◽  
Karen A. Fortner ◽  
Antoine Tinel ◽  
Isabel Ferrero ◽  
...  
Keyword(s):  
T Cells ◽  
Cell Death ◽  
T Cell ◽  
T Cell Receptor ◽  
Death Receptor ◽  
Cell Receptor ◽  
Caspase 8 ◽  
Activation Induced Cell Death

ABSTRACT The caspase 8 inhibitor c-FLIPL can act in vitro as a molecular switch between cell death and growth signals transmitted by the death receptor Fas (CD95). To elucidate its function in vivo, transgenic mice were generated that overexpress c-FLIPL in the T-cell compartment (c-FLIPL Tg mice). As anticipated, FasL-induced apoptosis was inhibited in T cells from the c-FLIPL Tg mice. In contrast, activation-induced cell death of T cells in c-FLIPL Tg mice was unaffected, suggesting that this deletion process can proceed in the absence of active caspase 8. Accordingly, c-FLIPL Tg mice differed from Fas-deficient mice by showing no accumulation of B220+ CD4− CD8− T cells. However, stimulation of T lymphocytes with suboptimal doses of anti-CD3 or antigen revealed increased proliferative responses in T cells from c-FLIPL Tg mice. Thus, a major role of c-FLIPL in vivo is the modulation of T-cell proliferation by decreasing the T-cell receptor signaling threshold.

Functional and Molecular Analysis of Maturation of Thymocytes in Bcl10 or Malt1 Deficient Mice.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 3323-3323
Author(s):  
Philipp J. Jost ◽  
Uta Ferch ◽  
Stephanie Weiss ◽  
Stephanie Leeder ◽  
Olaf Gross ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Transgenic Animals ◽  
Adaptor Proteins ◽  
Cell Receptor ◽  
Single Positive ◽  
T Cell Selection ◽  
Deficient Mice

Abstract Development of immature T cells in the thymus requires signals through the clonotypic T cell receptor (TCR). Thymocytes expressing a functionally inactive or autoreactive TCR are deleted via apoptosis (negative selection). Thymocytes expressing a functionally active but not autoreactive TCR are selected through inhibition of cell death (positive selection). Deregulation of this process is likely to result in autoimmunity or lymphomagenesis of T cells. The intracellular mechanisms by which the balance between TCR-dependent survival and apoptosis are regulated are largely unknown. A central regulator of survival and apoptosis in the immune system is the transcription factor NF-κB. Activation of NF-κB in mature T-cells requires the adaptor proteins Bcl10 and Malt1. Using gene-targeted mice deficient for Bcl10 or Malt1, we show that Bcl10 and Malt1 are also required for TCR-induced NF-κB activation in immature T cells. Furthermore, to elucidate the process of T cell selection within the thymus, we have crossed Bcl10 or Malt1 deficient mice into mice with genetic backgrounds expressing defined TCR transgenes. Using specific peptide agonists of these TCR transgenes, we show that neither in vivo nor in vitro development into single positive (SP) CD4 or CD8 positive T cells is altered in Bcl10 or Malt1 deficient mice. Absolute numbers and ratio of SP T cells found within the thymus or in peripheral lymphnodes of transgenic animals are normal. These findings indicate that Bcl10 and Malt1 activate NF-κB in thymocytes but are dispensable for maturation of immature T cells in this model system.

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