scholarly journals Disruption of Mekk2 in Mice Reveals an Unexpected Role for MEKK2 in Modulating T-Cell Receptor Signal Transduction

2002 ◽  
Vol 22 (16) ◽  
pp. 5761-5768 ◽  
Author(s):  
Zijian Guo ◽  
Gavin Clydesdale ◽  
Jinke Cheng ◽  
Kihwan Kim ◽  
Lin Gan ◽  
...  

ABSTRACT MEKK2 is a member of the mitogen-activated protein kinase (MAPK) kinase kinase gene family involved in regulating multiple MAPK signaling pathways. To elucidate the in vivo function of MEKK2, we generated mice carrying a targeted mutation in the Mekk2 locus. Mekk2 −/− mice are viable and fertile. Major subsets of thymic and spleen T cells in Mekk2-deficient mice were indistinguishable from those in wild-type mice. B-cell development appeared to proceed similarly in the bone marrow of Mekk2-deficient and wild-type mice. However, Mekk2 −/− T-cell proliferation was augmented in response to anti-CD3 monoclonal antibody (MAb) stimulation, and these T cells produced more interleukin 2 and gamma interferon than did the wild-type T cells, suggesting that MEKK2 may be involved in controlling the strength of T-cell receptor (TCR) signaling. Consistently, Mekk2 −/− thymocytes were more susceptible than wild-type thymocytes to anti-CD3 MAb-induced cell death. Furthermore, TCR-mediated c-Jun N-terminal kinase activation was not blocked but moderately enhanced in Mekk2 −/− T cells. Neither extracellular signal-regulated kinase nor p38 MAPK activation was affected in Mekk2 −/− T cells. In conclusion, we found that MEKK2 may be required for controlling the strength of TCR/CD3 signaling.

2001 ◽  
Vol 194 (6) ◽  
pp. 719-732 ◽  
Author(s):  
Saied Mirshahidi ◽  
Ching-Tai Huang ◽  
Scheherazade Sadegh-Nasseri

Induction of tolerance in self-reactive memory T cells is an important process in the prevention of autoimmune responses against peripheral self-antigens in autoimmune diseases. Although naive T cells can readily be tolerized, memory T cells are less susceptible to tolerance induction. Recently, we demonstrated that low avidity engagement of T cell receptor (TCR) by low densities of agonist peptides induced anergy in T cell clones. Since memory T cells are more responsive to lower antigenic stimulation, we hypothesized that a low avidity TCR engagement may induce tolerance in memory T cells. We have explored two antigenic systems in two transgenic mouse models, and have tracked specific T cells that are primed and show memory phenotype. We demonstrate that memory CD4+ T cells can be rendered anergic by presentation of low densities of agonist peptide–major histocompatibility complex complexes in vivo. We rule out other commonly accepted mechanisms for induction of T cell tolerance in vivo, such as deletion, ignorance, or immunosuppression. Anergy is the most likely mechanism because addition of interleukin 2–reversed anergy in specific T cells. Moreover, cytotoxic T lymphocyte antigen (CTLA)-4 plays a critical role in the induction of anergy because we observed that there was increased surface expression of CTLA-4 on anergized T cells, and that injection of anti–CTLA-4 blocking antibody restored anergy in vivo.


Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 3830-3830
Author(s):  
Yasmine Van Caeneghem ◽  
Glenn Goetgeluk ◽  
Sylvia Snauwaert ◽  
Fritz Offner ◽  
Reno Debets ◽  
...  

Abstract T cell therapy for the treatment of malignant diseases is based on the lenti- or retroviral introduction of an exogenous receptor in peripheral blood T cells. The exogenous receptor is either antibody based or T cell receptor (TCR) based. Chimeric antigen receptors (CAR) are antibody based receptors that can redirect T cells against membrane antigens expressed by malignant cells. CD19-specific CARs were reported to be very effective in the treatment of CD19+ acute leukemias. To redirect T cells based on cytoplasmic antigens, transduction of a TCR is required. However, this approach still faces technical problems, esp. interference of the endogenous TCR chains may cause loss of avidity and possibly induction of autoimmunity. We here present an alternative strategy, in which, not mature T cells but CD34+ hematopoietic precursor cells are transduced and subsequently differentiated to mature T cells after introduction of a wild type TCR or of a fusion TCR:CD3ζ with or without costimulator signal. When Wilms tumor 1 (WT1)/HLA-A2-specific T cell receptor α and β chain is introduced in CD34+ cells derived from human thymus, cord blood or adult mobilized precursor cells and subsequently induced to differentiate to T cells on OP9 stromal cells expressing Delta-like ligand 1(OP9-DL1) in the presence of stem cell factor, flt3 ligand and interleukin 7, massive proliferation is observed while the cells differentiate to CD4+CD8+double positive (DP) transduced TCR+ immature cells. Few mature T cells are generated in these cultures, but after addition of the specific peptide to HLA-A2+ cultures, DP cells rapidly differentiate to phenotypically mature naïve CD8 single positive T cells. Upon activation, these T cells specifically lyse WT1/HLA-A2 cell lines and produce interferon-γ. Microarray expression analysis revealed these culture-generated T cells to be similar to TCR-transduced peripheral blood T cells, except for 1) the expression of only one TCR α and β chain by the in vitro generated T cells and 2) the underexpression of costimulatory/inhibitory molecules such as CD28, CTLA-4 and PD-L1. The absence of CD28 on the cell membrane was confirmed by flow cytometry. Since it was shown that CD28 signaling is essential for in vivo functionality using CARs, we next generated fusion TCR constructs of a gp100/HLA-A2-specific TCR and the signaling cassettes of CD3ζ and CD28.The following constructs were introduced in CD34+ cells: wild type TCR, TCR:ζ or TCR:CD28ζ α and β chains. The α and β chain double-transduced cells were subsequently cultured on OP9-DL1 in the absence of the specific antigen. It was observed that TCR:ζ transduced precursors proliferated significantly less than wild type TCR transduced cells, but the majority of the cells differentiated towards DP TCR:ζ+ cells, which upon addition of the specific antigen differentiated to phenotypically mature T cells. TCR:CD28ζ transduced cells proliferated least of all and spontaneously matured to functional double negative T cells without passing through the DP stage. These observations are compatible with data obtained in mice showing that strong TCR activation during thymocyte differentiation inhibits the generation of DP cells. In all of these cultures, endogenous TCR rearrangements were suppressed, which resulted in single receptor tumoricidal cells. Functional analysis of these various cell populations showed similar proliferation on T cell growth factors and specific cytolytic activity of gp100+ HLA-A2+ tumor lines. However, the TCR:CD28ζ transduced cells produced significantly higher levels of TNFα and interferon-γ and were the only ones that produced interleukin-2 upon specific stimulation. In conclusion, we have shown that high numbers of polyfunctional single receptor TCR:CD28ζ+ cells can be generated in vitro from clinically relevant stem cell sources. These cells produce interleukin-2, TNFα and interferon-γ and specifically kill gp100/HLA-A2+ tumor cell lines. Disclosures No relevant conflicts of interest to declare.


2010 ◽  
Vol 207 (5) ◽  
pp. 1031-1044 ◽  
Author(s):  
Konstanze Pechloff ◽  
Julian Holch ◽  
Uta Ferch ◽  
Marc Schweneker ◽  
Kristina Brunner ◽  
...  

Peripheral T cell lymphomas (PTCLs) are highly aggressive malignancies with poor prognosis. Their molecular pathogenesis is not well understood and small animal models for the disease are lacking. Recently, the chromosomal translocation t(5;9)(q33;q22) generating the interleukin-2 (IL-2)–inducible T cell kinase (ITK)–spleen tyrosine kinase (SYK) fusion tyrosine kinase was identified as a recurrent event in PTCL. We show that ITK-SYK associates constitutively with lipid rafts in T cells and triggers antigen-independent phosphorylation of T cell receptor (TCR)–proximal proteins. These events lead to activation of downstream pathways and acute cellular outcomes that correspond to regular TCR ligation, including up-regulation of CD69 or production of IL-2 in vitro or deletion of thymocytes and activation of peripheral T cells in vivo. Ultimately, conditional expression of patient-derived ITK-SYK in mice induces highly malignant PTCLs with 100% penetrance that resemble the human disease. Our work demonstrates that constitutively enforced antigen receptor signaling can, in principle, act as a powerful oncogenic driver. Moreover, we establish a robust clinically relevant and genetically tractable model of human PTCL.


1994 ◽  
Vol 14 (2) ◽  
pp. 1095-1103
Author(s):  
A L Burkhardt ◽  
T Costa ◽  
Z Misulovin ◽  
B Stealy ◽  
J B Bolen ◽  
...  

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.


1987 ◽  
Vol 7 (12) ◽  
pp. 4472-4481
Author(s):  
C H June ◽  
J A Ledbetter ◽  
M M Gillespie ◽  
T Lindsten ◽  
C B Thompson

CD28 is a homodimeric glycoprotein expressed on the surface of a major subset of human T cells that has recently been identified as a member of the immunoglobulin supergene family. The binding of monoclonal antibodies to the CD28 antigen on purified T cells does not result in proliferation; however, previous studies have shown that the combination of CD28 stimulation and protein kinase C activation by phorbol myristate acetate (PMA) results in T-cell proliferation that is independent of both accessory cells and activation of the T-cell receptor-CD3 complex. In the present study, effects of stimulation by anti-CD28 on cell cycle progression and on the interleukin 2 (IL-2) and IL-2 receptor system have been investigated on primary cultures of purified peripheral-blood CD28+ T cells. There was no measurable effect on cell size or on DNA synthesis after stimulation of resting (G0) cells by CD28 alone. After 3 h of activation of T cells by PMA alone, a slight (8%) increase in cell volume occurred that did not progress to DNA synthesis. In contrast, T-cell stimulation by CD28 in combination with PMA resulted in a progressive increase in cell volume in approximately 100% of cells at 12 to 14 h after stimulation. Northern blot (RNA blot) analysis revealed that CD28 stimulation alone failed to cause expression of the alpha chain of the IL-2 receptor or of IL-2 mRNA, and in accord with previous studies, stimulation by PMA alone resulted in the accumulation of IL-2 receptor transcripts but no detectable IL-2 mRNA. In contrast, T-cell stimulation by the combination of CD28 and PMA resulted in the appearance of IL-2 transcripts and enhanced expression of IL-2 receptor mRNA. Functional studies revealed that the proliferation induced by CD28 and PMA stimulation was entirely resistant to cyclosporine, in contrast to T-cell activation induced by the CD3-T-cell receptor complex. Cyclosporine was found not to affect the accumulation of IL-2 mRNA after CD28 plus PMA stimulation, although there was no detectable IL-2 mRNA after stimulation by CD3 in the presence of the drug. Furthermore, stimulation by CD28 in combination with immobilized CD3 antibodies caused a striking enhancement of IL-2 mRNA expression that was, in part, resistant to the effects of cyclosporine. These studies indicate that the CD28 molecule synergizes with protein kinase C activation to induce IL-2 gene expression and demonstrate that stimulation by the CD28 pathway can cause vigorous T-cell proliferation even in the presence of cyclosporine and that cyclosporine does not prevent transcription of 16-2 mRNA, as has been suggested previously. Moreover, these findings suggest that a potential role for the CD28 molecule in vivo may be to augment IL-2 production after stimulation of the CD3-T-cell receptor molecular complex and thereby to amplify an antigen-specific immune response. Finally, these results provide further evidence that the CD28 molecule triggers T-cell proliferation in a manner that differs biochemically from CD3-T-cell receptor-induced proliferation.


1995 ◽  
Vol 182 (3) ◽  
pp. 759-767 ◽  
Author(s):  
K Sato ◽  
K Ohtsuka ◽  
K Hasegawa ◽  
S Yamagiwa ◽  
H Watanabe ◽  
...  

In addition to the major intrathymic pathway of T cell differentiation, extrathymic pathways of such differentiation have been shown to exist in the liver and intestine. In particular, hepatic T cells of T cell receptors or CD3 of intermediate levels (i.e., intermediate T cell receptor cells) always contain self-reactive clones and sometimes appear at other sites, including the target tissues in autoimmune diseases and the tumor sites in malignancies. To prove their extrathymic origin and self reactivity, in this study we used thymectomized, irradiated (B6 x C3H/He) F1 mice subjected to transplantation of bone marrow cells of B6 mice. It was clearly demonstrated that all T cells generated under athymic conditions in the peripheral immune organs are intermediate CD3 cells. In the case of nonthymectomized irradiated mice, not only intermediate CD3 cells but also high CD3 cells were generated. Phenotypic characterization showed that newly generated intermediate CD3 cells were unique (e.g., interleukin 2 receptor alpha-/beta+ and CD44+ L-selectin-) and were, therefore, distinguishable from thymus-derived T cells. The precursor cells of intermediate CD3 cells in the bone marrow were Thy-1+ CD3-. The extrathymic generation of intermediate CD3 cells was confirmed in other combinations of bone marrow transplantation, C3H --> C3H and B10.Thy1.1 --> B6.Thy1.2. The generated intermediate CD3 cells in the liver contained high levels of self-reactive clones estimated by anti-V beta monoclonal antibodies in conjunction with the endogenous superantigen minor lymphocyte-stimulating system, especially the combination of B6 --> (B6 x C3H/He) (graft-versus-host-situation).(ABSTRACT TRUNCATED AT 250 WORDS)


2001 ◽  
Vol 75 (2) ◽  
pp. 1065-1071 ◽  
Author(s):  
Mineki Saito ◽  
Graham P. Taylor ◽  
Akiko Saito ◽  
Yoshitaka Furukawa ◽  
Koichiro Usuku ◽  
...  

ABSTRACT Using HLA-peptide tetrameric complexes, we isolated human T-cell lymphotrophic virus type 1 Tax peptide-specific CD8+ T cells ex vivo. Antigen-specific amino acid motifs were identified in the T-cell receptor Vβ CDR3 region of clonally expanded CD8+ T cells. This result directly confirms the importance of the CDR3 region in determining the antigen specificity in vivo.


2021 ◽  
Vol 9 (Suppl 3) ◽  
pp. A185-A185
Author(s):  
Michelle Fleury ◽  
Derrick McCarthy ◽  
Holly Horton ◽  
Courtney Anderson ◽  
Amy Watt ◽  
...  

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.


1999 ◽  
Vol 189 (10) ◽  
pp. 1531-1544 ◽  
Author(s):  
Calvin B. Williams ◽  
Deborah L. Engle ◽  
Gilbert J. Kersh ◽  
J. Michael White ◽  
Paul M. Allen

We have developed a unique in vivo system to determine the relationship between endogenous altered peptide ligands and the development of major histocompatibility complex class II– restricted T cells. Our studies use the 3.L2 T cell receptor (TCR) transgenic mouse, in which T cells are specific for Hb(64–76)/I-Ek and positively selected on I-Ek plus self-peptides. To this endogenous peptide repertoire, we have individually added one of six well-characterized 3.L2 ligands. This transgenic approach expands rather than constrains the repertoire of self-peptides. We find that a broad range of ligands produce negative selection of thymocytes in vivo. When compared with the in vitro TCR–ligand binding kinetics, we find that these negatively selecting ligands all have a half-life of 2 s or greater. Additionally, one of two ligands examined with no detectable binding to the 3.L2 TCR and no activity on mature 3.L2 T cells (Q72) enhances the positive selection of transgenic thymocytes in vivo. Together, these data establish a kinetic threshold between negative and positive selection based on the longevity of TCR–ligand complexes.


Blood ◽  
2010 ◽  
Vol 116 (25) ◽  
pp. 5560-5570 ◽  
Author(s):  
Karla R. Wiehagen ◽  
Evann Corbo ◽  
Michelle Schmidt ◽  
Haina Shin ◽  
E. John Wherry ◽  
...  

Abstract The requirements for tonic T-cell receptor (TCR) signaling in CD8+ memory T-cell generation and homeostasis are poorly defined. The SRC homology 2 (SH2)-domain–containing leukocyte protein of 76 kDa (SLP-76) is critical for proximal TCR-generated signaling. We used temporally mediated deletion of SLP-76 to interrupt tonic and activating TCR signals after clearance of the lymphocytic choriomeningitis virus (LCMV). SLP-76–dependent signals are required during the contraction phase of the immune response for the normal generation of CD8 memory precursor cells. Conversely, LCMV-specific memory CD8 T cells generated in the presence of SLP-76 and then acutely deprived of TCR-mediated signals persist in vivo in normal numbers for more than 40 weeks. Tonic TCR signals are not required for the transition of the memory pool toward a central memory phenotype, but the absence of SLP-76 during memory homeostasis substantially alters the kinetics. Our data are consistent with a model in which tonic TCR signals are required at multiple stages of differentiation, but are dispensable for memory CD8 T-cell persistence.


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