scholarly journals Regulatory T cells engineered with TCR signaling–responsive IL-2 nanogels suppress alloimmunity in sites of antigen encounter

2020 ◽  
Vol 12 (569) ◽  
pp. eaaw4744
Author(s):  
Siawosh K. Eskandari ◽  
Ina Sulkaj ◽  
Mariane B. Melo ◽  
Na Li ◽  
Hazim Allos ◽  
...  
Keyword(s):  
T Cells ◽  
Regulatory T Cells ◽  
Ex Vivo ◽  
Interleukin 2 ◽  
Cell Receptor ◽  
Adoptive Cell Transfer ◽  
Protective Effects ◽  
Tcr Signaling ◽  
Reducing Conditions ◽  
Delivery Platform

Adoptive cell transfer of ex vivo expanded regulatory T cells (Tregs) has shown immense potential in animal models of auto- and alloimmunity. However, the effective translation of such Treg therapies to the clinic has been slow. Because Treg homeostasis is known to require continuous T cell receptor (TCR) ligation and exogenous interleukin-2 (IL-2), some investigators have explored the use of low-dose IL-2 injections to increase endogenous Treg responses. Systemic IL-2 immunotherapy, however, can also lead to the activation of cytotoxic T lymphocytes and natural killer cells, causing adverse therapeutic outcomes. Here, we describe a drug delivery platform, which can be engineered to autostimulate Tregs with IL-2 in response to TCR-dependent activation, and thus activate these cells in sites of antigen encounter. To this end, protein nanogels (NGs) were synthesized with cleavable bis(N-hydroxysuccinimide) cross-linkers and IL-2/Fc fusion (IL-2) proteins to form particles that release IL-2 under reducing conditions, as found at the surface of T cells receiving stimulation through the TCR. Tregs surface-conjugated with IL-2 NGs were found to have preferential, allograft-protective effects relative to unmodified Tregs or Tregs stimulated with systemic IL-2. We demonstrate that murine and human NG–modified Tregs carrying an IL-2 cargo perform better than conventional Tregs in suppressing alloimmunity in murine and humanized mouse allotransplantation models. In all, the technology presented in this study has the potential to improve Treg transfer therapy by enabling the regulated spatiotemporal provision of IL-2 to antigen-primed Tregs.

Repertoire Analysis of Ex Vivo Polyclonally Expanded Regulatory T Cells.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 3222-3222
Author(s):  
Jenny Zilberberg ◽  
Kira Goldgirsh ◽  
Robert Korngold ◽  
Thea M. Friedman
Keyword(s):  
T Cells ◽  
T Cell ◽  
Regulatory T Cells ◽  
Ex Vivo ◽  
Cell Receptor ◽  
Clinical Situation ◽  
Post Transplantation ◽  
Cell Repertoire ◽  
Hematopoietic Stem ◽  
Pcr Products

Abstract CD4+CD25+ regulatory T cells (Treg) are essential for the maintenance of self-tolerance and have also been implicated in the control of alloreactive immune responses. Several studies using murine models of graft-vs.-host disease (GVHD) have shown that addition of equivalent numbers of Treg to the donor T cell inoculum at time of hematopoietic stem cell transplantation can significantly reduce the incidence of GVHD. In addition, in an MHC-matched, minor histocompatibility disparate model, the infusion of Treg ten days post-transplantation was shown to ameliorate the progression of GVHD while permitting a graft-versus-leukemia effect. However, because Treg constitute <5% of peripheral CD4+ T cells in humans, the use of freshly isolated Treg to treat and/or prevent GVHD, as well as other diseases in the clinical situation, is limited. Therefore, much effort is now under way to expand Treg in order to have sufficient numbers for therapeutic use. There is little available information regarding the repertoire complexity of ex vivo, polyclonally expanded regulatory T cells. We hypothesize that like their CD4+CD25− T cell counterparts, the diversity of the Treg T cell receptor (TCR) repertoire will also be complex. To this end, CD4+CD25− and CD4+CD25+ T cells from B10.BR mice were purified using fluorescence activated cell sorting; both populations were polyclonally expanded using CD3/CD28 paramagnetic microbeads in combination with high levels (100 IU/ml) of hrIL-2. After achieving a greater than 50 fold expansion, RNA from 1–1.5×107 cells was isolated for RT-PCR. The complexity of the T cell repertoire of expanded CD4+CD25− and CD4+CD25+ was determined using TCR Vb CDR3-size spectratype analysis. The PCR products were run on a sequencing gel and analyzed by the GeneMapper Software from Applied Biosystems. This comparison revealed that the number of resolvable Vb families is more heterogeneous in the CD25− populations. Whether this reflected a lack of complexity in the regulatory repertoire warrants further investigation. However, for the resolvable Vb families there were no significant differences in the complexity indexes between these two groups.

scholarly journals Unc119, a Novel Activator of Lck/Fyn, Is Essential for T Cell Activation

2004 ◽  
Vol 199 (3) ◽  
pp. 369-379 ◽  
Author(s):  
Magdalena M. Gorska ◽  
Susan J. Stafford ◽  
Osman Cen ◽  
Sanjiv Sur ◽  
Rafeul Alam
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Cellular Proliferation ◽  
Interleukin 2 ◽  
Cell Receptor ◽  
The Novel ◽  
Tcr Signaling ◽  
Src Homology

The first step in T cell receptor for antigen (TCR) signaling is the activation of the receptor-bound Src kinases, Lck and Fyn. The exact mechanism of this process is unknown. Here, we report that the novel Src homology (SH) 3/SH2 ligand–Uncoordinated 119 (Unc119) associates with CD3 and CD4, and activates Lck and Fyn. Unc119 overexpression increases Lck/Fyn activity in T cells. In Unc119-deficient T cells, Lck/Fyn activity is dramatically reduced with concomitant decrease in interleukin 2 production and cellular proliferation. Reconstitution of cells with Unc119 reverses the signaling and functional outcome. Thus, Unc119 is a receptor-associated activator of Src-type kinases. It provides a novel mechanism of signal generation in the TCR complex.

scholarly journals T Cell Receptor–initiated Calcium Release Is Uncoupled from Capacitative Calcium Entry in Itk-deficient T Cells

1998 ◽  
Vol 187 (10) ◽  
pp. 1721-1727 ◽  
Author(s):  
Karen-Qianye Liu ◽  
Stephen C. Bunnell ◽  
Christine B. Gurniak ◽  
Leslie J. Berg
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Receptor ◽  
Calcium Release ◽  
Interleukin 2 ◽  
Cell Receptor ◽  
Calcium Entry ◽  
Tcr Signaling ◽  
Store Depletion ◽  
High Concentrations

Itk, a Tec family tyrosine kinase, plays an important but as yet undefined role in T cell receptor (TCR) signaling. Here we show that T cells from Itk-deficient mice have a TCR-proximal signaling defect, resulting in defective interleukin 2 secretion. Upon TCR stimulation, Itk−/− T cells release normal amounts of calcium from intracellular stores, but fail to open plasma membrane calcium channels. Since thapsigargin-induced store depletion triggers normal calcium entry in Itk−/− T cells, an impaired biochemical link between store depletion and channel opening is unlikely to be responsible for this defect. Biochemical studies indicate that TCR-induced inositol 1,4,5 tris-phosphate (IP3) generation and phospholipase C γ1 tyrosine phosphorylation are substantially reduced in Itk−/− T cells. In contrast, TCR-ζ and ZAP-70 are phosphorylated normally, suggesting that Itk functions downstream of, or in parallel to, ZAP-70 to facilitate TCR-induced IP3 production. These findings support a model in which quantitative differences in cytosolic IP3 trigger distinct responses, and in which only high concentrations of IP3 trigger the influx of extracellular calcium.

scholarly journals Membrane Raft-Dependent Regulation of Phospholipase Cγ-1 Activation in T Lymphocytes

2001 ◽  
Vol 21 (20) ◽  
pp. 6939-6950 ◽  
Author(s):  
Maria-Concetta Verı́ ◽  
Karen E. DeBell ◽  
Maria-Cristina Seminario ◽  
Angela DiBaldassarre ◽  
Ilona Reischl ◽  
...  
Keyword(s):  
T Cells ◽  
Lipid Rafts ◽  
Interleukin 2 ◽  
Cell Receptor ◽  
Jurkat Cells ◽  
Tcr Signaling ◽  
Surface Receptors ◽  
Influenza Virus Hemagglutinin ◽  
Tec Family Kinase ◽  
Signaling Components

ABSTRACT Numerous signaling molecules associate with lipid rafts, either constitutively or after engagement of surface receptors. One such molecule, phospholipase Cγ-1 (PLCγ1), translocates from the cytosol to lipid rafts during T-cell receptor (TCR) signaling. To investigate the role played by lipid rafts in the activation of this molecule in T cells, an influenza virus hemagglutinin A (HA)-tagged PLCγ1 was ectopically expressed in Jurkat T cells and targeted to these microdomains by the addition of a dual-acylation signal. Raft-targeted PLCγ1 was constitutively tyrosine phosphorylated and induced constitutive NF-AT-dependent transcription and interleukin-2 secretion in Jurkat cells. Tyrosine phosphorylation of raft-targeted PLCγ1 did not require Zap-70 or the interaction with the adapters Lat and Slp-76, molecules that are necessary for TCR signaling. In contrast, the Src family kinase Lck was required. Coexpression in HEK 293T cells of PLCγ1-HA with Lck or the Tec family kinase Rlk resulted in preferential phosphorylation of raft-targeted PLCγ1 over wild-type PLCγ1. These data show that localization of PLCγ1 in lipid rafts is sufficient for its activation and demonstrate a role for lipid rafts as microdomains that dynamically segregate and integrate PLCγ1 with other signaling components.

Induction of allopeptide-specific human CD4+CD25+ regulatory T cells ex vivo

Blood ◽  
2003 ◽  
Vol 102 (6) ◽  
pp. 2180-2186 ◽  
Author(s):  
Shuiping Jiang ◽  
Niels Camara ◽  
Giovanna Lombardi ◽  
Robert I. Lechler
Keyword(s):  
T Cells ◽  
T Cell ◽  
Regulatory T Cells ◽  
Cell Line ◽  
Ex Vivo ◽  
Interleukin 2 ◽  
Cell Lineage ◽  
Human Leukocyte ◽  
Regulatory Cells ◽  
Antigen Specificity

Abstract Although CD4+CD25+ regulatory T cells are pivotal in the prevention of autoimmunity and appear to mediate transplantation tolerance, little is known concerning their antigen specificity. Here we describe the induction of a human CD4+CD25+ regulatory T-cell line specific for a defined peptide alloantigen (human leukocyte antigen A2 [HLA-A2] 138-170) by priming purified CD4+CD25+ cells ex vivo. The regulatory cells were anergic and retained their ability to suppress antigen-driven responses of CD4+CD25– cells. They inhibited not only interleukin 2 (IL-2) secretion by CD4+CD25– T cells specific for the same peptide but also direct alloresponse of naive CD4+CD25– T cells stimulated by semiallogeneic dendritic cells (DCs) in the presence of the peptide (“linked suppression”). They also suppressed the response of CD4+ T cells specific for viral and bacterial antigens. The suppressive T-cell line showed sustained high CD25 expression. These findings suggest that peripheral CD4+CD25+ regulatory cells are a precommitted cell lineage from which cells with specificity for non–self-peptides can be selected. This may pave the way for inducing and expanding peptide antigen-specific regulatory T cells ex vivo for cell therapy in transplantation, allergy, and autoimmune disease.

scholarly journals Intestinal intraepithelial lymphocytes include precursors committed to the T cell receptor αβ lineage

1998 ◽  
Vol 95 (16) ◽  
pp. 9459-9464 ◽  
Author(s):  
Stephanie T. Page ◽  
Lisa Y. Bogatzki ◽  
Jessica A. Hamerman ◽  
Claire H. Sweenie ◽  
Philip J. Hogarth ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Receptor ◽  
Nude Mice ◽  
Interleukin 2 ◽  
Cell Receptor ◽  
Intraepithelial Lymphocytes ◽  
Tcr Signaling ◽  
Intestinal Intraepithelial Lymphocytes ◽  
Cell Commitment

The majority of T cells develop in the thymus and exhibit well characterized phenotypic changes associated with their maturation. Previous analysis of intestinal intraepithelial lymphocytes (IEL) from nude mice and a variety of experimentally manipulated models led to the view that at least a portion of these cells represent a distinct T cell population that matures extrathymically. The IEL that are postulated to mature within the intestine include both T cell receptor (TCR) αβ- and γδ-bearing subpopulations. They can be distinguished from conventional thymically derived T cells in that they express an unusual coreceptor, a CD8α homodimer. In addition, they can utilize the Fc receptor γ-chain in place of the CD3-associated ζ-chain for TCR signaling and their maturation depends on the interleukin 2 receptor β-chain. Moreover, TCRαβ+CD8αα+ IEL are not subject to conventional thymic selection processes. To determine whether CD3−CD8αα+ IEL represent precursors of T cells developing extrathymically, we examined IEL from knockout mice lacking the recombination activating gene-1 (rag-1), CD3ɛ, or both Lck and Fyn, in which thymic T cell development is arrested. CD3−CD8αα+CD16+ IEL from all three mutant strains, as well as from nude mice, included cells that express pre-TCRα transcripts, a marker of T cell commitment. These IEL from lck−/−fyn−/− animals exhibited TCR β-gene rearrangement. However, CD3−CD8αα+CD16+ IEL from ɛ-deficient mice had not undergone Dβ-Jβ joining, despite normal rearrangement at the TCRβ locus in thymocytes from these animals. These results revealed another distinction between thymocytes and IEL, and suggested an unexpectedly early role for CD3ɛ in IEL maturation.

scholarly journals 3BP2 Deficiency Impairs the Response of B Cells, but Not T Cells, to Antigen Receptor Ligation

2006 ◽  
Vol 26 (14) ◽  
pp. 5214-5225 ◽  
Author(s):  
Miguel A. de la Fuente ◽  
Lalit Kumar ◽  
Bao Lu ◽  
Raif S. Geha
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cells ◽  
B Cell ◽  
Cell Cycle Progression ◽  
Interleukin 2 ◽  
Cell Receptor ◽  
Normal Numbers ◽  
Tcr Signaling ◽  
And Function

ABSTRACT The adapter protein 3BP2 is expressed in lymphocytes; binds to Syk/ZAP-70, Vav, and phospholipase C-γ (PLC-γ); and is thought to be important for interleukin-2 gene transcription in T cells. To define the role of 3BP2 in lymphocyte development and function, we generated 3BP2-deficient mice. T-cell development, proliferation, cytokine secretion, and signaling in response to T-cell receptor (TCR) ligation were all normal in 3BP2−/− mice. 3BP2−/− mice had increased accumulation of pre-B cells in the bone marrow and a block in the progression of transitional B cells in the spleen from the T1 to the T2 stage, but normal numbers of mature B cells. B-cell proliferation, cell cycle progression, PLC-γ2 phosphorylation, calcium mobilization, NF-ATp dephosphorylation, and Erk and Jnk activation in response to B-cell receptor (BCR) ligation were all impaired. These results suggest that 3BP2 is important for BCR, but not for TCR signaling.

Overexpression of the Notch ligand, Jagged-1, induces alloantigen-specific human regulatory T cells

Blood ◽  
2003 ◽  
Vol 102 (10) ◽  
pp. 3815-3821 ◽  
Author(s):  
Eric S. Yvon ◽  
Stephane Vigouroux ◽  
Raphael F. Rousseau ◽  
Ettore Biagi ◽  
Persis Amrolia ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Regulatory T Cells ◽  
Transforming Growth Factor ◽  
Ex Vivo ◽  
Interleukin 2 ◽  
Notch Pathway ◽  
Cell Phenotype ◽  
Hematopoietic Stem ◽  
Notch Ligand

Abstract Graft-versus-host disease (GVHD) represents one of the major complications of allogeneic hematopoietic stem cell transplantation. Techniques to prevent GVHD have included ex vivo T-cell depletion of the graft or prolonged in vivo immunosuppression. Both reduce the frequency and severity of GVHD but also reduce T-cell-mediated graft-versus-malignancy effect, and increase the risk of infection. A major goal in transplantation is to prevent alloreactivity while preserving activity against tumors and infectious agents. We have used activation of the Notch pathway to try to generate T cells able to specifically regulate alloantigen responses. We used allogeneic Epstein-Barr virus lymphoblastoid B cells (EBV-LCLs) as stimulator cells. Such LCLs are excellent (allo) antigen-presenting cells and can be obtained in large numbers even from donors who have received extensive chemo/radiotherapy. We overexpressed a Notch ligand, Jagged-1, in these cells by adenoviral vector transduction. Stimulation of CD45RA+ naive T cells by Jagged-1 EBV-LCL reduces production of interferon-γ, interleukin-2, and interleukin-5, but up-regulates transforming growth factor-β1 synthesis, consistent with induction of a regulatory T-cell phenotype. Transfer of these T cells to fresh lymphocyte cultures inhibits proliferative and cytotoxic immune responses to the priming alloantigens while sparing responses to third-party stimulator cells. Notch activation in the presence of alloantigen-presenting cells may therefore be a means of inducing specific regulatory T cells while preserving other T-cell functionality. (Blood. 2003;102:3815-3821)

scholarly journals Transcriptome Signature of Vγ9Vδ2 T Cells Treated With Phosphoantigens and Notch Inhibitor Reveals Interplay Between TCR and Notch Signaling Pathways

2021 ◽  
Vol 12 ◽  
Author(s):  
Ayush Madhok ◽  
Sajad Ahmad Bhat ◽  
Chinna Susan Philip ◽  
Shalini Kashipathi Sureshbabu ◽  
Shubhada Chiplunkar ◽  
...  
Keyword(s):  
T Cells ◽  
Notch Signaling ◽  
Interleukin 2 ◽  
Γδ T Cells ◽  
Cell Receptor ◽  
Gamma Delta ◽  
Tcr Signaling ◽  
Transcriptional Changes ◽  
Vγ9vδ2 T Cells ◽  
Cytokine Stimulation

Gamma delta (γδ) T cells, especially the Vγ9Vδ2 subtype, have been implicated in cancer therapy and thus have earned the spotlight in the past decade. Although one of the most important properties of γδ T cells is their activation by phosphoantigens, which are intermediates of the Mevalonate and Rohmer pathway of isoprenoid biosynthesis, such as IPP and HDMAPP, respectively, the global effects of such treatments on Vγ9Vδ2 T cells remain elusive. Here, we used the high-throughput transcriptomics approach to elucidate the transcriptional changes in human Vγ9Vδ2 T cells upon HDMAPP, IPP, and anti-CD3 treatments in combination with interleukin 2 (IL2) cytokine stimulation. These activation treatments exhibited a dramatic surge in transcription with distinctly enriched pathways. We further assessed the transcriptional dynamics upon inhibition of Notch signaling coupled with activation treatments. We observed that the metabolic processes are most affected upon Notch inhibition via GSI-X. The key effector genes involved in gamma–delta cytotoxic function were downregulated upon Notch blockade even in combination with activation treatment, suggesting a transcriptional crosstalk between T-cell receptor (TCR) signaling and Notch signaling in Vγ9Vδ2 T cells. Collectively, we demonstrate the effect of the activation of TCR signaling by phosphoantigens or anti-CD3 on the transcriptional status of Vγ9Vδ2 T cells along with IL2 stimulation. We further show that the blockade of Notch signaling antagonistically affects this activation.

scholarly journals T cell receptor-mediated selection of functional rat CD8 T cells from defined immature thymocyte precursors in short-term suspension culture.

1991 ◽  
Vol 173 (3) ◽  
pp. 561-568 ◽  
Author(s):  
T Hünig ◽  
R Mitnacht
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Receptor ◽  
Cytotoxic T Lymphocyte ◽  
Ex Vivo ◽  
Interleukin 2 ◽  
Cell Receptor ◽  
Double Positive ◽  
Homogeneous Population

Recent results have indicated that positive and negative repertoire selection act on the major population of CD4,8 double-positive (DP) thymocytes that express 5-10-fold less T cell receptor (TCR) than mature T cells (i.e., they are TCRlow). Since DP cells obtained ex vivo are heterogeneous with regard to their stage within thymic selection, a homogeneous population of virgin DP cells suitable for selection studies was generated in vitro from their immediate precursors, the CD8 single-positive (SP) immature blast cells. To mimic TCR-mediated selection signals, these virgin DP cells were then cultured for another 2 d in the presence of immobilized anti-TCR monoclonal antibodies with or without interleukin 2 (IL-2). Daily monitoring of recovery and phenotype showed that without TCR stimulation, the cells remained DP and became small, TCRlow cells that were lost with a half-life of 1 d, regardless of the presence of IL-2. TCR stimulation resulted in rapid downregulation of CD4 and CD8, maintenance of a larger cell size, and induction of the CD53 antigen that marks mature and CD4,8 double-negative rat thymocytes. In the absence of IL-2, viability decreased as rapidly as without TCR stimulation. Addition of IL-2 rescued TCR-stimulated virgin DP cells and prevented CD8 downregulation, so that 50-80% of input DP cells were recovered after 2 d as CD4-8+53+ cells. After release from modulation, these in vitro generated CD8 SP cells quantitatively upregulated the TCR to the TCRhigh phenotype and were readily induced to proliferate and exhibit cytotoxic T lymphocyte (CTL) activity in a polyclonal readout. Evidence is presented implicating an IL-2 receptor (IL-2R) not containing the p55 chain (i.e., most likely the p70 intermediate affinity IL-2R) in the TCR plus IL-2-driven in vitro differentiation of virgin DP cells towards the mature CD8 SP phenotype.

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