scholarly journals Inhibition of T Cell Receptor Activation by Semi-Synthetic Sesquiterpene Lactone Derivatives and Molecular Modeling of Their Interaction with Glutathione and Tyrosine Kinase ZAP-70

Molecules ◽  
2019 ◽  
Vol 24 (2) ◽  
pp. 350 ◽  
Author(s):  
Andrei Khlebnikov ◽  
Igor Schepetkin ◽  
Anarkul Kishkentaeva ◽  
Zhanar Shaimerdenova ◽  
Gayane Atazhanova ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Tyrosine Kinase ◽  
T Cell Receptor ◽  
Sesquiterpene Lactones ◽  
Cell Receptor ◽  
Receptor Activation ◽  
Tcr Signaling ◽  
Jurkat T Cells ◽  
Tcr Activation

A variety of natural compounds have been shown to modulate T cell receptor (TCR) activation, including natural sesquiterpene lactones (SLs). In the present studies, we evaluated the biological activity of 11 novel semi-synthetic SLs to determine their ability to modulate TCR activation. Of these compounds, α -epoxyarglabin, cytisinyl epoxyarglabin, 1 β ,10 α -epoxyargolide, and chloroacetate grosheimin inhibited anti-CD3-induced Ca2+ mobilization and extracellular signal-regulated kinase 1/2 (ERK1/2) phosphorylation in Jurkat T cells. We also found that the active SLs depleted intracellular glutathione (GSH) in Jurkat T cells, supporting their reactivity towards thiol groups. Because the zeta-chain associated tyrosine kinase 70 kDa (ZAP-70) is essential for TCR signaling and contains a tandem SH2 region that is highly enriched with multiple cysteines, we performed molecular docking of natural SLs and their semi-synthetic derivatives into the ZAP-70 binding site. The docking showed that the distance between the carbon atom of the exocyclic methylene group and the sulfur atom in Cys39 of the ZAP-70 tandem SH2 module was 3.04–5.3 Å for active compounds. Furthermore, the natural SLs and their derivatives could be differentiated by their ability to react with the Cys39 SH-group. We suggest that natural and/or semi-synthetic SLs with an α -methylene- γ -lactone moiety can specifically target GSH and the kinase site of ZAP-70 and inhibit the initial phases of TCR activation.

scholarly journals Leukocyte-associated immunoglobulin-like receptor 1 inhibits T-cell signaling by decreasing protein phosphorylation in the T-cell signaling pathway

2020 ◽  
Vol 295 (8) ◽  
pp. 2239-2247 ◽  
Author(s):  
Jeoung-Eun Park ◽  
David D. Brand ◽  
Edward F. Rosloniec ◽  
Ae-Kyung Yi ◽  
John M. Stuart ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Tyrosine Kinase ◽  
Cell Signaling ◽  
Signaling Pathway ◽  
T Cell Receptor ◽  
Cell Receptor ◽  
T Cell Signaling ◽  
Tcr Signaling ◽  
Cell Signaling Pathway

Multiple observations implicate T-cell dysregulation as a central event in the pathogenesis of rheumatoid arthritis. Here, we investigated mechanisms for suppressing T-cell activation via the inhibitory receptor leukocyte-associated immunoglobulin-like receptor 1 (LAIR-1). To determine how LAIR-1 affects T-cell receptor (TCR) signaling, we compared 1) T cells from LAIR-1–sufficient and –deficient mice, 2) Jurkat cells expressing either LAIR-1 mutants or C-terminal Src kinase (CSK) mutants, and 3) T cells from mice that contain a CSK transgene susceptible to chemical inhibition. Our results indicated that LAIR-1 engagement by collagen or by complement C1q (C1Q, which contains a collagen-like domain) inhibits TCR signaling by decreasing the phosphorylation of key components in the canonical T-cell signaling pathway, including LCK proto-oncogene SRC family tyrosine kinase (LCK), LYN proto-oncogene SRC family tyrosine kinase (LYN), ζ chain of T-cell receptor–associated protein kinase 70 (ZAP-70), and three mitogen-activated protein kinases (extracellular signal–regulated kinase, c-Jun N-terminal kinase 1/2, and p38). The intracellular region of LAIR-1 contains two immunoreceptor tyrosine-based inhibition motifs that are both phosphorylated by LAIR-1 activation, and immunoprecipitation experiments revealed that Tyr-251 in LAIR-1 binds CSK. Using CRISPR/Cas9-mediated genome editing, we demonstrate that CSK is essential for the LAIR-1–induced inhibition of the human TCR signal transduction. T cells from mice that expressed a PP1 analog–sensitive form of CSK (CskAS) corroborated these findings, and we also found that Tyr-251 is critical for LAIR-1's inhibitory function. We propose that LAIR-1 activation may be a strategy for controlling inflammation and may offer a potential therapeutic approach for managing autoimmune diseases.

scholarly journals Bcl-2 differentially regulates Ca2+ signals according to the strength of T cell receptor activation

2006 ◽  
Vol 172 (1) ◽  
pp. 127-137 ◽  
Author(s):  
Fei Zhong ◽  
Michael C. Davis ◽  
Karen S. McColl ◽  
Clark W. Distelhorst
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Receptor ◽  
Cell Receptor ◽  
Receptor Activation ◽  
Receptor Subtypes ◽  
Activated T Cells ◽  
High Concentrations ◽  
Tcr Activation ◽  
Insp3 Receptor

To investigate the effect of Bcl-2 on Ca2+ signaling in T cells, we continuously monitored Ca2+ concentration in Bcl-2–positive and –negative clones of the WEHI7.2 T cell line after T cell receptor (TCR) activation by anti-CD3 antibody. In Bcl-2–negative cells, high concentrations of anti-CD3 antibody induced a transient Ca2+ elevation, triggering apoptosis. In contrast, low concentrations of anti-CD3 antibody induced Ca2+ oscillations, activating the nuclear factor of activated T cells (NFAT), a prosurvival transcription factor. Bcl-2 blocked the transient Ca2+ elevation induced by high anti-CD3, thereby inhibiting apoptosis, but did not inhibit Ca2+ oscillations and NFAT activation induced by low anti-CD3. Reduction in the level of all three inositol 1,4,5-trisphosphate (InsP3) receptor subtypes by small interfering RNA inhibited the Ca2+ elevation induced by high but not low anti-CD3, suggesting that Ca2+ responses to high and low anti-CD3 may have different requirements for the InsP3 receptor. Therefore, Bcl-2 selectively inhibits proapoptotic Ca2+ elevation induced by strong TCR activation without hindering prosurvival Ca2+ signals induced by weak TCR activation.

T cell receptor activation status as biological context for interpreting PD1/PDL1 biomarker measurements.

2018 ◽  
Vol 36 (5_suppl) ◽  
pp. 54-54
Author(s):  
Ralph E. Parchment ◽  
Tony Navas ◽  
Kristin Fino ◽  
Andy Fung ◽  
Facundo Cutuli ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Receptor ◽  
Tumor Immunity ◽  
Cd8 T Cells ◽  
Immune Checkpoint ◽  
Immunofluorescence Microscopy ◽  
Cell Receptor ◽  
Receptor Activation ◽  
Tcr Activation

54 Background: Direct cytolysis of tumor cells by CD8+ T cells results from the net effect of at least two biochemical pathways: (1) stimulatory signaling from the activated T cell receptor (TCR) complex in response to its recognition of a tumor neoantigen presented in the context of autologous MHC class I, and (2) suppressive signaling from immune checkpoints, such as the response of PD1 to binding its ligand, PDL1. Because the PD1:PDL1 immune checkpoint is significant for therapy only when there is tumor cell-specific TCR activation and signaling, it is not surprising that simple measurements of either PD1 or PDL1 in tumor biopsies are, at best, imperfect predictive biomarkers. Instead, a more precise test that quantifies PD1 signaling due to PDL1 binding only in the subset of CD8+ T cells exhibiting activated TCR signaling should provide a more accurate assessment of the extent of immune checkpoint suppression of tumor immunity and therefore be a more predictive biomarker of response to PD1/PDL1-targeted immunotherapy. Methods: We have developed a multiplexed immunofluorescence microscopy test capable of simultaneous quantitation of TCR activation (phospho-CD3zeta), immune checkpoint signaling via PD1 (phospho-SHP1 and -SHP2), and the net stimulation or inhibition resulting from the integration of these two pathways (phospho-ZAP70). Results: Specific antibodies to these biomarkers have been qualified, including peptide inhibition studies to establish antibody specificity, and their performance established by fit-for-purpose studies of in vitro models of CD8+ T cell activation. This multiplex biomarker panel is suitable for clinical use with formalin-fixed, paraffin embedded core needle biopsies of tumor and quantitative immunofluorescence microscopy (qIFA). Conclusions: The additional biomarkers of tumor immunity are expected to add an important context for interpreting PD1/PDL1 measurements. Funded by NCI Contract No. HHSN261200800001E.

scholarly journals Loss of tonic T-cell receptor signals alters the generation but not the persistence of CD8+ memory T cells

Blood ◽  
2010 ◽  
Vol 116 (25) ◽  
pp. 5560-5570 ◽  
Author(s):  
Karla R. Wiehagen ◽  
Evann Corbo ◽  
Michelle Schmidt ◽  
Haina Shin ◽  
E. John Wherry ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Receptor ◽  
Cell Receptor ◽  
Lymphocytic Choriomeningitis ◽  
Sh2 Domain ◽  
Normal Numbers ◽  
Tcr Signaling ◽  
Tcr Signals

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.

scholarly journals Fyn-Binding Protein (Fyb)/Slp-76–Associated Protein (Slap), Ena/Vasodilator-Stimulated Phosphoprotein (Vasp) Proteins and the Arp2/3 Complex Link T Cell Receptor (Tcr) Signaling to the Actin Cytoskeleton

2000 ◽  
Vol 149 (1) ◽  
pp. 181-194 ◽  
Author(s):  
Matthias Krause ◽  
Antonio S. Sechi ◽  
Marlies Konradt ◽  
David Monner ◽  
Frank B. Gertler ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Actin Cytoskeleton ◽  
T Cell Receptor ◽  
Cell Receptor ◽  
T Cell Signaling ◽  
Tcr Signaling ◽  
Activated T Cells ◽  
Antigen Presenting ◽  
Syndrome Protein

T cell receptor (TCR)-driven activation of helper T cells induces a rapid polarization of their cytoskeleton towards bound antigen presenting cells (APCs). We have identified the Fyn- and SLP-76–associated protein Fyb/SLAP as a new ligand for Ena/ vasodilator-stimulated phosphoprotein (VASP) homology 1 (EVH1) domains. Upon TCR engagement, Fyb/SLAP localizes at the interface between T cells and anti-CD3–coated beads, where Evl, a member of the Ena/VASP family, Wiskott-Aldrich syndrome protein (WASP) and the Arp2/3 complex are also found. In addition, Fyb/SLAP is restricted to lamellipodia of spreading platelets. In activated T cells, Fyb/SLAP associates with Ena/VASP family proteins and is present within biochemical complexes containing WASP, Nck, and SLP-76. Inhibition of binding between Fyb/SLAP and Ena/VASP proteins or WASP and the Arp2/3 complex impairs TCR-dependent actin rearrangement, suggesting that these interactions play a key role in linking T cell signaling to remodeling of the actin cytoskeleton.

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