scholarly journals Phosphatidylserine binding directly regulates TIM-3 function

2021 ◽  
Vol 478 (17) ◽  
pp. 3331-3349
Author(s):  
Courtney M. Smith ◽  
Alice Li ◽  
Nithya Krishnamurthy ◽  
Mark A. Lemmon
Keyword(s):  
T Cell ◽  
T Cell Receptor ◽  
Therapeutic Target ◽  
Immune Modulation ◽  
Cell Receptor ◽  
Jurkat Cells ◽  
Potential Therapeutic Target ◽  
Signaling Receptors ◽  
Ligand Regulation ◽  
Regulatory Ligands

Co-signaling receptors for the T cell receptor (TCR) are important therapeutic targets, with blockade of co-inhibitory receptors such as PD-1 now central in immuno-oncology. Advancing additional therapeutic immune modulation approaches requires understanding ligand regulation of other co-signaling receptors. One poorly understood potential therapeutic target is TIM-3 (T cell immunoglobulin and mucin domain containing-3). Which of TIM-3's several proposed regulatory ligands is/are relevant for signaling is unclear, and different studies have reported TIM-3 as a co-inhibitory or co-stimulatory receptor in T cells. Here, we show that TIM-3 promotes NF-κB signaling and IL-2 secretion following TCR stimulation in Jurkat cells, and that this activity is regulated by binding to phosphatidylserine (PS). TIM-3 signaling is stimulated by PS exposed constitutively in cultured Jurkat cells, and can be blocked by mutating the PS-binding site or by occluding this site with an antibody. We also find that TIM-3 signaling alters CD28 phosphorylation. Our findings clarify the importance of PS as a functional TIM-3 ligand, and may inform the future exploitation of TIM-3 as a therapeutic target.

scholarly journals Phosphatidylserine binding regulates TIM-3 effects on T cell receptor signaling

2021 ◽  
Author(s):  
Courtney M Smith ◽  
Alice Li ◽  
Nithya Krishnamurthy ◽  
Mark A Lemmon
Keyword(s):  
T Cell ◽  
T Cell Receptor ◽  
Therapeutic Target ◽  
Immune Modulation ◽  
Cell Receptor ◽  
Jurkat Cells ◽  
T Cell Receptor Signaling ◽  
Signaling Receptors ◽  
Ligand Regulation ◽  
Cell Receptor Signaling

Co-signaling receptors for the T cell receptor are important therapeutic targets, with blocking co-inhibitory receptors such as PD-1 now central in immuno-oncology. Advancing additional therapeutic immune modulation approaches requires understanding ligand regulation of other co-signaling receptors. One poorly understood therapeutic target is TIM-3 (T cell immunoglobulin and mucin domain containing-3). Which ligands are relevant for TIM-3 signaling is unclear, and different studies have reported it as co-inhibitory or co-stimulatory. Here, we show that TIM-3 promotes NF-κB signaling and IL-2 secretion following T cell receptor stimulation in Jurkat cells, and is regulated by phosphatidylserine (PS) binding. TIM-3 signaling is stimulated by PS exposed constitutively in cultured Jurkat cells, and can be blocked by mutating the PS-binding site or by occluding this site with an antibody. We also find that TIM-3 signaling alters CD28 phosphorylation. Our findings help clarify conflicting literature results with TIM-3, and inform its exploitation as a therapeutic target.

scholarly journals LCK as a Potential Therapeutic Target for Acute Rejection after Kidney Transplantation: A Bioinformatics Clue

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Linpei Jia ◽  
Rufu Jia ◽  
Yinping Li ◽  
Xiaoxia Li ◽  
Qiang Jia ◽  
...  
Keyword(s):  
Kidney Transplantation ◽  
T Cell ◽  
Acute Rejection ◽  
T Cell Receptor ◽  
Protein Interactions ◽  
Therapeutic Target ◽  
Cell Receptor ◽  
Functional Enrichment ◽  
Literature Mining ◽  
Potential Therapeutic Target

Objectives. We aim to identify the key biomarker of acute rejection (AR) after kidney transplantation via bioinformatics methods. Methods. The gene expression data GSE75693 of 30 samples with stable kidney transplantation recipients and 15 AR samples were downloaded and analyzed by the limma package to identify differentially expressed genes (DEGs). Then, Gene Ontology (GO) functional enrichment analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis were done to explore the biological functions and potential important pathways of DEGs. Finally, protein-protein interactions (PPIs) and literature mining were applied to construct the cocitation network and to select the hub protein. Results. A total of 437 upregulated genes and 353 downregulated genes were selected according to P<0.01 and log2fold change>1.0. DEGs of AR are mainly located on membranes and impact the activation of receptors in immune responses. In the PPI network, Src kinase, lymphocyte kinase (LCK), CD3G, B2M, interferon-γ, CD3D, tumor necrosis factor, VAV1, and CD3E in the T cell receptor signaling pathway were selected as important factors, and LCK was identified as the hub protein. Conclusion. LCK, via acting on T-cell receptor, might be a potential therapeutic target for AR after kidney transplantation.

scholarly journals Usp12 stabilizes the T-cell receptor complex at the cell surface during signaling

2016 ◽  
Vol 113 (6) ◽  
pp. E705-E714 ◽  
Author(s):  
Akhee S. Jahan ◽  
Maxime Lestra ◽  
Lee Kim Swee ◽  
Ying Fan ◽  
Mart M. Lamers ◽  
...  
Keyword(s):  
T Cell ◽  
T Cell Receptor ◽  
Posttranslational Modifications ◽  
Protein Function ◽  
Adaptor Proteins ◽  
Cell Receptor ◽  
Surface Expression ◽  
Jurkat Cells ◽  
Tcr Signaling ◽  
Primary Mouse

Posttranslational modifications are central to the spatial and temporal regulation of protein function. Among others, phosphorylation and ubiquitylation are known to regulate proximal T-cell receptor (TCR) signaling. Here we used a systematic and unbiased approach to uncover deubiquitylating enzymes (DUBs) that participate during TCR signaling in primary mouse T lymphocytes. Using a C-terminally modified vinyl methyl ester variant of ubiquitin (HA-Ub-VME), we captured DUBs that are differentially recruited to the cytosol on TCR activation. We identified ubiquitin-specific peptidase (Usp) 12 and Usp46, which had not been previously described in this pathway. Stimulation with anti-CD3 resulted in phosphorylation and time-dependent translocation of Usp12 from the nucleus to the cytosol. Usp12−/− Jurkat cells displayed defective NFκB, NFAT, and MAPK activities owing to attenuated surface expression of TCR, which were rescued on reconstitution of wild type Usp12. Proximity-based labeling with BirA-Usp12 revealed several TCR adaptor proteins acting as interactors in stimulated cells, of which LAT and Trat1 displayed reduced expression in Usp12−/− cells. We demonstrate that Usp12 deubiquitylates and prevents lysosomal degradation of LAT and Trat1 to maintain the proximal TCR complex for the duration of signaling. Our approach benefits from the use of activity-based probes in primary cells without any previous genome modification, and underscores the importance of ubiquitin-mediated regulation to refine signaling cascades.

scholarly journals Stimulation of T cells through the CD3/T-cell receptor complex: role of cytoplasmic calcium, protein kinase C translocation, and phosphorylation of pp60c-src in the activation pathway.

1987 ◽  
Vol 7 (2) ◽  
pp. 650-656 ◽  
Author(s):  
J A Ledbetter ◽  
L E Gentry ◽  
C H June ◽  
P S Rabinovitch ◽  
A F Purchio
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Receptor ◽  
Solid Phase ◽  
Interleukin 2 ◽  
Cell Receptor ◽  
Jurkat Cells ◽  
Receptor Complex ◽  
Kinase C ◽  
Stimulation Of

Stimulation of T cells or the Jurkat T-cell line with soluble antibodies to the CD3/T-cell receptor complex causes mobilization of cytoplasmic Ca2+, which is blocked by pertussis toxin but not by ethylene glycol-bis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid, and translocation of protein kinase C activity from the cytoplasm to the membrane. Such stimulation also causes phosphorylation of pp60c-src at an amino-terminal serine residue. These activities are consistent with induction of phosphatidylinositol metabolism after antibody binding. Anti-CD3 stimulation with antibody in solution, however, does not cause Jurkat cells to release interleukin 2 and blocks rather than induces proliferation of T cells. Induction of interleukin 2 production by Jurkat cells and proliferation by normal T cells requires anti-CD3 stimulation with antibody on a solid support, such as Sepharose beads or a plastic dish. Thus, we examined phosphorylation of pp60c-src after stimulation of Jurkat cells with anti-CD3 in solution or on solid phase. Both of these caused serine phosphorylation of pp60c-src that was indistinguishable even after 4 h of stimulation. These results indicate that the mode of anti-CD3 stimulation (in solution or on solid phase) controls a cellular function that modifies the consequences of signal transduction through phosphatidylinositol turnover.

scholarly journals Inhibition or activation of human T cell receptor transfectants is controlled by defined, soluble antigen arrays.

1992 ◽  
Vol 176 (5) ◽  
pp. 1421-1430 ◽  
Author(s):  
D E Symer ◽  
R Z Dintzis ◽  
D J Diamond ◽  
H M Dintzis
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Receptor ◽  
Interleukin 2 ◽  
Cell Receptor ◽  
Jurkat Cells ◽  
Soluble Antigen ◽  
Human T Cell ◽  
Human T Cells ◽  
Binding Avidity

We present evidence that direct T cell receptor (TCR) occupancy by antigen can either activate or inhibit T cells, depending upon whether or not a threshold number of local TCRs are crosslinked by multivalent arrays of the antigen. Variants of Jurkat cells were previously transfected with TCR alpha and beta chains that bind fluorescein, yielding FL-TCR+ human T cells. The transfectants are activated upon binding soluble multivalent antigen arrays at concentrations well below those required for monovalent interactions. This activation, measured by calcium fluxes and interleukin 2 (IL-2) production, indicates the superior binding avidity of multivalent ligands. Smaller, less multivalent arrays do not activate the cells, but antagonize larger arrays, demonstrating that antigen can bind TCR as either agonist or antagonist. The balance between activation and inhibition depends upon antigen array size, ligand valence, and concentration, indicating that a threshold extent of receptor crosslinking, and not individual perturbations of single TCR, is required for activation by antigen. Approximately 100 stimulatory arrays specifically bind per FL-TCR+ cell at concentrations where IL-2 production is half-maximal.

T cell receptor peptide and immune modulation

2017 ◽  
pp. 171-177
Author(s):  
Bailin Liang ◽  
James Y. Wang ◽  
Ronald R. Watson
Keyword(s):  
T Cell ◽  
T Cell Receptor ◽  
Immune Modulation ◽  
Cell Receptor

scholarly journals Thymic expression of a T-cell receptor targeting a tumor-associated antigen coexpressed in the thymus induces T-ALL

Blood ◽  
2015 ◽  
Vol 125 (19) ◽  
pp. 2958-2967 ◽  
Author(s):  
Yongzhi Cui ◽  
Masahiro Onozawa ◽  
Haven R. Garber ◽  
Leigh Samsel ◽  
Ziyao Wang ◽  
...  
Keyword(s):  
T Cell ◽  
T Cell Receptor ◽  
Cell Receptor ◽  
Receptor Targeting ◽  
Tumor Associated Antigen ◽  
Key Points ◽  
Signaling Receptors

Key Points Thymocyte signaling via a transgenic survivin-reactive TCR induced T-ALL with 100% penetrance. Thymic expression of signaling receptors targeting TAAs coexpressed in the thymus poses a risk for leukemogenesis.

scholarly journals Modulation of promiscuous T cell receptor recognition by mutagenesis of CDR2 residues.

1996 ◽  
Vol 183 (5) ◽  
pp. 2043-2051 ◽  
Author(s):  
J V Brawley ◽  
P Concannon
Keyword(s):  
T Cell ◽  
T Cell Receptor ◽  
Cell Receptor ◽  
Jurkat Cells ◽  
Single Amino Acid ◽  
Peptide Antigen ◽  
T Cell Clones ◽  
Human T Cell ◽  
Cdr3 Region ◽  
Cell Clones

The T cell receptor (TCR) recognizes a ligand composed of a major histocompatibility complex (MHC) molecule and a peptide antigen. Prior studies of murine T cell clones have demonstrated that residues in the CDR3 region of TCR interact with amino acids in the peptide during MHC-restricted antigen recognition. However, the questions of whether direct TCR MHC contacts are made and where such contact sites might map in the TCR have not been resolved. In this study, we have taken advantage of the promiscuous recognition of a peptide from influenza virus (HA 307-319) by human T cell clones to map sites in the TCR that mediate differences in human leukocyte antigen-D related (HLA-DR) restriction in the presence of a common peptide antigen. Site-specific mutagenesis of cloned TCR genes and transfection into Jurkat cells were used to demonstrate that single amino acid substitutions in CDR2 of the TCR-alpha chain controlled whether a T cell was restricted by the product of a single DR allele (DR7) or would respond to the HA 307-319 peptide when presented by the products of one of several different DR alleles (DR1, DR4, DR5, or DR7). Because the relevant DR alleles are defined by polymorphism in the DR-beta chain, these results also suggest a rotational orientation for recognition in which TCR-alpha interacts with DR beta.

scholarly journals Signal transduction by the CD2 antigen in T cells and natural killer cells: requirement for expression of a functional T cell receptor or binding of antibody Fc to the Fc receptor, Fc gamma RIIIA (CD16).

1991 ◽  
Vol 174 (6) ◽  
pp. 1407-1415 ◽  
Author(s):  
L L Spruyt ◽  
M J Glennie ◽  
A D Beyers ◽  
A F Williams
Keyword(s):  
Signal Transduction ◽  
T Cells ◽  
T Cell ◽  
Nk Cells ◽  
Natural Killer ◽  
T Cell Receptor ◽  
Nk Cell ◽  
Cell Receptor ◽  
Fc Receptor ◽  
Jurkat Cells

Crosslinking of CD2 antigen on T lymphocytes and natural killer (NK) cells leads to a rise in cytoplasmic-free Ca2+ concentration ([Ca2+]i). However, CD2 seems unlikely to interact directly with the second messenger pathways since signaling via CD2 is poor in T cells that lack the T cell receptor (TCR) and is absent in L cells or insect cells that express CD2. In contrast, NK cells that are also TCR- can be triggered via CD2, but it is unclear as to whether the CD16 Fc receptor (FcR) may facilitate this effect. The CD16 transmembrane molecule is expressed in a complex with the zeta homodimer or the zeta/gamma heterodimer and these dimers are also associated with the TCR complex. Thus, it seemed that zeta chains may provide the link between signaling on NK cells and T cells. This could be tested on TCR- cells since when CD16 is transfected into T cells it is expressed in a complex with TCR zeta homodimer or the zeta/gamma heterodimer. At first, potentiation of CD2 signaling was seen on TCR- Jurkat cells expressing CD16, but this was found to be dependent on trace levels (1%) of IgG in F(ab')2 antibody preparations. With pure F(ab')2, the effect was lost. Signaling on a rat NK cell line was also re-examined with F(ab')2 antibodies that had no IgG contamination, and again no signal transduction via CD2 was seen. We thus conclude that there is no clear evidence for potent signaling via CD2 on cells that lack a TCR complex and that TCR zeta chain expressed at the cell surface is not sufficient to potentiate signaling via CD2 as measured by an increase in [Ca2+]i.

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