scholarly journals Activation of Hematopoietic Progenitor Kinase 1 Involves Relocation, Autophosphorylation, and Transphosphorylation by Protein Kinase D1

2005 ◽  
Vol 25 (6) ◽  
pp. 2364-2383 ◽  
Author(s):  
Rüdiger Arnold ◽  
Irene M. Patzak ◽  
Brit Neuhaus ◽  
Sadia Vancauwenbergh ◽  
André Veillette ◽  
...  
Keyword(s):  
T Cell ◽  
Protein Kinase ◽  
Adaptor Protein ◽  
Cell Receptor ◽  
Hematopoietic Progenitor ◽  
Kinase Activation ◽  
Protein Kinase D1 ◽  
Enzymatic Activation ◽  
Antigen Presenting

ABSTRACT Adaptive immune signaling can be coupled to stress-activated protein kinase (SAPK)/c-Jun N-terminal kinase (JNK) and NF-κB activation by the hematopoietic progenitor kinase 1 (HPK1), a mammalian hematopoiesis-specific Ste20 kinase. To gain insight into the regulation of leukocyte signal transduction, we investigated the molecular details of HPK1 activation. Here we demonstrate the capacity of the Src family kinase Lck and the SLP-76 family adaptor protein Clnk (cytokine-dependent hematopoietic cell linker) to induce HPK1 tyrosine phosphorylation and relocation to the plasma membrane, which in lymphocytes results in recruitment of HPK1 to the contact site of antigen-presenting cell (APC)-T-cell conjugates. Relocation and clustering of HPK1 cause its enzymatic activation, which is accompanied by phosphorylation of regulatory sites in the HPK1 kinase activation loop. We show that full activation of HPK1 is dependent on autophosphorylation of threonine 165 and phosphorylation of serine 171, which is a target site for protein kinase D (PKD) in vitro. Upon T-cell receptor stimulation, PKD robustly augments HPK1 kinase activity in Jurkat T cells and enhances HPK1-driven SAPK/JNK and NF-κB activation; conversely, antisense down-regulation of PKD results in reduced HPK1 activity. Thus, activation of major lymphocyte signaling pathways via HPK1 involves (i) relocation, (ii) autophosphorylation, and (iii) transphosphorylation of HPK1 by PKD.

scholarly journals Cd8− T Cell Transfectants That Express a High Affinity T Cell Receptor Exhibit Enhanced Peptide-Dependent Activation

2001 ◽  
Vol 194 (8) ◽  
pp. 1043-1052 ◽  
Author(s):  
Phillip D. Holler ◽  
Alice R. Lim ◽  
Bryan K. Cho ◽  
Laurie A. Rund ◽  
David M. Kranz
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Receptor ◽  
Cytotoxic T Lymphocyte ◽  
Cell Activity ◽  
Cell Receptor ◽  
Wild Type ◽  
High Affinity ◽  
Antigen Presenting

T cells are activated by binding of the T cell receptor (TCR) to a peptide-major histocompatibility complex (MHC) complex (pMHC) expressed on the surface of antigen presenting cells. Various models have predicted that activation is limited to a narrow window of affinities (or dissociation rates) for the TCR–pMHC interaction and that above or below this window, T cells will fail to undergo activation. However, to date there have not been TCRs with sufficiently high affinities in order to test this hypothesis. In this report we examined the activity of a CD8-negative T cell line transfected with a high affinity mutant TCR (KD = 10 nM) derived from cytotoxic T lymphocyte clone 2C by in vitro engineering. The results show that despite a 300-fold higher affinity and a 45-fold longer off-rate compared with the wild-type TCR, T cells that expressed the mutant TCRs were activated by peptide. In fact, activation could be detected at significantly lower peptide concentrations than with T cells that expressed the wild-type TCR. Furthermore, binding and functional analyses of a panel of peptide variants suggested that pMHC stability could account for apparent discrepancies between TCR affinity and T cell activity observed in several prior studies.

SASH3 variants cause a novel form of X-linked combined immunodeficiency with immune dysregulation

Blood ◽  
2021 ◽  
Author(s):  
Ottavia M. Delmonte ◽  
Jenna Ruth Ember Bergerson ◽  
Tomoki Kawai ◽  
Hye Sun Kuehn ◽  
David H. McDermott ◽  
...  
Keyword(s):  
T Cell ◽  
Cell Cycle Progression ◽  
Nk Cell ◽  
Adaptor Protein ◽  
Cell Receptor ◽  
Immune Dysregulation ◽  
Lymphocyte Function ◽  
Combined Immunodeficiency ◽  
In Vitro Proliferation

SAM and SH3 domain-containing 3 (SASH3), also called SH3-containing Lymphocyte Protein (SLY1) is a putative adaptor protein that is postulated to play an important role in the organization of signaling complexes and propagation of signal transduction cascades in lymphocytes. The SASH3 gene is located on the X-chromosome. Here, we identified three novel SASH3 deleterious variants in four unrelated male patients with a history of combined immunodeficiency and immune dysregulation manifesting as recurrent sinopulmonary, cutaneous and mucosal infections, and refractory autoimmune cytopenias. Patients exhibited CD4+ T cell lymphopenia, decreased T cell proliferation and cell cycle progression, and increased T cell apoptosis in response to mitogens. In vitro T-cell differentiation of CD34+ cells and molecular signatures of rearrangements at the T-cell receptor alpha (TRA) locus were indicative of impaired thymocyte survival. These patients also manifested neutropenia and B and NK cell lymphopenia. Lentivirus-mediated transfer of the SASH3 cDNA corrected protein expression, in vitro proliferation and signaling in SASH3-deficient Jurkat and patient-derived T cells. These findings define a new type of X-linked combined immunodeficiency in humans that recapitulates many of the abnormalities reported in Sly1-/- and Sly1D/Dmutant mice, highlighting an important role of SASH3 in human lymphocyte function and survival.

Interleukin-15 redirects the outcome of a tolerizing T-cell stimulus from apoptosis to anergy

Blood ◽  
2000 ◽  
Vol 96 (3) ◽  
pp. 1006-1012 ◽  
Author(s):  
Hans Dooms ◽  
Tom Van Belle ◽  
Marjory Desmedt ◽  
Pieter Rottiers ◽  
Johan Grooten
Keyword(s):  
T Cell ◽  
Cell Receptor ◽  
T Cell Response ◽  
Peripheral Tolerance ◽  
Clonal Deletion ◽  
Cell Clones ◽  
Receptor Signal ◽  
Cytokine Milieu ◽  
Antigen Presenting

Clonal deletion and anergy are 2 mechanisms used by the immune system to establish peripheral tolerance. In vitro, these mechanisms are induced in T lymphocytes by triggering the T-cell receptor (signal 1) in the absence of costimulation (signal 2). T-cell clones have been shown either to become anergic or to die in response to signal 1 alone; yet the factors that govern this choice remain unknown. This study evaluated the influence of the cytokines interleukin (IL)-2 and IL-15 on the response of the Th1 clone hemagglutinin (T-HA) to signal 1, delivered by stimulation with immobilized anti-CD3 monoclonal antibody (mAb). The response induced by immobilized anti-CD3 mAb was dependent on the cytokine milieu; in the presence of IL-2, T-HA cells were subject to apoptosis, whereas in the presence of IL-15 the cells remained viable but showed proliferative unresponsiveness. After release from the anti-CD3 stimulus, the IL-15-rescued T-HA cells regained responsiveness to IL-2 and IL-15 growth factor activity. However, they were unable to proliferate when stimulated with their cognate antigen presented by professional antigen-presenting cells (signal 1 plus 2) and thus had acquired an anergic phenotype. These data assign a novel function to the previously reported antiapoptotic activity of IL-15, namely, the capacity to redirect the T-cell response to partial stimulation from clonal deletion to anergy. Furthermore, they emphasize that the cytokine environment can critically influence the outcome of a tolerizing stimulus.

scholarly journals Regulation and Function of the CD3γ DxxxLL Motif: A Binding Site for Adaptor Protein-1 and Adaptor Protein-2 in Vitro

1997 ◽  
Vol 138 (2) ◽  
pp. 271-281 ◽  
Author(s):  
Jes Dietrich ◽  
Jesper Kastrup ◽  
Bodil L. Nielsen ◽  
Niels Ødum ◽  
Carsten Geisler
Keyword(s):  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Tolerance Induction ◽  
Adaptor Protein ◽  
Adaptor Proteins ◽  
Cell Receptor ◽  
Coated Vesicle

Several receptors are downregulated by internalization after ligand binding. Regulation of T cell receptor (TCR) expression is an important step in T cell activation, desensitization, and tolerance induction. One way T cells regulate TCR expression is by phosphorylation/dephosphorylation of the TCR subunit clusters of differentiation (CD)3γ. Thus, phosphorylation of CD3γ serine 126 (S126) causes a downregulation of the TCR. In this study, we have analyzed the CD3γ internalization motif in three different systems in parallel: in the context of the complete multimeric TCR; in monomeric CD4/CD3γ chimeras; and in vitro by binding CD3γ peptides to clathrin-coated vesicle adaptor proteins (APs). We find that the CD3γ D127xxxLL131/132 sequence represents one united motif for binding of both AP-1 and AP-2, and that this motif functions as an active sorting motif in monomeric CD4/ CD3γ molecules independently of S126. An acidic amino acid is required at position 127 and a leucine (L) is required at position 131, whereas the requirements for position 132 are more relaxed. The spacing between aspartic acid 127 (D127) and L131 is crucial for the function of the motif in vivo and for AP binding in vitro. Furthermore, we provide evidence indicating that phosphorylation of CD3γ S126 in the context of the complete TCR induces a conformational change that exposes the DxxxLL sequence for AP binding. Exposure of the DxxxLL motif causes an increase in the TCR internalization rate and we demonstrate that this leads to an impairment of TCR signaling. On the basis of the present results, we propose the existence of at least three different types of L-based receptor sorting motifs.

scholarly journals Protein Kinase D1 Phosphorylates HDAC7 and Induces Its Nuclear Export after T-cell Receptor Activation

2004 ◽  
Vol 280 (14) ◽  
pp. 13762-13770 ◽  
Author(s):  
Maribel Parra ◽  
Herbert Kasler ◽  
Timothy A. McKinsey ◽  
Eric N. Olson ◽  
Eric Verdin
Keyword(s):  
T Cell ◽  
Protein Kinase ◽  
T Cell Receptor ◽  
Nuclear Export ◽  
Cell Receptor ◽  
Receptor Activation ◽  
Protein Kinase D1

scholarly journals CIN85 drives B cell responses by linking BCR signals to the canonical NF-κB pathway

2011 ◽  
Vol 208 (7) ◽  
pp. 1447-1457 ◽  
Author(s):  
Kohei Kometani ◽  
Takayuki Yamada ◽  
Yoshiteru Sasaki ◽  
Tadashi Yokosuka ◽  
Takashi Saito ◽  
...  
Keyword(s):  
T Cell ◽  
B Cell ◽  
Adaptor Protein ◽  
Cellular Responses ◽  
Cell Receptor ◽  
Antibody Responses ◽  
Cell Responses ◽  
Subsequent Degradation

CIN85, an adaptor protein which binds the C-terminal domain of tyrosine phosphorylated Cbl and Cbl-b, has been thought to be involved in the internalization and subsequent degradation of receptors. However, its physiological function remains unclear. To determine its role in B cells, we used Mb1-cre to generate mice with a B cell–specific deletion of CIN85. These mice had impaired T cell–independent type II antibody responses in vivo and diminished IKK-β activation and cellular responses to B cell receptor (BCR) cross-linking in vitro. Introduction of a constitutively active IKK-β construct corrected the defective antibody responses as well as cellular responses in the mutant mice. Together, our results suggest that CIN85 links the BCR to IKK-β activation, thereby contributing to T cell–independent immune responses.

scholarly journals In Vivo Significance of ITK-SLP-76 Interaction in Cytokine Production

2010 ◽  
Vol 30 (14) ◽  
pp. 3596-3609 ◽  
Author(s):  
Juris A. Grasis ◽  
David M. Guimond ◽  
Nicholas R. Cam ◽  
Krystal Herman ◽  
Paola Magotti ◽  
...  
Keyword(s):  
T Cell ◽  
Biological Significance ◽  
Adaptor Protein ◽  
Cell Receptor ◽  
Sh3 Domain ◽  
Live Cells ◽  
Pharmacological Intervention ◽  
Cell Contact

ABSTRACT In vitro data have suggested that activation of the inducible T-cell kinase (ITK) requires an interaction with the adaptor protein SLP-76. One means for this interaction involves binding of the ITK SH3 domain to the polyproline-rich (PR) region of SLP-76. However, the biological significance of this association in live cells and the consequences of its disruption have not been demonstrated. Here, we utilized a polyarginine-rich, cell-permeable peptide that represents the portion of the SLP-76 PR region that interacts with the ITK SH3 domain as a competitive inhibitor to disrupt the association between ITK and SLP-76 in live cells. We demonstrate that treatment of cells with this peptide, by either in vitro incubation or intraperitoneal injection of the peptide in mice, inhibits the T-cell receptor (TCR)-induced association between ITK and SLP-76, recruitment and transphosphorylation of ITK, actin polarization at the T-cell contact site, and expression of Th2 cytokines. The inhibition is specific, as indicated by lack of effects by the polyarginine vehicle alone or a scrambled sequence of the cargo peptide. In view of the role of ITK as a regulator of Th2 cytokine expression, the data underscore the significance of ITK as a target for pharmacological intervention.

Interleukin-15 redirects the outcome of a tolerizing T-cell stimulus from apoptosis to anergy

Blood ◽  
2000 ◽  
Vol 96 (3) ◽  
pp. 1006-1012 ◽  
Author(s):  
Hans Dooms ◽  
Tom Van Belle ◽  
Marjory Desmedt ◽  
Pieter Rottiers ◽  
Johan Grooten
Keyword(s):  
T Cell ◽  
Cell Receptor ◽  
T Cell Response ◽  
Peripheral Tolerance ◽  
Clonal Deletion ◽  
Cell Clones ◽  
Receptor Signal ◽  
Cytokine Milieu ◽  
Antigen Presenting

Abstract Clonal deletion and anergy are 2 mechanisms used by the immune system to establish peripheral tolerance. In vitro, these mechanisms are induced in T lymphocytes by triggering the T-cell receptor (signal 1) in the absence of costimulation (signal 2). T-cell clones have been shown either to become anergic or to die in response to signal 1 alone; yet the factors that govern this choice remain unknown. This study evaluated the influence of the cytokines interleukin (IL)-2 and IL-15 on the response of the Th1 clone hemagglutinin (T-HA) to signal 1, delivered by stimulation with immobilized anti-CD3 monoclonal antibody (mAb). The response induced by immobilized anti-CD3 mAb was dependent on the cytokine milieu; in the presence of IL-2, T-HA cells were subject to apoptosis, whereas in the presence of IL-15 the cells remained viable but showed proliferative unresponsiveness. After release from the anti-CD3 stimulus, the IL-15-rescued T-HA cells regained responsiveness to IL-2 and IL-15 growth factor activity. However, they were unable to proliferate when stimulated with their cognate antigen presented by professional antigen-presenting cells (signal 1 plus 2) and thus had acquired an anergic phenotype. These data assign a novel function to the previously reported antiapoptotic activity of IL-15, namely, the capacity to redirect the T-cell response to partial stimulation from clonal deletion to anergy. Furthermore, they emphasize that the cytokine environment can critically influence the outcome of a tolerizing stimulus.

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.

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