scholarly journals Genetic immunodeficiency and autoimmune disease reveal distinct roles of Hem1 in the WAVE2 and mTORC2 complexes

2019 ◽  
Author(s):  
William A. Comrie ◽  
M. Cecilia Poli ◽  
Sarah A. Cook ◽  
Morgan Similuk ◽  
Andrew J. Oler ◽  
...  
Keyword(s):  
T Cell ◽  
T Cell Activation ◽  
Actin Polymerization ◽  
Cell Activation ◽  
Synapse Formation ◽  
Immune Cell ◽  
Loss Of Function ◽  
Cortical Actin ◽  
Akt Phosphorylation ◽  
Regulatory Complex

AbstractImmunodeficiency often coincides with immune hyperresponsiveness such as autoimmunity, lymphoproliferation, or atopy, but the molecular basis of this paradox is typically unknown. We describe four families with immunodeficiency coupled with atopy, lymphoproliferation, cytokine overproduction, hemophagocytic lymphohistocytosis, and autoimmunity. We discovered loss-of-function variants in the gene NCKAP1L, encoding the hematopoietic-specific Hem1 protein. Three mutations cause Hem1 protein and WAVE regulatory complex (WRC) loss, thereby disrupting actin polymerization, synapse formation, and immune cell migration. Another mutant, M371V encodes a stable Hem1 protein but abrogates binding of the Arf1 GTPase and identifies Arf1 as a critical Hem1 regulator. All mutations reduce the cortical actin barrier to cytokine release explaining immune hyperresponsiveness. Finally, Hem1 loss blocked mTORC2-dependent AKT phosphorylation, T cell proliferation, and effector cytokine production during T cell activation. Thus, our data show that Hem1 independently governs two key regulatory complexes, the WRC and mTORC2, and how Hem1 loss causes a combined immunodeficiency and immune hyperresponsiveness disease.One sentence summaryHem1 loss of function mutations cause a congenital immunodysregulatory disease and reveal its role regulating WAVE2 and mTORC2 signaling.

scholarly journals HEM1 deficiency disrupts mTORC2 and F-actin control in inherited immunodysregulatory disease

Science ◽  
2020 ◽  
Vol 369 (6500) ◽  
pp. 202-207 ◽  
Author(s):  
Sarah A. Cook ◽  
William A. Comrie ◽  
M. Cecilia Poli ◽  
Morgan Similuk ◽  
Andrew J. Oler ◽  
...  
Keyword(s):  
Actin Polymerization ◽  
Synapse Formation ◽  
Immune Cell ◽  
Filamentous Actin ◽  
Cortical Actin ◽  
Akt Phosphorylation ◽  
Actin Networks ◽  
Evolutionarily Conserved ◽  
Regulatory Complex ◽  
Immune Cell Migration

Immunodeficiency often coincides with hyperactive immune disorders such as autoimmunity, lymphoproliferation, or atopy, but this coincidence is rarely understood on a molecular level. We describe five patients from four families with immunodeficiency coupled with atopy, lymphoproliferation, and cytokine overproduction harboring mutations in NCKAP1L, which encodes the hematopoietic-specific HEM1 protein. These mutations cause the loss of the HEM1 protein and the WAVE regulatory complex (WRC) or disrupt binding to the WRC regulator, Arf1, thereby impairing actin polymerization, synapse formation, and immune cell migration. Diminished cortical actin networks caused by WRC loss led to uncontrolled cytokine release and immune hyperresponsiveness. HEM1 loss also blocked mechanistic target of rapamycin complex 2 (mTORC2)–dependent AKT phosphorylation, T cell proliferation, and selected effector functions, leading to immunodeficiency. Thus, the evolutionarily conserved HEM1 protein simultaneously regulates filamentous actin (F-actin) and mTORC2 signaling to achieve equipoise in immune responses.

scholarly journals Fyn and PTP-PEST–mediated Regulation of Wiskott-Aldrich Syndrome Protein (WASp) Tyrosine Phosphorylation Is Required for Coupling T Cell Antigen Receptor Engagement to WASp Effector Function and T Cell Activation

2004 ◽  
Vol 199 (1) ◽  
pp. 99-112 ◽  
Author(s):  
Karen Badour ◽  
Jinyi Zhang ◽  
Fabio Shi ◽  
Yan Leng ◽  
Michael Collins ◽  
...  
Keyword(s):  
T Cell ◽  
Tyrosine Phosphorylation ◽  
T Cell Activation ◽  
Actin Polymerization ◽  
Cell Activation ◽  
Synapse Formation ◽  
Tyrosine Phosphatase ◽  
Structural Constraints ◽  
Wiskott Aldrich Syndrome ◽  
Syndrome Protein

Involvement of the Wiskott-Aldrich syndrome protein (WASp) in promoting cell activation requires its release from autoinhibitory structural constraints and has been attributed to WASp association with activated cdc42. Here, however, we show that T cell development and T cell receptor (TCR)-induced proliferation and actin polymerization proceed normally in WASp−/− mice expressing a WASp transgene lacking the cdc42 binding domain. By contrast, mutation of tyrosine residue Y291, identified here as the major site of TCR-induced WASp tyrosine phosphorylation, abrogated induction of WASp tyrosine phosphorylation and its effector activities, including nuclear factor of activated T cell transcriptional activity, actin polymerization, and immunological synapse formation. TCR-induced WASp tyrosine phosphorylation was also disrupted in T cells lacking Fyn, a kinase shown here to bind, colocalize with, and phosphorylate WASp. By contrast, WASp was tyrosine dephosphorylated by protein tyrosine phosphatase (PTP)-PEST, a tyrosine phosphatase shown here to interact with WASp via proline, serine, threonine phosphatase interacting protein (PSTPIP)1 binding. Although Fyn enhanced WASp-mediated Arp2/3 activation and was required for synapse formation, PTP-PEST combined with PSTPIP1 inhibited WASp-driven actin polymerization and synapse formation. These observations identify key roles for Fyn and PTP-PEST in regulating WASp and imply that inducible WASp tyrosine phosphorylation can occur independently of cdc42 binding, but unlike the cdc42 interaction, is absolutely required for WASp contributions to T cell activation.

scholarly journals T Cell Immune Deficiency in zap70 Mutant Zebrafish

2016 ◽  
Vol 36 (23) ◽  
pp. 2868-2876 ◽  
Author(s):  
John C. Moore ◽  
Timothy S. Mulligan ◽  
Nora Torres Yordán ◽  
Daniel Castranova ◽  
Van N. Pham ◽  
...  
Keyword(s):  
Immune Deficiency ◽  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Immune Cell ◽  
Cell Loss ◽  
Loss Of Function ◽  
Severe Combined Immune Deficiency ◽  
Transcription Activator

ZAP70 [ zeta-chain (TCR)-associated protein kinase , 70-kDa ], is required for T cell activation. ZAP70 deficiencies in humans and null mutations in mice lead to severe combined immune deficiency. Here, we describe a zap70 loss-of-function mutation in zebrafish ( zap70 y442 ) that was created using transcription activator-like effector nucleases (TALENs). In contrast to what has been reported for morphant zebrafish, zap70 y442 homozygous mutant zebrafish displayed normal development of blood and lymphatic vasculature. Hematopoietic cell development was also largely unaffected in mutant larvae. However, mutant fish had reduced lck : GFP + thymic T cells by 5 days postfertilization that persisted into adult stages. Morphological analysis, RNA sequencing, and single-cell gene expression profiling of whole kidney marrow cells of adult fish revealed complete loss of mature T cells in zap70 y442 mutant animals. T cell immune deficiency was confirmed through transplantation of unmatched normal and malignant donor cells into zap70 y442 mutant zebrafish, with T cell loss being sufficient for robust allogeneic cell engraftment. zap70 mutant zebrafish show remarkable conservation of immune cell dysfunction as found in mice and humans and will serve as a valuable model to study zap70 immune deficiency.

Altered immune cell profiles and impaired CD4 T cell activation in single and multi‐food allergic adolescents

2021 ◽  
Author(s):  
Melanie R. Neeland ◽  
Sandra Andorf ◽  
Thanh D. Dang ◽  
Vicki L. McWilliam ◽  
Kirsten P. Perrett ◽  
...  
Keyword(s):  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Immune Cell ◽  
Cd4 T Cell

scholarly journals Retrograde And Anterograde Transport Of LAT-Vesicles During The Immunological Synapse Formation: Defining The Finely-Tuned Mechanism

2020 ◽  
Author(s):  
Juan José Saez ◽  
Stéphanie Dogniaux ◽  
Massiullah Shafaq-Zadah ◽  
Ludger Johannes ◽  
Claire Hivroz ◽  
...  
Keyword(s):  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Synapse Formation ◽  
Immunological Synapse ◽  
Retrograde Transport ◽  
Anterograde Transport ◽  
Immune Synapse ◽  
Cellular Context ◽  
Intracellular Compartments

ABSTRACTLAT is an important player of the signaling cascade induced by TCR activation. This adapter molecule is present at the plasma membrane of T lymphocytes and more abundantly in intracellular compartments. Upon T-cell activation the intracellular pool of LAT is recruited to the immune synapse (IS). We previously described two pathways controlling LAT trafficking: retrograde transport from endosomes to the TGN, and anterograde traffic from the Golgi to the IS. We address the specific role of 4 proteins, the GTPase Rab6, the t-SNARE syntaxin-16, the v-SNARE VAMP7 and the golgin GMAP210, in each pathway. Using different methods (endocytosis and Golgi trap assays, confocal and TIRF microscopy, TCR-signalosome pull down) we show that syntaxin-16 is regulating the retrograde transport of LAT whereas VAMP7 is regulating the anterograde transport. Moreover, GMAP210 and Rab6, known to contribute in both pathways, are in our cellular context specifically and respectively involved in anterograde and retrograde transport of LAT. Altogether, our data describe how retrograde and anterograde pathways coordinate LAT enrichment at the IS and point the Golgi as a central hub for the polarized recruitment of LAT to the IS. The role that this finely-tuned transport of signaling molecules plays in T-cell activation is discussed.

scholarly journals Actin Cytoskeleton Regulates Calcium Dynamics and NFAT Nuclear Duration

2004 ◽  
Vol 24 (4) ◽  
pp. 1628-1639 ◽  
Author(s):  
Fabiola V. Rivas ◽  
James P. O'Keefe ◽  
Maria-Luisa Alegre ◽  
Thomas F. Gajewski
Keyword(s):  
T Cell ◽  
Actin Cytoskeleton ◽  
T Cell Activation ◽  
Actin Polymerization ◽  
Cell Activation ◽  
Cell Function ◽  
Immunological Synapse ◽  
Interleukin 2 ◽  
Actin Dynamics ◽  
Activated T Cells

ABSTRACT T-cell activation by antigen-presenting cells is accompanied by actin polymerization, T-cell receptor (TCR) capping, and formation of the immunological synapse. However, whether actin-dependent events are required for T-cell function is poorly understood. Herein, we provide evidence for an unexpected negative regulatory role of the actin cytoskeleton on TCR-induced cytokine production. Disruption of actin polymerization resulted in prolonged intracellular calcium elevation in response to anti-CD3, thapsigargin, or phorbol myristate acetate plus ionomycin, leading to persistent NFAT (nuclear factor of activated T cells) nuclear duration. These events were dominant, as the net effect of actin blockade was augmented interleukin 2 promoter activity. Increased surface expression of the plasma membrane Ca2+ ATPase was observed upon stimulation, which was inhibited by cytochalasin D, suggesting that actin polymerization contributes to calcium export. Our results imply a novel role for the actin cytoskeleton in modulating the duration of Ca2+-NFAT signaling and indicate that actin dynamics regulate features of T-cell activation downstream of receptor clustering.

IMMU-04. UNVEILING THE TUMOR-METABOLOME-IMMUNITY AXIS OF GLIOMA

2021 ◽  
Vol 23 (Supplement_6) ◽  
pp. vi92-vi92
Author(s):  
Mirco Friedrich ◽  
Lukas Bunse ◽  
Roman Sankowski ◽  
Wolfgang Wick ◽  
Marco Prinz ◽  
...  
Keyword(s):  
T Cell ◽  
Single Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Immune Cell ◽  
Myeloid Cell ◽  
Tumor Evolution ◽  
Large Neutral Amino Acid ◽  
Immune Microenvironment ◽  
Idh Mutations

Abstract The glioma microenvironment orchestrates tumor evolution, progression, and resistance to therapy. In high-grade gliomas, microglia and monocyte-derived macrophages constitute up to 70% of the tumor mass. However, the dynamics and phenotypes of intratumoral myeloid cells during tumor progression are poorly understood. Here we define myeloid cellular states in gliomas by longitudinal single-cell profiling and demonstrate their strict control by the tumor genotype. We report the unexpected and clinically highly relevant finding that human as well as murine gliomas with Isocitrate Dehydrogenase (IDH)1-R132H, a key oncogenic driver mutation of glioma, subdue their innate immune microenvironment by prompting a multifaceted reprogramming of myeloid and T cell metabolism. We employed integrated single-cell transcriptomic, time-of-flight mass cytometry and proteomic analyses of human healthy cortex control and glioma samples to identify myeloid cell subsets with distinct fates in IDH-mutated glioma that diverge from canonical trajectories of antigen-presenting cells as a result of a monocyte-to-macrophage differentiation block. Moving beyond single time point assessments, we now longitudinally describe differential immune cell infiltration and phenotype dynamics during glioma progression that are orchestrated by a fluctuating network of resident microglial cells and educated recruited immune cells. IDH mutations in glioma induce a tolerogenic alignment of their immune microenvironment through increased tryptophan uptake via large neutral amino acid transporter (LAT1)-CD98 and subsequent activation of the aryl hydrocarbon receptor (AHR) in educated blood-borne macrophages. In experimental tumor models, this immunosuppressive phenotype was reverted by LAT1-CD98 and AHR inhibitors. Taken together with direct effects on T cell activation, our findings not only link this oncogenic metabolic pathway to distinct immunosuppressive pathways but also provide the rationale and novel molecular targets for the development of immunotherapeutic concepts addressing the disease-defining microenvironmental effects of IDH mutations.

scholarly journals T Cell Activation Machinery: Form and Function in Natural and Engineered Immune Receptors

2020 ◽  
Vol 21 (19) ◽  
pp. 7424
Author(s):  
Nicholas J. Chandler ◽  
Melissa J. Call ◽  
Matthew E. Call
Keyword(s):  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Immune Cell ◽  
Single Chain ◽  
Design Work ◽  
Cell Therapies ◽  
Form And Function ◽  
Car T ◽  
And Function

The impressive success of chimeric antigen receptor (CAR)-T cell therapies in treating advanced B-cell malignancies has spurred a frenzy of activity aimed at developing CAR-T therapies for other cancers, particularly solid tumors, and optimizing engineered T cells for maximum clinical benefit in many different disease contexts. A rapidly growing body of design work is examining every modular component of traditional single-chain CARs as well as expanding out into many new and innovative engineered immunoreceptor designs that depart from this template. New approaches to immune cell and receptor engineering are being reported with rapidly increasing frequency, and many recent high-quality reviews (including one in this special issue) provide comprehensive coverage of the history and current state of the art in CAR-T and related cellular immunotherapies. In this review, we step back to examine our current understanding of the structure-function relationships in natural and engineered lymphocyte-activating receptors, with an eye towards evaluating how well the current-generation CAR designs recapitulate the most desirable features of their natural counterparts. We identify key areas that we believe are under-studied and therefore represent opportunities to further improve our grasp of form and function in natural and engineered receptors and to rationally design better therapeutics.

scholarly journals IMMU-46. EXAMINATION OF THE EFFECTS OF DEXAMETHASONE ON THE EFFICACY OF IMMUNOTHERAPY IN GLIOMA USING GENE-MEDIATED CYTOTOXIC IMMUNOTHERAPY

2019 ◽  
Vol 21 (Supplement_6) ◽  
pp. vi129-vi129
Author(s):  
Marilin Koch ◽  
Mykola Zdioruk ◽  
M Oskar Nowicki ◽  
Estuardo Aguilar ◽  
Laura Aguilar ◽  
...  
Keyword(s):  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Cell Function ◽  
Immune Cell ◽  
Symptomatic Treatment ◽  
Tumor Cell Death ◽  
The Impact

Abstract RATIONALE Dexamethasone is frequently used in symptomatic treatment of glioma patients, although it is known to cause immune suppression. Checkpoint inhibitor immunotherapies have not yet been successful in glioma treatments. Gene-mediated cytotoxic immunotherapy (GMCI) is an immunotherapeutic approach that uses aglatimagene besadenovec with an anti-herpetic prodrug to induce immunogenic tumor cell death and immune cell attraction to the tumor site with potent CD8 T cell activation. GMCI is currently in clinical trials for solid tumors including glioblastoma, where it showed encouraging survival results in a Phase 2 study that did not limit the use of dexamethasone. However, the effects of dexamethasone on its efficacy have not been explored. METHODS We investigated the effects of dexamethasone on GMCI in vitro using cytotoxicity and T-cell-killing assays in glioblastoma cell lines. The impact of dexamethasone in vivo was assessed in an orthotopic syngeneic murine glioblastoma model. RESULTS Cyotoxicity assays showed that Dexamethasone has a slight impact on GMCI in vitro. In contrast, we observed a highly significant effect in T-cell-functional assays in which killing was greatly impaired. Immune cell response assays revealed a reduced T-cell proliferation after co-culture with supernatant from dexamethasone or combination treated glioblastoma cells in contrast to GMCI alone. In a murine model, the combination of GMCI and dexamethasone resulted in a significant reduction in median symptom-free survival (29d) in comparison to GMCI alone (39.5d) (P = 0.0184). CONCLUSION Our data suggest that high doses of dexamethasone may negatively impact the efficacy of immunotherapy for glioma, which may be a consequence of impaired T cell function. These results support the idea that there is a need in identifying possible alternatives to dexamethasone to maximize the effectiveness of immunostimulatory therapies such as GMCI.

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