1
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Benavides N, Giraudo CG. Extended-Synaptotagmin-1 and -2 control T cell signaling and function. EMBO Rep 2024; 25:286-303. [PMID: 38177911 PMCID: PMC10897422 DOI: 10.1038/s44319-023-00011-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Revised: 10/22/2023] [Accepted: 11/13/2023] [Indexed: 01/06/2024] Open
Abstract
Upon T-cell activation, the levels of the secondary messenger diacylglycerol (DAG) at the plasma membrane need to be controlled to ensure appropriate T-cell receptor signaling and T-cell functions. Extended-Synaptotagmins (E-Syts) are a family of inter-organelle lipid transport proteins that bridge the endoplasmic reticulum and the plasma membrane. In this study, we identify a novel regulatory mechanism of DAG-mediated signaling for T-cell effector functions based on E-Syt proteins. We demonstrate that E-Syts downmodulate T-cell receptor signaling, T-cell-mediated cytotoxicity, degranulation, and cytokine production by reducing plasma membrane levels of DAG. Mechanistically, E-Syt2 predominantly modulates DAG levels at the plasma membrane in resting-state T cells, while E-Syt1 and E-Syt2 negatively control T-cell receptor signaling upon stimulation. These results reveal a previously underappreciated role of E-Syts in regulating DAG dynamics in T-cell signaling.
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Affiliation(s)
- Nathalia Benavides
- Department of Microbiology and Immunology-Sidney Kimmel Medical College-Thomas Jefferson University, Philadelphia, PA, USA
| | - Claudio G Giraudo
- Department of Microbiology and Immunology-Sidney Kimmel Medical College-Thomas Jefferson University, Philadelphia, PA, USA.
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2
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Ganesan S, Alvarez NN, Steiner S, Fowler KM, Corona AK, Roy CR. Syntaxin 11 Contributes to the Interferon-Inducible Restriction of Coxiella burnetii Intracellular Infection. mBio 2023; 14:e0354522. [PMID: 36728431 PMCID: PMC9972978 DOI: 10.1128/mbio.03545-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Accepted: 01/04/2023] [Indexed: 02/03/2023] Open
Abstract
There is a limited understanding of host defense mechanisms targeting intracellular pathogens that proliferate in a lysosome. Coxiella burnetii is a model bacterial pathogen capable of replicating in the hydrolytic and acidic environment of the lysosome. It has been shown that gamma interferon (IFNγ)-stimulated host cells restrict C. burnetii replication by a mechanism that involves host IDO1 depletion of tryptophan. Host cells deficient in IDO1 activity, however, retain the ability to restrict C. burnetii replication when stimulated with IFNγ, which suggests additional mechanisms of host defense. This study identified syntaxin 11 (STX11) as a host protein that contributes to IFNγ-mediated suppression of C. burnetii replication. STX11 is a SNARE protein; SNARE proteins are proteins that mediate fusion of host vesicles with specific subcellular organelles. Depletion of STX11 using either small interfering RNA (siRNA)- or CRISPR-based approaches enhanced C. burnetii replication intracellularly. Stable expression of STX11 reduced C. burnetii replication in epithelial cells and macrophages, which indicates that this STX11-dependent cell-autonomous response is operational in multiple cell types and can function independently of other IFNγ-induced factors. Fluorescently tagged STX11 localized to the Coxiella-containing vacuole (CCV), and STX11 restriction was found to involve an interaction with STX8. Thus, STX11 regulates a vesicle fusion pathway that limits replication of this intracellular pathogen in a lysosome-derived organelle. IMPORTANCE Cell intrinsic defense mechanisms are used by eukaryotic cells to restrict the replication and dissemination of pathogens. This study identified a human protein called syntaxin 11 (STX11) as a host restriction factor that inhibits the intracellular replication of Coxiella burnetii. Syntaxins regulate the delivery of cargo inside vesicles by promoting specific membrane fusion events between donor and acceptor vesicles. Data presented here demonstrate that STX11 regulates an immunological defense pathway that controls replication of pathogens in lysosome-derived organelles, which provides new insight into the function of this SNARE protein.
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Affiliation(s)
- Sandhya Ganesan
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Natalie N. Alvarez
- Department of Pediatrics, School of Medicine, Emory University, Atlanta, Georgia, USA
| | - Samuel Steiner
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Karen M. Fowler
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Abigail K. Corona
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Craig R. Roy
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, Connecticut, USA
- Department of Immunobiology, Yale University School of Medicine, New Haven, Connecticut, USA
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3
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Li W, Xing Y, Wang Y, Xu T, Song E, Feng W. A non-canonical target-binding site in Munc18-1 domain 3b for assembling the Mint1-Munc18-1-syntaxin-1 complex. Structure 2023; 31:68-77.e5. [PMID: 36608665 DOI: 10.1016/j.str.2022.11.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Revised: 10/10/2022] [Accepted: 11/04/2022] [Indexed: 01/07/2023]
Abstract
As the prototype of Sec1/Munc18 (SM) family proteins, Munc18-1 can manipulate the distinct conformations of syntaxin-1 for controlling intracellular membrane fusion. The Munc18-1-interacting domain of Mint1 (Mint1-MID) binds to Munc18-1 together with syntaxin-1 to form a Mint1-Munc18-1-syntaxin-1 complex, but the mechanism underlying the complex assembly remains unclear. Here, we determine the structure of the Mint1-MID-Munc18-1-syntaxin-1 complex. Unexpectedly, Munc18-1 recognizes Mint1-MID and syntaxin-1 simultaneously via two opposite sites. The canonical central cavity between domains 1 and 3a of Munc18-1 embraces closed syntaxin-1, whereas the non-canonical basic pocket in domain 3b captures the acidic Mint1-MID helix. The domain 3b-mediated recognition of an acidic-helical motif is distinct from other target-recognition modes of Munc18-1. Mutations in the interface between domain 3b and Mint1-MID disrupt the assembly of the Mint1-Munc18-1-syntaxin-1 complex. This work reveals a non-canonical target-binding site in Munc18-1 domain 3b for assembling the Mint1-Munc18-1-syntaxin-1 complex.
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Affiliation(s)
- Wei Li
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Beijing 100101, China
| | - Ying Xing
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Beijing 100101, China; College of Life Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yue Wang
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Beijing 100101, China; College of Life Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Tao Xu
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Beijing 100101, China; College of Life Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Eli Song
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Beijing 100101, China.
| | - Wei Feng
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Beijing 100101, China; College of Life Sciences, University of Chinese Academy of Sciences, Beijing 100049, China.
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4
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Cappelletti P, Filareti M, Masuelli L, Bei R, Hassanzadeh K, Corbo M, Feligioni M. Syntaxin-1a and SNAP-25 expression level is increased in the blood samples of ischemic stroke patients. Sci Rep 2022; 12:14483. [PMID: 36008522 PMCID: PMC9411545 DOI: 10.1038/s41598-022-18719-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Accepted: 08/18/2022] [Indexed: 11/09/2022] Open
Abstract
The interest for the discovery of blood biomarkers for several neurological disorders, including Ischemic Stroke (IS), is growing and their identification in blood samples would be revolutionary allowing a fast and better pathology prediction or outcome and to collect information on patient recovery. The increased permeability of the blood-brain barrier, following a brain infarct, allows the detection of brain proteins in the blood flow. In this work, we analyzed the expression levels of two synaptic proteins Syntaxin (STX)-1a and Synaptosomal Associated Protein, 25 kDa (SNAP-25), in Peripheral Blood Mononuclear Cell (PBMC), serum and in Neuronal Derived Extracellular vesicles (NDEs) of IS patients, age and sex matched healthy control (HC) and younger HC (Y-HC). Interestingly, we identified STX-1a protein in the cytoplasm of PBMC and both STX-1a and SNAP-25 expression levels were significantly augmented in all IS patient's blood fractions compared to control subjects. In addition, STX-1a blood levels correlated with the IS clinical scales National Institutes of Health Stroke Scale (NIH-SS) and the modified Barthel Index (BI). These results prompted us to speculate that STX-1a and SNAP-25 hematic fluctuations depict the brain damage after an ischemic attack and that their hematic detection could represent a novel and accessible IS biomarkers.
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Affiliation(s)
- Pamela Cappelletti
- Department of Neuro-Rehabilitation Sciences, Casa Cura Policlinico, Milan, Italy
| | - Melania Filareti
- Department of Neuro-Rehabilitation Sciences, Casa Cura Policlinico, Milan, Italy
| | - Laura Masuelli
- Department of Experimental Medicine, University of Rome "Sapienza", Rome, Italy
| | - Roberto Bei
- Department of Clinical Sciences and Translational Medicine, University of Rome "Tor Vergata", Rome, Italy
| | - Kambiz Hassanzadeh
- European Brain Research Institute (EBRI) Rita Levi Montalcini Foundation, Viale Regina Elena 295, 00161, Rome, Italy.,Fondazione Pisana per la Scienza (FPS), Pisa, Italy
| | - Massimo Corbo
- Department of Neuro-Rehabilitation Sciences, Casa Cura Policlinico, Milan, Italy
| | - Marco Feligioni
- Department of Neuro-Rehabilitation Sciences, Casa Cura Policlinico, Milan, Italy. .,European Brain Research Institute (EBRI) Rita Levi Montalcini Foundation, Viale Regina Elena 295, 00161, Rome, Italy.
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5
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Ham H, Medlyn M, Billadeau DD. Locked and Loaded: Mechanisms Regulating Natural Killer Cell Lytic Granule Biogenesis and Release. Front Immunol 2022; 13:871106. [PMID: 35558071 PMCID: PMC9088006 DOI: 10.3389/fimmu.2022.871106] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Accepted: 03/29/2022] [Indexed: 11/22/2022] Open
Abstract
NK cell-mediated cytotoxicity is a critical element of our immune system required for protection from microbial infections and cancer. NK cells bind to and eliminate infected or cancerous cells via direct secretion of cytotoxic molecules toward the bound target cells. In this review, we summarize the current understanding of the molecular regulations of NK cell cytotoxicity, focusing on lytic granule development and degranulation processes. NK cells synthesize apoptosis-inducing proteins and package them into specialized organelles known as lytic granules (LGs). Upon activation of NK cells, LGs converge with the microtubule organizing center through dynein-dependent movement along microtubules, ultimately polarizing to the cytotoxic synapse where they subsequently fuse with the NK plasma membrane. From LGs biogenesis to degranulation, NK cells utilize several strategies to protect themselves from their own cytotoxic molecules. Additionally, molecular pathways that enable NK cells to perform serial killing are beginning to be elucidated. These advances in the understanding of the molecular pathways behind NK cell cytotoxicity will be important to not only improve current NK cell-based anti-cancer therapies but also to support the discovery of additional therapeutic opportunities.
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Affiliation(s)
- Hyoungjun Ham
- Division of Oncology Research, Mayo Clinic, Rochester, MN, United States
| | - Michael Medlyn
- Department of Immunology College of Medicine, Mayo Clinic, Rochester, MN, United States
| | - Daniel D Billadeau
- Division of Oncology Research, Mayo Clinic, Rochester, MN, United States.,Department of Immunology College of Medicine, Mayo Clinic, Rochester, MN, United States
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Steen EA, Hermiston ML, Nichols KE, Meyer LK. Digenic Inheritance: Evidence and Gaps in Hemophagocytic Lymphohistiocytosis. Front Immunol 2021; 12:777851. [PMID: 34868048 PMCID: PMC8635482 DOI: 10.3389/fimmu.2021.777851] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Accepted: 10/19/2021] [Indexed: 12/26/2022] Open
Abstract
Hemophagocytic lymphohistiocytosis (HLH) is a hyperinflammatory disorder characterized by the inability to properly terminate an immune response. Familial HLH (FHLH) and related immune dysregulation syndromes are associated with mutations in the genes PRF1, UNC13D, STX11, STXBP2, LYST, AP3B1, and RAB27A, all of which are required for the assembly, exocytosis, and function of cytotoxic granules within CD8+ T cells and natural killer (NK) cells. Loss-of-function mutations in these genes render the cytotoxicity pathway ineffective, thereby failing to eradicate immune stimuli, such as infectious pathogens or malignant cells. The resulting persistent immune system stimulation drives hypercytokinemia, ultimately leading to severe tissue inflammation and end-organ damage. Traditionally, a diagnosis of FHLH requires the identification of biallelic loss-of-function mutations in one of these degranulation pathway genes. However, this narrow definition fails to encompass patients with other genetic mechanisms underlying degranulation pathway dysfunction. In particular, mounting clinical evidence supports a potential digenic mode of inheritance of FHLH in which single loss-of-function mutations in two different degranulation pathway genes cooperate to impair pathway activity. Here, we review the functions of the FHLH-associated genes within the degranulation pathway and summarize clinical evidence supporting a model in which cumulative defects along this mechanistic pathway may underlie HLH.
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Affiliation(s)
- Erica A Steen
- University of California, San Diego, San Diego, CA, United States
| | - Michelle L Hermiston
- Department of Pediatrics, University of California, San Francisco, San Francisco, CA, United States
| | - Kim E Nichols
- Department of Oncology, St. Jude Children's Research Hospital, Memphis, TN, United States
| | - Lauren K Meyer
- Department of Pediatrics, University of California, San Francisco, San Francisco, CA, United States
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7
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Plooster M, Rossi G, Farrell MS, McAfee JC, Bell JL, Ye M, Diering GH, Won H, Gupton SL, Brennwald P. Schizophrenia-Linked Protein tSNARE1 Regulates Endosomal Trafficking in Cortical Neurons. J Neurosci 2021; 41:9466-9481. [PMID: 34642214 PMCID: PMC8580139 DOI: 10.1523/jneurosci.0556-21.2021] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 10/04/2021] [Accepted: 10/04/2021] [Indexed: 12/13/2022] Open
Abstract
TSNARE1, which encodes the protein tSNARE1, is a high-confidence gene candidate for schizophrenia risk, but nothing is known about its cellular or physiological function. We identified the major gene products of TSNARE1 and their cytoplasmic localization and function in endosomal trafficking in cortical neurons. We validated three primary isoforms of TSNARE1 expressed in human brain, all of which encode a syntaxin-like Qa SNARE domain. RNA-sequencing data from adult and fetal human brain suggested that the majority of tSNARE1 lacks a transmembrane domain that is thought to be necessary for membrane fusion. Biochemical data demonstrate that tSNARE1 can compete with Stx12 for incorporation into an endosomal SNARE complex, supporting its possible role as an inhibitory SNARE. Live-cell imaging in cortical neurons from mice of both sexes demonstrated that brain tSNARE1 isoforms localized to the endosomal network. The most abundant brain isoform, tSNARE1c, localized most frequently to Rab7+ late endosomes, and endogenous tSNARE1 displayed a similar localization in human neural progenitor cells and neuroblastoma cells. In mature rat neurons from both sexes, tSNARE1 localized to the dendritic shaft and dendritic spines, supporting a role for tSNARE1 at the postsynapse. Expression of either tSNARE1b or tSNARE1c, which differ only in their inclusion or exclusion of an Myb-like domain, delayed the trafficking of the dendritic endosomal cargo Nsg1 into late endosomal and lysosomal compartments. These data suggest that tSNARE1 regulates endosomal trafficking in cortical neurons, likely by negatively regulating early endosomal to late endosomal trafficking.SIGNIFICANCE STATEMENT Schizophrenia is a severe and polygenic neuropsychiatric disorder. Understanding the functions of high-confidence candidate genes is critical toward understanding how their dysfunction contributes to schizophrenia pathogenesis. TSNARE1 is one of the high-confidence candidate genes for schizophrenia risk, yet nothing was known about its cellular or physiological function. Here we describe the major isoforms of TSNARE1 and their cytoplasmic localization and function in the endosomal network in cortical neurons. Our results are consistent with the hypothesis that the majority of brain tSNARE1 acts as a negative regulator to endolysosomal trafficking.
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Affiliation(s)
- Melissa Plooster
- Department of Cell Biology and Physiology, University of North Carolina, Chapel Hill, North Carolina 27599
| | - Guendalina Rossi
- Department of Cell Biology and Physiology, University of North Carolina, Chapel Hill, North Carolina 27599
| | - Martilias S Farrell
- Department of Genetics, University of North Carolina, Chapel Hill, North Carolina 27599
| | - Jessica C McAfee
- Department of Genetics, University of North Carolina, Chapel Hill, North Carolina 27599
- UNC Neuroscience Center, University of North Carolina, Chapel Hill, North Carolina 27599
| | - Jessica L Bell
- Department of Genetics, University of North Carolina, Chapel Hill, North Carolina 27599
- UNC Neuroscience Center, University of North Carolina, Chapel Hill, North Carolina 27599
| | - Michael Ye
- Department of Cell Biology and Physiology, University of North Carolina, Chapel Hill, North Carolina 27599
| | - Graham H Diering
- Department of Cell Biology and Physiology, University of North Carolina, Chapel Hill, North Carolina 27599
- UNC Neuroscience Center, University of North Carolina, Chapel Hill, North Carolina 27599
- Carolina Institute for Developmental Disabilities, University of North Carolina, Chapel Hill, North Carolina 27599
| | - Hyejung Won
- Department of Genetics, University of North Carolina, Chapel Hill, North Carolina 27599
- UNC Neuroscience Center, University of North Carolina, Chapel Hill, North Carolina 27599
| | - Stephanie L Gupton
- Department of Cell Biology and Physiology, University of North Carolina, Chapel Hill, North Carolina 27599
- UNC Neuroscience Center, University of North Carolina, Chapel Hill, North Carolina 27599
- Lineberger Cancer Center, University of North Carolina, Chapel Hill, North Carolina 27599
| | - Patrick Brennwald
- Department of Cell Biology and Physiology, University of North Carolina, Chapel Hill, North Carolina 27599
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Phatarpekar PV, Overlee BL, Leehan A, Wilton KM, Ham H, Billadeau DD. The septin cytoskeleton regulates natural killer cell lytic granule release. J Cell Biol 2021; 219:152040. [PMID: 32841357 PMCID: PMC7594501 DOI: 10.1083/jcb.202002145] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Revised: 06/26/2020] [Accepted: 07/28/2020] [Indexed: 11/22/2022] Open
Abstract
Natural killer (NK) cell–mediated killing involves the membrane fusion of preformed lytic granules. While the roles of actin and microtubules are well accepted during this process, the function of septins, another cytoskeletal component that associates with actin and microtubules, has not been investigated. Here we show that genetic depletion or pharmacologic stabilization of the septin cytoskeleton significantly inhibited NK cell cytotoxicity. Although the stabilization of septin filaments impaired conjugate formation, depletion of septin proteins had no impact on conjugate formation, lytic granule convergence, or MTOC polarization to the cytotoxic synapse (CS). Interestingly, septins copurify and accumulate near the polarized lytic granules at the CS, where they regulate lytic granule release. Mechanistically, we find that septin 7 interacts with the SNARE protein syntaxin 11 and facilitates its interaction with syntaxin binding protein 2 to promote lytic granule fusion. Altogether, our data identify a critical role for septins in regulating the release of lytic granule contents during NK cell–mediated killing.
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Affiliation(s)
| | - Brittany L Overlee
- Department of Immunology, College of Medicine, Mayo Clinic, Rochester, MN
| | - Alexander Leehan
- Department of Immunology, College of Medicine, Mayo Clinic, Rochester, MN
| | - Katelynn M Wilton
- Department of Immunology, College of Medicine, Mayo Clinic, Rochester, MN
| | - Hyoungjun Ham
- Department of Immunology, College of Medicine, Mayo Clinic, Rochester, MN
| | - Daniel D Billadeau
- Department of Immunology, College of Medicine, Mayo Clinic, Rochester, MN
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Peñas-Martínez J, Barrachina MN, Cuenca-Zamora EJ, Luengo-Gil G, Bravo SB, Caparrós-Pérez E, Teruel-Montoya R, Eliseo-Blanco J, Vicente V, García Á, Martínez-Martínez I, Ferrer-Marín F. Qualitative and Quantitative Comparison of Plasma Exosomes from Neonates and Adults. Int J Mol Sci 2021; 22:ijms22041926. [PMID: 33672065 PMCID: PMC7919666 DOI: 10.3390/ijms22041926] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Revised: 02/09/2021] [Accepted: 02/11/2021] [Indexed: 02/07/2023] Open
Abstract
Exosomes are extracellular vesicles that contain nucleic acids, lipids and metabolites, and play a critical role in health and disease as mediators of intercellular communication. The majority of extracellular vesicles in the blood are platelet-derived. Compared to adults, neonatal platelets are hyporeactive and show impaired granule release, associated with defects in Soluble N-ethylmaleimide-sensitive fusion Attachment protein REceptor (SNARE) proteins. Since these proteins participate in biogenesis of exosomes, we investigated the potential differences between newborn and adult plasma-derived exosomes. Plasma-derived exosomes were isolated by ultracentrifugation of umbilical cord blood from full-term neonates or peripheral blood from adults. Exosome characterization included size determination by transmission electron microscopy and quantitative proteomic analysis. Plasma-derived exosomes from neonates were significantly smaller and contained 65% less protein than those from adults. Remarkably, 131 proteins were found to be differentially expressed, 83 overexpressed and 48 underexpressed in neonatal (vs. adult) exosomes. Whereas the upregulated proteins in plasma exosomes from neonates are associated with platelet activation, coagulation and granule secretion, most of the underexpressed proteins are immunoglobulins. This is the first study showing that exosome size and content change with age. Our findings may contribute to elucidating the potential “developmental hemostatic mismatch risk” associated with transfusions containing plasma exosomes from adults.
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Affiliation(s)
- Julia Peñas-Martínez
- Servicio de Hematología y Oncología Médica, Hospital Universitario Morales Meseguer, Centro Regional de Hemodonación, Universidad de Murcia, IMIB-Arrixaca, 30003 Murcia, Spain; (J.P.-M.); (E.J.C.-Z.); (G.L.-G.); (E.C.-P.); (R.T.-M.); (V.V.)
| | - María N. Barrachina
- Platelet Proteomics Group, Centro Singular de Investigación en Medicina Molecular y Enfermedades Crónicas (CIMUS), Universidad de Santiago de Compostela e Instituto de Investigación Sanitaria de Santiago (IDIS), 15706 Santiago de Compostela, Spain; (M.N.B.); (Á.G.)
| | - Ernesto José Cuenca-Zamora
- Servicio de Hematología y Oncología Médica, Hospital Universitario Morales Meseguer, Centro Regional de Hemodonación, Universidad de Murcia, IMIB-Arrixaca, 30003 Murcia, Spain; (J.P.-M.); (E.J.C.-Z.); (G.L.-G.); (E.C.-P.); (R.T.-M.); (V.V.)
| | - Ginés Luengo-Gil
- Servicio de Hematología y Oncología Médica, Hospital Universitario Morales Meseguer, Centro Regional de Hemodonación, Universidad de Murcia, IMIB-Arrixaca, 30003 Murcia, Spain; (J.P.-M.); (E.J.C.-Z.); (G.L.-G.); (E.C.-P.); (R.T.-M.); (V.V.)
- Grupo de Investigación en Patología Molecular y Farmacogenética, Departamento de Dermatología, Estomatología, Radiología y Medicina Física, Hospital General Universitario Santa Lucía, Universidad de Murcia, IMIB-Arrixaca, 30202 Cartagena, Spain
| | - Susana Belén Bravo
- Servicio de Proteomica, e Instituto de Investigación Sanitaria de Santiago de Compostela (IDIS), Hospital ClínicoUniversitario de Santiago de Compostela, 15706 Santiago de Compostela, Spain;
| | - Eva Caparrós-Pérez
- Servicio de Hematología y Oncología Médica, Hospital Universitario Morales Meseguer, Centro Regional de Hemodonación, Universidad de Murcia, IMIB-Arrixaca, 30003 Murcia, Spain; (J.P.-M.); (E.J.C.-Z.); (G.L.-G.); (E.C.-P.); (R.T.-M.); (V.V.)
| | - Raúl Teruel-Montoya
- Servicio de Hematología y Oncología Médica, Hospital Universitario Morales Meseguer, Centro Regional de Hemodonación, Universidad de Murcia, IMIB-Arrixaca, 30003 Murcia, Spain; (J.P.-M.); (E.J.C.-Z.); (G.L.-G.); (E.C.-P.); (R.T.-M.); (V.V.)
- U-765-CIBERER, Instituto de Salud Carlos III (ISCIII), 28220 Madrid, Spain
| | - José Eliseo-Blanco
- Servicio de Obstetricia y Ginecología, Hospital Clínico Virgen de la Arrixaca, 30120 Murcia, Spain;
| | - Vicente Vicente
- Servicio de Hematología y Oncología Médica, Hospital Universitario Morales Meseguer, Centro Regional de Hemodonación, Universidad de Murcia, IMIB-Arrixaca, 30003 Murcia, Spain; (J.P.-M.); (E.J.C.-Z.); (G.L.-G.); (E.C.-P.); (R.T.-M.); (V.V.)
- U-765-CIBERER, Instituto de Salud Carlos III (ISCIII), 28220 Madrid, Spain
| | - Ángel García
- Platelet Proteomics Group, Centro Singular de Investigación en Medicina Molecular y Enfermedades Crónicas (CIMUS), Universidad de Santiago de Compostela e Instituto de Investigación Sanitaria de Santiago (IDIS), 15706 Santiago de Compostela, Spain; (M.N.B.); (Á.G.)
| | - Irene Martínez-Martínez
- Servicio de Hematología y Oncología Médica, Hospital Universitario Morales Meseguer, Centro Regional de Hemodonación, Universidad de Murcia, IMIB-Arrixaca, 30003 Murcia, Spain; (J.P.-M.); (E.J.C.-Z.); (G.L.-G.); (E.C.-P.); (R.T.-M.); (V.V.)
- U-765-CIBERER, Instituto de Salud Carlos III (ISCIII), 28220 Madrid, Spain
- Correspondence: (I.M.-M.); (F.F.-M.); Tel.: +34-968341990 (I.M-M. & F.F.-M.)
| | - Francisca Ferrer-Marín
- Servicio de Hematología y Oncología Médica, Hospital Universitario Morales Meseguer, Centro Regional de Hemodonación, Universidad de Murcia, IMIB-Arrixaca, 30003 Murcia, Spain; (J.P.-M.); (E.J.C.-Z.); (G.L.-G.); (E.C.-P.); (R.T.-M.); (V.V.)
- U-765-CIBERER, Instituto de Salud Carlos III (ISCIII), 28220 Madrid, Spain
- Grado de Medicina, Universidad Católica San Antonio de Murcia, 30107 Murcia, Spain
- Correspondence: (I.M.-M.); (F.F.-M.); Tel.: +34-968341990 (I.M-M. & F.F.-M.)
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10
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Hu Y, Zhu L, Ma C. Structural Roles for the Juxtamembrane Linker Region and Transmembrane Region of Synaptobrevin 2 in Membrane Fusion. Front Cell Dev Biol 2021; 8:609708. [PMID: 33490074 PMCID: PMC7815645 DOI: 10.3389/fcell.2020.609708] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Accepted: 12/09/2020] [Indexed: 11/13/2022] Open
Abstract
Formation of the trans-SNARE complex is believed to generate a force transfer to the membranes to promote membrane fusion, but the underlying mechanism remains elusive. In this study, we show that helix-breaking and/or length-increasing insertions in the juxtamembrane linker region of synaptobrevin-2 exert diverse effects on liposome fusion, in a manner dependent on the insertion position relative to the two conserved tryptophan residues (W89/W90). Helical extension of synaptobrevin-2 to W89/W90 is a prerequisite for initiating membrane merger. The transmembrane region of synaptobrevin-2 enables proper localization of W89/W90 at the membrane interface to gate force transfer. Besides, our data indicate that the SNARE regulatory components Munc18-1 and Munc13-1 impose liposome fusion strong demand on tight coupling between the SNARE motif and the transmembrane region of synaptobrevin-2.
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Affiliation(s)
- Yaru Hu
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, China
| | - Le Zhu
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, China
| | - Cong Ma
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, China
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11
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Benavides N, Spessott WA, Sanmillan ML, Vargas M, Livingston MS, Erickson N, Pozos TC, McCormick ME, Scharrig E, Messinger YH, Giraudo CG. STXBP2-R190C Variant in a Patient With Neonatal Hemophagocytic Lymphohistiocytosis (HLH) and G6PD Deficiency Reveals a Critical Role of STXBP2 Domain 2 on Granule Exocytosis. Front Immunol 2020; 11:545414. [PMID: 33162974 PMCID: PMC7580532 DOI: 10.3389/fimmu.2020.545414] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Accepted: 08/27/2020] [Indexed: 11/18/2022] Open
Abstract
Neonatal hemophagocytic lymphohistiocytosis (HLH) is a medical emergency that can be associated with significant morbidity and mortality. Often these patients present with familial HLH (f-HLH), which is caused by gene mutations interfering with the cytolytic pathway of cytotoxic T-lymphocytes (CTLs) and natural killer cells. Here we describe a male newborn who met the HLH diagnostic criteria, presented with profound cholestasis, and carried a maternally inherited heterozygous mutation in syntaxin-binding protein-2 [STXBP2, c.568C>T (p.Arg190Cys)] in addition to a severe pathogenic variant in glucose 6-phosphate dehydrogenase [G6PD, hemizygous c.1153T>C (Cys385Arg)]. Although mutations in STXBP2 gene are associated with f-HLH type 5, the clinical and biological relevance of the p.Arg190Cys mutation identified in this patient was uncertain. To assess its role in disease pathogenesis, we performed functional assays and biochemical and microscopic studies. We found that p.Arg190Cys mutation did not alter the expression or subcellular localization of STXBP2 or STX11, neither impaired the STXBP2/STX11 interaction. In contrast, forced expression of the mutated protein into normal CTLs strongly inhibited degranulation and reduced the cytolytic activity outcompeting the effect of endogenous wild-type STXBP2. Interestingly, arginine 190 is located in a structurally conserved region of STXBP2 where other f-HLH-5 mutations have been identified. Collectively, data strongly suggest that STXBP2-R190C is a deleterious variant that may act in a dominant-negative manner by probably stabilizing non-productive interactions between STXBP2/STX11 complex and other still unknown factors such as the membrane surface or Munc13-4 protein and thus impairing the release of cytolytic granules. In addition to the contribution of STXBP2-R190C to f-HLH, the accompanied G6PD mutation may have compounded the clinical symptoms; however, the extent by which G6PD deficiency has contributed to HLH in our patient remains unclear.
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Affiliation(s)
- Nathalia Benavides
- Department of Microbiology and Immunology- Sydney Kimmel Medical College- Thomas Jefferson University, Philadelphia, PA, United States
| | - Waldo A Spessott
- Department of Microbiology and Immunology- Sydney Kimmel Medical College- Thomas Jefferson University, Philadelphia, PA, United States
| | - Maria L Sanmillan
- Department of Microbiology and Immunology- Sydney Kimmel Medical College- Thomas Jefferson University, Philadelphia, PA, United States
| | - Marcelo Vargas
- Department of Medical Genetics and Genomics, Children's Minnesota, Minneapolis, MN, United States
| | - Mylynda S Livingston
- Department of Pediatric Hematology-Oncology, Children's Minnesota, Minneapolis, MN, United States
| | - Nissa Erickson
- Minnesota Gastroenterology, P.A., Minneapolis, MN, United States
| | - Tamara C Pozos
- Department of Immunology, Children's Minnesota, Minneapolis, MN, United States
| | - Margaret E McCormick
- Department of Microbiology and Immunology- Sydney Kimmel Medical College- Thomas Jefferson University, Philadelphia, PA, United States
| | - Emilia Scharrig
- Department of Microbiology and Immunology- Sydney Kimmel Medical College- Thomas Jefferson University, Philadelphia, PA, United States
| | - Yoav H Messinger
- Department of Pediatric Hematology-Oncology, Children's Minnesota, Minneapolis, MN, United States
| | - Claudio G Giraudo
- Department of Microbiology and Immunology- Sydney Kimmel Medical College- Thomas Jefferson University, Philadelphia, PA, United States
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12
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Tang BL. SNAREs and developmental disorders. J Cell Physiol 2020; 236:2482-2504. [PMID: 32959907 DOI: 10.1002/jcp.30067] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Revised: 08/20/2020] [Accepted: 09/09/2020] [Indexed: 12/12/2022]
Abstract
Members of the soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) family mediate membrane fusion processes associated with vesicular trafficking and autophagy. SNAREs mediate core membrane fusion processes essential for all cells, but some SNAREs serve cell/tissue type-specific exocytic/endocytic functions, and are therefore critical for various aspects of embryonic development. Mutations or variants of their encoding genes could give rise to developmental disorders, such as those affecting the nervous system and immune system in humans. Mutations to components in the canonical synaptic vesicle fusion SNARE complex (VAMP2, STX1A/B, and SNAP25) and a key regulator of SNARE complex formation MUNC18-1, produce variant phenotypes of autism, intellectual disability, movement disorders, and epilepsy. STX11 and MUNC18-2 mutations underlie 2 subtypes of familial hemophagocytic lymphohistiocytosis. STX3 mutations contribute to variant microvillus inclusion disease. Chromosomal microdeletions involving STX16 play a role in pseudohypoparathyroidism type IB associated with abnormal imprinting of the GNAS complex locus. In this short review, I discuss these and other SNARE gene mutations and variants that are known to be associated with a variety developmental disorders, with a focus on their underlying cellular and molecular pathological basis deciphered through disease modeling. Possible pathogenic potentials of other SNAREs whose variants could be disease predisposing are also speculated upon.
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Affiliation(s)
- Bor L Tang
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
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13
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Bowman SL, Bi-Karchin J, Le L, Marks MS. The road to lysosome-related organelles: Insights from Hermansky-Pudlak syndrome and other rare diseases. Traffic 2020; 20:404-435. [PMID: 30945407 DOI: 10.1111/tra.12646] [Citation(s) in RCA: 120] [Impact Index Per Article: 30.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Revised: 04/02/2019] [Accepted: 04/02/2019] [Indexed: 12/11/2022]
Abstract
Lysosome-related organelles (LROs) comprise a diverse group of cell type-specific, membrane-bound subcellular organelles that derive at least in part from the endolysosomal system but that have unique contents, morphologies and functions to support specific physiological roles. They include: melanosomes that provide pigment to our eyes and skin; alpha and dense granules in platelets, and lytic granules in cytotoxic T cells and natural killer cells, which release effectors to regulate hemostasis and immunity; and distinct classes of lamellar bodies in lung epithelial cells and keratinocytes that support lung plasticity and skin lubrication. The formation, maturation and/or secretion of subsets of LROs are dysfunctional or entirely absent in a number of hereditary syndromic disorders, including in particular the Hermansky-Pudlak syndromes. This review provides a comprehensive overview of LROs in humans and model organisms and presents our current understanding of how the products of genes that are defective in heritable diseases impact their formation, motility and ultimate secretion.
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Affiliation(s)
- Shanna L Bowman
- Department of Pathology and Laboratory Medicine, Children's Hospital of Philadelphia Research Institute, Philadelphia, Pennsylvania.,Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.,Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Jing Bi-Karchin
- Department of Pathology and Laboratory Medicine, Children's Hospital of Philadelphia Research Institute, Philadelphia, Pennsylvania.,Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.,Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Linh Le
- Department of Pathology and Laboratory Medicine, Children's Hospital of Philadelphia Research Institute, Philadelphia, Pennsylvania.,Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.,Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.,Cell and Molecular Biology Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Michael S Marks
- Department of Pathology and Laboratory Medicine, Children's Hospital of Philadelphia Research Institute, Philadelphia, Pennsylvania.,Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.,Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
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14
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Phatarpekar PV, Billadeau DD. Molecular regulation of the plasma membrane-proximal cellular steps involved in NK cell cytolytic function. J Cell Sci 2020; 133:133/5/jcs240424. [PMID: 32086255 DOI: 10.1242/jcs.240424] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Natural killer (NK) cells, cytolytic lymphocytes of the innate immune system, play a crucial role in the immune response against infection and cancer. NK cells kill target cells through exocytosis of lytic granules that contain cytotoxic proteins, such as perforin and granzymes. Formation of a functional immune synapse, i.e. the interface between the NK cell and its target cell enhances lysis through accumulation of polymerized F-actin at the NK cell synapse, leading to convergence of lytic granules to the microtubule organizing center (MTOC) and its subsequent polarization along microtubules to deliver the lytic granules to the synapse. In this review, we focus on the molecular mechanisms regulating the cellular processes that occur after the lytic granules are delivered to the cytotoxic synapse. We outline how - once near the synapse - the granules traverse the clearings created by F-actin remodeling to dock, tether and fuse with the plasma membrane in order to secrete their lytic content into the synaptic cleft through exocytosis. Further emphasis is given to the role of Ca2+ mobilization during degranulation and, whenever applicable, we compare these mechanisms in NK cells and cytotoxic T lymphocytes (CTLs) as adaptive immune system effectors.
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Affiliation(s)
- Prasad V Phatarpekar
- Department of Immunology, Mayo Clinic College of Medicine, Rochester, MN 55905, USA
| | - Daniel D Billadeau
- Department of Immunology, Mayo Clinic College of Medicine, Rochester, MN 55905, USA
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15
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Guo X, Jiang M, Tang X, Li Q. Familial hemophagocytic lymphohistiocytosis in a girl with a novel homozygous mutation of STX11: A case report. Medicine (Baltimore) 2019; 98:e18107. [PMID: 31770233 PMCID: PMC6890335 DOI: 10.1097/md.0000000000018107] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
RATIONALE Familial hemophagocytic lymphohistiocytosis (FHL) is a rare fatal autosomal recessively inherited disease and can be divided into five types. The mortality of untreated patients is up to 95% and it can be healed only after immunochemotherapy for disease control and hematopoietic stem cell transplantation. Clinical data of a girl with late-onset and recurrent hemophagocytic lymphohistiocytosis (HLH) was retrospectively analyzed to determine the etiology and potential pathogenic gene. PATIENT CONCERNS AND CLINICAL FINDINGS The proband was a female child patient from a consanguineous marriage family who was 11 years old, and clinically manifested delayed (onset at the age of 4 years and 6 months) and recrudescent HLH. Both of her elder brothers died at the ages of 4 and 5 years, respectively. The patient had a degranulation function defect of CD107a in natural killer (NK) cells, and the degranulation function of cytotoxic T lymphocytes (CTL) obviously declined (ΔMFI: 1.4%, normal ≧2.8%); the degranulation function of NK cells and CTL of her father was also obviously reduced. To identify possible underlying genetic causes, gene mutation analysis was undertaken. A novel homozygous nonsense mutation in STX11 (c.49C>T, p.Q17X) was documented, arising from both her parents. DIAGNOSIS According to the clinical manifestations and detection results of STX11, the diagnosis of FHL-type 4 was confirmed and her parents were heterozygotic carriers. INTERVENTIONS AND OUTCOMES Good responses to HLH-2004 chemotherapy had been achieved for each onset, and the maximum remission duration (without taking any drug) was 23 months. The patient has been alive for 82 months since the onset, and has stopped taking dexamethasone and etoposide, but is still on oral cyclosporine to maintain the treatment. She has performed HLA matching and now is actively looking for a donor to prepare hematopoietic stem cell transplantation. CONCLUSIONS Relevant gene detections should be implemented at the earliest for young patients from consanguineous marriages and with a family history of HLH so as to provide a basis for etiological diagnosis and radical treatment by hematopoietic stem cell transplantation and provide accurate genetic counseling for family members.
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16
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Chitirala P, Ravichandran K, Galgano D, Sleiman M, Krause E, Bryceson YT, Rettig J. Cytotoxic Granule Exocytosis From Human Cytotoxic T Lymphocytes Is Mediated by VAMP7. Front Immunol 2019; 10:1855. [PMID: 31447853 PMCID: PMC6692471 DOI: 10.3389/fimmu.2019.01855] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2019] [Accepted: 07/23/2019] [Indexed: 11/13/2022] Open
Abstract
Cytotoxic T lymphocytes kill infected or malignant cells through the directed release of cytotoxic substances at the site of target cell contact, the immunological synapse. While genetic association studies of genes predisposing to early-onset life-threatening hemophagocytic lymphohistiocytosis has identified components of the plasma membrane fusion machinery, the identity of the vesicular components remain enigmatic. Here, we identify VAMP7 as an essential component of the vesicular fusion machinery of primary, human T cells. VAMP7 co-localizes with granule markers throughout all stages of T cell maturation and simultaneously fuses with granule markers at the IS. Knock-down of VAMP7 expression significantly decreased the killing efficiency of T cells, without diminishing early T cell receptor signaling. VAMP7 exerts its function in a SNARE complex with Syntaxin11 and SNAP-23 on the plasma membrane. The identification of the minimal fusion machinery in T cells provides a starting point for the development of potential drugs in immunotherapy.
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Affiliation(s)
- Praneeth Chitirala
- Cellular Neurophysiology, Center for Integrative Physiology and Molecular Medicine (CIPMM), Saarland University, Homburg, Germany
| | - Keerthana Ravichandran
- Cellular Neurophysiology, Center for Integrative Physiology and Molecular Medicine (CIPMM), Saarland University, Homburg, Germany
| | - Donatella Galgano
- Center for Hematology and Regenerative Medicine (HERM), Karolinska Institute, Stockholm, Sweden
| | - Marwa Sleiman
- Cellular Neurophysiology, Center for Integrative Physiology and Molecular Medicine (CIPMM), Saarland University, Homburg, Germany
| | - Elmar Krause
- Cellular Neurophysiology, Center for Integrative Physiology and Molecular Medicine (CIPMM), Saarland University, Homburg, Germany
| | - Yenan T. Bryceson
- Center for Hematology and Regenerative Medicine (HERM), Karolinska Institute, Stockholm, Sweden
| | - Jens Rettig
- Cellular Neurophysiology, Center for Integrative Physiology and Molecular Medicine (CIPMM), Saarland University, Homburg, Germany
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17
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Lysosome-related organelles as functional adaptations of the endolysosomal system. Curr Opin Cell Biol 2019; 59:147-158. [PMID: 31234051 DOI: 10.1016/j.ceb.2019.05.003] [Citation(s) in RCA: 79] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Revised: 05/10/2019] [Accepted: 05/13/2019] [Indexed: 12/19/2022]
Abstract
Unique functions of specialised cells such as those of the immune and haemostasis systems, skin, blood vessels, lung, and bone require specialised compartments, collectively referred to as lysosome-related organelles (LROs), that share features of endosomes and lysosomes. LROs harbour unique morphological features and cell type-specific contents, and most if not all undergo regulated secretion for diverse functions. Ongoing research, largely driven by analyses of inherited diseases and their model systems, is unravelling the mechanisms involved in LRO generation, maturation, transport and secretion. A molecular understanding of these features will provide targets and markers that can be exploited for diagnosis and therapy of a myriad of diseases.
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18
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Kinoshita D, Sakurai C, Morita M, Tsunematsu M, Hori N, Hatsuzawa K. Syntaxin 11 regulates the stimulus-dependent transport of Toll-like receptor 4 to the plasma membrane by cooperating with SNAP-23 in macrophages. Mol Biol Cell 2019; 30:1085-1097. [PMID: 30811271 PMCID: PMC6724512 DOI: 10.1091/mbc.e18-10-0653] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Syntaxin 11 (stx11) is a soluble N-ethylmaleimide–sensitive factor attachment protein receptor (SNARE) that is selectively expressed in immune cells; however, its precise role in macrophages is unclear. We showed that stx11 knockdown reduces the phagocytosis of Escherichia coli in interferon-γ–activated macrophages. stx11 knockdown decreased Toll-like receptor 4 (TLR4) localization on the plasma membrane without affecting total expression. Plasma membrane–localized TLR4 was primarily endocytosed within 1 h by lipopolysaccharide (LPS) stimulation and gradually relocalized 4 h after removal of LPS. This relocalization was significantly impaired by stx11 knockdown. The lack of TLR4 transport to the plasma membrane is presumably related to TLR4 degradation in acidic endosomal organelles. Additionally, an immunoprecipitation experiment suggested that stx11 interacts with SNAP-23, a plasma membrane–localized SNARE protein, whose depletion also inhibits TLR4 replenishment in LPS-stimulated cells. Using an intramolecular Förster resonance energy transfer (FRET) probe for SNAP-23, we showed that the high FRET efficiency caused by LPS stimulation is reduced by stx11 knockdown. These findings suggest that stx11 regulates the stimulus-dependent transport of TLR4 to the plasma membrane by cooperating with SNAP-23 in macrophages. Our results clarify the regulatory mechanisms underlying intracellular transport of TLR4 and have implications for microbial pathogenesis and immune responses.
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Affiliation(s)
- Daiki Kinoshita
- Division of Molecular Biology, School of Life Sciences, Faculty of Medicine, Tottori University, Yonago, Tottori 683-8503, Japan
| | - Chiye Sakurai
- Division of Molecular Biology, School of Life Sciences, Faculty of Medicine, Tottori University, Yonago, Tottori 683-8503, Japan
| | - Maya Morita
- Division of Molecular Biology, School of Life Sciences, Faculty of Medicine, Tottori University, Yonago, Tottori 683-8503, Japan
| | - Masashi Tsunematsu
- Division of Molecular Biology, School of Life Sciences, Faculty of Medicine, Tottori University, Yonago, Tottori 683-8503, Japan
| | - Naohiro Hori
- Division of Molecular Biology, School of Life Sciences, Faculty of Medicine, Tottori University, Yonago, Tottori 683-8503, Japan
| | - Kiyotaka Hatsuzawa
- Division of Molecular Biology, School of Life Sciences, Faculty of Medicine, Tottori University, Yonago, Tottori 683-8503, Japan
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19
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Lopez JA, Noori T, Minson A, Li Jovanoska L, Thia K, Hildebrand MS, Akhlaghi H, Darcy PK, Kershaw MH, Brown NJ, Grigg A, Trapani JA, Voskoboinik I. Bi-Allelic Mutations in STXBP2 Reveal a Complementary Role for STXBP1 in Cytotoxic Lymphocyte Killing. Front Immunol 2018; 9:529. [PMID: 29599780 PMCID: PMC5862791 DOI: 10.3389/fimmu.2018.00529] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Accepted: 02/28/2018] [Indexed: 11/13/2022] Open
Abstract
The ability of cytotoxic lymphocytes (CL) to eliminate virus-infected or cancerous target cells through the granule exocytosis death pathway is critical to immune homeostasis. Congenital loss of CL function due to bi-allelic mutations in PRF1, UNC13D, STX11, or STXBP2 leads to a potentially fatal immune dysregulation, familial haemophagocytic lymphohistiocytosis (FHL). This occurs due to the failure of CLs to release functional pore-forming protein perforin and, therefore, inability to kill the target cell. Bi-allelic mutations in partner proteins STXBP2 or STX11 impair CL cytotoxicity due to failed docking/fusion of cytotoxic secretory granules with the plasma membrane. One unique feature of STXBP2- and STX11-deficient patient CLs is that their short-term in vitro treatment with a low concentration of IL-2 partially or completely restores natural killer (NK) cell degranulation and cytotoxicity, suggesting the existence of a secondary, yet unknown, pathway for secretory granule exocytosis. In the current report, we studied NK and T-cell function in an individual with late presentation of FHL due to hypomorphic bi-allelic mutations in STXBP2. Intriguingly, in addition to the expected alterations in the STXBP2 and STX11 proteins, we also observed a concomitant significant reduction in the expression of homologous STXBP1 protein and its partner STX1, which had never been implicated in CL function. Further analysis of human NK and T cells demonstrated a functional role for the STXBP1/STX1 axis in NK and CD8+ T-cell cytotoxicity, where it appears to be responsible for as much as 50% of their cytotoxic activity. This discovery suggests a unique and previously unappreciated interplay between STXBP/Munc proteins regulating the same essential granule exocytosis pathway.
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Affiliation(s)
- Jamie A Lopez
- Cancer Immunology Program, Peter MacCallum Cancer Centre, Melbourne, VIC, Australia.,Sir Peter MacCallum Department of Oncology, The University of Melbourne, Parkville, VIC, Australia
| | - Tahereh Noori
- Cancer Immunology Program, Peter MacCallum Cancer Centre, Melbourne, VIC, Australia
| | - Adrian Minson
- Department of Clinical Haematology, Austin Health, Heidelberg, VIC, Australia
| | - Lu Li Jovanoska
- Cancer Immunology Program, Peter MacCallum Cancer Centre, Melbourne, VIC, Australia
| | - Kevin Thia
- Cancer Immunology Program, Peter MacCallum Cancer Centre, Melbourne, VIC, Australia
| | | | - Hedieh Akhlaghi
- Cancer Immunology Program, Peter MacCallum Cancer Centre, Melbourne, VIC, Australia
| | - Phillip K Darcy
- Cancer Immunology Program, Peter MacCallum Cancer Centre, Melbourne, VIC, Australia.,Sir Peter MacCallum Department of Oncology, The University of Melbourne, Parkville, VIC, Australia
| | - Michael H Kershaw
- Cancer Immunology Program, Peter MacCallum Cancer Centre, Melbourne, VIC, Australia.,Sir Peter MacCallum Department of Oncology, The University of Melbourne, Parkville, VIC, Australia
| | - Natasha J Brown
- Department of Clinical Genetics, Austin Health, Heidelberg, VIC, Australia
| | - Andrew Grigg
- Department of Clinical Haematology, Austin Health, Heidelberg, VIC, Australia
| | - Joseph A Trapani
- Cancer Immunology Program, Peter MacCallum Cancer Centre, Melbourne, VIC, Australia.,Sir Peter MacCallum Department of Oncology, The University of Melbourne, Parkville, VIC, Australia
| | - Ilia Voskoboinik
- Cancer Immunology Program, Peter MacCallum Cancer Centre, Melbourne, VIC, Australia.,Sir Peter MacCallum Department of Oncology, The University of Melbourne, Parkville, VIC, Australia
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20
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Christie MP, Hu SH, Whitten AE, Rehman A, Jarrott RJ, King GJ, Collins BM, Martin JL. Revisiting interaction specificity reveals neuronal and adipocyte Munc18 membrane fusion regulatory proteins differ in their binding interactions with partner SNARE Syntaxins. PLoS One 2017; 12:e0187302. [PMID: 29088285 PMCID: PMC5663490 DOI: 10.1371/journal.pone.0187302] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2017] [Accepted: 10/17/2017] [Indexed: 01/01/2023] Open
Abstract
The efficient delivery of cellular cargo relies on the fusion of cargo-carrying vesicles with the correct membrane at the correct time. These spatiotemporal fusion events occur when SNARE proteins on the vesicle interact with cognate SNARE proteins on the target membrane. Regulatory Munc18 proteins are thought to contribute to SNARE interaction specificity through interaction with the SNARE protein Syntaxin. Neuronal Munc18a interacts with Syntaxin1 but not Syntaxin4, and adipocyte Munc18c interacts with Syntaxin4 but not Syntaxin1. Here we show that this accepted view of specificity needs revision. We find that Munc18c interacts with both Syntaxin4 and Syntaxin1, and appears to bind “non-cognate” Syntaxin1 a little more tightly than Syntaxin4. Munc18a binds Syntaxin1 and Syntaxin4, though it interacts with its cognate Syntaxin1 much more tightly. We also observed that when bound to non-cognate Munc18c, Syntaxin1 captures its neuronal SNARE partners SNAP25 and VAMP2, and Munc18c can bind to pre-formed neuronal SNARE ternary complex. These findings reveal that Munc18a and Munc18c bind Syntaxins differently. Munc18c relies principally on the Syntaxin N-peptide interaction for binding Syntaxin4 or Syntaxin1, whereas Munc18a can bind Syntaxin1 tightly whether or not the Syntaxin1 N-peptide is present. We conclude that Munc18a and Munc18c differ in their binding interactions with Syntaxins: Munc18a has two tight binding modes/sites for Syntaxins as defined previously but Munc18c has just one that requires the N-peptide. These results indicate that the interactions between Munc18 and Syntaxin proteins, and the consequences for in vivo function, are more complex than can be accounted for by binding specificity alone.
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Affiliation(s)
- Michelle P. Christie
- Division of Chemistry and Structural Biology, Institute for Molecular Bioscience, University of Queensland, St Lucia, Queensland, Australia
- * E-mail: (MPC); (JLM)
| | - Shu-Hong Hu
- Division of Chemistry and Structural Biology, Institute for Molecular Bioscience, University of Queensland, St Lucia, Queensland, Australia
| | - Andrew E. Whitten
- Division of Chemistry and Structural Biology, Institute for Molecular Bioscience, University of Queensland, St Lucia, Queensland, Australia
| | - Asma Rehman
- Division of Chemistry and Structural Biology, Institute for Molecular Bioscience, University of Queensland, St Lucia, Queensland, Australia
| | - Russell J. Jarrott
- Division of Chemistry and Structural Biology, Institute for Molecular Bioscience, University of Queensland, St Lucia, Queensland, Australia
| | - Gordon J. King
- Division of Chemistry and Structural Biology, Institute for Molecular Bioscience, University of Queensland, St Lucia, Queensland, Australia
| | - Brett M. Collins
- Division of Cell Biology and Molecular Medicine, Institute for Molecular Bioscience, University of Queensland, St Lucia, Queensland, Australia
| | - Jennifer L. Martin
- Division of Chemistry and Structural Biology, Institute for Molecular Bioscience, University of Queensland, St Lucia, Queensland, Australia
- Griffith Institute for Drug Discovery, Griffith University, Nathan, Queensland, Australia
- * E-mail: (MPC); (JLM)
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21
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Two Disease-Causing SNAP-25B Mutations Selectively Impair SNARE C-terminal Assembly. J Mol Biol 2017; 430:479-490. [PMID: 29056461 DOI: 10.1016/j.jmb.2017.10.012] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2017] [Revised: 10/09/2017] [Accepted: 10/10/2017] [Indexed: 12/17/2022]
Abstract
Synaptic exocytosis relies on assembly of three soluble N-ethylmaleimide-sensitive factor attachment receptor (SNARE) proteins into a parallel four-helix bundle to drive membrane fusion. SNARE assembly occurs by stepwise zippering of the vesicle-associated SNARE (v-SNARE) onto a binary SNARE complex on the target plasma membrane (t-SNARE). Zippering begins with slow N-terminal association followed by rapid C-terminal zippering, which serves as a power stroke to drive membrane fusion. SNARE mutations have been associated with numerous diseases, especially neurological disorders. It remains unclear how these mutations affect SNARE zippering, partly due to difficulties to quantify the energetics and kinetics of SNARE assembly. Here, we used single-molecule optical tweezers to measure the assembly energy and kinetics of SNARE complexes containing single mutations I67T/N in neuronal SNARE synaptosomal-associated protein of 25kDa (SNAP-25B), which disrupt neurotransmitter release and have been implicated in neurological disorders. We found that both mutations significantly reduced the energy of C-terminal zippering by ~10 kBT, but did not affect N-terminal assembly. In addition, we observed that both mutations lead to unfolding of the C-terminal region in the t-SNARE complex. Our findings suggest that both SNAP-25B mutations impair synaptic exocytosis by destabilizing SNARE assembly, rather than stabilizing SNARE assembly as previously proposed. Therefore, our measurements provide insights into the molecular mechanism of the disease caused by SNARE mutations.
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22
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Vogel GF, van Rijn JM, Krainer IM, Janecke AR, Posovszky C, Cohen M, Searle C, Jantchou P, Escher JC, Patey N, Cutz E, Müller T, Middendorp S, Hess MW, Huber LA. Disrupted apical exocytosis of cargo vesicles causes enteropathy in FHL5 patients with Munc18-2 mutations. JCI Insight 2017; 2:94564. [PMID: 28724787 DOI: 10.1172/jci.insight.94564] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2017] [Accepted: 06/06/2017] [Indexed: 01/07/2023] Open
Abstract
Familial hemophagocytic lymphohistiocytosis 5 (FHL5) is an autosomal recessive disease caused by mutations in STXBP2, coding for Munc18-2, which is required for SNARE-mediated membrane fusion. FHL5 causes hematologic and gastrointestinal symptoms characterized by chronic enteropathy that is reminiscent of microvillus inclusion disease (MVID). However, the molecular pathophysiology of FHL5-associated diarrhea is poorly understood. Five FHL5 patients, including four previously unreported patients, were studied. Morphology of duodenal sections was analyzed by electron and fluorescence microscopy. Small intestinal enterocytes and organoid-derived monolayers displayed the subcellular characteristics of MVID. For the analyses of Munc18-2-dependent SNARE-protein interactions, a Munc18-2 CaCo2-KO model cell line was generated by applying CRISPR/Cas9 technology. Munc18-2 is required for Slp4a/Stx3 interaction in fusion of cargo vesicles with the apical plasma membrane. Cargo trafficking was investigated in patient biopsies, patient-derived organoids, and the genome-edited model cell line. Loss of Munc18-2 selectively disrupts trafficking of certain apical brush-border proteins (NHE3 and GLUT5), while transport of DPPIV remained unaffected. Here, we describe the molecular mechanism how the loss of function of Munc18-2 leads to cargo-selective mislocalization of brush-border components and a subapical accumulation of cargo vesicles, as it is known from the loss of polarity phenotype in MVID.
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Affiliation(s)
- Georg F Vogel
- Department of Paediatrics I and.,Division of Cell Biology, Medical University of Innsbruck, Innsbruck, Austria
| | - Jorik M van Rijn
- Division of Paediatrics, Department of Paediatric Gastroenterology and Regenerative Medicine Center Utrecht, Wilhelmina Children's Hospital, University Medical Centre (UMC) Utrecht, Utrecht, The Netherlands
| | - Iris M Krainer
- Department of Paediatrics I and.,Division of Cell Biology, Medical University of Innsbruck, Innsbruck, Austria
| | | | - Carsten Posovszky
- Department of Pediatrics and Adolescent Medicine, University Medical Center Ulm, Ulm, Germany
| | - Marta Cohen
- Sheffield Children's Hospital NHS Trust, Western Bank, Sheffield, United Kingdom
| | - Claire Searle
- Clinical Genetics, Nottingham University Hospitals NHS Trust, Nottingham, United Kingdom
| | - Prevost Jantchou
- Gastroentérologie Hépatologie et Nutrition Pédiatrique Hôpital Sainte-Justine, Université de Montréal, Montréal, Quebec, Canada
| | - Johanna C Escher
- Department of Pediatric Gastroenterology, Sophia Children's Hospital, Erasmus MC, Rotterdam, The Netherlands
| | - Natalie Patey
- Clinical Genetics, Nottingham University Hospitals NHS Trust, Nottingham, United Kingdom
| | - Ernest Cutz
- The Hospital for Sick Children, Toronto, Canada
| | | | - Sabine Middendorp
- Division of Paediatrics, Department of Paediatric Gastroenterology and Regenerative Medicine Center Utrecht, Wilhelmina Children's Hospital, University Medical Centre (UMC) Utrecht, Utrecht, The Netherlands
| | - Michael W Hess
- Division of Histology and Embryology, Medical University of Innsbruck, Innsbruck, Austria
| | - Lukas A Huber
- Division of Cell Biology, Medical University of Innsbruck, Innsbruck, Austria
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Spessott WA, Sanmillan ML, Kulkarni VV, McCormick ME, Giraudo CG. Syntaxin 4 mediates endosome recycling for lytic granule exocytosis in cytotoxic T-lymphocytes. Traffic 2017; 18:442-452. [PMID: 28471021 PMCID: PMC5513838 DOI: 10.1111/tra.12490] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2016] [Revised: 04/30/2017] [Accepted: 05/01/2017] [Indexed: 12/15/2022]
Abstract
Adaptive and innate immunity utilize the perforin-killing pathway to eliminate virus-infected or cancer cells. Cytotoxic T-lymphocytes (CTLs) and natural killer cells mediate this process by releasing toxic proteins at the contact area with target cells known as immunological synapse (IS). Formation of a stable IS and exocytosis of toxic proteins requires persistent fusion of Rab11a recycling endosomes with the plasma membrane (PM) that may assure the delivery of key effector proteins. Despite the importance of the recycling endosomal compartment, the membrane fusion proteins that control this process at the IS remain elusive. Here, by performing knockdown experiments we found that syntaxin 4 (STX4) is necessary for cytotoxic activity and CD107a degranulation against target cells in a similar fashion to syntaxin 11, which is involved in lytic granule (LG) exocytosis and immunodeficiency when it is mutated. Using total internal reflection fluorescent microscopy we identified that STX4 mediates fusion of EGFP-Rab11a vesicles at the IS. Immunoprecipitation experiments in lysates of activated CTLs indicate that endogenous STX4 may drive this fusion step by interacting with cognate proteins: Munc18-3/SNAP23/VAMP7 and/or VAMP8. These results reveal the role of STX4 in mediating fusion of Rab11a endosomes upstream of lytic granules (LGs) exocytosis and further demonstrate the importance of this pathway in controlling CTL-mediated cytotoxicity.
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Affiliation(s)
- Waldo A. Spessott
- Department of Pathology and Laboratory Medicine, University of Pennsylvania – The Children’s Hospital of Philadelphia - 3615 Civic Center Blvd, Philadelphia PA, 19104
| | - Maria L. Sanmillan
- Department of Pathology and Laboratory Medicine, University of Pennsylvania – The Children’s Hospital of Philadelphia - 3615 Civic Center Blvd, Philadelphia PA, 19104
| | - Vineet V. Kulkarni
- Department of Pathology and Laboratory Medicine, University of Pennsylvania – The Children’s Hospital of Philadelphia - 3615 Civic Center Blvd, Philadelphia PA, 19104
- Biomedical Graduate Studies- University of Pennsylvania
| | - Margaret E. McCormick
- Department of Pathology and Laboratory Medicine, University of Pennsylvania – The Children’s Hospital of Philadelphia - 3615 Civic Center Blvd, Philadelphia PA, 19104
| | - Claudio G. Giraudo
- Department of Pathology and Laboratory Medicine, University of Pennsylvania – The Children’s Hospital of Philadelphia - 3615 Civic Center Blvd, Philadelphia PA, 19104
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