1
|
D’Amico S, Tempora P, Melaiu O, Lucarini V, Cifaldi L, Locatelli F, Fruci D. Targeting the antigen processing and presentation pathway to overcome resistance to immune checkpoint therapy. Front Immunol 2022; 13:948297. [PMID: 35936007 PMCID: PMC9352877 DOI: 10.3389/fimmu.2022.948297] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Accepted: 06/29/2022] [Indexed: 11/17/2022] Open
Abstract
Despite the significant clinical advances with the use of immune checkpoint inhibitors (ICIs) in a wide range of cancer patients, response rates to the therapy are variable and do not always result in long-term tumor regression. The development of ICI-resistant disease is one of the pressing issue in clinical oncology, and the identification of new targets and combination therapies is a crucial point to improve response rates and duration. Antigen processing and presentation (APP) pathway is a key element for an efficient response to ICI therapy. Indeed, malignancies that do not express tumor antigens are typically poor infiltrated by T cells and unresponsive to ICIs. Therefore, improving tumor immunogenicity potentially increases the success rate of ICI therapy. In this review, we provide an overview of the key elements of the APP machinery that can be exploited to enhance tumor immunogenicity and increase the efficacy of ICI-based immunotherapy.
Collapse
Affiliation(s)
- Silvia D’Amico
- Department of Paediatric Haematology/Oncology and of Cell and Gene Therapy, Bambino Gesù Children’s Hospital, Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS), Rome, Italy
| | - Patrizia Tempora
- Department of Paediatric Haematology/Oncology and of Cell and Gene Therapy, Bambino Gesù Children’s Hospital, Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS), Rome, Italy
| | - Ombretta Melaiu
- Department of Paediatric Haematology/Oncology and of Cell and Gene Therapy, Bambino Gesù Children’s Hospital, Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS), Rome, Italy
- Department of Clinical Sciences and Translational Medicine, University of Rome “Tor Vergata”, Rome, Italy
| | - Valeria Lucarini
- Department of Paediatric Haematology/Oncology and of Cell and Gene Therapy, Bambino Gesù Children’s Hospital, Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS), Rome, Italy
| | - Loredana Cifaldi
- Department of Clinical Sciences and Translational Medicine, University of Rome “Tor Vergata”, Rome, Italy
- Academic Department of Pediatrics (DPUO), Bambino Gesù Children Hospital, Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS), Rome, Italy
| | - Franco Locatelli
- Department of Paediatric Haematology/Oncology and of Cell and Gene Therapy, Bambino Gesù Children’s Hospital, Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS), Rome, Italy
- Catholic University of the Sacred Heart, Rome, Italy
| | - Doriana Fruci
- Department of Paediatric Haematology/Oncology and of Cell and Gene Therapy, Bambino Gesù Children’s Hospital, Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS), Rome, Italy
- *Correspondence: Doriana Fruci,
| |
Collapse
|
2
|
The Function of Immunoproteasomes-An Immunologists' Perspective. Cells 2021; 10:cells10123360. [PMID: 34943869 PMCID: PMC8699091 DOI: 10.3390/cells10123360] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Revised: 11/23/2021] [Accepted: 11/25/2021] [Indexed: 01/02/2023] Open
Abstract
Proteasomes are responsible for intracellular proteolysis and play an important role in cellular protein homeostasis. Cells of the immune system assemble a specialized form of proteasomes, known as immunoproteasomes, in which the constitutive catalytic sites are replaced for cytokine-inducible homologues. While immunoproteasomes may fulfill all standard proteasome’ functions, they seem specially adapted for a role in MHC class I antigen processing and CD8+ T-cell activation. In this way, they may contribute to CD8+ T-cell-mediated control of intracellular infections, but also to the immunopathogenesis of autoimmune diseases. Starting at the discovery of its catalytic subunits in the genome, here, we review the observations shaping our current understanding of immunoproteasome function, and the consequential novel opportunities for immune intervention.
Collapse
|
3
|
French T, Israel N, Düsedau HP, Tersteegen A, Steffen J, Cammann C, Topfstedt E, Dieterich D, Schüler T, Seifert U, Dunay IR. The Immunoproteasome Subunits LMP2, LMP7 and MECL-1 Are Crucial Along the Induction of Cerebral Toxoplasmosis. Front Immunol 2021; 12:619465. [PMID: 33968021 PMCID: PMC8099150 DOI: 10.3389/fimmu.2021.619465] [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: 10/20/2020] [Accepted: 03/16/2021] [Indexed: 11/28/2022] Open
Abstract
Cell survival and function critically relies on the fine-tuned balance of protein synthesis and degradation. In the steady state, the standard proteasome is sufficient to maintain this proteostasis. However, upon inflammation, the sharp increase in protein production requires additional mechanisms to limit protein-associated cellular stress. Under inflammatory conditions and the release of interferons, the immunoproteasome (IP) is induced to support protein processing and recycling. In antigen-presenting cells constitutively expressing IPs, inflammation-related mechanisms contribute to the formation of MHC class I/II-peptide complexes, which are required for the induction of T cell responses. The control of Toxoplasma gondii infection relies on Interferon-γ (IFNγ)-related T cell responses. Whether and how the IP affects the course of anti-parasitic T cell responses along the infection as well as inflammation of the central nervous system is still unknown. To answer this question we used triple knockout (TKO) mice lacking the 3 catalytic subunits of the immunoproteasome (β1i/LMP2, β2i/MECL-1 and β5i/LMP7). Here we show that the numbers of dendritic cells, monocytes and CD8+ T cells were reduced in Toxoplasma gondii-infected TKO mice. Furthermore, impaired IFNγ, TNF and iNOS production was accompanied by dysregulated chemokine expression and altered immune cell recruitment to the brain. T cell differentiation was altered, apoptosis rates of microglia and monocytes were elevated and STAT3 downstream signaling was diminished. Consequently, anti-parasitic immune responses were impaired in TKO mice leading to elevated T. gondii burden and prolonged neuroinflammation. In summary we provide evidence for a critical role of the IP subunits β1i/LMP2, β2i/MECL-1 and β5i/LMP7 for the control of cerebral Toxoplasma gondii infection and subsequent neuroinflammation.
Collapse
Affiliation(s)
- Timothy French
- Institute of Inflammation and Neurodegeneration, Otto-von-Guericke-University Magdeburg, Magdeburg, Germany
| | - Nicole Israel
- Friedrich Loeffler-Institute of Medical Microbiology-Virology, University Medicine Greifswald, Greifswald, Germany.,Institute of Molecular and Clinical Immunology, Otto-von-Guericke-University Magdeburg, Magdeburg, Germany
| | - Henning Peter Düsedau
- Institute of Inflammation and Neurodegeneration, Otto-von-Guericke-University Magdeburg, Magdeburg, Germany
| | - Anne Tersteegen
- Institute of Inflammation and Neurodegeneration, Otto-von-Guericke-University Magdeburg, Magdeburg, Germany
| | - Johannes Steffen
- Institute of Inflammation and Neurodegeneration, Otto-von-Guericke-University Magdeburg, Magdeburg, Germany
| | - Clemens Cammann
- Friedrich Loeffler-Institute of Medical Microbiology-Virology, University Medicine Greifswald, Greifswald, Germany.,Institute of Molecular and Clinical Immunology, Otto-von-Guericke-University Magdeburg, Magdeburg, Germany
| | - Eylin Topfstedt
- Friedrich Loeffler-Institute of Medical Microbiology-Virology, University Medicine Greifswald, Greifswald, Germany
| | - Daniela Dieterich
- Institute of Pharmacology, Otto-von-Guericke-University Magdeburg, Magdeburg, Germany.,Center for Behavioral Brain Sciences, Magdeburg, Germany
| | - Thomas Schüler
- Institute of Molecular and Clinical Immunology, Otto-von-Guericke-University Magdeburg, Magdeburg, Germany
| | - Ulrike Seifert
- Friedrich Loeffler-Institute of Medical Microbiology-Virology, University Medicine Greifswald, Greifswald, Germany.,Institute of Molecular and Clinical Immunology, Otto-von-Guericke-University Magdeburg, Magdeburg, Germany
| | - Ildiko Rita Dunay
- Institute of Inflammation and Neurodegeneration, Otto-von-Guericke-University Magdeburg, Magdeburg, Germany.,Center for Behavioral Brain Sciences, Magdeburg, Germany
| |
Collapse
|
4
|
Neumaier HL, Harel S, Klingel K, Kaya Z, Heuser A, Kespohl M, Beling A. ONX 0914 Lacks Selectivity for the Cardiac Immunoproteasome in CoxsackievirusB3 Myocarditis of NMRI Mice and Promotes Virus-Mediated Tissue Damage. Cells 2020; 9:cells9051093. [PMID: 32354159 PMCID: PMC7290815 DOI: 10.3390/cells9051093] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Revised: 04/21/2020] [Accepted: 04/23/2020] [Indexed: 12/16/2022] Open
Abstract
: Inhibition of proteasome function by small molecules is highly efficacious in cancer treatment. Other than non-selective proteasome inhibitors, immunoproteasome-specific inhibitors allow for specific targeting of the proteasome in immune cells and the profound anti-inflammatory potential of such compounds revealed implications for inflammatory scenarios. For pathogen-triggered inflammation, however, the efficacy of immunoproteasome inhibitors is controversial. In this study, we investigated how ONX 0914, an immunoproteasome-selective inhibitor, influences CoxsackievirusB3 infection in NMRI mice, resulting in the development of acute and chronic myocarditis, which is accompanied by formation of the immunoproteasome in heart tissue. In groups in which ONX 0914 treatment was initiated once viral cytotoxicity had emerged in the heart, ONX 0914 had no anti-inflammatory effect in the acute or chronic stages. ONX 0914 treatment initiated prior to infection, however, increased viral cytotoxicity in cardiomyocytes, promoting infiltration of myeloid immune cells into the heart. At this stage, ONX 0914 completely inhibited the β5 subunit of the standard cardiac proteasome and less efficiently blocked its immunoproteasome counterpart LMP7. In conclusion, ONX 0914 unselectively perturbs cardiac proteasome function in viral myocarditis of NMRI mice, reduces the capacity of the host to control the viral burden and promotes cardiac inflammation.
Collapse
Affiliation(s)
- Hannah Louise Neumaier
- Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health (BIH), Institute of Biochemistry, 10117 Berlin, Germany; (H.L.N.); (S.H.); (M.K.)
| | - Shelly Harel
- Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health (BIH), Institute of Biochemistry, 10117 Berlin, Germany; (H.L.N.); (S.H.); (M.K.)
| | - Karin Klingel
- Institute for Cardiopathology, University of Tuebingen, 72074 Tuebingen, Germany;
| | - Ziya Kaya
- Medizinische Klinik für Innere Medizin III: Kardiologie, Angiologie und Pneumologie, Universitätsklinikum Heidelberg, Medizinische Klinik für Innere Medizin III: Kardiologie, Angiologie und Pneumologie, Universitätsklinikum Heidelberg, 69120 Heidelberg, Germany;
- Deutsches Zentrum für Herz-Kreislauf-Forschung (DZHK), partner side Heidelberg/Mannheim, 69120 Heidelberg, Germany
| | - Arnd Heuser
- Max-Delbrueck-Center for Molecular Medicine, 10115 Berlin, Germany;
| | - Meike Kespohl
- Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health (BIH), Institute of Biochemistry, 10117 Berlin, Germany; (H.L.N.); (S.H.); (M.K.)
- Deutsches Zentrum für Herz-Kreislauf-Forschung (DZHK), partner side Berlin, 10785 Berlin, Germany
| | - Antje Beling
- Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health (BIH), Institute of Biochemistry, 10117 Berlin, Germany; (H.L.N.); (S.H.); (M.K.)
- Deutsches Zentrum für Herz-Kreislauf-Forschung (DZHK), partner side Berlin, 10785 Berlin, Germany
- Correspondence:
| |
Collapse
|
5
|
Colston JM, Hutchings C, Chinnakannan S, Highton A, Perez‐Shibayama C, Ludewig B, Klenerman P. Divergent memory responses driven by adenoviral vectors are impacted by epitope competition. Eur J Immunol 2019; 49:1356-1363. [PMID: 31106398 PMCID: PMC6772135 DOI: 10.1002/eji.201948143] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Revised: 03/29/2019] [Accepted: 05/16/2019] [Indexed: 11/11/2022]
Abstract
Adenoviral vectors induce robust epitope-specific CD8+ T cell responses. Within the repertoire of responses generated both conventional memory evolution and the phenomenon of memory inflation are seen. The rules governing which epitopes inflate are not fully known, but may include a role for both antigen processing and competition. To investigate this, we looked at memory generated from vectors targeting the Gp33-41 (KAVYNFATC/K9C) epitope from the gp of lymphocytic choriomeningitis virus (LCMV) in mice. This well-described epitope has both the Gp33-41 and Gp34-41 epitopes embedded within it. Vaccination with a full-length gp or a minigene Ad-Gp33/K9C vector-induced conventional memory responses against the immunodominant Gp33/K9C epitope but a strong inflationary response against the Gp34/A8C epitope. These responses showed sustained in vivo function, with complete protection against LCMV infectious challenge. Given the unexpected competition between epitopes seen in the minigene model, we further tested epitope competition using the full-length Ad-LacZ (β-galactosidase) model. Generation of an Ad-LacZ vector with a single amino acid disruption of the inflationary β-gal96-103 /D8V epitope transformed the β-gal497-504 /I8V epitope from conventional to inflationary memory. This work collectively demonstrates the importance of epitope competition within adenoviral vector inserts and is of relevance to future studies using adenoviral vectored immunogens.
Collapse
Affiliation(s)
- Julia M Colston
- Nuffield Department of MedicinePeter Medawar Building for Pathogen Research, University of OxfordOxfordUK
- Institute of ImmunobiologyKantonsspital St. GallenSt. GallenSwitzerland
| | - Claire Hutchings
- Nuffield Department of MedicinePeter Medawar Building for Pathogen Research, University of OxfordOxfordUK
| | - Senthil Chinnakannan
- Nuffield Department of MedicinePeter Medawar Building for Pathogen Research, University of OxfordOxfordUK
| | - Andrew Highton
- Nuffield Department of MedicinePeter Medawar Building for Pathogen Research, University of OxfordOxfordUK
| | | | - Burkhard Ludewig
- Institute of ImmunobiologyKantonsspital St. GallenSt. GallenSwitzerland
| | - Paul Klenerman
- Nuffield Department of MedicinePeter Medawar Building for Pathogen Research, University of OxfordOxfordUK
| |
Collapse
|
6
|
Beling A, Kespohl M. Proteasomal Protein Degradation: Adaptation of Cellular Proteolysis With Impact on Virus-and Cytokine-Mediated Damage of Heart Tissue During Myocarditis. Front Immunol 2018; 9:2620. [PMID: 30546359 PMCID: PMC6279938 DOI: 10.3389/fimmu.2018.02620] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Accepted: 10/24/2018] [Indexed: 12/26/2022] Open
Abstract
Viral myocarditis is an inflammation of the heart muscle triggered by direct virus-induced cytolysis and immune response mechanisms with most severe consequences during early childhood. Acute and long-term manifestation of damaged heart tissue and disturbances of cardiac performance involve virus-triggered adverse activation of the immune response and both immunopathology, as well as, autoimmunity account for such immune-destructive processes. It is a matter of ongoing debate to what extent subclinical virus infection contributes to the debilitating sequela of the acute disease. In this review, we conceptualize the many functions of the proteasome in viral myocarditis and discuss the adaptation of this multi-catalytic protease complex together with its implications on the course of disease. Inhibition of proteasome function is already highly relevant as a strategy in treating various malignancies. However, cardiotoxicity and immune-related adverse effects have proven significant hurdles, representative of the target's wide-ranging functions. Thus, we further discuss the molecular details of proteasome-mediated activity of the immune response for virus-mediated inflammatory heart disease. We summarize how the spatiotemporal flexibility of the proteasome might be tackled for therapeutic purposes aiming to mitigate virus-mediated adverse activation of the immune response in the heart.
Collapse
Affiliation(s)
- Antje Beling
- Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health (BIH), Institute of Biochemistry, Berlin, Germany.,Deutsches Zentrum für Herz-Kreislauf-Forschung (DZHK), Partner Site Berlin, Berlin, Germany
| | - Meike Kespohl
- Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health (BIH), Institute of Biochemistry, Berlin, Germany.,Deutsches Zentrum für Herz-Kreislauf-Forschung (DZHK), Partner Site Berlin, Berlin, Germany
| |
Collapse
|
7
|
Cicin-Sain L, Arens R. Exhaustion and Inflation at Antipodes of T Cell Responses to Chronic Virus Infection. Trends Microbiol 2017; 26:498-509. [PMID: 29249600 DOI: 10.1016/j.tim.2017.11.012] [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: 07/03/2017] [Revised: 11/22/2017] [Accepted: 11/30/2017] [Indexed: 12/21/2022]
Abstract
Viruses that have coevolved with their host establish chronic infections that are well tolerated by the host. Other viruses, that are partly adapted to their host, may induce chronic infections where persistent replication and viral antigen expression occur. The former induce highly functional and resilient CD8T cell responses called memory inflation. The latter induce dysfunctional and exhausted responses. The reasons compelling T cell responses towards inflationary or exhausted responses are only partly understood. In this review we compare the two conditions and describe mechanistic similarities and differences. We also provide a list of potential reasons why exhaustion or inflation occur in different virus infections. We propose that T cell-mediated transcriptional repression of viral gene expression provides a critical feature of inflation that allows peaceful virus and host coexistence. The virus is controlled, but its genome is not eradicated. If this mechanism is not available, as in the case of RNA viruses, the virus and the host are compelled to an arms race. If virus proliferation and spread proceed uncontrolled for too long, T cells are forced to strike a balance between viral control and tissue destruction, losing antiviral potency and facilitating virus persistence.
Collapse
Affiliation(s)
- Luka Cicin-Sain
- Department of Vaccinology and Applied Microbiology, Helmholtz Centre for Infection Research, Braunschweig, Germany; Institute for Virology, Medical School Hannover, Hannover, Germany; German Center for Infection Research (DZIF), Partner site Hannover/Braunschweig, Germany.
| | - Ramon Arens
- Department of Immunohematology and Blood Transfusion, Leiden University Medical Center, Leiden, The Netherlands
| |
Collapse
|
8
|
Immunoproteasome induction is suppressed in hepatitis C virus-infected cells in a protein kinase R-dependent manner. Exp Mol Med 2016; 48:e270. [PMID: 27833096 PMCID: PMC5133375 DOI: 10.1038/emm.2016.98] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2016] [Accepted: 06/11/2016] [Indexed: 02/08/2023] Open
Abstract
By changing the relative abundance of generated antigenic peptides through alterations in the proteolytic activity, interferon (IFN)-γ-induced immunoproteasomes influence the outcome of CD8+ cytotoxic T lymphocyte responses. In the present study, we investigated the effects of hepatitis C virus (HCV) infection on IFN-γ-induced immunoproteasome expression using a HCV infection cell culture system. We found that, although IFN-γ induced the transcriptional expression of mRNAs encoding the β1i/LMP2, β2i/MECL-1 and β5i/LMP7 immunoproteasome subunits, the formation of immunoproteasomes was significantly suppressed in HCV-infected cells. This finding indicated that immunoproteasome induction was impaired at the translational or posttranslational level by HCV infection. Gene silencing studies showed that the suppression of immunoproteasome induction is essentially dependent on protein kinase R (PKR). Indeed, the generation of a strictly immunoproteasome-dependent cytotoxic T lymphocyte epitope was impaired in in vitro processing experiments using isolated 20S proteasomes from HCV-infected cells and was restored by the silencing of PKR expression. In conclusion, our data point to a novel mechanism of immune regulation by HCV that affects the antigen-processing machinery through the PKR-mediated suppression of immunoproteasome induction in infected cells.
Collapse
|
9
|
Kincaid EZ, Murata S, Tanaka K, Rock KL. Specialized proteasome subunits have an essential role in the thymic selection of CD8(+) T cells. Nat Immunol 2016; 17:938-45. [PMID: 27294792 PMCID: PMC4955723 DOI: 10.1038/ni.3480] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2015] [Accepted: 05/02/2016] [Indexed: 12/11/2022]
Abstract
The cells that stimulate positive selection express specialized proteasome β-subunits different from those expressed by all other cells, including those involved in negative selection. Mice that lack all four specialized proteasome β-subunits, and therefore express only constitutive proteasomes in all cells, had a profound defect in the generation of CD8(+) T cells. While a defect in positive selection would reflect an inability to generate the appropriate positively selecting peptides, a block at negative selection would point to the potential need to switch peptides between positive selection and negative selection to avoid the two processes' often cancelling each other out. We found that the block in T cell development occurred around the checkpoints of positive selection and, unexpectedly, negative selection as well.
Collapse
Affiliation(s)
- Eleanor Z. Kincaid
- Department of Pathology, University of Massachusetts Medical School, Worcester, MA, U.S.A
| | - Shigeo Murata
- Laboratory of Protein Metabolism, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan
| | - Keiji Tanaka
- Laboratory of Protein Metabolism, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | - Kenneth L. Rock
- Department of Pathology, University of Massachusetts Medical School, Worcester, MA, U.S.A
| |
Collapse
|
10
|
Kammerl IE, Meiners S. Proteasome function shapes innate and adaptive immune responses. Am J Physiol Lung Cell Mol Physiol 2016; 311:L328-36. [PMID: 27343191 DOI: 10.1152/ajplung.00156.2016] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Accepted: 06/17/2016] [Indexed: 11/22/2022] Open
Abstract
The proteasome system degrades more than 80% of intracellular proteins into small peptides. Accordingly, the proteasome is involved in many essential cellular functions, such as protein quality control, transcription, immune responses, cell signaling, and apoptosis. Moreover, degradation products are loaded onto major histocompatibility class I molecules to communicate the intracellular protein composition to the immune system. The standard 20S proteasome core complex contains three distinct catalytic active sites that are exchanged upon stimulation with inflammatory cytokines to form the so-called immunoproteasome. Immunoproteasomes are constitutively expressed in immune cells and have different proteolytic activities compared with standard proteasomes. They are rapidly induced in parenchymal cells upon intracellular pathogen infection and are crucial for priming effective CD8(+) T-cell-mediated immune responses against infected cells. Beyond shaping these adaptive immune reactions, immunoproteasomes also regulate the function of immune cells by degradation of inflammatory and immune mediators. Accordingly, they emerge as novel regulators of innate immune responses. The recently unraveled impairment of immunoproteasome function by environmental challenges and by genetic variations of immunoproteasome genes might represent a currently underestimated risk factor for the development and progression of lung diseases. In particular, immunoproteasome dysfunction will dampen resolution of infections, thereby promoting exacerbations, may foster autoimmunity in chronic lung diseases, and possibly contributes to immune evasion of tumor cells. Novel pharmacological tools, such as site-specific inhibitors of the immunoproteasome, as well as activity-based probes, however, hold promises as innovative therapeutic drugs for respiratory diseases and biomarker profiling, respectively.
Collapse
Affiliation(s)
- Ilona E Kammerl
- Comprehensive Pneumology Center, University Hospital, Ludwig-Maximilians University and Helmholtz Zentrum München, Member of the German Center for Lung Research (DZL), Munich, Germany
| | - Silke Meiners
- Comprehensive Pneumology Center, University Hospital, Ludwig-Maximilians University and Helmholtz Zentrum München, Member of the German Center for Lung Research (DZL), Munich, Germany
| |
Collapse
|
11
|
Mundt S, Engelhardt B, Kirk CJ, Groettrup M, Basler M. Inhibition and deficiency of the immunoproteasome subunit LMP7 attenuates LCMV-induced meningitis. Eur J Immunol 2015; 46:104-13. [PMID: 26464284 DOI: 10.1002/eji.201545578] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2015] [Revised: 09/07/2015] [Accepted: 10/08/2015] [Indexed: 11/05/2022]
Abstract
In addition to antigen processing, immunoproteasomes were recently shown to exert functions influencing cytokine production by monocytes and T cells, T-helper cell differentiation, and T-cell survival. Moreover, selective inhibition of the immunoproteasome subunit LMP7 ameliorated symptoms of autoimmune diseases including CD4(+) T-cell mediated EAE. In this study, we show that LMP7 also plays a crucial role in the pathogenesis of lymphocytic choriomeningitis virus (LCMV)-induced meningitis mediated by CTLs. Mice lacking functional LMP7 display delayed and reduced clinical signs of disease accompanied by a strongly decreased inflammatory infiltration into the brain. Interestingly, we found that selective inhibition and genetic deficiency of LMP7 affect the pathogenesis of LCMV-induced meningitis in a distinct manner. Our findings support the important role of LMP7 in inflammatory disorders and suggest immunoproteasome inhibition as a novel strategy against inflammation-induced neuropathology in the CNS.
Collapse
Affiliation(s)
- Sarah Mundt
- Division of Immunology, Department of Biology, University of Konstanz, Konstanz, Germany.,Konstanz Research School Chemical Biology (KoRS-CB), University of Konstanz, Konstanz, Germany
| | | | | | - Marcus Groettrup
- Division of Immunology, Department of Biology, University of Konstanz, Konstanz, Germany.,Biotechnology Institute Thurgau at the University of Konstanz (BITg), Kreuzlingen, Switzerland
| | - Michael Basler
- Division of Immunology, Department of Biology, University of Konstanz, Konstanz, Germany.,Biotechnology Institute Thurgau at the University of Konstanz (BITg), Kreuzlingen, Switzerland
| |
Collapse
|
12
|
Duan X, Imai T, Chou B, Tu L, Himeno K, Suzue K, Hirai M, Taniguchi T, Okada H, Shimokawa C, Hisaeda H. Resistance to malaria by enhanced phagocytosis of erythrocytes in LMP7-deficient mice. PLoS One 2013; 8:e59633. [PMID: 23527234 PMCID: PMC3602297 DOI: 10.1371/journal.pone.0059633] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2013] [Accepted: 02/15/2013] [Indexed: 12/18/2022] Open
Abstract
General cellular functions of proteasomes occur through protein degradation, whereas the specific function of immunoproteasomes is the optimization of antigen processing associated with MHC class I. We and others previously reported that deficiency in subunits of immunoproteasomes impaired the activation of antigen-specific CD8+ T cells, resulting in higher susceptibility to tumor and infections. We demonstrated that CD8+ T cells contributed to protection against malaria parasites. In this study, we evaluated the role of immunoproteasomes in the course of infection with rodent malaria parasites. Unexpectedly, Plasmodium yoelii infection of mice deficient in LMP7, a catalytic subunit of immunoproteasomes, showed lower parasite growth in the early phase of infection and lower lethality compared with control mice. The protective characteristics of LMP7-deficient mice were not associated with enhanced immune responses, as the mutant mice showed comparable or diminished activation of innate and acquired immunity. The remarkable difference was observed in erythrocytes instead of immune responses. Parasitized red blood cells (pRBCs) purified from LMP7-deficient mice were more susceptible to phagocytosis by macrophages compared with those from wild-type mice. The susceptibility of pRBC to phagocytosis appeared to correlate with deformity of the membrane structures that were only observed after infection. Our results suggest that RBCs of LMP7-deficient mice were more likely to deform in response to infection with malaria parasites, presumably resulting in higher susceptibility to phagocytosis and in the partial resistance to malaria.
Collapse
Affiliation(s)
- Xuefeng Duan
- Department of Parasitology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Takashi Imai
- Department of Parasitology, Graduate School of Medicine, Gunma University, Maebashi, Japan
| | - Bin Chou
- Department of Parasitology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Liping Tu
- Department of Parasitology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Kunisuke Himeno
- Department of Parasitology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Kazutomo Suzue
- Department of Parasitology, Graduate School of Medicine, Gunma University, Maebashi, Japan
| | - Makoto Hirai
- Department of Parasitology, Graduate School of Medicine, Gunma University, Maebashi, Japan
| | - Tomoyo Taniguchi
- Department of Parasitology, Graduate School of Medicine, Gunma University, Maebashi, Japan
| | - Hiroko Okada
- Department of Parasitology, Graduate School of Medicine, Gunma University, Maebashi, Japan
| | - Chikako Shimokawa
- Department of Parasitology, Graduate School of Medicine, Gunma University, Maebashi, Japan
| | - Hajime Hisaeda
- Department of Parasitology, Graduate School of Medicine, Gunma University, Maebashi, Japan
- * E-mail:
| |
Collapse
|
13
|
The immunoproteasome in antigen processing and other immunological functions. Curr Opin Immunol 2012; 25:74-80. [PMID: 23219269 DOI: 10.1016/j.coi.2012.11.004] [Citation(s) in RCA: 168] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2012] [Revised: 11/12/2012] [Accepted: 11/13/2012] [Indexed: 01/30/2023]
Abstract
Treatment of cells with interferon-γ leads to the replacement of the constitutive catalytic proteasome subunits β1, β2, and β5 by the inducible subunits LMP2 (β1i), MECL-1 (β2i), and LMP7 (β5i), respectively, building the so-called immunoproteasome. The incorporation of these subunits is required for the production of numerous MHC class-I restricted T cell epitopes. Recently, new evidence for an involvement of the immunoproteasome in other facets of the immune response emerged. Investigations of autoimmune diseases in animal models and a genetic predisposition of β5i in human autoimmune disorders suggest a crucial function of the immunoproteasome in proinflammatory diseases. The recent elucidation of the high-resolution structure of the immunoproteasome will facilitate the design of immunoproteasome selective inhibitors for pharmacological intervention.
Collapse
|
14
|
A selective inhibitor of the immunoproteasome subunit LMP2 induces apoptosis in PC-3 cells and suppresses tumour growth in nude mice. Br J Cancer 2012; 107:53-62. [PMID: 22677907 PMCID: PMC3389428 DOI: 10.1038/bjc.2012.243] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Although the proteasome is a validated anticancer target, the clinical application of its inhibitors has been limited because of inherent systemic toxicity. To broaden clinical utility of proteasome inhibitors as anticancer agents, it is critical to develop strategies to selectively target proteasomes in cancer cells. The immunoproteasome is an alternative form of the constitutive proteasome that is expressed at high levels in cancer tissues, but not in most normal cells in the body. METHODS To validate the immunoproteasome as a chemotherapeutic target, an immunoproteasome catalytic subunit LMP2-targeting inhibitor and siRNA were used. The sensitivity of PC-3 prostate cancer cells to these reagents was investigated using viability assays. Further, a xenograft model of prostate cancer was studied to test the in vivo effects of LMP2 inhibition. RESULTS A small molecule inhibitor of the immunoproteasome subunit LMP2, UK-101, induced apoptosis of PC-3 cells and resulted in significant inhibition (~50-60%) of tumour growth in vivo. Interestingly, UK-101 did not block degradation of IκBα in PC-3 cells treated with TNF-α, suggesting that its mode of action may be different from that of general proteasome inhibitors, such as bortezomib, which block IκBα degradation. CONCLUSION These results strongly suggest that the immunoproteasome has important roles in cancer cell growth and thus provide a rationale for targeting the immunoproteasome in the treatment of prostate cancer.
Collapse
|
15
|
Immunodominance: a pivotal principle in host response to viral infections. Clin Immunol 2012; 143:99-115. [PMID: 22391152 DOI: 10.1016/j.clim.2012.01.015] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2011] [Revised: 01/25/2012] [Accepted: 01/28/2012] [Indexed: 11/24/2022]
Abstract
We encounter pathogens on a daily basis and our immune system has evolved to mount an immune response following an infection. An interesting phenomenon that has evolved in response to clearing bacterial and viral infections is called immunodominance. Immunodominance refers to the phenomenon that, despite co-expression of multiple major histocompatibility complex class I alleles by host cells and the potential generation of hundreds of distinct antigenic peptides for recognition following an infection, a large portion of the anti-viral cytotoxic T lymphocyte population targets only some peptide/MHC class I complexes. Here we review the main factors contributing to immunodominance in relation to influenza A and HIV infection. Of special interest are the factors contributing to immunodominance in humans and rodents following influenza A infection. By critically reviewing these findings, we hope to improve understanding of the challenges facing the discovery of new factors enabling better anti-viral vaccine strategies in the future.
Collapse
|
16
|
Krüger E, Kloetzel PM. Immunoproteasomes at the interface of innate and adaptive immune responses: two faces of one enzyme. Curr Opin Immunol 2012; 24:77-83. [DOI: 10.1016/j.coi.2012.01.005] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2011] [Revised: 12/19/2011] [Accepted: 01/09/2012] [Indexed: 12/24/2022]
|
17
|
Kincaid EZ, Che JW, York I, Escobar H, Reyes-Vargas E, Delgado JC, Welsh RM, Karow ML, Murphy AJ, Valenzuela DM, Yancopoulos GD, Rock KL. Mice completely lacking immunoproteasomes show major changes in antigen presentation. Nat Immunol 2011; 13:129-35. [PMID: 22197977 PMCID: PMC3262888 DOI: 10.1038/ni.2203] [Citation(s) in RCA: 208] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2011] [Accepted: 11/30/2011] [Indexed: 01/17/2023]
Abstract
The importance of immunoproteasomes to antigen presentation has been unclear because animals totally lacking immunoproteasomes have not been previously developed. Here we show that dendritic cells from mice lacking the three immunoproteasome catalytic subunits display defects in presenting multiple major histocompatability (MHC) class I epitopes. During viral infection in vivo, the presentation of a majority of MHC class I epitopes is markedly reduced in immunoproteasome-deficient animals, while presentation of MHC class II peptides is unaffected. By mass spectrometry the repertoire of MHC class I-presented peptides is ~50% different and these differences are sufficient to stimulate robust transplant rejection of wild type cells in mutant mice. These results indicate that immunoproteasomes play a much more important role in antigen presentation than previously thought.
Collapse
Affiliation(s)
- Eleanor Z Kincaid
- Department of Pathology, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
18
|
Berhane S, Aresté C, Ablack JN, Ryan GB, Blackbourn DJ, Mymryk JS, Turnell AS, Steele JC, Grand RJA. Adenovirus E1A interacts directly with, and regulates the level of expression of, the immunoproteasome component MECL1. Virology 2011; 421:149-58. [PMID: 22018786 DOI: 10.1016/j.virol.2011.09.025] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2011] [Revised: 07/29/2011] [Accepted: 09/27/2011] [Indexed: 10/16/2022]
Abstract
Proteasomes represent the major non-lysosomal mechanism responsible for the degradation of proteins. Following interferon γ treatment 3 proteasome subunits are replaced producing immunoproteasomes. Adenovirus E1A interacts with components of the 20S and 26S proteasome and can affect presentation of peptides. In light of these observations we investigated the relationship of AdE1A to the immunoproteasome. AdE1A interacts with the immunoproteasome subunit, MECL1. In contrast, AdE1A binds poorly to the proteasome β2 subunit which is replaced by MECL1 in the conversion of proteasomes to immunoproteasomes. Binding sites on E1A for MECL1 correspond to the N-terminal region and conserved region 3. Furthermore, AdE1A causes down-regulation of MECL1 expression, as well as LMP2 and LMP7, induced by interferon γ treatment during Ad infections or following transient transfection. Consistent with previous reports AdE1A reduced IFNγ-stimulated STAT1 phosphorylation which appeared to be responsible for its ability to reduce expression of immunoproteasome subunits.
Collapse
Affiliation(s)
- Sarah Berhane
- Cancer Research UK, School of Cancer Sciences, University of Birmingham, Birmingham B15 2TT, UK
| | | | | | | | | | | | | | | | | |
Collapse
|
19
|
Kriegenburg F, Poulsen EG, Koch A, Krüger E, Hartmann-Petersen R. Redox control of the ubiquitin-proteasome system: from molecular mechanisms to functional significance. Antioxid Redox Signal 2011; 15:2265-99. [PMID: 21314436 DOI: 10.1089/ars.2010.3590] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
In their natural environments, cells are regularly exposed to oxidizing conditions that may lead to protein misfolding. If such misfolded proteins are allowed to linger, they may form insoluble aggregates and pose a serious threat to the cell. Accumulation of misfolded, oxidatively damaged proteins is characteristic of many diseases and during aging. To counter the adverse effects of oxidative stress, cells can initiate an antioxidative response in an attempt to repair the damage, or rapidly channel the damaged proteins for degradation by the ubiquitin-proteasome system (UPS). Recent studies have shown that elements of the oxidative stress response and the UPS are linked on many levels. To manage the extra burden of misfolded proteins, the UPS is induced by oxidative stress, and special proteasome subtypes protect cells against oxidative damage. In addition, the proteasome is directly associated with a thioredoxin and other cofactors that may adjust the particle's response during an oxidative challenge. Here, we give an overview of the UPS and a detailed description of the degradation of oxidized proteins and of the crosstalk between oxidative stress and protein degradation in health and disease.
Collapse
Affiliation(s)
- Franziska Kriegenburg
- Department of Biology, University of Copenhagen, Ole Maaløes Vej 5,Copenhagen, Denmark
| | | | | | | | | |
Collapse
|
20
|
Opitz E, Koch A, Klingel K, Schmidt F, Prokop S, Rahnefeld A, Sauter M, Heppner FL, Völker U, Kandolf R, Kuckelkorn U, Stangl K, Krüger E, Kloetzel PM, Voigt A. Impairment of immunoproteasome function by β5i/LMP7 subunit deficiency results in severe enterovirus myocarditis. PLoS Pathog 2011; 7:e1002233. [PMID: 21909276 PMCID: PMC3164653 DOI: 10.1371/journal.ppat.1002233] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2010] [Accepted: 07/07/2011] [Indexed: 12/18/2022] Open
Abstract
Proteasomes recognize and degrade poly-ubiquitinylated proteins. In infectious disease, cells activated by interferons (IFNs) express three unique catalytic subunits β1i/LMP2, β2i/MECL-1 and β5i/LMP7 forming an alternative proteasome isoform, the immunoproteasome (IP). The in vivo function of IPs in pathogen-induced inflammation is still a matter of controversy. IPs were mainly associated with MHC class I antigen processing. However, recent findings pointed to a more general function of IPs in response to cytokine stress. Here, we report on the role of IPs in acute coxsackievirus B3 (CVB3) myocarditis reflecting one of the most common viral disease entities among young people. Despite identical viral load in both control and IP-deficient mice, IP-deficiency was associated with severe acute heart muscle injury reflected by large foci of inflammatory lesions and severe myocardial tissue damage. Exacerbation of acute heart muscle injury in this host was ascribed to disequilibrium in protein homeostasis in viral heart disease as indicated by the detection of increased proteotoxic stress in cytokine-challenged cardiomyocytes and inflammatory cells from IP-deficient mice. In fact, due to IP-dependent removal of poly-ubiquitinylated protein aggregates in the injured myocardium IPs protected CVB3-challenged mice from oxidant-protein damage. Impaired NFκB activation in IP-deficient cardiomyocytes and inflammatory cells and proteotoxic stress in combination with severe inflammation in CVB3-challenged hearts from IP-deficient mice potentiated apoptotic cell death in this host, thus exacerbating acute tissue damage. Adoptive T cell transfer studies in IP-deficient mice are in agreement with data pointing towards an effective CD8 T cell immune. This study therefore demonstrates that IP formation primarily protects the target organ of CVB3 infection from excessive inflammatory tissue damage in a virus-induced proinflammatory cytokine milieu.
Collapse
Affiliation(s)
- Elisa Opitz
- Medizinische Klinik für Kardiologie, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Annett Koch
- Institut für Biochemie, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Karin Klingel
- Abteilung Molekulare Pathologie, Institut für Pathologie und Neuropathologie, Eberhard-Karls-Universität, Tuebingen, Germany
| | - Frank Schmidt
- Interfakultäres Institut für Genetik und Funktionelle Genomforschung, Ernst-Moritz-Arndt-Universität, Greifswald, Germany
| | - Stefan Prokop
- Institut für Neuropathologie, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Anna Rahnefeld
- Medizinische Klinik für Kardiologie, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Martina Sauter
- Abteilung Molekulare Pathologie, Institut für Pathologie und Neuropathologie, Eberhard-Karls-Universität, Tuebingen, Germany
| | - Frank L. Heppner
- Institut für Neuropathologie, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Uwe Völker
- Interfakultäres Institut für Genetik und Funktionelle Genomforschung, Ernst-Moritz-Arndt-Universität, Greifswald, Germany
| | - Reinhard Kandolf
- Abteilung Molekulare Pathologie, Institut für Pathologie und Neuropathologie, Eberhard-Karls-Universität, Tuebingen, Germany
| | - Ulrike Kuckelkorn
- Institut für Biochemie, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Karl Stangl
- Medizinische Klinik für Kardiologie, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Elke Krüger
- Institut für Biochemie, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Peter M. Kloetzel
- Institut für Biochemie, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Antje Voigt
- Medizinische Klinik für Kardiologie, Charité-Universitätsmedizin Berlin, Berlin, Germany
| |
Collapse
|
21
|
Zaiss DMW, Bekker CPJ, Gröne A, Lie BA, Sijts AJAM. Proteasome immunosubunits protect against the development of CD8 T cell-mediated autoimmune diseases. THE JOURNAL OF IMMUNOLOGY 2011; 187:2302-9. [PMID: 21804012 DOI: 10.4049/jimmunol.1101003] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Exposure of cells to inflammatory cytokines induces the expression of three proteasome immunosubunits, two of which are encoded in the MHC class II region. The induced subunits replace their constitutive homologs in newly formed "so-called" immunoproteasomes. Immunosubunit incorporation enhances the proteasome's proteolytic activity and modifies the proteasome's cleavage-site preferences, which improves the generation of many MHC class I-presented peptides and shapes the fine specificity of pathogen-specific CD8 T cell responses. In this article, we report on a second effect of immunoproteasome formation on CD8 T cell responses. We show that mice deficient for the immunosubunits β5i/low molecular mass polypeptide (LMP7) and β2i/multicatalytic endopeptidase complex-like-1 develop early-stage multiorgan autoimmunity following irradiation and bone marrow transplantation. Disease symptoms are caused by CD8 T cells and are transferable into immunosubunit-deficient, RAG1-deficient mice. Moreover, using the human Type 1 Diabetes Genetics Consortium MHC dataset, we identified two single nucleotide polymorphisms within the β5i/LMP7-encoding gene sequences, which were in strong linkage disequilibrium, as independent genetic risk factors for type 1 diabetes development in humans. Strikingly, these single nucleotide polymorphisms significantly enhanced the risk conferred by HLA haplotypes that were previously shown to predispose for type 1 diabetes. These data suggested that inflammation-induced immunosubunit expression in peripheral tissues constitutes a mechanism that prevents the development of CD8 T cell-mediated autoimmune diseases.
Collapse
Affiliation(s)
- Dietmar M W Zaiss
- Division of Immunology, Faculty of Veterinary Medicine, University of Utrecht, 3584CL Utrecht, The Netherlands
| | | | | | | | | |
Collapse
|
22
|
Tisoncik JR, Billharz R, Burmakina S, Belisle SE, Proll SC, Korth MJ, García-Sastre A, Katze MG. The NS1 protein of influenza A virus suppresses interferon-regulated activation of antigen-presentation and immune-proteasome pathways. J Gen Virol 2011; 92:2093-2104. [PMID: 21593271 DOI: 10.1099/vir.0.032060-0] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The NS1 protein of influenza virus counters host antiviral defences primarily by antagonizing the type I interferon (IFN) response. Both the N-terminal dsRNA-binding domain and the C-terminal effector domain are required for optimal suppression of host responses during infection. To better understand the regulatory role of the NS1 effector domain, we used an NS1-truncated mutant virus derived from human H1N1 influenza isolate A/Texas/36/91 (Tx/91) and assessed global transcriptional profiles from two independent human lung cell-culture models. Relative to the wild-type Tx/91-induced gene expression, the NS1 mutant virus induced enhanced expression of innate immune genes, specifically NF-κB signalling-pathway genes and IFN-α and -β target genes. We queried an experimentally derived IFN gene set to gauge the proportion of IFN-responsive genes that are suppressed specifically by NS1. We show that the C-terminally truncated NS1 mutant virus is less efficient at suppressing IFN-regulated gene expression associated with activation of antigen-presentation and immune-proteasome pathways. This is the first report integrating genomic analysis from two independent human culture systems, including primary lung cells, using genetically similar H1N1 influenza viruses that differ only in the length of the NS1 protein.
Collapse
Affiliation(s)
- Jennifer R Tisoncik
- Department of Microbiology, University of Washington, Seattle, WA 98195, USA
| | - Rosalind Billharz
- Department of Microbiology, University of Washington, Seattle, WA 98195, USA
| | - Svetlana Burmakina
- Department of Microbiology, Mount Sinai School of Medicine, New York, NY, USA
| | - Sarah E Belisle
- Department of Microbiology, University of Washington, Seattle, WA 98195, USA
| | - Sean C Proll
- Department of Microbiology, University of Washington, Seattle, WA 98195, USA
| | - Marcus J Korth
- Department of Microbiology, University of Washington, Seattle, WA 98195, USA
| | - Adolfo García-Sastre
- Global Health and Emerging Pathogens Institute, Mount Sinai School of Medicine, New York, NY, USA.,Department of Medicine, Division of Infectious Diseases, Mount Sinai School of Medicine, New York, NY, USA.,Department of Microbiology, Mount Sinai School of Medicine, New York, NY, USA
| | - Michael G Katze
- Washington National Primate Research Center, University of Washington, Seattle, WA 98195, USA.,Department of Microbiology, University of Washington, Seattle, WA 98195, USA
| |
Collapse
|
23
|
The role of the proteasome in the generation of MHC class I ligands and immune responses. Cell Mol Life Sci 2011; 68:1491-502. [PMID: 21387144 PMCID: PMC3071949 DOI: 10.1007/s00018-011-0657-y] [Citation(s) in RCA: 186] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2011] [Revised: 02/17/2011] [Accepted: 02/18/2011] [Indexed: 02/07/2023]
Abstract
The ubiquitin–proteasome system (UPS) degrades intracellular proteins into peptide fragments that can be presented by major histocompatibility complex (MHC) class I molecules. While the UPS is functional in all mammalian cells, its subunit composition differs depending on cell type and stimuli received. Thus, cells of the hematopoietic lineage and cells exposed to (pro)inflammatory cytokines express three proteasome immunosubunits, which form the catalytic centers of immunoproteasomes, and the proteasome activator PA28. Cortical thymic epithelial cells express a thymus-specific proteasome subunit that induces the assembly of thymoproteasomes. We here review new developments regarding the role of these different proteasome components in MHC class I antigen processing, T cell repertoire selection and CD8 T cell responses. We further discuss recently discovered functions of proteasomes in peptide splicing, lymphocyte survival and the regulation of cytokine production and inflammatory responses.
Collapse
|
24
|
de Graaf N, van Helden MJG, Textoris-Taube K, Chiba T, Topham DJ, Kloetzel PM, Zaiss DMW, Sijts AJAM. PA28 and the proteasome immunosubunits play a central and independent role in the production of MHC class I-binding peptides in vivo. Eur J Immunol 2011; 41:926-35. [PMID: 21360704 DOI: 10.1002/eji.201041040] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2010] [Revised: 12/02/2010] [Accepted: 01/05/2011] [Indexed: 11/08/2022]
Abstract
Proteasomes play a fundamental role in the processing of intracellular antigens into peptides that bind to MHC class I molecules for the presentation of CD8(+) T cells. Three IFN-γ-inducible catalytic proteasome (immuno)subunits as well as the IFN-γ-inducible proteasome activator PA28 dramatically accelerate the generation of a subset of MHC class I-presented antigenic peptides. To determine whether these IFN-γ-inducible proteasome components play a compounded role in antigen processing, we generated mice lacking both PA28 and immunosubunits β5i/LMP7 and β2i/MECL-1. Analyses of MHC class I cell-surface levels ex vivo demonstrated that PA28 deficiency reduced the production of MHC class I-binding peptides both in cells with and without immunosubunits, in the latter cells further decreasing an already diminished production of MHC ligands in the absence of immunoproteasomes. In contrast, the immunosubunits but not PA28 appeared to be of critical importance for the induction of CD8(+) T-cell responses to multiple dominant Influenza and Listeria-derived epitopes. Taken together, our data demonstrate that PA28 and the proteasome immunosubunits use fundamentally different mechanisms to enhance the supply of MHC class I-binding peptides; however, only the immunosubunit-imposed effects on proteolytic epitope processing appear to have substantial influence on the specificity of pathogen-specific CD8(+) T-cell responses.
Collapse
Affiliation(s)
- Natascha de Graaf
- Department of Infectious Diseases and Immunology, Faculty of Veterinary Medicine, University of Utrecht, Utrecht, The Netherlands
| | | | | | | | | | | | | | | |
Collapse
|
25
|
Hutchinson S, Sims S, O'Hara G, Silk J, Gileadi U, Cerundolo V, Klenerman P. A dominant role for the immunoproteasome in CD8+ T cell responses to murine cytomegalovirus. PLoS One 2011; 6:e14646. [PMID: 21304910 PMCID: PMC3033404 DOI: 10.1371/journal.pone.0014646] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2010] [Accepted: 01/06/2011] [Indexed: 01/08/2023] Open
Abstract
Murine cytomegalovirus (MCMV) is an important animal model of human cytomegalovirus (HCMV), a β-Herpesvirus that infects the majority of the world's population and causes disease in neonates and immunocompromised adults. CD8+ T cells are a major part of the immune response to MCMV and HCMV. Processing of peptides for presentation to CD8+ T cells may be critically dependent on the immunoproteasome, expression of which is affected by MCMV. However, the overall importance of the immunoproteasome in the generation of immunodominant peptides from MCMV is not known. We therefore examined the role of the immunoproteasome in stimulation of CD8+ T cell responses to MCMV – both conventional memory responses and those undergoing long-term expansion or “inflation”. We infected LMP7−/− and C57BL/6 mice with MCMV or with newly-generated recombinant vaccinia viruses (rVVs) encoding the immunodominant MCMV protein M45 in either full-length or epitope-only minigene form. We analysed CD8+ T cell responses using intracellular cytokine stain (ICS) and MHC Class I tetramer staining for a panel of MCMV-derived epitopes. We showed a critical role for immunoproteasome in MCMV affecting all epitopes studied. Interestingly we found that memory “inflating” epitopes demonstrate reduced immunoproteasome dependence compared to non-inflating epitopes. M45-specific responses induced by rVVs remain immunoproteasome-dependent. These results help to define a critical restriction point for CD8+ T cell epitopes in natural cytomegalovirus (CMV) infection and potentially in vaccine strategies against this and other viruses.
Collapse
Affiliation(s)
- Sarah Hutchinson
- Nuffield Department of Clinical Medicine, Peter Medawar Building for Pathogen Research, University of Oxford, Oxford, United Kingdom
| | - Stuart Sims
- Nuffield Department of Clinical Medicine, Peter Medawar Building for Pathogen Research, University of Oxford, Oxford, United Kingdom
| | - Geraldine O'Hara
- Nuffield Department of Clinical Medicine, Peter Medawar Building for Pathogen Research, University of Oxford, Oxford, United Kingdom
| | - Jon Silk
- Weatherall Institute of Molecular Medicine, Molecular Immunology Group, Nuffield Department of Medicine, John Radcliffe Hospital, Oxford, United Kingdom
| | - Uzi Gileadi
- Weatherall Institute of Molecular Medicine, Molecular Immunology Group, Nuffield Department of Medicine, John Radcliffe Hospital, Oxford, United Kingdom
| | - Vincenzo Cerundolo
- Weatherall Institute of Molecular Medicine, Molecular Immunology Group, Nuffield Department of Medicine, John Radcliffe Hospital, Oxford, United Kingdom
| | - Paul Klenerman
- Nuffield Department of Clinical Medicine, Peter Medawar Building for Pathogen Research, University of Oxford, Oxford, United Kingdom
- * E-mail:
| |
Collapse
|
26
|
PSMB8 encoding the β5i proteasome subunit is mutated in joint contractures, muscle atrophy, microcytic anemia, and panniculitis-induced lipodystrophy syndrome. Am J Hum Genet 2010; 87:866-72. [PMID: 21129723 DOI: 10.1016/j.ajhg.2010.10.031] [Citation(s) in RCA: 263] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2010] [Revised: 10/18/2010] [Accepted: 10/25/2010] [Indexed: 11/24/2022] Open
Abstract
We performed homozygosity mapping in two recently reported pedigrees from Portugal and Mexico with an autosomal-recessive autoinflammatory syndrome characterized by joint contractures, muscle atrophy, microcytic anemia, and panniculitis-induced lipodystrophy (JMP). This revealed only one homozygous region spanning 2.4 Mb (5818 SNPs) on chromosome 6p21 shared by all three affected individuals from both families. We directly sequenced genes involved in immune response located in this critical region, excluding the HLA complex genes. We found a homozygous missense mutation c.224C>T (p.Thr75Met) in the proteasome subunit, beta-type, 8 (PSMB8) gene in affected patients from both pedigrees. The mutation segregated in an autosomal-recessive fashion and was not detected in 275 unrelated ethnically matched healthy subjects. PSMB8 encodes a catalytic subunit of the 20S immunoproteasomes called β5i. Immunoproteasome-mediated proteolysis generates immunogenic epitopes presented by major histocompatibility complex (MHC) class I molecules. Threonine at position 75 is highly conserved and its substitution with methionine disrupts the tertiary structure of PSMB8. As compared to normal lymphoblasts, those from an affected patient showed significantly reduced chymotrypsin-like proteolytic activity mediated by immunoproteasomes. We conclude that mutations in PSMB8 cause JMP syndrome, most probably by affecting MHC class I antigen processing.
Collapse
|
27
|
Seifert U, Bialy LP, Ebstein F, Bech-Otschir D, Voigt A, Schröter F, Prozorovski T, Lange N, Steffen J, Rieger M, Kuckelkorn U, Aktas O, Kloetzel PM, Krüger E. Immunoproteasomes preserve protein homeostasis upon interferon-induced oxidative stress. Cell 2010; 142:613-24. [PMID: 20723761 DOI: 10.1016/j.cell.2010.07.036] [Citation(s) in RCA: 424] [Impact Index Per Article: 30.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2008] [Revised: 04/01/2010] [Accepted: 06/22/2010] [Indexed: 11/29/2022]
Abstract
Interferon (IFN)-induced immunoproteasomes (i-proteasomes) have been associated with improved processing of major histocompatibility complex (MHC) class I antigens. Here, we show that i-proteasomes function to protect cell viability under conditions of IFN-induced oxidative stress. IFNs trigger the production of reactive oxygen species, which induce protein oxidation and the formation of nascent, oxidant-damaged proteins. We find that the ubiquitylation machinery is concomitantly upregulated in response to IFNs, functioning to target defective ribosomal products (DRiPs) for degradation by i-proteasomes. i-proteasome-deficiency in cells and in murine inflammation models results in the formation of aggresome-like induced structures and increased sensitivity to apoptosis. Efficient clearance of these aggregates by the enhanced proteolytic activity of the i-proteasome is important for the preservation of cell viability upon IFN-induced oxidative stress. Our findings suggest that rather than having a specific role in the production of class I antigens, i-proteasomes increase the peptide supply for antigen presentation as part of a more general role in the maintenance of protein homeostasis.
Collapse
Affiliation(s)
- Ulrike Seifert
- Institut für Biochemie CC2, Charité - Universitätsmedizin Berlin, Oudenarder Strasse 16, D-13347 Berlin, Germany
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
28
|
Sukriti S, Pati NT, Bose S, Hissar SS, Sarin SK. Impaired antigen processing and presentation machinery is associated with immunotolerant state in chronic hepatitis B virus infection. J Clin Immunol 2010; 30:419-25. [PMID: 20300807 DOI: 10.1007/s10875-010-9379-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2009] [Accepted: 02/05/2010] [Indexed: 01/19/2023]
Abstract
BACKGROUND AND AIMS The mechanism of hepatitis B virus (HBV)-specific T cell hyporesponsiveness in hepatitis Be antigen (HBeAg)-positive subjects is not well understood. Inefficient antigen processing and transport to major histocompatibility complex class I molecules, namely due to low molecular weight protein (LMP) 2 and 7 and transporter associated with antigen processing (TAP) 1 and 2 genes could be playing a role. PATIENTS AND METHODS Forty patients with chronic hepatitis B (CHB) infection, hepatitis B surface antigen, and HBeAg positive; 26 with raised (Gr. I) and 14 with persistently normal ALT levels (Gr. II) and 11 healthy controls (Gr. III) were studied. Total RNA was isolated from peripheral blood mononuclear cells and mRNA expression of TAP1, TAP2, LMP2, and LMP7 genes was analyzed by semi-quantitative reverse transcriptase-polymerase chain reaction method. Gamma interferon (IFN-gamma) and tumor necrosis factor-alpha (TNF-alpha) levels were quantified by enzyme-linked immunosorbent assay (ELISA) using log-log and linear graphs, respectively. RESULTS Group II CHB patients had significantly lower mRNA expression for TAP1 (p = 0.003) and LMP2 (p = 0.002) genes as compared to Gr. I patients. The mRNA expression of TAP2 and LMP7 genes was comparable between the groups. However, expression of TAP1 (p = 0.02), TAP2 (p = 0.035), and LMP2 (p = 0.041) was found to be significantly higher in Gr. III subjects compared to Gr. I and Gr. II patients. In Gr. I and II, the IFN-gamma {s54.2{9.4-165} pg/ml), (59.5{28.5-110} pg/ml)}, and TNF-alpha {12.0 (8.0-23.2)},{10.8(6.2-20.8)} pg/ml levels were comparable but were significantly (p = 0.00,0.004, respectively) higher than Gr. III subjects. CONCLUSIONS Low expression of TAP1 and LMP2 suggests an important role of these genes in defective viral antigen processing in immune tolerant state of CHB patients. Higher IFN-gamma and TNF-alpha production in CHB are probably enough to potentiate liver injury but not enough to clear the chronic HBV infection. These novel observations could pave way for new therapeutic strategies for immune restoration in CHB infected patients.
Collapse
Affiliation(s)
- Sukriti Sukriti
- Department of Gastroenterology, G.B. Pant Hospital, University of Delhi, 201, Academic Block, New Delhi, India
| | | | | | | | | |
Collapse
|
29
|
Hensley SE, Zanker D, Dolan BP, David A, Hickman HD, Embry AC, Skon CN, Grebe KM, Griffin TA, Chen W, Bennink JR, Yewdell JW. Unexpected role for the immunoproteasome subunit LMP2 in antiviral humoral and innate immune responses. THE JOURNAL OF IMMUNOLOGY 2010; 184:4115-22. [PMID: 20228196 DOI: 10.4049/jimmunol.0903003] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Proteasomes are multisubunit proteases that initiate degradation of many Ags presented by MHC class I molecules. Vertebrates express alternate forms of each of the three catalytic proteasome subunits: standard subunits, and immunosubunits, which are constitutively expressed by APCs and are induced in other cell types by exposure to cytokines. The assembly of mixed proteasomes containing standard subunits and immunosubunits is regulated in a tissue specific manner. In this study, we report that the presence of mixed proteasomes in immune cells in LMP2(-/-) mice compromises multiple components that contribute to the generation of antiviral Ab responses, including splenic B cell numbers, survival and function of adoptively transferred B cells, Th cell function, and dendritic cell secretion of IL-6, TNF-alpha, IL-1beta, and type I IFNs. These defects did not result from compromised overall protein degradation, rather they were associated with altered NF-kappaB activity. These findings demonstrate an important role for immunoproteasomes in immune cell function beyond their contribution to Ag processing.
Collapse
Affiliation(s)
- Scott E Hensley
- Laboratory of Viral Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
30
|
Groettrup M, Kirk CJ, Basler M. Proteasomes in immune cells: more than peptide producers? Nat Rev Immunol 2009; 10:73-8. [PMID: 20010787 DOI: 10.1038/nri2687] [Citation(s) in RCA: 256] [Impact Index Per Article: 17.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
When cells are stimulated with pro-inflammatory cytokines, most of their constitutively expressed proteasomes are replaced with immunoproteasomes, which increase the production of peptides for presentation on MHC class I molecules. In addition, cortical thymic epithelial cells selectively express a type of proteasome known as the thymoproteasome that is required for the positive selection of thymocytes. Here, we discuss how these specialized types of proteasome shape the T cell receptor repertoire of cytotoxic T lymphocytes and propose that immunoproteasomes have functions, in addition to antigen processing, that influence cytokine production and T cell differentiation, survival and function. We also discuss how inhibitors of immunoproteasomes can suppress undesired T cell responses in autoimmune diseases.
Collapse
Affiliation(s)
- Marcus Groettrup
- Division of Immunology, Department of Biology, University of Constance, Konstanz, Germany.
| | | | | |
Collapse
|
31
|
Kimura HJ, Chen CY, Tzou SC, Rocchi R, Landek-Salgado MA, Suzuki K, Kimura M, Rose NR, Caturegli P. Immunoproteasome overexpression underlies the pathogenesis of thyroid oncocytes and primary hypothyroidism: studies in humans and mice. PLoS One 2009; 4:e7857. [PMID: 19924240 PMCID: PMC2773418 DOI: 10.1371/journal.pone.0007857] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2009] [Accepted: 10/14/2009] [Indexed: 01/27/2023] Open
Abstract
Background Oncocytes of the thyroid gland (Hürthle cells) are found in tumors and autoimmune diseases. They have a unique appearance characterized by abundant granular eosinophilic cytoplasm and hyperchromatic nucleus. Their pathogenesis has remained, thus far, unknown. Methodology/Principal Findings Using transgenic mice chronically expressing IFNγ in thyroid gland, we showed changes in the thyroid follicular epithelium reminiscent of the human oncocyte. Transcriptome analysis comparing transgenic to wild type thyrocytes revealed increased levels of immunoproteasome subunits like LMP2 in transgenics, suggesting an important role of the immunoproteasome in oncocyte pathogenesis. Pharmacologic blockade of the proteasome, in fact, ameliorated the oncocytic phenotype. Genetic deletion of LMP2 subunit prevented the development of the oncocytic phenotype and primary hypothyroidism. LMP2 was also found expressed in oncocytes from patients with Hashimoto thyroiditis and Hürthle cell tumors. Conclusions/Significance In summary, we report that oncocytes are the result of an increased immunoproteasome expression secondary to a chronic inflammatory milieu, and suggest LMP2 as a novel therapeutic target for the treatment of oncocytic lesions and autoimmune hypothyroidism.
Collapse
Affiliation(s)
- Hiroaki J. Kimura
- Department of Pathology, The Johns Hopkins School of Medicine, Baltimore, Maryland, United States of America
| | - Cindy Y. Chen
- Department of Pathology, The Johns Hopkins School of Medicine, Baltimore, Maryland, United States of America
| | - Shey-Cherng Tzou
- Department of Pathology, The Johns Hopkins School of Medicine, Baltimore, Maryland, United States of America
| | - Roberto Rocchi
- Department of Pathology, The Johns Hopkins School of Medicine, Baltimore, Maryland, United States of America
| | - Melissa A. Landek-Salgado
- Department of Pathology, The Johns Hopkins School of Medicine, Baltimore, Maryland, United States of America
| | - Koichi Suzuki
- Department of Bioregulation, Leprosy Research Center, National Institute of Infectious Diseases, Tokyo, Japan
| | - Miho Kimura
- Department of Pathology, The Johns Hopkins School of Medicine, Baltimore, Maryland, United States of America
| | - Noel R. Rose
- Department of Pathology, The Johns Hopkins School of Medicine, Baltimore, Maryland, United States of America
- Feinstone Department of Molecular Microbiology and Immunology, The Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, United States of America
| | - Patrizio Caturegli
- Department of Pathology, The Johns Hopkins School of Medicine, Baltimore, Maryland, United States of America
- Feinstone Department of Molecular Microbiology and Immunology, The Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, United States of America
- * E-mail:
| |
Collapse
|
32
|
Muchamuel T, Basler M, Aujay MA, Suzuki E, Kalim KW, Lauer C, Sylvain C, Ring ER, Shields J, Jiang J, Shwonek P, Parlati F, Demo SD, Bennett MK, Kirk CJ, Groettrup M. A selective inhibitor of the immunoproteasome subunit LMP7 blocks cytokine production and attenuates progression of experimental arthritis. Nat Med 2009; 15:781-7. [PMID: 19525961 DOI: 10.1038/nm.1978] [Citation(s) in RCA: 465] [Impact Index Per Article: 31.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2009] [Accepted: 04/29/2009] [Indexed: 01/11/2023]
Abstract
The immunoproteasome, a distinct class of proteasome found predominantly in monocytes and lymphocytes, is known to shape the antigenic repertoire presented on class I major histocompatibility complexes (MHC-I). However, a specific role for the immunoproteasome in regulating other facets of immune responses has not been established. We describe here the characterization of PR-957, a selective inhibitor of low-molecular mass polypeptide-7 (LMP7, encoded by Psmb8), the chymotrypsin-like subunit of the immunoproteasome. PR-957 blocked presentation of LMP7-specific, MHC-I-restricted antigens in vitro and in vivo. Selective inhibition of LMP7 by PR-957 blocked production of interleukin-23 (IL-23) by activated monocytes and interferon-gamma and IL-2 by T cells. In mouse models of rheumatoid arthritis, PR-957 treatment reversed signs of disease and resulted in reductions in cellular infiltration, cytokine production and autoantibody levels. These studies reveal a unique role for LMP7 in controlling pathogenic immune responses and provide a therapeutic rationale for targeting LMP7 in autoimmune disorders.
Collapse
|
33
|
Human immunodeficiency virus type 1 Gag p24 alters the composition of immunoproteasomes and affects antigen presentation. J Virol 2009; 83:7049-61. [PMID: 19403671 DOI: 10.1128/jvi.00327-09] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Proteasomes are the major source of proteases responsible for the generation of peptides bound to major histocompatibility complex class I molecules. Antigens, adjuvants, and cytokines can modulate the composition and enzymatic activity of proteasomes and thus alter the epitopes generated. In the present study, we examined the effect of human immunodeficiency virus type 1 (HIV-1) p24 on proteasomes from a dendritic cell line (JAWS II), from a macrophage cell line (C2.3), and from murine primary bone marrow-derived macrophages and dendritic cells. HIV-1 p24 downregulated PA28beta and the beta2i subunit of the immunoproteasome complex in JAWS II cells but did not decrease the immunoproteasome subunits in macrophages, whereas in primary dendritic cells, PA28alpha, beta2i, and beta5i were downregulated. Exposure of JAWS II cells and primary dendritic cells to HIV-1 p24 for 90 min significantly decreased the presentation of ovalbumin to a SIINFEKL-specific CD8(+) T-cell hybridoma. The decrease in antigen presentation and the downmodulation of the immunoproteasome subunits in JAWS II cells and primary dendritic cells could be overcome by pretreating the cells with gamma interferon for 6 h or by exposing the cells to HIV-1 p24 encapsulated in liposomes containing lipid A. These results suggest that early antigen processing kinetics could influence the immunogenicity of CD8(+) T-cell epitopes generated.
Collapse
|
34
|
Abstract
Proteasomal degradation of intracellular proteins facilitates the recognition of foreign proteins through interactions with major histocompatibility complex molecules presented to T cells. Interferon-gamma enhances the efficiency of this antigen presentation process by inducing a switch of proteasome to immunoproteasome catalytic subunits. The finding that immunoproteasomes are upregulated in IgA nephropathy may prompt further exploration of the role and mechanism of proteasome activation and intensify the quest for infectious agents that may induce IgA nephritis.
Collapse
|
35
|
Pang KC, Sanders MT, Monaco JJ, Doherty PC, Turner SJ, Chen W. Immunoproteasome subunit deficiencies impact differentially on two immunodominant influenza virus-specific CD8+ T cell responses. THE JOURNAL OF IMMUNOLOGY 2007; 177:7680-8. [PMID: 17114438 DOI: 10.4049/jimmunol.177.11.7680] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Primary CD8+ T cell (T(CD8+)) responses to viruses are directed toward multiple Ags and shaped by both the level of Ag presentation and the underlying Ag-specific T(CD8+) repertoire. The relative importance of these factors in deciding the hierarchy of T(CD8+) responses and how they are influenced by the immunoproteasome are not well understood. Using an influenza infection model in mice deficient in various immunoproteasome subunits, we observe that Ag presentation and T(CD8+) repertoire are altered in an epitope-specific and immunoproteasome subunit-dependent manner. More importantly, we find that the level of Ag presentation and the extent of the underlying repertoire can work either alone or in concert to determine definitively the magnitude of the individual T(CD8+) responses and hence the overall T(CD8+) hierarchy. Together, these results provide a clearer understanding of how immunodominance hierarchies are established.
Collapse
Affiliation(s)
- Ken C Pang
- T Cell Laboratory, Melbourne Centre for Clinical Sciences, Ludwig Institute for Cancer Research, Austin Health, Heidelberg, Victoria 3084, Australia
| | | | | | | | | | | |
Collapse
|
36
|
Strehl B, Joeris T, Rieger M, Visekruna A, Textoris-Taube K, Kaufmann SHE, Kloetzel PM, Kuckelkorn U, Steinhoff U. Immunoproteasomes are essential for clearance of Listeria monocytogenes in nonlymphoid tissues but not for induction of bacteria-specific CD8+ T cells. THE JOURNAL OF IMMUNOLOGY 2006; 177:6238-44. [PMID: 17056553 DOI: 10.4049/jimmunol.177.9.6238] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Microbial infections induce the replacement of constitutive proteasomes by immunoproteasomes (I-proteasomes). I-proteasomes support efficient generation of MHC class I epitopes and influence immunodominance hierarchies of CD8(+) T cells. Recently, the function of I-proteasomes in antimicrobial responses was challenged by showing that the lack of I-proteasomes has no effect on induction and function of lymphocytic choriomeningitis virus-specific CD8(+) T cells. Here, we show that infection with Listeria monocytogenes rapidly induces I-proteasomes in nonlymphoid tissues, which leads to enhanced generation of protection relevant CD8(+) T cell epitopes. I-proteasome-deficient mice (beta5i(-/-) mice) exhibited normal frequencies of L. monocytogenes-specific CD8(+) T cells. However, clearance of L. monocytogenes in liver but not spleen was significantly impaired in I-proteasome-deficient mice. In summary, our studies demonstrate that induction of I-proteasomes is required for CD8(+) T cell-mediated elimination of L. monocytogenes from nonlymphoid but not lymphoid tissues.
Collapse
Affiliation(s)
- Britta Strehl
- Institut für Biochemie, Charité-Universitätsmedizin, Berlin, Germany
| | | | | | | | | | | | | | | | | |
Collapse
|
37
|
Robek MD, Garcia ML, Boyd BS, Chisari FV. Role of immunoproteasome catalytic subunits in the immune response to hepatitis B virus. J Virol 2006; 81:483-91. [PMID: 17079320 PMCID: PMC1797445 DOI: 10.1128/jvi.01779-06] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Inhibition of hepatitis B virus (HBV) replication and viral clearance from an infected host requires both the innate and adaptive immune responses. Expression of interferon (IFN)-inducible proteasome catalytic and regulatory subunits correlates with the IFN-alpha/beta- and IFN-gamma-mediated noncytopathic inhibition of HBV in transgenic mice and hepatocytes, as well as with clearance of the virus in acutely infected chimpanzees. The immunoproteasome catalytic subunits LMP2 and LMP7 alter proteasome specificity and influence the pool of peptides available for presentation by major histocompatibility complex class I molecules. We found that these subunits influenced both the magnitude and specificity of the CD8 T-cell response to the HBV polymerase and envelope proteins in immunized HLA-A2-transgenic mice. We also examined the role of LMP2 and LMP7 in the IFN-alpha/beta- and IFN-gamma-mediated inhibition of virus replication using HBV transgenic mice and found that they do not play a direct role in this process. These results demonstrate the ability of the IFN-induced proteasome catalytic subunits to shape the HBV-specific CD8 T-cell response and thus potentially influence the progression of infection to acute or chronic disease. In addition, these studies identify a potential key role for IFN in regulating the adaptive immune response to HBV through alterations in viral antigen processing.
Collapse
Affiliation(s)
- Michael D Robek
- Department of Pathology, Yale University School of Medicine, New Haven, CT 06510, USA.
| | | | | | | |
Collapse
|
38
|
Masopust D, Ha SJ, Vezys V, Ahmed R. Stimulation History Dictates Memory CD8 T Cell Phenotype: Implications for Prime-Boost Vaccination. THE JOURNAL OF IMMUNOLOGY 2006; 177:831-9. [PMID: 16818737 DOI: 10.4049/jimmunol.177.2.831] [Citation(s) in RCA: 246] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Heterologous prime-boost vaccination results in increased frequencies of memory T cells. Although these quantitative effects of reexposure to Ag are well documented, little is known about the impact of boosting on the functional qualities of memory T cells. To address this critical issue, we have used three different types of immunization regimens and examined how boosting effects the function and anatomic location of memory CD8 T cells. We found that memory T cell phenotype differed substantially depending on the number of immunizations and that secondary and tertiary responses resulted in the generation of memory CD8 T cells that retained effector-like properties and showed preferential accumulation in nonlymphoid tissues. These results show that memory differentiation is coupled to the history of Ag experience and that prime-boost vaccination strategies have important consequences on memory CD8 T cell quality and surveillance within mucosal tissues.
Collapse
Affiliation(s)
- David Masopust
- Emory Vaccine Center and Department of Microbiology and Immunology, Emory University School of Medicine, 1510 Clifton Road, Atlanta, GA 30322, USA.
| | | | | | | |
Collapse
|
39
|
York IA, Brehm MA, Zendzian S, Towne CF, Rock KL. Endoplasmic reticulum aminopeptidase 1 (ERAP1) trims MHC class I-presented peptides in vivo and plays an important role in immunodominance. Proc Natl Acad Sci U S A 2006; 103:9202-7. [PMID: 16754858 PMCID: PMC1482590 DOI: 10.1073/pnas.0603095103] [Citation(s) in RCA: 157] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
CD8(+) T cells respond to short peptides bound to MHC class I molecules. Although most antigenic proteins contain many sequences that could bind to MHC class I, few of these peptides actually stimulate CD8(+) T cell responses. Moreover, the T cell responses that are generated often follow a very reproducible hierarchy to different peptides for reasons that are poorly understood. We find that the loss of a single enzyme, endoplasmic reticulum aminopeptidase 1 (ERAP1), in the antigen-processing pathway results in a marked shift in the hierarchy of immunodominance in viral infections, even when the responding T cells have the same T cell receptor repertoire. In mice, ERAP1 is the major enzyme that trims precursor peptides in the endoplasmic reticulum and, in this process, can generate or destroy antigenic peptides. Consequently, when ERAP1 is lost, the immune response to some viral peptides is reduced, to others increased, and to yet others unchanged. Therefore, many epitopes must be initially generated as precursors that are normally trimmed by ERAP1 before binding to MHC class I, whereas others are normally degraded by ERAP1 to lengths that are too short to bind to MHC class I. Moreover, peptide trimming and the resulting abundance of peptide-MHC complexes are dominant factors in establishing immunodominance.
Collapse
Affiliation(s)
- Ian A York
- Department of Pathology, University of Massachusetts Medical School, 55 Lake Avenue North, Worcester, MA 01655, USA.
| | | | | | | | | |
Collapse
|
40
|
Osterloh P, Linkemann K, Tenzer S, Rammensee HG, Radsak MP, Busch DH, Schild H. Proteasomes shape the repertoire of T cells participating in antigen-specific immune responses. Proc Natl Acad Sci U S A 2006; 103:5042-7. [PMID: 16549793 PMCID: PMC1458791 DOI: 10.1073/pnas.0509256103] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Differences in the cleavage specificities of constitutive proteasomes and immunoproteasomes significantly affect the generation of MHC class I ligands and therefore the activation of CD8-positive T cells. Based on these findings, we investigated whether proteasomal specificity also influences CD8-positive T cells during thymic selection by peptides derived from self proteins. We find that one of the self peptides responsible for positive selection of ovalbumin-specific OT-1 T cells, which is derived from the f-actin capping protein (Cpalpha1), is efficiently generated only by immunoproteasomes. Furthermore, OT-1 mice backcrossed onto low molecular mass protein 7 (LMP7)-deficient mice show a 50% reduction of OT-1 cells. This deficiency is also observed after transfer of BM from OT-1 mice in LMP7-deficient mice and can be corrected by the injection of the Cpalpha1 peptide. Interestingly, WT and LMP7-deficient mice mount comparable immune responses to the ovalbumin-derived epitope SIINFEKL. However, their cytotoxic T lymphocytes (CTL) differ in the use of T cell receptor Vbeta genes. CTL derived from WT mice use Vbeta8 or Vbeta5 (the latter is also used by OT-1 cells), whereas SIINFEKL-specific CTL from LMP7-deficient mice are exclusively Vbeta8-positive. Taken together, our experiments provide strong evidence that proteasomal specificity shapes the repertoire of T cells participating in antigen-specific immune responses.
Collapse
Affiliation(s)
- Philipp Osterloh
- *Institute of Immunology, University of Mainz, Obere Zahlbacherstrasse 67, 55131 Mainz, Germany
| | - Kathrin Linkemann
- Institute for Medical Microbiology, Immunology, and Hygiene, Technical University of Munich, Trogerstrasse 9, D-81675 Munich, Germany; and
- Clinical Cooperation Group, Antigen Specific Immunotherapy, GSF, Institute of Health and Environment and Technical University of Munich, D-81675 Munich, Germany
| | - Stefan Tenzer
- *Institute of Immunology, University of Mainz, Obere Zahlbacherstrasse 67, 55131 Mainz, Germany
| | - Hans-Georg Rammensee
- Institute for Cell Biology, Department of Immunology, University of Tübingen, Auf der Morgenstelle 15, 72076 Tübingen, Germany
| | - Markus P. Radsak
- *Institute of Immunology, University of Mainz, Obere Zahlbacherstrasse 67, 55131 Mainz, Germany
| | - Dirk H. Busch
- Institute for Medical Microbiology, Immunology, and Hygiene, Technical University of Munich, Trogerstrasse 9, D-81675 Munich, Germany; and
- Clinical Cooperation Group, Antigen Specific Immunotherapy, GSF, Institute of Health and Environment and Technical University of Munich, D-81675 Munich, Germany
| | - Hansjörg Schild
- *Institute of Immunology, University of Mainz, Obere Zahlbacherstrasse 67, 55131 Mainz, Germany
- To whom correspondence should be addressed. E-mail:
| |
Collapse
|