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Nelke C, Spatola M, Schroeter CB, Wiendl H, Lünemann JD. Neonatal Fc Receptor-Targeted Therapies in Neurology. Neurotherapeutics 2022; 19:729-740. [PMID: 34997443 PMCID: PMC9294083 DOI: 10.1007/s13311-021-01175-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/21/2021] [Indexed: 12/23/2022] Open
Abstract
Autoantibodies are increasingly recognized for their pathogenic potential in a growing number of neurological diseases. While myasthenia gravis represents the prototypic antibody (Ab)-mediated neurological disease, many more disorders characterized by Abs targeting neuronal or glial antigens have been identified over the past two decades. Depletion of humoral immune components including immunoglobulin G (IgG) through plasma exchange or immunoadsorption is a successful therapeutic strategy in most of these disease conditions. The neonatal Fc receptor (FcRn), primarily expressed by endothelial and myeloid cells, facilitates IgG recycling and extends the half-life of IgG molecules. FcRn blockade prevents binding of endogenous IgG to FcRn, which forces these antibodies into lysosomal degradation, leading to IgG depletion. Enhancing the degradation of endogenous IgG by FcRn-targeted therapies proved to be a powerful therapeutic approach in patients with generalized MG and is currently being tested in clinical trials for several other neurological diseases including autoimmune encephalopathies, neuromyelitis optica spectrum disorders, and inflammatory neuropathies. This review illustrates mechanisms of FcRn-targeted therapies and appraises their potential to treat neurological diseases.
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Affiliation(s)
- Christopher Nelke
- Department of Neurology, Medical Faculty, Heinrich Heine University Düsseldorf, Dusseldorf, Germany
| | - Marianna Spatola
- MIT and Harvard Medical School, Ragon Institute of MGH, Cambridge, MA, USA
| | - Christina B Schroeter
- Department of Neurology, Medical Faculty, Heinrich Heine University Düsseldorf, Dusseldorf, Germany
| | - Heinz Wiendl
- Department of Neurology With Institute of Translational Neurology, University Hospital Münster, Munster, Germany
| | - Jan D Lünemann
- Department of Neurology With Institute of Translational Neurology, University Hospital Münster, Munster, Germany.
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Benitez JC, Besse B. Narrative review of immunotherapy in thymic malignancies. Transl Lung Cancer Res 2021; 10:3001-3013. [PMID: 34295693 PMCID: PMC8264314 DOI: 10.21037/tlcr-20-1222] [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: 12/01/2020] [Accepted: 06/07/2021] [Indexed: 12/11/2022]
Abstract
Thymomas and thymic carcinomas (TCs) (also known as Thymic Epithelial Tumors or TETs) are rare cancers and the most frequent masses of the anterior mediastinum. These tumors appear in the epithelial component of the thymus, a primary lymphoid organ, and they have reported a high risk of auto-immunity due to a unique biology. Indeed, up to 30% of patients with TETs could present an autoimmune disorder (AID), the most frequent being Myasthenia Gravis (MG). Moreover, AIDs have been reported not only at tumor diagnosis but before and during the follow-up. These tumors have a lack of specific therapeutic targets for metastatic setting. Immune checkpoint inhibitors (ICI) may defeat cancer cells' capacity to evade the immune system and proliferate. The long-term benefit of ICIs in the metastatic setting in several tumors, such as melanoma or non-small cell lung cancer (NSCLC), let to evaluate ICI approaches in TETs. The high rate of AIDs and distribution of autoimmune events among TET's histological subtypes may have an influence on the decision regarding a treatment based on ICI due to the increased risk of toxicity. We summarize the current evidence for the efficacy of ICI in thymoma and TC and discuss several unresolved challenges and concerns for the use of this agents in TETs.
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Affiliation(s)
| | - Benjamin Besse
- Gustave Roussy, Department of Cancer Medicine, Villejuif, France.,Université Paris-Saclay, Orsay, France
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Zouvelou V, Michail M, Belimezi M, Zisimopoulou P. Subunit specificity of the acetylcholine receptor antibodies in double seropositive myasthenia gravis. Muscle Nerve 2021; 63:E36-E37. [PMID: 33471417 DOI: 10.1002/mus.27177] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Revised: 01/10/2021] [Accepted: 01/16/2021] [Indexed: 11/06/2022]
Affiliation(s)
- Vasiliki Zouvelou
- 1st Department of Neurology, Eginition Hospital, National and Kapodistrian University of Athens, Athens, Greece
| | - Maria Michail
- Laboratory of Molecular Neurobiology and Immunology, Hellenic Pasteur Institute, Athens, Greece
| | - Maria Belimezi
- Diagnostic Department, Hellenic Pasteur Institute, Athens, Greece
| | - Paraskevi Zisimopoulou
- Laboratory of Molecular Neurobiology and Immunology, Hellenic Pasteur Institute, Athens, Greece
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Guo F, Wang C, Wang S, Zhang J, Yan Y, Guan Z, Meng F. Alteration in gene expression profile of thymomas with or without myasthenia gravis linked with the nuclear factor-kappaB/autoimmune regulator pathway to myasthenia gravis pathogenesis. Thorac Cancer 2019; 10:564-570. [PMID: 30734484 PMCID: PMC6397909 DOI: 10.1111/1759-7714.12980] [Citation(s) in RCA: 5] [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: 09/26/2018] [Revised: 12/26/2018] [Accepted: 12/27/2018] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND To investigate the gene expression profile of a set of candidate genes for a better understanding of the molecular mechanism underlying the pathogenesis of thymoma with or without myasthenia gravis. METHODS Thymoma patients and thymoma patients with myasthenia gravis were analyzed using microarray profiling to identify significant changes in gene expression of autoimmune regulator pathway genes including AIRE, IL-7R, CHRNA3, SYMD1, THRA, and CAV3. RESULTS Across all of our samples, we found that 1484 mRNAs were upregulated and 770 were downregulated in thymoma patients compared with thymoma with myasthenia gravis patients. Gene ontology and pathway analysis revealed that a large number of genes participated in cellular functions for humoral immune response, sequence-specific DNA binding RNA polymerase II transcription factor activity, positive regulation of gene expression, regulation of neuron projection development, extracellular ligand-gated ion channel activity, positive regulation of striated muscle cell differentiation, and regulation of nuclear factor-kappaB import into the nucleus. CONCLUSION Our results revealed genetic differences between thymomas and myasthenia gravis, and identified the key candidate genes/pathways for molecular mechanism.
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Affiliation(s)
- Feng Guo
- Department of Endoscopy, Key Laboratory of Cancer Prevention and TherapyTianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Tianjin's Clinical Research Center for CancerTianjinChina
| | - Chun‐Yang Wang
- Department of NeurologyTianjin Medical University General HospitalTianjinChina
| | - Shuo Wang
- Department of Thoracic SurgeryThe Second Hospital of Tianjin Medical UniversityTianjinChina
| | - Jun Zhang
- Department of Thoracic SurgeryThe Second Hospital of Tianjin Medical UniversityTianjinChina
| | - Yi‐Jie Yan
- Department of Thoracic SurgeryThe Second Hospital of Tianjin Medical UniversityTianjinChina
| | - Zhi‐Yu Guan
- Department of Thoracic SurgeryThe Second Hospital of Tianjin Medical UniversityTianjinChina
| | - Fan‐Jie Meng
- Department of Thoracic SurgeryThe Second Hospital of Tianjin Medical UniversityTianjinChina
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Heterogeneity of auto-antibodies against nAChR in myasthenic serum and their pathogenic roles in experimental autoimmune myasthenia gravis. J Neuroimmunol 2018; 320:64-75. [PMID: 29759142 DOI: 10.1016/j.jneuroim.2018.04.014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2018] [Revised: 04/23/2018] [Accepted: 04/23/2018] [Indexed: 11/20/2022]
Abstract
Many myasthenia gravis (MG) patients have auto-antibodies against the nicotinic acetylcholine receptor (nAChR), and monoclonal antibodies against the main immunogenic region (MIR) of nAChR can induce experimental autoimmune MG (EAMG). We investigated whether Fab fragment of MIR antibody (Fab35) could block the pathogenicity of polyclonal antibodies. Fab35 partially inhibited nAChR downmodulation, blocked EAMG serum-induced binding of polyclonal antibodies and complement deposition in vitro. Moreover, Fab35 did not ameliorate the EAMG serum-induced EAMG phenotype in rats. These results suggested that the EAMG serum possessed several different pathogenic antibodies that might be sufficient to induce the EAMG phenotype.
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Wang S, Breskovska I, Gandhy S, Punga AR, Guptill JT, Kaminski HJ. Advances in autoimmune myasthenia gravis management. Expert Rev Neurother 2018; 18:573-588. [PMID: 29932785 PMCID: PMC6289049 DOI: 10.1080/14737175.2018.1491310] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
INTRODUCTION Myasthenia gravis (MG) is an autoimmune neuromuscular disorder with no cure and conventional treatments limited by significant adverse effects and variable benefit. In the last decade, therapeutic development has expanded based on improved understanding of autoimmunity and financial incentives for drug development in rare disease. Clinical subtypes exist based on age, gender, thymic pathology, autoantibody profile, and other poorly defined factors, such as genetics, complicate development of specific therapies. Areas covered: Clinical presentation and pathology vary considerably among patients with some having weakness limited to the ocular muscles and others having profound generalized weakness leading to respiratory insufficiency. MG is an antibody-mediated disorder dependent on autoreactive B cells which require T-cell support. Treatments focus on elimination of circulating autoantibodies or inhibition of effector mechanisms by a broad spectrum of approaches from plasmapheresis to B-cell elimination to complement inhibition. Expert commentary: Standard therapies and those under development are disease modifying and not curative. As a rare disease, clinical trials are challenged in patient recruitment. The great interest in development of treatments specific for MG is welcome, but decisions will need to be made to focus on those that offer significant benefits to patients.
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Affiliation(s)
- Shuhui Wang
- Department of Neurology, George Washington University, Washington DC 20008
| | - Iva Breskovska
- Department of Neurology, George Washington University, Washington DC 20008
| | - Shreya Gandhy
- Department of Neurology, George Washington University, Washington DC 20008
| | - Anna Rostedt Punga
- Department of Neuroscience, Clinical Neurophysiology, Uppsala University, Uppsala, Sweden
| | - Jeffery T. Guptill
- Department of Neurology, Duke University Medical Center, Durham, North Carolina, USA
| | - Henry J. Kaminski
- Department of Neurology, George Washington University, Washington DC 20008
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Luo J, Lindstrom J. Acetylcholine receptor-specific immunosuppressive therapy of experimental autoimmune myasthenia gravis and myasthenia gravis. Ann N Y Acad Sci 2018; 1413:76-81. [PMID: 29377167 DOI: 10.1111/nyas.13550] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Revised: 10/13/2017] [Accepted: 10/18/2017] [Indexed: 12/14/2022]
Abstract
Experimental autoimmune myasthenia gravis (EAMG) and myasthenia gravis (MG) are caused by autoantibodies to the extracellular domain of muscle nicotinic acetylcholine receptors (AChRs). Autoantibodies to the cytoplasmic domain of AChRs do not cause EAMG because they cannot bind AChRs in vivo. The ideal MG therapy would quickly and permanently suppress only the pathological autoimmune response to AChRs. We have developed a specific immunosuppressive therapy for EAMG that involves immunizing rats with bacterially expressed cytoplasmic domains of human muscle AChRs. Therapy prevents onset of chronic EAMG, rapidly suppresses ongoing EAMG, and is potent, robust, long lasting, and safe, because the therapeutic antigen cannot induce EAMG. The therapy was developed using incomplete Freund's adjuvant, but is likely to work equally well with alum adjuvants routinely used for human immunizations. Therapeutic mechanisms may involve a combination of antibody-mediated feedback suppression and regulatory T and/or B lymphocytes.
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Affiliation(s)
- Jie Luo
- Department of Clinical Sciences and Advanced Medicine, University of Pennsylvania School of Veterinary Medicine, Philadelphia, Pennsylvania
| | - Jon Lindstrom
- Department of Neuroscience, Medical School of the University of Pennsylvania, Philadelphia, Pennsylvania
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Lin Y, Song C, Xu J, Yang Y, Qin H, Zhao C, Lin J, Liu R, Li Z. Irrelevance of anti-nAChR cytoplasmic loop antibody in the degree of myasthenia gravis. Int J Mol Med 2017; 40:931-939. [DOI: 10.3892/ijmm.2017.3074] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2016] [Accepted: 07/10/2017] [Indexed: 11/05/2022] Open
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Melzer N, Ruck T, Fuhr P, Gold R, Hohlfeld R, Marx A, Melms A, Tackenberg B, Schalke B, Schneider-Gold C, Zimprich F, Meuth SG, Wiendl H. Clinical features, pathogenesis, and treatment of myasthenia gravis: a supplement to the Guidelines of the German Neurological Society. J Neurol 2016; 263:1473-94. [PMID: 26886206 PMCID: PMC4971048 DOI: 10.1007/s00415-016-8045-z] [Citation(s) in RCA: 148] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2015] [Revised: 01/20/2016] [Accepted: 01/21/2016] [Indexed: 01/20/2023]
Abstract
Myasthenia gravis (MG) is an autoimmune antibody-mediated disorder of neuromuscular synaptic transmission. The clinical hallmark of MG consists of fluctuating fatigability and weakness affecting ocular, bulbar and (proximal) limb skeletal muscle groups. MG may either occur as an autoimmune disease with distinct immunogenetic characteristics or as a paraneoplastic syndrome associated with tumors of the thymus. Impairment of central thymic and peripheral self-tolerance mechanisms in both cases is thought to favor an autoimmune CD4(+) T cell-mediated B cell activation and synthesis of pathogenic high-affinity autoantibodies of either the IgG1 and 3 or IgG4 subclass. These autoantibodies bind to the nicotinic acetylcholine receptor (AchR) itself, or muscle-specific tyrosine-kinase (MuSK), lipoprotein receptor-related protein 4 (LRP4) and agrin involved in clustering of AchRs within the postsynaptic membrane and structural maintenance of the neuromuscular synapse. This results in disturbance of neuromuscular transmission and thus clinical manifestation of the disease. Emphasizing evidence from clinical trials, we provide an updated overview on immunopathogenesis, and derived current and future treatment strategies for MG divided into: (a) symptomatic treatments facilitating neuromuscular transmission, (b) antibody-depleting treatments, and
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Affiliation(s)
- Nico Melzer
- Department of Neurology, University of Münster, Albert-Schweitzer-Campus 1, 48149 Münster, Germany
| | - Tobias Ruck
- Department of Neurology, University of Münster, Albert-Schweitzer-Campus 1, 48149 Münster, Germany
| | - Peter Fuhr
- Department of Neurology, University of Basel, Basel, Switzerland
| | - Ralf Gold
- Department of Neurology, University of Bochum, Bochum, Germany
| | - Reinhard Hohlfeld
- Institute of Clinical Neuroimmunology, Ludwig-Maximilians-University Munich, Munich, Germany
| | - Alexander Marx
- Institute of Pathology, University Medical Centre Mannheim, University of Heidelberg, Mannheim, Germany
| | - Arthur Melms
- Department of Neurology, University of Erlangen, Erlangen, Germany
| | - Björn Tackenberg
- Department of Neurology, University of Marburg, Marburg, Germany
| | - Berthold Schalke
- Department of Neurology, University of Regensburg, Regensburg, Germany
| | | | - Fritz Zimprich
- Department of Neurology, Medical University of Vienna, Vienna, Austria
| | - Sven G. Meuth
- Department of Neurology, University of Münster, Albert-Schweitzer-Campus 1, 48149 Münster, Germany
| | - Heinz Wiendl
- Department of Neurology, University of Münster, Albert-Schweitzer-Campus 1, 48149 Münster, Germany
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Kanduc D. Measles virus hemagglutinin epitopes are potential hotspots for crossreactions with immunodeficiency-related proteins. Future Microbiol 2016; 10:503-15. [PMID: 25865190 DOI: 10.2217/fmb.14.137] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
AIMS Measles virus (MV) infection induces a protective immunity that is accompanied by a transient pathologic suppression of the immune system. This immunologic paradox remains unexplained in spite of the numerous hypotheses that have been advanced (i.e., cytokine production, soluble immunosuppressive factor, cell cycle block, signaling lymphocyte activation molecule receptor and MV infection of dendritic cells, among others). METHODS Searching for molecular link(s) between MV infection and host immunodeficiency, this study used the Immune Epitope DataBase to analyze the peptide sharing between the antigenic MV hemagglutinin (H) protein and human proteins associated with immunodeficiency. RESULTS It was found that the majority of MVH derived epitopes share several exact pentapeptide sequences with numerous human proteins involved in immune functions and immunodeficiency, such as B- and T-cell antigens, and complement components. CONCLUSION The data suggest that crossreactivity might contribute to our understanding of the link between MV immunogenicity and MV-induced immunosuppression, and highlight peptides unique to MV as a basis for developing effective and safe anti-MV vaccines.
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Losen M, Martinez-Martinez P, Molenaar PC, Lazaridis K, Tzartos S, Brenner T, Duan RS, Luo J, Lindstrom J, Kusner L. Standardization of the experimental autoimmune myasthenia gravis (EAMG) model by immunization of rats with Torpedo californica acetylcholine receptors--Recommendations for methods and experimental designs. Exp Neurol 2015; 270:18-28. [PMID: 25796590 PMCID: PMC4466156 DOI: 10.1016/j.expneurol.2015.03.010] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2015] [Revised: 03/06/2015] [Accepted: 03/10/2015] [Indexed: 12/21/2022]
Abstract
Myasthenia gravis (MG) with antibodies against the acetylcholine receptor (AChR) is characterized by a chronic, fatigable weakness of voluntary muscles. The production of autoantibodies involves the dysregulation of T cells which provide the environment for the development of autoreactive B cells. The symptoms are caused by destruction of the postsynaptic membrane and degradation of the AChR by IgG autoantibodies, predominantly of the G1 and G3 subclasses. Active immunization of animals with AChR from mammalian muscles, AChR from Torpedo or Electrophorus electric organs, and recombinant or synthetic AChR fragments generates a chronic model of MG, termed experimental autoimmune myasthenia gravis (EAMG). This model covers cellular mechanisms involved in the immune response against the AChR, e.g. antigen presentation, T cell-help and regulation, B cell selection and differentiation into plasma cells. Our aim is to define standard operation procedures and recommendations for the rat EAMG model using purified AChR from the Torpedo californica electric organ, in order to facilitate more rapid translation of preclinical proof of concept or efficacy studies into clinical trials and, ultimately, clinical practice.
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Affiliation(s)
- Mario Losen
- Division Neuroscience, Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience, Maastricht University, Maastricht, The Netherlands.
| | - Pilar Martinez-Martinez
- Division Neuroscience, Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience, Maastricht University, Maastricht, The Netherlands
| | - Peter C Molenaar
- Division Neuroscience, Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience, Maastricht University, Maastricht, The Netherlands
| | | | - Socrates Tzartos
- Department of Neurobiology, Hellenic Pasteur Institute, Athens, Greece
| | - Talma Brenner
- Laboratory of Neuroimmunology, Department of Neurology, The Agnes Ginges Center for Human Neurogenetics, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - Rui-Sheng Duan
- Department of Neurology, Shandong Provincial Qianfoshan Hospital, Shandong University, PR China
| | - Jie Luo
- Department of Neuroscience, University of Pennsylvania Medical School, Philadelphia, PA, USA
| | - Jon Lindstrom
- Department of Neuroscience, University of Pennsylvania Medical School, Philadelphia, PA, USA
| | - Linda Kusner
- Department of Pharmacology & Physiology, The George Washington University, Washington, DC, USA
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Luo J, Lindstrom J. Antigen-specific immunotherapeutic vaccine for experimental autoimmune myasthenia gravis. THE JOURNAL OF IMMUNOLOGY 2014; 193:5044-55. [PMID: 25288571 DOI: 10.4049/jimmunol.1401392] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Myasthenia gravis (MG) and experimental autoimmune myasthenia gravis (EAMG) are caused by Ab-mediated autoimmune responses to muscle nicotinic acetylcholine receptors (AChRs) that impair neuromuscular transmission, thereby causing muscle weakness. Previously, we discovered that i.p. injection of a therapeutic vaccine consisting of bacterially expressed cytoplasmic domains of human AChR subunits reduced the development of chronic EAMG in rats. In this article, we show that immunization with the therapeutic vaccine in adjuvants does not induce EAMG and, thus, is safe. The potency and efficacy of the therapeutic vaccine were greatly increased by s.c. administration of repeated low doses in IFA. Onset of chronic EAMG could be prevented. Established chronic EAMG could be rapidly reversed, modeling therapy of chronic MG. Therapy reduced pathological Abs assayed by immune precipitation of a main immunogenic region chimera. Successfully treated rats exhibited long-term resistance to reinduction of EAMG, suggesting a lasting cure of MG. A long-term effect of therapy was to change the isotype of the pathogenic Ab response from IgG2b, which fixes complement, to IgG1, which does not. Prevention and reversal of chronic EAMG was not caused by the isotype switch, but the isotype switch may contribute to resistance to reinduction of EAMG. Immunization with AChR cytoplasmic domains in adjuvant is promising as a safe, Ag-specific, potent, effective, rapidly acting, and long-lasting therapeutic approach to MG.
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Affiliation(s)
- Jie Luo
- Department of Neuroscience, University of Pennsylvania Medical School, Philadelphia, PA 19104
| | - Jon Lindstrom
- Department of Neuroscience, University of Pennsylvania Medical School, Philadelphia, PA 19104
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Liu Y, Zhang H, Zhang P, Meng F, Chen Y, Wang Y, Yao Y, Qi B. Autoimmune regulator expression in thymomas with or without autoimmune disease. Immunol Lett 2014; 161:50-6. [PMID: 24768600 DOI: 10.1016/j.imlet.2014.04.008] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2014] [Revised: 04/10/2014] [Accepted: 04/11/2014] [Indexed: 11/21/2022]
Abstract
BACKGROUND The autoimmune regulator (AIRE) regulates autoimmunity and self-antigen expression, such as acetylcholine receptor (AchR), in the thymus. Regulatory T cells (Tregs) can down-regulate autoimmunity, but also promote tumor growth. The objective of this study was to examine the levels of AIRE, AchR, and Foxp3 expression in thymomas. METHODS The relative levels of AIRE, AchR, and Foxp3 mRNA transcripts and the frequency of AIRE+, AchR+, and Foxp3+ cells were determined by quantitative RT-PCR and immunohistochemistry in 79 thymoma tissue samples from 21 patients with simple thymoma (the Tm group), 39 patients with myasthenia gravis (the MG group) and 19 patients with myasthenia gravis and one other autoimmune disease (the AD group). The numbers of peripheral blood CD4+CD25+Foxp3+ Tregs were determined by flow cytometry analysis. RESULTS The relative levels of AIRE and AchR mRNA transcripts in the MG group were significantly lower than that in the Tm group (p=0.04, p=0.03), but higher than that in the AD group (p=0.03, p=0.04). The relative levels of Foxp3 mRNA transcripts in the Tm group were significantly higher than that in the MG and AD groups (p=0.03 for both). A similar pattern of the percentages of AIRE+, AchR+, and Foxp3+ cells in the thymoma tissues and the numbers of peripheral blood Tregs were detected in these patients. The levels of AIRE mRNA transcripts were correlated positively with that of the AchR and Foxp3 in this population. The levels of AIRE and AchR mRNA transcripts in the A/AB/B1 types of thymomas were significantly higher than that in the B2/B3/C types of thymomas in this population. CONCLUSION Significantly lower levels of AIRE, AchR, and Foxp3 expression are associated with the development of thymoma-related autoimmune diseases.
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Affiliation(s)
- Yimei Liu
- Department of Cardiothoracic Surgery General Hospital at Tianjin Medical University, No. 154, Anshan Road, Heping District, Tianjin300052 PR China
| | - Hui Zhang
- Department of Cardiothoracic Surgery General Hospital at Tianjin Medical University, No. 154, Anshan Road, Heping District, Tianjin300052 PR China
| | - Peng Zhang
- Department of Cardiothoracic Surgery General Hospital at Tianjin Medical University, No. 154, Anshan Road, Heping District, Tianjin300052 PR China.
| | - Fanjie Meng
- Department of Cardiothoracic Surgery General Hospital at Tianjin Medical University, No. 154, Anshan Road, Heping District, Tianjin300052 PR China
| | - Yuan Chen
- Department of Cardiothoracic Surgery General Hospital at Tianjin Medical University, No. 154, Anshan Road, Heping District, Tianjin300052 PR China
| | - Yuanguo Wang
- Department of Cardiothoracic Surgery General Hospital at Tianjin Medical University, No. 154, Anshan Road, Heping District, Tianjin300052 PR China
| | - Yuanyuan Yao
- Department of Cardiothoracic Surgery General Hospital at Tianjin Medical University, No. 154, Anshan Road, Heping District, Tianjin300052 PR China
| | - Bin Qi
- Department of Cardiothoracic Surgery General Hospital at Tianjin Medical University, No. 154, Anshan Road, Heping District, Tianjin300052 PR China
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Huijbers MG, Lipka AF, Plomp JJ, Niks EH, van der Maarel SM, Verschuuren JJ. Pathogenic immune mechanisms at the neuromuscular synapse: the role of specific antibody-binding epitopes in myasthenia gravis. J Intern Med 2014; 275:12-26. [PMID: 24215230 DOI: 10.1111/joim.12163] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Autoantibodies against three different postsynaptic antigens and one presynaptic antigen at the neuromuscular junction are known to cause myasthenic syndromes. The mechanisms by which these antibodies cause muscle weakness vary from antigenic modulation and complement-mediated membrane damage to inhibition of endogenous ligand binding and blocking of essential protein-protein interactions. These mechanisms are related to the autoantibody titre, specific epitopes on the target proteins and IgG autoantibody subclass. We here review the role of specific autoantibody-binding epitopes in myasthenia gravis, their possible relevance to the pathophysiology of the disease and potential implications of epitope mapping knowledge for new therapeutic strategies.
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Affiliation(s)
- M G Huijbers
- Department of Neurology, Leiden University Medical Center, Leiden, the Netherlands; Department of Human Genetics, Leiden University Medical Center, Leiden, the Netherlands
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Marx A, Pfister F, Schalke B, Saruhan-Direskeneli G, Melms A, Ströbel P. The different roles of the thymus in the pathogenesis of the various myasthenia gravis subtypes. Autoimmun Rev 2013; 12:875-84. [DOI: 10.1016/j.autrev.2013.03.007] [Citation(s) in RCA: 218] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/12/2013] [Indexed: 01/13/2023]
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Abstract
In myasthenia gravis (MG) and experimental autoimmune MG (EAMG), many pathologically significant autoantibodies are directed to the main immunogenic region (MIR) of muscle nicotinic acetylcholine receptors (AChRs), a conformation-dependent region at the extracellular tip of α1 subunits of AChRs. Human muscle AChR α1 MIR sequences were integrated into Aplesia ACh-binding protein (AChBP). The chimera potently induced EAMG, while AChBP induced EAMG much less potently. AChBP is a water-soluble protein resembling the extracellular domain of AChRs; yet, rats immunized with chimeras developed autoantibodies to both extracellular and cytoplasmic domains of muscle AChRs. We propose that an initial autoimmune response directed at the MIR leads to an autoimmune response sustained by muscle AChRs. Autoimmune stimulation sustained by endogenous muscle AChR may be a target for specific immunosuppression. These studies show that the α1 MIR is highly myasthenogenic, and that AChR-like proteins distantly related to muscle AChR can induce EAMG and, potentially, MG.
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Affiliation(s)
- Jon Lindstrom
- Department of Neuroscience, Medical School of the University of Pennsylvania, Philadelphia, 19104-6074, USA.
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