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Cavalcante P, Mantegazza R, Antozzi C. Targeting autoimmune mechanisms by precision medicine in Myasthenia Gravis. Front Immunol 2024; 15:1404191. [PMID: 38903526 PMCID: PMC11187261 DOI: 10.3389/fimmu.2024.1404191] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2024] [Accepted: 05/24/2024] [Indexed: 06/22/2024] Open
Abstract
Myasthenia Gravis (MG) is a chronic disabling autoimmune disease caused by autoantibodies to the neuromuscular junction (NMJ), characterized clinically by fluctuating weakness and early fatigability of ocular, skeletal and bulbar muscles. Despite being commonly considered a prototypic autoimmune disorder, MG is a complex and heterogeneous condition, presenting with variable clinical phenotypes, likely due to distinct pathophysiological settings related with different immunoreactivities, symptoms' distribution, disease severity, age at onset, thymic histopathology and response to therapies. Current treatment of MG based on international consensus guidelines allows to effectively control symptoms, but most patients do not reach complete stable remission and require life-long immunosuppressive (IS) therapies. Moreover, a proportion of them is refractory to conventional IS treatment, highlighting the need for more specific and tailored strategies. Precision medicine is a new frontier of medicine that promises to greatly increase therapeutic success in several diseases, including autoimmune conditions. In MG, B cell activation, antibody recycling and NMJ damage by the complement system are crucial mechanisms, and their targeting by innovative biological drugs has been proven to be effective and safe in clinical trials. The switch from conventional IS to novel precision medicine approaches based on these drugs could prospectively and significantly improve MG care. In this review, we provide an overview of key immunopathogenetic processes underlying MG, and discuss on emerging biological drugs targeting them. We also discuss on future direction of research to address the need for patients' stratification in endotypes according with genetic and molecular biomarkers for successful clinical decision making within precision medicine workflow.
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Affiliation(s)
- Paola Cavalcante
- Neurology 4 – Neuroimmunology and Neuromuscular Diseases Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Renato Mantegazza
- Neurology 4 – Neuroimmunology and Neuromuscular Diseases Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Carlo Antozzi
- Neurology 4 – Neuroimmunology and Neuromuscular Diseases Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
- Immunotherapy and Apheresis Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
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2
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Iorio R. Myasthenia gravis: the changing treatment landscape in the era of molecular therapies. Nat Rev Neurol 2024; 20:84-98. [PMID: 38191918 DOI: 10.1038/s41582-023-00916-w] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/06/2023] [Indexed: 01/10/2024]
Abstract
Myasthenia gravis (MG) is an autoimmune disorder that affects the neuromuscular junction, leading to muscle weakness and fatigue. MG is caused by antibodies against the acetylcholine receptor (AChR), the muscle-specific kinase (MuSK) or other AChR-related proteins that are expressed in the postsynaptic muscle membrane. The standard therapeutic approach for MG has relied on acetylcholinesterase inhibitors, corticosteroids and immunosuppressants, which have shown good efficacy in improving MG-related symptoms in most people with the disease; however, these therapies can carry a considerable burden of long-term adverse effects. Moreover, up to 15% of individuals with MG exhibit limited or no response to these standard therapies. The emergence of molecular therapies, including monoclonal antibodies, B cell-depleting agents and chimeric antigen receptor T cell-based therapies, has the potential to revolutionize the MG treatment landscape. This Review provides a comprehensive overview of the progress achieved in molecular therapies for MG associated with AChR antibodies and MuSK antibodies, elucidating both the challenges and the opportunities these therapies present to the field. The latest developments in MG treatment are described, exploring the potential for personalized medicine approaches.
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Affiliation(s)
- Raffaele Iorio
- Department of Neuroscience, Università Cattolica del Sacro Cuore, Rome, Italy.
- Neurology Unit, Fondazione Policlinico Universitario A. Gemelli IRCCS, Rome, Italy.
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3
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Crisafulli S, Boccanegra B, Carollo M, Bottani E, Mantuano P, Trifirò G, De Luca A. Myasthenia Gravis Treatment: From Old Drugs to Innovative Therapies with a Glimpse into the Future. CNS Drugs 2024; 38:15-32. [PMID: 38212553 DOI: 10.1007/s40263-023-01059-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 12/11/2023] [Indexed: 01/13/2024]
Abstract
Myasthenia gravis (MG) is a rare autoimmune disease that causes debilitating muscle weakness due to impaired neuromuscular transmission. Since most (about 80-90%) MG patients present autoantibodies against the acetylcholine receptor, standard medical therapy consists of symptomatic treatment with acetylcholinesterase inhibitors (e.g., pyridostigmine). In addition, considering the autoimmune basis of MG, standard therapy includes immunomodulating agents, such as corticosteroids, azathioprine, cyclosporine A, and cyclophosphamide. New strategies have been proposed for the treatment of MG and include complement blockade (i.e., eculizumab, ravulizumab, and zilucoplan) and neonatal Fc receptor antagonism (i.e., efgartigimod and rozanolixizumab). The aim of this review is to provide a detailed overview of the pre- and post-marketing evidence on the five pharmacological treatments most recently approved for the treatment of MG, by identifying both preclinical and clinical studies registered in clinicaltrials.gov. A description of the molecules currently under evaluation for the treatment of MG is also provided.
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Affiliation(s)
| | - Brigida Boccanegra
- Department of Pharmacy-Drug Sciences, University of Bari "Aldo Moro", Bari, Italy
| | - Massimo Carollo
- Department of Diagnostics and Public Health, University of Verona, P.le L.A. Scuro 10, 37124, Verona, Italy
| | - Emanuela Bottani
- Department of Diagnostics and Public Health, University of Verona, P.le L.A. Scuro 10, 37124, Verona, Italy
| | - Paola Mantuano
- Department of Pharmacy-Drug Sciences, University of Bari "Aldo Moro", Bari, Italy
| | - Gianluca Trifirò
- Department of Diagnostics and Public Health, University of Verona, P.le L.A. Scuro 10, 37124, Verona, Italy.
| | - Annamaria De Luca
- Department of Pharmacy-Drug Sciences, University of Bari "Aldo Moro", Bari, Italy
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4
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Huang EJC, Wu MH, Wang TJ, Huang TJ, Li YR, Lee CY. Myasthenia Gravis: Novel Findings and Perspectives on Traditional to Regenerative Therapeutic Interventions. Aging Dis 2023; 14:1070-1092. [PMID: 37163445 PMCID: PMC10389825 DOI: 10.14336/ad.2022.1215] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2022] [Accepted: 12/15/2022] [Indexed: 05/12/2023] Open
Abstract
The prevalence of myasthenia gravis (MG), an autoimmune disorder, is increasing among all subsets of the population leading to an elevated economic and social burden. The pathogenesis of MG is characterized by the synthesis of autoantibodies against the acetylcholine receptor (AChR), low-density lipoprotein receptor-related protein 4 (LRP4), or muscle-specific kinase at the neuromuscular junction, thereby leading to muscular weakness and fatigue. Based on clinical and laboratory examinations, the research is focused on distinguishing MG from other autoimmune, genetic diseases of neuromuscular transmission. Technological advancements in machine learning, a subset of artificial intelligence (AI) have been assistive in accurate diagnosis and management. Besides, addressing the clinical needs of MG patients is critical to improving quality of life (QoL) and satisfaction. Lifestyle changes including physical exercise and traditional Chinese medicine/herbs have also been shown to exert an ameliorative impact on MG progression. To achieve enhanced therapeutic efficacy, cholinesterase inhibitors, immunosuppressive drugs, and steroids in addition to plasma exchange therapy are widely recommended. Under surgical intervention, thymectomy is the only feasible alternative to removing thymoma to overcome thymoma-associated MG. Although these conventional and current therapeutic approaches are effective, the associated adverse events and surgical complexity limit their wide application. Moreover, Restivo et al. also, to increase survival and QoL, further recent developments revealed that antibody, gene, and regenerative therapies (such as stem cells and exosomes) are currently being investigated as a safer and more efficacious alternative. Considering these above-mentioned points, we have comprehensively reviewed the recent advances in pathological etiologies of MG including COVID-19, and its therapeutic management.
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Affiliation(s)
- Evelyn Jou-Chen Huang
- Department of Ophthalmology, Taipei Medical University Hospital, Taipei, Taiwan.
- Department of Ophthalmology, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan.
| | - Meng-Huang Wu
- Department of Orthopedics, Taipei Medical University Hospital, Taipei, Taiwan.
- Department of Orthopaedics, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan.
| | - Tsung-Jen Wang
- Department of Ophthalmology, Taipei Medical University Hospital, Taipei, Taiwan.
- Department of Ophthalmology, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan.
| | - Tsung-Jen Huang
- Department of Orthopedics, Taipei Medical University Hospital, Taipei, Taiwan.
- Department of Orthopaedics, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan.
| | - Yan-Rong Li
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Linkou Chang Gung Memorial Hospital and College of Medicine, Chang Gung University, Taoyuan, Taiwan.
| | - Ching-Yu Lee
- Department of Orthopedics, Taipei Medical University Hospital, Taipei, Taiwan.
- Department of Orthopaedics, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan.
- International PhD Program for Cell Therapy and Regeneration Medicine, College of Medicine, Taipei Medical University, Taipei 11031, Taiwan.
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5
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Ibtehaj N, Bahauddin A, Ivannikov M, Rytting E, Jamaluddin M, Liang Y, Sun J, Haller SL, Wu X, Huda R. B cell-specific mAb-siRNA conjugates improve experimental myasthenia. J Autoimmun 2023; 135:102983. [PMID: 36640636 DOI: 10.1016/j.jaut.2022.102983] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Accepted: 12/15/2022] [Indexed: 01/13/2023]
Abstract
Myasthenia gravis (MG) is a debilitating autoimmune disease characterized by muscle fatigue and weakness caused by autoantibody- and complement-mediated damage to the neuromuscular junction. This study sought to compare the efficacy of unique sets of monoclonal antibody-siRNA conjugates, individually (mono) or in combination (duo), against the crucial receptors predominantly or solely expressed on two subsets of B cells-plasma B cells and their precursor (transitional mature B) cells in a mouse model of MG. At the optimized doses, the conjugates, likely due to the combined activities of mAb and siRNA, substantially decreased the expression levels of CD268 (B cell-activating factor receptor) in mature B cells and CD269 (B-cell maturation antigen) in plasma cells concomitantly with reducing the levels of acetylcholine receptor (AChR)-specific autoantibodies. PEGylation, but not pretreatment with an antibody against type 1 interferon receptor, further improved duoconjugate-induced reduction in the autoantibody levels. Our results show that the duoconjugate treatment significantly improved the clinical symptoms of MG, consistent with the preservation of bungarotoxin-bound functional AChRs. In the future, developing similar target-specific combination molecules can potentially turn into a new and effective therapeutic approach for MG.
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Affiliation(s)
- Naazneen Ibtehaj
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX, United States
| | - Afrin Bahauddin
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX, United States
| | - Maxim Ivannikov
- Optical Microscopy Core, University of Texas Medical Branch, Galveston, TX, United States
| | - Erik Rytting
- Departments of Obstetrics & Gynecology and Pharmacology & Toxicology, University of Texas Medical Branch, Galveston, TX, United States
| | - Mohammad Jamaluddin
- Pediatric Infectious Diseases, University of Texas Medical Branch, Galveston, TX, United States
| | - Yuejin Liang
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX, United States
| | - Jiaren Sun
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX, United States
| | - Sherry L Haller
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX, United States
| | - Xiaorong Wu
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX, United States
| | - Ruksana Huda
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX, United States.
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6
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Complement Activation Profile in Myasthenia Gravis Patients: Perspectives for Tailoring Anti-Complement Therapy. Biomedicines 2022; 10:biomedicines10061360. [PMID: 35740382 PMCID: PMC9220000 DOI: 10.3390/biomedicines10061360] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Revised: 06/01/2022] [Accepted: 06/06/2022] [Indexed: 12/03/2022] Open
Abstract
The complement system plays a key role in myasthenia gravis (MG). Anti-complement drugs are emerging as effective therapies to treat anti-acetylcholine receptor (AChR) antibody-positive MG patients, though their usage is still limited by the high costs. Here, we searched for plasma complement proteins as indicators of complement activation status in AChR-MG patients, and potential biomarkers for tailoring anti-complement therapy in MG. Plasma was collected from AChR-MG and MuSK-MG patients, and healthy controls. Multiplex immunoassays and ELISA were used to quantify a panel of complement components (C1Q, C2, C3, C4, C5, Factor B, Factor H, MBL, and properdin) and activation products (C4b, C3b, C5a, and C5b-9), of classical, alternative and lectin pathways. C2 and C5 levels were significantly reduced, and C3, C3b, and C5a increased, in plasma of AChR-MG, but not MuSK-MG, patients compared to controls. This protein profile was indicative of complement activation. We obtained sensitivity and specificity performance results suggesting plasma C2, C3, C3b, and C5 as biomarkers for AChR-MG. Our findings reveal a plasma complement “C2, C3, C5, C3b, and C5a” profile associated with AChR-MG to be further investigated as a biomarker of complement activation status in AChR-MG patients, opening new perspectives for tailoring of anti-complement therapies to improve the disease treatment.
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7
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Novel treatment strategies for acetylcholine receptor antibody-positive myasthenia gravis and related disorders. Autoimmun Rev 2022; 21:103104. [PMID: 35452851 DOI: 10.1016/j.autrev.2022.103104] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Accepted: 04/18/2022] [Indexed: 11/21/2022]
Abstract
The presence of autoantibodies directed against the muscle nicotinic acetylcholine receptor (AChR) is the most common cause of myasthenia gravis (MG). These antibodies damage the postsynaptic membrane of the neuromuscular junction and cause muscle weakness by depleting AChRs and thus impairing synaptic transmission. As one of the best-characterized antibody-mediated autoimmune diseases, AChR-MG has often served as a reference model for other autoimmune disorders. Classical pharmacological treatments, including broad-spectrum immunosuppressive drugs, are effective in many patients. However, complete remission cannot be achieved in all patients, and 10% of patients do not respond to currently used therapies. This may be attributed to production of autoantibodies by long-lived plasma cells which are resistant to conventional immunosuppressive drugs. Hence, novel therapies specifically targeting plasma cells might be a suitable therapeutic approach for selected patients. Additionally, in order to reduce side effects of broad-spectrum immunosuppression, targeted immunotherapies and symptomatic treatments will be required. This review presents established therapies as well as novel therapeutic approaches for MG and related conditions, with a focus on AChR-MG.
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8
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Song J, Zhao R, Yan C, Luo S, Xi J, Ding P, Li L, Hu W, Zhao C. A Targeted Complement Inhibitor CRIg/FH Protects Against Experimental Autoimmune Myasthenia Gravis in Rats via Immune Modulation. Front Immunol 2022; 13:746068. [PMID: 35154091 PMCID: PMC8825366 DOI: 10.3389/fimmu.2022.746068] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Accepted: 01/04/2022] [Indexed: 11/13/2022] Open
Abstract
Antibody-induced complement activation may cause injury of the neuromuscular junction (NMJ) and is thus considered as a primary pathogenic factor in human myasthenia gravis (MG) and animal models of experimental autoimmune myasthenia gravis (EAMG). In this study, we tested whether CRIg/FH, a targeted complement inhibitor, could attenuate NMJ injury in rat MG models. We first demonstrated that CRIg/FH could inhibit complement-dependent cytotoxicity on human rhabdomyosarcoma TE671 cells induced by MG patient-derived IgG in vitro. Furthermore, we investigated the therapeutic effect of CRIg/FH in a passive and an active EAMG rodent model. In both models, administration of CRIg/FH could significantly reduce the complement-mediated end-plate damage and suppress the development of EAMG. In the active EAMG model, we also found that CRIg/FH treatment remarkably reduced the serum concentration of autoantibodies and of the cytokines including IFN-γ, IL-2, IL-6, and IL-17, and upregulated the percentage of Treg cells in the spleen, which was further verified in vitro. Therefore, our findings indicate that CRIg/FH may hold the potential for the treatment of MG via immune modulation.
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Affiliation(s)
- Jie Song
- Department of Neurology, Huashan Hospital Fudan University, Shanghai, China.,National Center for Neurological Disorders, Shanghai, China
| | - Rui Zhao
- Department of Neurology, Huashan Hospital Fudan University, Shanghai, China.,National Center for Neurological Disorders, Shanghai, China
| | - Chong Yan
- Department of Neurology, Huashan Hospital Fudan University, Shanghai, China.,National Center for Neurological Disorders, Shanghai, China
| | - Sushan Luo
- Department of Neurology, Huashan Hospital Fudan University, Shanghai, China.,National Center for Neurological Disorders, Shanghai, China
| | - Jianying Xi
- Department of Neurology, Huashan Hospital Fudan University, Shanghai, China.,National Center for Neurological Disorders, Shanghai, China
| | - Peipei Ding
- Fudan University Shanghai Cancer Center and Institutes of Biomedical Sciences, Shanghai Medical College, Fudan University, Shanghai, China
| | - Ling Li
- Fudan University Shanghai Cancer Center and Institutes of Biomedical Sciences, Shanghai Medical College, Fudan University, Shanghai, China
| | - Weiguo Hu
- Fudan University Shanghai Cancer Center and Institutes of Biomedical Sciences, Shanghai Medical College, Fudan University, Shanghai, China.,Key Laboratory of Breast Cancer in Shanghai, Fudan University Shanghai Cancer Center, Fudan University, Shanghai, China
| | - Chongbo Zhao
- Department of Neurology, Huashan Hospital Fudan University, Shanghai, China.,National Center for Neurological Disorders, Shanghai, China
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9
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Lee JD, Woodruff TM. The emerging role of complement in neuromuscular disorders. Semin Immunopathol 2021; 43:817-828. [PMID: 34705082 DOI: 10.1007/s00281-021-00895-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Accepted: 09/22/2021] [Indexed: 12/14/2022]
Abstract
The complement cascade is a key arm of the immune system that protects the host from exogenous and endogenous toxic stimuli through its ability to potently regulate inflammation, phagocytosis, and cell lysis. Due to recent clinical trial successes and drug approvals for complement inhibitors, there is a resurgence in targeting complement as a therapeutic approach to prevent ongoing tissue destruction in several diseases. In particular, neuromuscular diseases are undergoing a recent focus, with demonstrated links between complement activation and disease pathology. This review aims to provide a comprehensive overview of complement activation and its role during the initiation and progression of neuromuscular disorders including myasthenia gravis, amyotrophic lateral sclerosis, and Duchenne muscular dystrophy. We will review the preclinical and clinical evidence for complement in these diseases, with an emphasis on the complement-targeting drugs in clinical trials for these indications.
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Affiliation(s)
- John D Lee
- School of Biomedical Sciences, The University of Queensland, St Lucia, Brisbane, QLD, 4072, Australia.
| | - Trent M Woodruff
- School of Biomedical Sciences, The University of Queensland, St Lucia, Brisbane, QLD, 4072, Australia.,Queensland Brain Institute, The University of Queensland, St Lucia, Brisbane, QLD, 4072, Australia
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10
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Zhao R, Luo S, Zhao C. The role of innate immunity in myasthenia gravis. Autoimmun Rev 2021; 20:102800. [PMID: 33722749 DOI: 10.1016/j.autrev.2021.102800] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Accepted: 01/22/2021] [Indexed: 12/19/2022]
Abstract
Myasthenia gravis (MG) is a T cell-driven, B cell-mediated and autoantibody-dependent autoimmune disorder against neuromuscular junctions (NMJ). Accumulated evidence has emerged regarding the role of innate immunity in the pathogenesis of MG. In this review, we proposed two hypothesis underlying the pathological mechanism. In the context of gene predisposition, on the one hand, Toll-like receptors (TLRs) pathways were initiated by viral infection in the thymus with MG to generate chemokines and pro-inflammatory cytokines such as Type I interferon (IFN), which facilitate the thymus to function as a tertiary lymphoid organ (TLO). On the another hand, the antibodies against acetylcholine receptors (AChR) generated by thymus then activated the classical pathways on thymus and neuromuscular junction (NMJ). Futher, we also highlight the role of innate immune cells in the pathogenic response. Finally, we provide some future perspectives in developing new therapeutic approaches particularly targeting the innate immunity for MG.
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Affiliation(s)
- Rui Zhao
- Department of Neurology, Huashan hospital Fudan University, 200040 Shanghai, China
| | - Sushan Luo
- Department of Neurology, Huashan hospital Fudan University, 200040 Shanghai, China
| | - Chongbo Zhao
- Department of Neurology, Huashan hospital Fudan University, 200040 Shanghai, China.
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11
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Mantegazza R, Vanoli F, Frangiamore R, Cavalcante P. Complement Inhibition for the Treatment of Myasthenia Gravis. Immunotargets Ther 2020; 9:317-331. [PMID: 33365280 PMCID: PMC7751298 DOI: 10.2147/itt.s261414] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2020] [Accepted: 12/02/2020] [Indexed: 12/11/2022] Open
Abstract
Generalized myasthenia gravis (gMG) is a rare autoimmune disorder affecting the neuromuscular junction (NMJ). Approximately 80-90% of patients display antibodies directed against the nicotinic acetylcholine receptor (AChR). A major drive of AChR antibody-positive MG pathology is represented by complement activation. The role of the complement cascade has been largely demonstrated in patients and in MG animal models. Complement activation at the NMJ leads to focal lysis of the post-synaptic membrane, disruption of the characteristic folds, and reduction of AChR. Given that the complement system works as an activation cascade, there are many potential targets that can be considered for therapeutic intervention. Preclinical studies have confirmed the efficacy of complement inhibition in ameliorating MG symptoms. Eculizumab, an antibody directed towards C5, has recently been approved for the treatment of AChR antibody-positive gMG. Other complement inhibitors, targeting C5 as well, are currently under phase III study. Complement inhibitors, however, may present prohibitive costs. Therefore, the identification of a subset of patients more or less prone to respond to such therapies would be beneficial. For such purpose, there is a critical need to identify possible biomarkers predictive of therapeutic response, a field not yet sufficiently explored in MG. This review aims to give an overview of the complement cascade involvement in MG, the evolution of complement-inhibiting therapies and possible biomarkers useful to tailor and monitor complement-directed therapies.
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Affiliation(s)
- Renato Mantegazza
- Neurology IV - Neuroimmunology and Neuromuscular Diseases Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Fiammetta Vanoli
- Neurology IV - Neuroimmunology and Neuromuscular Diseases Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Rita Frangiamore
- Neurology IV - Neuroimmunology and Neuromuscular Diseases Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Paola Cavalcante
- Neurology IV - Neuroimmunology and Neuromuscular Diseases Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
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12
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Yang Q, Fang J, Lei Z, Sluijter JPG, Schiffelers R. Repairing the heart: State-of the art delivery strategies for biological therapeutics. Adv Drug Deliv Rev 2020; 160:1-18. [PMID: 33039498 DOI: 10.1016/j.addr.2020.10.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Revised: 10/01/2020] [Accepted: 10/03/2020] [Indexed: 12/23/2022]
Abstract
Myocardial infarction (MI) is one of the leading causes of mortality worldwide. It is caused by an acute imbalance between oxygen supply and demand in the myocardium, usually caused by an obstruction in the coronary arteries. The conventional therapy is based on the application of (a combination of) anti-thrombotics, reperfusion strategies to open the occluded artery, stents and bypass surgery. However, numerous patients cannot fully recover after these interventions. In this context, new therapeutic methods are explored. Three decades ago, the first biologicals were tested to improve cardiac regeneration. Angiogenic proteins gained popularity as potential therapeutics. This is not straightforward as proteins are delicate molecules that in order to have a reasonably long time of activity need to be stabilized and released in a controlled fashion requiring advanced delivery systems. To ensure long-term expression, DNA vectors-encoding for therapeutic proteins have been developed. Here, the nuclear membrane proved to be a formidable barrier for efficient expression. Moreover, the development of delivery systems that can ensure entry in the target cell, and also correct intracellular trafficking towards the nucleus are essential. The recent introduction of mRNA as a therapeutic entity has provided an attractive intermediate: prolonged but transient expression from a cytoplasmic site of action. However, protection of the sensitive mRNA and correct delivery within the cell remains a challenge. This review focuses on the application of synthetic delivery systems that target the myocardium to stimulate cardiac repair using proteins, DNA or RNA.
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Affiliation(s)
- Qiangbing Yang
- Division LAB, CDL Research, University Medical Center Utrecht, Utrecht, the Netherlands
| | - Juntao Fang
- Division Heart & Lungs, Department of Cardiology, Experimental Cardiology Laboratory, University Medical Center Utrecht, Utrecht, the Netherlands
| | - Zhiyong Lei
- Division LAB, CDL Research, University Medical Center Utrecht, Utrecht, the Netherlands; Division Heart & Lungs, Department of Cardiology, Experimental Cardiology Laboratory, University Medical Center Utrecht, Utrecht, the Netherlands
| | - Joost P G Sluijter
- Division Heart & Lungs, Department of Cardiology, Experimental Cardiology Laboratory, University Medical Center Utrecht, Utrecht, the Netherlands; Regenerative Medicine Utrecht, Circulatory Health Laboratory, Utrecht University, Utrecht, the Netherlands
| | - Raymond Schiffelers
- Division LAB, CDL Research, University Medical Center Utrecht, Utrecht, the Netherlands.
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13
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Albazli K, Kaminski HJ, Howard JF. Complement Inhibitor Therapy for Myasthenia Gravis. Front Immunol 2020; 11:917. [PMID: 32582144 PMCID: PMC7283905 DOI: 10.3389/fimmu.2020.00917] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2019] [Accepted: 04/20/2020] [Indexed: 01/01/2023] Open
Abstract
Complement activation as a driver of pathology in myasthenia gravis (MG) has been appreciated for decades. The terminal complement component [membrane attack complex (MAC)] is found at the neuromuscular junctions of patients with MG. Animals with experimental autoimmune MG are dependent predominantly on an active complement system to develop weakness. Mice deficient in intrinsic complement regulatory proteins demonstrate a significant increase in the destruction of the neuromuscular junction. As subtypes of MG have been better defined, it has been appreciated that acetylcholine receptor antibody-positive disease is driven by complement activation. Preclinical assessments have confirmed that complement inhibition would be a viable therapeutic approach. Eculizumab, an antibody directed toward the C5 component of complement, was demonstrated to be effective in a Phase 3 trial with subsequent approval by the Federal Drug Administration of the United States and other worldwide regulatory agencies for its use in acetylcholine receptor antibody-positive MG. Second- and third-generation complement inhibitors are in development and approaching pivotal efficacy evaluations. This review will summarize the history and present the state of knowledge of this new therapeutic modality.
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Affiliation(s)
- Khaled Albazli
- Department of Neurology, George Washington University, Washington, DC, United States
| | - Henry J. Kaminski
- Department of Neurology, George Washington University, Washington, DC, United States
| | - James F. Howard
- Department of Neurology, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
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Chamberlain JL, Huda S, Whittam DH, Matiello M, Morgan BP, Jacob A. Role of complement and potential of complement inhibitors in myasthenia gravis and neuromyelitis optica spectrum disorders: a brief review. J Neurol 2019; 268:1643-1664. [PMID: 31482201 DOI: 10.1007/s00415-019-09498-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Revised: 08/02/2019] [Accepted: 08/05/2019] [Indexed: 02/08/2023]
Abstract
The complement system is a powerful member of the innate immune system. It is highly adept at protecting against pathogens, but exists in a delicate balance between its protective functions and overactivity, which can result in autoimmune disease. A cascade of complement proteins that requires sequential activation, and numerous complement regulators, exists to regulate a proportionate response to pathogens. In spite of these mechanisms there is significant evidence for involvement of the complement system in driving the pathogenesis of variety of diseases including neuromyelitis optica spectrum disorders (NMOSD) and myasthenia gravis (MG). As an amplification cascade, there are an abundance of molecular targets that could be utilized for therapeutic intervention. Clinical trials assessing complement pathway inhibition in both these conditions have recently been completed and include the first randomized placebo-controlled trial in NMOSD showing positive results. This review aims to review and update the reader on the complement system and the evolution of complement-based therapeutics in these two disorders.
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Affiliation(s)
| | - Saif Huda
- Department of Neurology, The Walton Centre, Lower Lane, Liverpool, L9 7LJ, UK
| | - Daniel H Whittam
- Department of Neurology, The Walton Centre, Lower Lane, Liverpool, L9 7LJ, UK
| | - Marcelo Matiello
- Department of Neurology, Massachusetts General Hospital, 55 Fruit Street, Boston, MA, 02114, USA
| | - B Paul Morgan
- School of Medicine, Henry Wellcome Building for Biomedical Research, University Hospital of Wales, Heath Park, Cardiff, CF14 4XN, UK
| | - Anu Jacob
- Department of Neurology, The Walton Centre, Lower Lane, Liverpool, L9 7LJ, UK.,University of Liverpool, Liverpool, UK
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15
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Myasthenia Gravis: Pathogenic Effects of Autoantibodies on Neuromuscular Architecture. Cells 2019; 8:cells8070671. [PMID: 31269763 PMCID: PMC6678492 DOI: 10.3390/cells8070671] [Citation(s) in RCA: 84] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Revised: 06/26/2019] [Accepted: 06/28/2019] [Indexed: 12/13/2022] Open
Abstract
Myasthenia gravis (MG) is an autoimmune disease of the neuromuscular junction (NMJ). Autoantibodies target key molecules at the NMJ, such as the nicotinic acetylcholine receptor (AChR), muscle-specific kinase (MuSK), and low-density lipoprotein receptor-related protein 4 (Lrp4), that lead by a range of different pathogenic mechanisms to altered tissue architecture and reduced densities or functionality of AChRs, reduced neuromuscular transmission, and therefore a severe fatigable skeletal muscle weakness. In this review, we give an overview of the history and clinical aspects of MG, with a focus on the structure and function of myasthenic autoantigens at the NMJ and how they are affected by the autoantibodies' pathogenic mechanisms. Furthermore, we give a short overview of the cells that are implicated in the production of the autoantibodies and briefly discuss diagnostic challenges and treatment strategies.
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Kusner LL, Yucius K, Sengupta M, Sprague AG, Desai D, Nguyen T, Charisse K, Kuchimanchi S, Kallanthottathil R, Fitzgerald K, Kaminski HJ, Borodovsky A. Investigational RNAi Therapeutic Targeting C5 Is Efficacious in Pre-clinical Models of Myasthenia Gravis. MOLECULAR THERAPY-METHODS & CLINICAL DEVELOPMENT 2019; 13:484-492. [PMID: 31193726 PMCID: PMC6539425 DOI: 10.1016/j.omtm.2019.04.009] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Accepted: 04/26/2019] [Indexed: 10/26/2022]
Abstract
Complement-mediated damage to the neuromuscular junction (NMJ) is a key mechanism of pathology in myasthenia gravis (MG), and therapeutics inhibiting complement have shown evidence of efficacy in the treatment of MG. In this study, we describe the development of a subcutaneously administered N-acetylgalactosamine (GalNAc)-conjugated small interfering RNA (siRNA) targeting the C5 component of complement that silences C5 expression in the liver (ALN-CC5). Treatment of wild-type rodents with ALN-CC5 resulted in robust and durable suppression of liver C5 expression. Dose-dependent serum C5 suppression was observed in non-human primates, with a lowering of serum C5 of up to 97.5% and the concomitant inhibition of serum complement activity. C5 silencing was efficacious in ameliorating disease symptoms in two standard rat models of MG, demonstrating the key role of circulating C5 in pathology at the NMJ. Improvement in disease activity scores and NMJ pathology was observed at intermediate levels of complement activity inhibition, suggesting that complete ablation of complement activity may not be required for efficacy in MG. The pre-clinical studies of ALN-CC5 and efficacy of C5 silencing in rat models of MG support further clinical development of ALN-CC5 as a potential therapeutic for the treatment of MG and other complement-mediated disorders.
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Affiliation(s)
- Linda L Kusner
- Department of Pharmacology and Physiology, George Washington University, Washington, DC 20037, USA
| | | | - Manjistha Sengupta
- Department of Neurology, George Washington University, Washington, DC 20037, USA
| | | | - Dhruv Desai
- Alnylam Pharmaceuticals, Cambridge, MA 02142, USA
| | - Tuyen Nguyen
- Alnylam Pharmaceuticals, Cambridge, MA 02142, USA
| | | | | | | | | | - Henry J Kaminski
- Department of Neurology, George Washington University, Washington, DC 20037, USA
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17
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Muppidi S, Utsugisawa K, Benatar M, Murai H, Barohn RJ, Illa I, Jacob S, Vissing J, Burns TM, Kissel JT, Nowak RJ, Andersen H, Casasnovas C, de Bleecker JL, Vu TH, Mantegazza R, O'Brien FL, Wang JJ, Fujita KP, Howard JF. Long-term safety and efficacy of eculizumab in generalized myasthenia gravis. Muscle Nerve 2019; 60:14-24. [PMID: 30767274 PMCID: PMC6619057 DOI: 10.1002/mus.26447] [Citation(s) in RCA: 108] [Impact Index Per Article: 21.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/10/2019] [Indexed: 01/16/2023]
Abstract
Introduction: Eculizumab is effective and well tolerated in patients with antiacetylcholine receptor antibody‐positive refractory generalized myasthenia gravis (gMG; REGAIN; NCT01997229). We report an interim analysis of an open‐label extension of REGAIN, evaluating eculizumab's long‐term safety and efficacy. Methods: Eculizumab (1,200 mg every 2 weeks for 22.7 months [median]) was administered to 117 patients. Results: The safety profile of eculizumab was consistent with REGAIN; no cases of meningococcal infection were reported during the interim analysis period. Myasthenia gravis exacerbation rate was reduced by 75% from the year before REGAIN (P < 0.0001). Improvements with eculizumab in activities of daily living, muscle strength, functional ability, and quality of life in REGAIN were maintained through 3 years; 56% of patients achieved minimal manifestations or pharmacological remission. Patients who had received placebo during REGAIN experienced rapid and sustained improvements during open‐label eculizumab (P < 0.0001). Discussion: These findings provide evidence for the long‐term safety and sustained efficacy of eculizumab for refractory gMG. Muscle Nerve 2019 See editorial on pages 7–9 in this issue.
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Affiliation(s)
- Srikanth Muppidi
- Department of Neurology and Neurosciences, Stanford University School of Medicine, Stanford, California, USA
| | | | - Michael Benatar
- Department of Neurology, University of Miami Miller School of Medicine, Miami, Florida, USA
| | - Hiroyuki Murai
- Department of Neurology, International University of Health and Welfare, Narita, Japan
| | - Richard J Barohn
- Department of Neurology, University of Kansas Medical Center, Kansas City, Kansas, USA
| | - Isabel Illa
- Neurology Department, Hospital Sant Pau, Autonomous University of Barcelona, Barcelona, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Spain
| | - Saiju Jacob
- Queen Elizabeth Neuroscience Centre and Wellcome Trust Clinical Research Facility, University Hospital Birmingham, Birmingham, United Kingdom
| | - John Vissing
- Department of Neurology, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Ted M Burns
- Department of Neurology, University of Virginia Health System, Charlottesville, Virginia, USA
| | - John T Kissel
- Department of Neurology, The Ohio State University, Columbus, Ohio, USA
| | - Richard J Nowak
- Department of Neurology, Yale School of Medicine, Yale University, New Haven, Connecticut, USA
| | - Henning Andersen
- Department of Neurology, Aarhus University Hospital, Aarhus, Denmark
| | - Carlos Casasnovas
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Spain.,Department of Neurology, Bellvitge University Hospital, Barcelona, Spain
| | - Jan L de Bleecker
- Neuromuscular Reference Centre, Ghent University Hospital, Ghent, Belgium
| | - Tuan H Vu
- Department of Neurology, University of South Florida, Tampa, Florida, USA
| | - Renato Mantegazza
- Foundation of the Carlo Besta Neurological Institute, IRCSS, Milan, Italy
| | | | | | | | - James F Howard
- Department of Neurology, University of North Carolina, Chapel Hill, North Carolina, USA
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Lin G, Li L, Panwar N, Wang J, Tjin SC, Wang X, Yong KT. Non-viral gene therapy using multifunctional nanoparticles: Status, challenges, and opportunities. Coord Chem Rev 2018. [DOI: 10.1016/j.ccr.2018.07.001] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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19
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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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20
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Kusner LL, Sengupta M, Kaminski HJ. Acetylcholine receptor antibody-mediated animal models of myasthenia gravis and the role of complement. Ann N Y Acad Sci 2018; 1413:136-142. [PMID: 29356015 DOI: 10.1111/nyas.13555] [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: 09/28/2017] [Revised: 10/23/2017] [Accepted: 10/25/2017] [Indexed: 12/22/2022]
Abstract
Because of the failure of many promising therapeutics identified in preclinical evaluation, funding sources have established guidelines for increased rigor in animal evaluations. The myasthenia gravis (MG) community of scientists has developed guidelines for preclinical assessment for potential MG treatments. Here, we provide a focused summary of these recommendations and the role of complement in disease development in experimental models of MG.
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Affiliation(s)
- Linda L Kusner
- Department of Pharmacology and Physiology, George Washington University School of Medicine and Health Sciences, Washington, DC
| | - Manjistha Sengupta
- Department of Neurology, George Washington University School of Medicine and Health Sciences, Washington, DC
| | - Henry J Kaminski
- Department of Neurology, George Washington University School of Medicine and Health Sciences, Washington, DC
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21
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Howard JF. Myasthenia gravis: the role of complement at the neuromuscular junction. Ann N Y Acad Sci 2017; 1412:113-128. [PMID: 29266249 DOI: 10.1111/nyas.13522] [Citation(s) in RCA: 108] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2017] [Revised: 09/12/2017] [Accepted: 09/13/2017] [Indexed: 12/11/2022]
Abstract
Generalized myasthenia gravis (gMG) is a rare autoimmune disorder characterized by skeletal muscle weakness caused by disrupted neurotransmission at the neuromuscular junction (NMJ). Approximately 74-88% of patients with gMG have acetylcholine receptor (AChR) autoantibodies. Complement plays an important role in innate and antibody-mediated immunity, and activation and amplification of complement results in the formation of membrane attack complexes (MACs), lipophilic proteins that damage cell membranes. The role of complement in gMG has been demonstrated in animal models and patients. Studies in animals lacking specific complement proteins have confirmed that MAC formation is required to induce experimental autoimmune MG (EAMG) and NMJ damage. Complement inhibition in EAMG models can prevent disease induction and reverse its progression. Patients with anti-AChR+ MG have autoantibodies and MACs present at NMJs. Damaged NMJs are associated with more severe disease, fewer AChRs, and MACs in synaptic debris. Current MG therapies do not target complement directly. Eculizumab is a humanized monoclonal antibody that inhibits cleavage of complement protein C5, preventing MAC formation. Eculizumab treatment improved symptoms compared with placebo in a phase II study in patients with refractory gMG. Direct complement inhibition could preserve NMJ physiology and muscle function in patients with anti-AChR+ gMG.
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Affiliation(s)
- James F Howard
- Department of Neurology, University of North Carolina, Chapel Hill, North Carolina
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22
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High-dose BAFF receptor specific mAb-siRNA conjugate generates Fas-expressing B cells in lymph nodes and high-affinity serum autoantibody in a myasthenia mouse model. Clin Immunol 2017; 176:122-130. [DOI: 10.1016/j.clim.2017.01.005] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2016] [Accepted: 01/11/2017] [Indexed: 01/04/2023]
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23
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Xue HY, Guo P, Wen WC, Wong HL. Lipid-Based Nanocarriers for RNA Delivery. Curr Pharm Des 2016; 21:3140-7. [PMID: 26027572 PMCID: PMC4618487 DOI: 10.2174/1381612821666150531164540] [Citation(s) in RCA: 138] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2015] [Accepted: 05/29/2015] [Indexed: 11/23/2022]
Abstract
RNA-interference (RNAi) agents such as small-interfering RNA (siRNA) and micro-RNA (miRNA) have strong potential as therapeutic agents for the treatment of a broad range of diseases such as malignancies, infections, autoimmune diseases and neurological diseases that are associated with undesirable gene expression. In recent years, several clinical trials of RNAi therapeutics especially siRNAs have been conducted with limited success so far. For systemic administration of these poorly permeable and easily degradable macromolecules, it is obvious that a safe and efficient delivery platform is highly desirable. Because of high biocompatibility, biodegradability and solid track record for clinical use, nanocarriers made of lipids and/or phospholipids have been commonly employed to facilitate RNA delivery. In this article, the key features of the major sub-classes of lipid-based nanocarriers, e.g. liposomes, lipid nanoparticles and lipid nanoemulsions, will be reviewed. Focus of the discussion is on the various challenges researchers face when developing lipid-based RNA nanocarriers, such as the toxicity of cationic lipids and issues related to PEGylated lipids, as well as the strategies employed in tackling these challenges. It is hoped that by understanding more about the pros and cons of these most frequently used RNA delivery systems, the pharmaceutical scientists, biomedical researchers and clinicians will be more successful in overcoming some of the obstacles that currently limit the clinical translation of RNAi therapy.
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Affiliation(s)
| | | | | | - Ho Lun Wong
- School of Pharmacy, Temple University, 3307 North Broad Street, Philadelphia, Pennsylvania, US 19140.
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24
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Abstract
Clinicians are facing unexpected issues in everyday practice, and these may become counterintuitive or challenging. Illustrative examples are provided by the hypersensitivity to universally used immunosuppressants such as corticosteroids or antibiotics such as beta-lactam. Secondly, additional issues are represented by the discovery of new pathogenetic mechanisms involved in rheumatoid and psoriatic arthritis or other chronic inflammatory diseases, genomic susceptibility to enigmatic diseases such as giant cell arteritis, or the shared role of specific mediators such as semaphorins. Third, the therapeutic armamentarium has dramatically changed over the past decade following the introduction of biotechnological drugs, and new mechanisms are being proposed to reduce adverse events or increase the drug effectiveness, particularly on cardiovascular comorbidities. Finally, rare diseases continue to represent difficult cases, as for Cogan's syndrome, with limited literature available for clinical recommendations. For these reason, the present issue of Clinical Reviews in Allergy and Immunology is timely and dedicated to these and other unique topics in clinical immunology and allergy. The aim of this issue is thus to help clinicians involved in internal medicine as well as allergists and clinical immunologists while discussing new pathways that will prove important in the near future.
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25
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Guidelines for standard preclinical experiments in the mouse model of myasthenia gravis induced by acetylcholine receptor immunization. Exp Neurol 2015; 270:11-7. [DOI: 10.1016/j.expneurol.2015.02.009] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2014] [Revised: 01/13/2015] [Accepted: 02/04/2015] [Indexed: 01/25/2023]
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26
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Huda R, Strait RT, Tüzün E, Finkelman FD, Christadoss P. IgG1 deficiency exacerbates experimental autoimmune myasthenia gravis in BALB/c mice. J Neuroimmunol 2015; 281:68-72. [PMID: 25867470 PMCID: PMC4395862 DOI: 10.1016/j.jneuroim.2015.03.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2014] [Revised: 03/02/2015] [Accepted: 03/04/2015] [Indexed: 10/23/2022]
Abstract
Myasthenia gravis is an autoimmune disease characterized by muscle weakness due to neuromuscular junction (NMJ) damage by anti-acetylcholine receptor (AChR) auto-antibodies and complement. In experimental autoimmune myasthenia gravis (EAMG), which is induced by immunization with Torpedo AChR in CFA, anti-AChR IgG2b and IgG1 are the predominant isotypes in the circulation. Complement activation by isotypes such as IgG2b plays a crucial role in EAMG pathogenesis; this suggested the possibility that IgG1, which does not activate complement through the classical pathway, may suppress EAMG. In this study, we show that AChR-immunized BALB/c mice genetically deficient for IgG1 produce higher levels of complement-activating isotypes of anti-AChR, especially IgG3 and IgG2a, and develop increased IgG3/IgG2a deposits at the NMJ, as compared to wild type (WT) BALB/c mice. Consistent with this, AChR-immunized IgG1(-/-) BALB/c mice lose muscle strength and muscle AChR to a greater extent than AChR-immunized WT mice. These observations demonstrate that IgG1 deficiency leads to increased severity of EAMG associated with an increase in complement activating IgG isotypes. Further studies are needed to dissect the specific role or mechanism of IgG1 in limiting EAMG and that of EAMG exacerbating role of complement activating IgG3 and IgG2a in IgG1 deficiency.
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Affiliation(s)
- Ruksana Huda
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX 77555-1070, USA.
| | - Richard T Strait
- Division of Emergency Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA; Department of Pediatrics, University of Cincinnati, College of Medicine, Cincinnati, OH 45267, USA
| | - Erdem Tüzün
- Department of Neuroscience, Institute for Experimental Medical Research, University of Istanbul, Istanbul 34390, Turkey
| | - Fred D Finkelman
- Division of Immunobiology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA; Division of Allergy, Immunology and Rheumatology, Department of Internal Medicine, University of Cincinnati, College of Medicine, Cincinnati, OH 45267, USA; Department of Medicine, Cincinnati Veterans Affairs Medical Center, Cincinnati, OH 45220, USA
| | - Premkumar Christadoss
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX 77555-1070, USA.
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Xue HY, Liu S, Wong HL. Nanotoxicity: a key obstacle to clinical translation of siRNA-based nanomedicine. Nanomedicine (Lond) 2014; 9:295-312. [PMID: 24552562 DOI: 10.2217/nnm.13.204] [Citation(s) in RCA: 178] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
siRNAs have immense therapeutic potential for the treatment of various gene-related diseases ranging from cancer, viral infections and neuropathy to autoimmune diseases. However, their bench-to-bedside translation in recent years has faced several challenges, with inefficient siRNA delivery being one of the most frequently encountered issues. In order to improve the siRNA delivery especially for systemic treatment, nanocarriers made of polymers, lipids or inorganic materials have become almost essential. The 'negative' aspects of these carriers such as their nanotoxicity and immunogenicity thus can no longer be overlooked. In this article, we will extensively review the nanotoxicity of siRNA carriers. The strategies for mitigating the risks of nanotoxicity and the methodology for evaluating these strategies will also be discussed. By addressing this often overlooked but important issue, it will help clear the way for siRNAs to fulfill their promise as a versatile class of therapeutic agents.
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Affiliation(s)
- Hui Yi Xue
- School of Pharmacy, Temple University, 3307 North Broad Street, Philadelphia, PA 19140, USA
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Selective inhibition of PI3K/Akt/mTOR signaling pathway regulates autophagy of macrophage and vulnerability of atherosclerotic plaque. PLoS One 2014; 9:e90563. [PMID: 24599185 PMCID: PMC3944201 DOI: 10.1371/journal.pone.0090563] [Citation(s) in RCA: 121] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2013] [Accepted: 01/31/2014] [Indexed: 12/21/2022] Open
Abstract
Macrophage infiltration contributes to the instability of atherosclerotic plaques. In the present study, we investigated whether selective inhibition of PI3K/Akt/mTOR signaling pathway can enhance the stability of atherosclerotic plaques by activation of macrophage autophagy. In vitro study, selective inhibitors or siRNA of PI3K/Akt/mTOR pathways were used to treat the rabbit's peritoneal primary macrophage cells. Inflammation related cytokines secreted by macrophages were measured. Ultrastructure changes of macrophages were examined by transmission electron microscope. mRNA or protein expression levels of autophagy related gene Beclin 1, protein 1 light chain 3 II dots (LC3-II) or Atg5-Atg12 conjugation were assayed by quantitative RT-PCR or Western blot. In vivo study, vulnerable plaque models were established in 40 New Zealand White rabbits and then drugs or siRNA were given for 8 weeks to inhibit the PI3K/Akt/mTOR signaling pathway. Intravascular ultrasound (IVUS) was performed to observe the plaque imaging. The ultrastructure of the abdominal aortic atherosclerosis lesions were analyzed with histopathology. RT-PCR or Western blot methods were used to measure the expression levels of corresponding autophagy related molecules. We found that macrophage autophagy was induced in the presence of Akt inhibitor, mTOR inhibitor and mTOR-siRNA in vitro study, while PI3K inhibitor had the opposite role. In vivo study, we found that macrophage autophagy increased significantly and the rabbits had lower plaque rupture incidence, lower plaque burden and decreased vulnerability index in the inhibitors or siRNA treated groups. We made a conclusion that selective inhibition of the Akt/mTOR signal pathway can reduce macrophages and stabilize the vulnerable atherosclerotic plaques by promoting macrophage autophagy.
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29
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Huda R, Tüzün E, Christadoss P. Targeting complement system to treat myasthenia gravis. Rev Neurosci 2014; 25:575-83. [DOI: 10.1515/revneuro-2014-0021] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2014] [Accepted: 03/26/2014] [Indexed: 11/15/2022]
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