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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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Kuzu B, Alagoz MA, Demir Y, Gulcin I, Burmaoglu S, Algul O. Structure-based inhibition of acetylcholinesterase and butyrylcholinesterase with 2-Aryl-6-carboxamide benzoxazole derivatives: synthesis, enzymatic assay, and in silico studies. Mol Divers 2024:10.1007/s11030-024-10828-6. [PMID: 38554169 DOI: 10.1007/s11030-024-10828-6] [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: 06/26/2023] [Accepted: 02/21/2024] [Indexed: 04/01/2024]
Abstract
An important research topic is the discovery of multifunctional compounds targeting different disease-causing components. This research aimed to design and synthesize a series of 2-aryl-6-carboxamide benzoxazole derivatives that inhibit cholinesterases on both the peripheral anionic and catalytic anionic sides. Compounds (7-48) were prepared from 4-amino-3-hydroxybenzoic acid in three steps. The Ellman test, molecular docking with Maestro, and molecular dynamics simulation studies with Desmond were done (Schrodinger, 12.8.117). Compound 36, the most potent compound among the 42 new compounds synthesized, had an inhibitory concentration of IC50 12.62 nM for AChE and IC50 25.45 nM for BChE (whereas donepezil was 69.3 nM and 63.0 nM, respectively). Additionally, compound 36 had docking values of - 7.29 kcal/mol for AChE and - 6.71 kcal/mol for BChE (whereas donepezil was - 6.49 kcal/mol and - 5.057 kcal/mol, respectively). Furthermore, molecular dynamics simulations revealed that compound 36 is stable in the active gorges of both AChE (average RMSD: 1.98 Å) and BChE (average RMSD: 2.2 Å) (donepezil had average RMSD: 1.65 Å and 2.7 Å, respectively). The results show that compound 36 is a potent, selective, mixed-type dual inhibitor of both acetylcholinesterase and butyrylcholinesterase. It does this by binding to both the catalytically active and peripheral anionic sites of cholinesterases at the same time. These findings show that target compounds may be useful for establishing the structural basis for new anti-Alzheimer agents.
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Affiliation(s)
- Burak Kuzu
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Van Yuzuncu Yil University, Van, 65080, Turkey
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Mersin University, Mersin, 33169, Turkey
| | - M Abdullah Alagoz
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, İnonu University, Malatya, 44280, Turkey
| | - Yeliz Demir
- Department of Pharmacy Services, Nihat Delibalta Göle Vocational High School, Ardahan University, Ardahan, 75000, Turkey
| | - Ilhami Gulcin
- Department of Chemistry, Faculty of Science, Ataturk University, Erzurum, 25240, Turkey
| | - Serdar Burmaoglu
- Department of Chemistry, Faculty of Science, Ataturk University, Erzurum, 25240, Turkey.
| | - Oztekin Algul
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Mersin University, Mersin, 33169, Turkey.
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Erzincan Binali Yildirim University, Erzincan, 24100, Turkey.
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Sun J, Sun M, Li X, Xie Q, Zhang W, Wang M. MicroRNA‑155‑5p affects regulatory T cell activation and immunosuppressive function by targeting BCL10 in myasthenia gravis. Exp Ther Med 2024; 27:6. [PMID: 38223327 PMCID: PMC10785013 DOI: 10.3892/etm.2023.12293] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Accepted: 10/20/2023] [Indexed: 01/16/2024] Open
Abstract
The imbalance in immune homeostasis plays a crucial role in the pathogenesis of myasthenia gravis (MG). MicroRNAs (miRs) have been identified as key regulators of immune homeostasis. B-cell lymphoma/leukemia 10 (BCL10) has been implicated in the activation and suppressive function of regulatory T cells (Tregs). This study aimed to investigate the potential role of miR-155-5p in modulating the activation and function of Tregs in MG. To achieve this objective, blood samples were collected from MG patients to assess the expression levels of miR-155-5p and BCL10, as well as the proportion of circulating Tregs, in comparison to healthy controls. The correlation between miR-155-5p and BCL10 levels was evaluated in human samples. The expression levels of miR-155-5p and the numbers of circulating Tregs were also examined in an animal model of experimental autoimmune MG (EAMG). A dual-luciferase reporter assay was used to verify whether miR-155-5p can target BCL10. To determine the regulatory function of BCL10 in Tregs, CD4+ CD25+ Tregs were transfected with either small interfering-BCL10 or miR-155-5p inhibitor, and the expression levels of the anti-inflammatory cytokine IL-10 and transcription factors Foxp3, TGF-β1, CTLA4, and ICOS were measured. The results demonstrated that the expression level of miR-155-5p was significantly higher in patients with MG compared with that in healthy controls, whereas the expression level of BCL10 was significantly decreased in patients with MG. Furthermore, there was a significant negative correlation between the expression levels of miR-155-5p and BCL10. The number of circulating Tregs was significantly reduced in patients with MG and in the spleen of rats with EAMG compared with that in the corresponding control groups. The dual-luciferase reporter assay demonstrated that miR-155-5p could target BCL10. The Tregs transfected with si-BCL10 demonstrated significant decreases in the protein levels of TGF-β1 and IL-10, as well as in the mRNA expression levels of Foxp3, TGF-β1, CTLA-4 and ICOS. Conversely, the Tregs transfected with the miR-155-5p inhibitor exhibited a substantial increase in these protein and mRNA expression levels compared with their respective control groups. Furthermore, the knockdown of BCL10 exhibited a decline in the suppressive efficacy of Tregs on the proliferation of CD4+ T cells. Conversely, the suppression of miR-155-5p expression attenuated the inhibition of the BCL10 gene, potentially causing an indirect influence on the suppressive capability of Tregs on the proliferation of CD4+ T cells. BCL10 was thus found to contribute to the activation and immunosuppressive function of Tregs. In summary, the present study demonstrated that miR-155-5p inhibited the activation and immunosuppressive function of Tregs by targeting BCL10, which may be used as a future potential target for the treatment of MG.
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Affiliation(s)
- Jing Sun
- Department of Neurology, Lanzhou University Second Hospital, Lanzhou, Gansu 730030, P.R. China
| | - Mengjiao Sun
- Department of Neurology, Lanzhou University Second Hospital, Lanzhou, Gansu 730030, P.R. China
| | - Xiaoling Li
- Department of Neurology, Lanzhou University Second Hospital, Lanzhou, Gansu 730030, P.R. China
| | - Qinfang Xie
- Department of Neurology, Lanzhou University Second Hospital, Lanzhou, Gansu 730030, P.R. China
| | - Wenjing Zhang
- Department of Neurology, Qinghai Provincial People's Hospital, Xining, Qinghai 810007, P.R. China
| | - Manxia Wang
- Department of Neurology, Lanzhou University Second Hospital, Lanzhou, Gansu 730030, P.R. China
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Weng S, Huang L, Cai B, He L, Wen S, Li J, Zhong Z, Zhang H, Huang C, Yang Y, Jiang Q, Liu F. Astragaloside IV ameliorates experimental autoimmune myasthenia gravis by regulating CD4 + T cells and altering gut microbiota. Chin Med 2023; 18:97. [PMID: 37542273 PMCID: PMC10403896 DOI: 10.1186/s13020-023-00798-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2023] [Accepted: 07/10/2023] [Indexed: 08/06/2023] Open
Abstract
BACKGROUND Myasthenia gravis (MG) is an antibody-mediated autoimmune disease and its pathogenesis is closely related to CD4 + T cells. In recent years, gut microbiota is considered to play an important role in the pathogenesis of MG. Astragaloside IV (AS-IV) is one of the main active components extracted from Astragalus membranaceus and has immunomodulatory effects. To study the immunomodulatory effect of AS-IV and the changes of gut microbiota on experimental autoimmune myasthenia gravis (EAMG) mice, we explore the possible mechanism of AS-IV in improving MG. METHODS In this study, network pharmacology was utilized to screen the crucial targets of AS-IV in the treatment of MG. Subsequently, a Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis was performed to identify potential pathways through which AS-IV acts against MG. Furthermore, experimental investigations were conducted to validate the underlying mechanism of AS-IV in MG treatment. Before modeling, 5 mice were randomly selected as the control group (CFA group), and the other 10 were induced to EAMG model. These mice were randomly divided into EAMG group and EAMG + AS-IV group, n = 5/group. In EAMG + AS-IV group, AS-IV was administered by gavage. CFA and EAMG groups were given the same volume of PBS. Body weight, grip strength and clinical symptoms were assessed and recorded weekly. At the last administration, the feces were collected for 16S RNA microbiota analysis. The levels of Treg, Th1 and Th17 cells in spleen and Th1 and Th17 cells in thymus were detected by flow cytometry. The levels of IFN-γ, IL-17 and TGF-β in serum were measured by ELISA. Furthermore, fecal microbial transplantation (FMT) experiments were performed for exploring the influence of changed intestinal flora on EAMG. After EAMG model was induced, the mice were treated with antibiotics daily for 4 weeks to germ-free. Then germ-free EAMG mice were randomly divided into two groups: FMT EAMG group, FMT AS-IV group, n = 3/group. Fecal extractions from EAMG and EAMG + AS-IV groups as gathered above were used to administered daily to the respective groups for 4 weeks. Body weight, grip strength and clinical symptoms were assessed and recorded weekly. The levels of Treg, Th1 and Th17 cells in spleen and Th1 and Th17 cells in thymus were detected at the last administration. The levels of IFN-γ, IL-17 and TGF-β in serum were measured by ELISA. RESULTS The network pharmacology and KEGG pathway analysis revealed that AS-IV regulates T cell pathways, including T cell receptor signaling pathway and Th17 cell differentiation, suggesting its potential in improving MG. Further experimental verification demonstrated that AS-IV administration improved muscle strength and body weight, reduced the level of Th1 and Th17 cells, enhanced the level of Treg cells, and resulted in alterations of the gut microbiota, including changes in beta diversity, the Firmicutes/Bacteroidetes (F/B) ratio, and the abundance of Clostridia in EAMG mice. We further conducted FMT tests and demonstrated that the EAMG Abx-treated mice which were transplanted the feces of mice treated with AS-IV significantly alleviated myasthenia symptoms, reduced Th1 and Th17 cells levels, and increased Treg cell levels. CONCLUSION This study speculated that AS-IV ameliorates EAMG by regulating CD4 + T cells and altering the structure and species of gut microbiota of EAMG.
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Affiliation(s)
- Senhui Weng
- Department of Spleen and Stomach Diseases, Guangdong Provincial Hospital of Chinese Medicine, No. 111 Dade Road, Yuexiu District, Guangzhou, 510120, China
- Guangzhou University of Chinese Medicine, No.12 Airport Road, Baiyun District, Guangzhou, 510422, China
- Lingnan Medical Research Center of Guangzhou University of Chinese Medicine, No.12 Airport Road, Baiyun District, Guangzhou, 510422, China
| | - Linwen Huang
- Guangzhou University of Chinese Medicine, No.12 Airport Road, Baiyun District, Guangzhou, 510422, China
| | - Bingxing Cai
- Guangzhou University of Chinese Medicine, No.12 Airport Road, Baiyun District, Guangzhou, 510422, China
| | - Long He
- Guangzhou University of Chinese Medicine, No.12 Airport Road, Baiyun District, Guangzhou, 510422, China
- Department of Spleen and Stomach Diseases, First Affiliated Hospital of Guangzhou University of Chinese Medicine, No.16 Airport Road, Baiyun District, Guangzhou, 510422, China
| | - Shuting Wen
- Department of Spleen and Stomach Diseases, Guangdong Provincial Hospital of Chinese Medicine, No. 111 Dade Road, Yuexiu District, Guangzhou, 510120, China
- Guangzhou University of Chinese Medicine, No.12 Airport Road, Baiyun District, Guangzhou, 510422, China
- Lingnan Medical Research Center of Guangzhou University of Chinese Medicine, No.12 Airport Road, Baiyun District, Guangzhou, 510422, China
| | - Jinghao Li
- Department of Traditional Chinese Medicine of the Sixth Affiliated Hospital, School of Medicine, South China University of Technology, Foshan, 528000, China
| | - Zhuotai Zhong
- Guangzhou University of Chinese Medicine, No.12 Airport Road, Baiyun District, Guangzhou, 510422, China
- Lingnan Medical Research Center of Guangzhou University of Chinese Medicine, No.12 Airport Road, Baiyun District, Guangzhou, 510422, China
| | - Haiyan Zhang
- Department of Spleen and Stomach Diseases, Guangdong Provincial Hospital of Chinese Medicine, No. 111 Dade Road, Yuexiu District, Guangzhou, 510120, China
| | - Chongyang Huang
- Department of Spleen and Stomach Diseases, Guangdong Provincial Hospital of Chinese Medicine, No. 111 Dade Road, Yuexiu District, Guangzhou, 510120, China
| | - Yunying Yang
- Department of Spleen and Stomach Diseases, First Affiliated Hospital of Guangzhou University of Chinese Medicine, No.16 Airport Road, Baiyun District, Guangzhou, 510422, China
| | - Qilong Jiang
- Department of Spleen and Stomach Diseases, First Affiliated Hospital of Guangzhou University of Chinese Medicine, No.16 Airport Road, Baiyun District, Guangzhou, 510422, China.
| | - Fengbin Liu
- Lingnan Medical Research Center of Guangzhou University of Chinese Medicine, No.12 Airport Road, Baiyun District, Guangzhou, 510422, China.
- Department of Spleen and Stomach Diseases, First Affiliated Hospital of Guangzhou University of Chinese Medicine, No.16 Airport Road, Baiyun District, Guangzhou, 510422, China.
- Baiyun Hospital of the First Affiliated Hospital of Guangzhou University of Chinese Medicine, No. 2, Helongqi Road, Renhe Town, Baiyun District, Guangzhou, 510000, China.
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Pham MC, Masi G, Patzina R, Obaid AH, Oxendine SR, Oh S, Payne AS, Nowak RJ, O'Connor KC. Individual myasthenia gravis autoantibody clones can efficiently mediate multiple mechanisms of pathology. Acta Neuropathol 2023; 146:319-336. [PMID: 37344701 DOI: 10.1007/s00401-023-02603-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Revised: 06/15/2023] [Accepted: 06/16/2023] [Indexed: 06/23/2023]
Abstract
Serum autoantibodies targeting the nicotinic acetylcholine receptor (AChR) in patients with autoimmune myasthenia gravis (MG) can mediate pathology via three distinct molecular mechanisms: complement activation, receptor blockade, and antigenic modulation. However, it is unclear whether multi-pathogenicity is mediated by individual or multiple autoantibody clones. Using an unbiased B cell culture screening approach, we generated a library of 11 human-derived AChR-specific recombinant monoclonal autoantibodies (mAb) and assessed their binding properties and pathogenic profiles using specialized cell-based assays. Five mAbs activated complement, three blocked α-bungarotoxin binding to the receptor, and seven induced antigenic modulation. Furthermore, two clonally related mAbs derived from one patient were each highly efficient at more than one of these mechanisms, demonstrating that pathogenic mechanisms are not mutually exclusive at the monoclonal level. Using novel Jurkat cell lines that individually express each monomeric AChR subunit (α2βδε), these two mAbs with multi-pathogenic capacity were determined to exclusively bind the α-subunit of AChR, demonstrating an association between mAb specificity and pathogenic capacity. These findings provide new insight into the immunopathology of MG, demonstrating that single autoreactive clones can efficiently mediate multiple modes of pathology. Current therapeutic approaches targeting only one autoantibody-mediated pathogenic mechanism may be evaded by autoantibodies with multifaceted capacity.
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Affiliation(s)
- Minh C Pham
- Department of Immunobiology, Yale University School of Medicine, 300 George Street-Room 353J, New Haven, CT, 06511, USA
| | - Gianvito Masi
- Department of Immunobiology, Yale University School of Medicine, 300 George Street-Room 353J, New Haven, CT, 06511, USA
- Department of Neurology, Yale University School of Medicine, New Haven, CT, 06511, USA
| | - Rosa Patzina
- Department of Immunobiology, Yale University School of Medicine, 300 George Street-Room 353J, New Haven, CT, 06511, USA
- Department of Neurology, Yale University School of Medicine, New Haven, CT, 06511, USA
| | - Abeer H Obaid
- Department of Immunobiology, Yale University School of Medicine, 300 George Street-Room 353J, New Haven, CT, 06511, USA
- Department of Neurology, Yale University School of Medicine, New Haven, CT, 06511, USA
- Institute of Biomedical Studies, Baylor University, Waco, TX, 76706, USA
| | - Seneca R Oxendine
- Department of Immunobiology, Yale University School of Medicine, 300 George Street-Room 353J, New Haven, CT, 06511, USA
- Department of Neurology, Yale University School of Medicine, New Haven, CT, 06511, USA
| | - Sangwook Oh
- Department of Dermatology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Aimee S Payne
- Department of Dermatology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Richard J Nowak
- Department of Neurology, Yale University School of Medicine, New Haven, CT, 06511, USA
| | - Kevin C O'Connor
- Department of Immunobiology, Yale University School of Medicine, 300 George Street-Room 353J, New Haven, CT, 06511, USA.
- Department of Neurology, Yale University School of Medicine, New Haven, CT, 06511, USA.
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miRNAs as the important regulators of myasthenia gravis: involvement of major cytokines and immune cells. Immunol Res 2022; 71:153-163. [PMID: 36396903 DOI: 10.1007/s12026-022-09342-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Accepted: 11/09/2022] [Indexed: 11/18/2022]
Abstract
Myasthenia gravis (MG) is a type of muscle paralysis created by immune responses against acetylcholine receptor proteins in neuromuscular synapses. This disease is characterized by muscle weakness, especially ocular weakness symptoms that could be ptosis (fall of the upper eyelid) or diplopia (double vision of a single object). Some patients also identified with speech and swallowing problems. The main goals of MG therapeutic approaches are to achieve remission, reduce symptoms, and improve life quality. Recently, other studies have revealed the potential role of various microRNAs (miRNAs) in the development of MG through different mechanisms and have proposed these molecules as effective biomarkers for the treatment of MG. This review was aimed at providing an overview of the critical regulatory roles of various miRNAs in the pathogenesis of this autoimmune disease focusing on human MG studies and the interaction between different miRNAs with important cytokines and immune cells during the development of this autoimmune disease.
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Abstract
PURPOSE OF REVIEW This review summarizes recent insights into the immunopathogenesis of autoimmune myasthenia gravis (MG). Mechanistic understanding is presented according to MG disease subtypes and by leveraging the knowledge gained through the use of immunomodulating biological therapeutics. RECENT FINDINGS The past two years of research on MG have led to a more accurate definition of the mechanisms through which muscle-specific tyrosine kinase (MuSK) autoantibodies induce pathology. Novel insights have also emerged from the collection of stronger evidence on the pathogenic capacity of low-density lipoprotein receptor-related protein 4 autoantibodies. Clinical observations have revealed a new MG phenotype triggered by cancer immunotherapy, but the underlying immunobiology remains undetermined. From a therapeutic perspective, MG patients can now benefit from a wider spectrum of treatment options. Such therapies have uncovered profound differences in clinical responses between and within the acetylcholine receptor and MuSK MG subtypes. Diverse mechanisms of immunopathology between the two subtypes, as well as qualitative nuances in the autoantibody repertoire of each patient, likely underpin the variability in therapeutic outcomes. Although predictive biomarkers of clinical response are lacking, these observations have ignited the development of assays that might assist clinicians in the choice of specific therapeutic strategies. SUMMARY Recent advances in the understanding of autoantibody functionalities are bringing neuroimmunologists closer to a more detailed appreciation of the mechanisms that govern MG pathology. Future investigations on the immunological heterogeneity among MG patients will be key to developing effective, individually tailored therapies.
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Affiliation(s)
- Gianvito Masi
- Department of Neurology, Yale School of Medicine, New Haven, CT 06511 USA
- Department of Immunobiology, Yale School of Medicine, New Haven, CT 06511 USA
| | - Kevin C. O’Connor
- Department of Neurology, Yale School of Medicine, New Haven, CT 06511 USA
- Department of Immunobiology, Yale School of Medicine, New Haven, CT 06511 USA
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Obaid RJ, Naeem N, Mughal EU, Al-Rooqi MM, Sadiq A, Jassas RS, Moussa Z, Ahmed SA. Inhibitory potential of nitrogen, oxygen and sulfur containing heterocyclic scaffolds against acetylcholinesterase and butyrylcholinesterase. RSC Adv 2022; 12:19764-19855. [PMID: 35919585 PMCID: PMC9275557 DOI: 10.1039/d2ra03081k] [Citation(s) in RCA: 27] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Accepted: 06/27/2022] [Indexed: 01/15/2023] Open
Abstract
Heterocycles are the key structures in organic chemistry owing to their immense applications in the biological, chemical, and pharmaceutical fields. Heterocyclic compounds perform various noteworthy functions in nature, medication, innovation etc. Most frequently, pure nitrogen heterocycles or various positional combinations of nitrogen, oxygen, and sulfur atoms in five or six-membered rings can be found. Inhibition of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes is a popular strategy for the management of numerous mental diseases. In this context, cholinesterase inhibitors are utilized to relieve the symptoms of neurological illnesses like dementia and Alzheimer's disease (AD). The present review focuses on various heterocyclic scaffolds and their role in designing and developing new potential AChE and BChE inhibitors to treat AD. Moreover, a detailed structure-activity relationship (SAR) has been established for the future discovery of novel drugs for the treatment of AD. Most of the heterocyclic motifs have been used in the design of new potent cholinesterase inhibitors. In this regard, this review is an endeavor to summarize the biological and chemical studies over the past decade (2010-2022) describing the pursuit of new N, O and S containing heterocycles which can offer a rich supply of promising AChE and BChE inhibitory activities.
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Affiliation(s)
- Rami J Obaid
- Department of Chemistry, Faculty of Applied Sciences, Umm Al-Qura University Makkah 21955 Saudi Arabia
| | - Nafeesa Naeem
- Department of Chemistry, University of Gujrat Gujrat-50700 Pakistan
| | | | - Munirah M Al-Rooqi
- Department of Chemistry, Faculty of Applied Sciences, Umm Al-Qura University Makkah 21955 Saudi Arabia
| | - Amina Sadiq
- Department of Chemistry, Govt. College Women University Sialkot-51300 Pakistan
| | - Rabab S Jassas
- Department of Chemistry, Jamoum University College, Umm Al-Qura University 21955 Makkah Saudi Arabia
| | - Ziad Moussa
- Department of Chemistry, College of Science, United Arab Emirates University P.O. Box 15551 Al Ain Abu Dhabi United Arab Emirates
| | - Saleh A Ahmed
- Department of Chemistry, Faculty of Applied Sciences, Umm Al-Qura University Makkah 21955 Saudi Arabia
- Department of Chemistry, Faculty of Science, Assiut University 71516 Assiut Egypt
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9
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Zografou C, Vakrakou AG, Stathopoulos P. Short- and Long-Lived Autoantibody-Secreting Cells in Autoimmune Neurological Disorders. Front Immunol 2021; 12:686466. [PMID: 34220839 PMCID: PMC8248361 DOI: 10.3389/fimmu.2021.686466] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Accepted: 05/28/2021] [Indexed: 12/24/2022] Open
Abstract
As B cells differentiate into antibody-secreting cells (ASCs), short-lived plasmablasts (SLPBs) are produced by a primary extrafollicular response, followed by the generation of memory B cells and long-lived plasma cells (LLPCs) in germinal centers (GCs). Generation of IgG4 antibodies is T helper type 2 (Th2) and IL-4, -13, and -10-driven and can occur parallel to IgE, in response to chronic stimulation by allergens and helminths. Although IgG4 antibodies are non-crosslinking and have limited ability to mobilize complement and cellular cytotoxicity, when self-tolerance is lost, they can disrupt ligand-receptor binding and cause a wide range of autoimmune disorders including neurological autoimmunity. In myasthenia gravis with predominantly IgG4 autoantibodies against muscle-specific kinase (MuSK), it has been observed that one-time CD20+ B cell depletion with rituximab commonly leads to long-term remission and a marked reduction in autoantibody titer, pointing to a short-lived nature of autoantibody-secreting cells. This is also observed in other predominantly IgG4 autoantibody-mediated neurological disorders, such as chronic inflammatory demyelinating polyneuropathy and autoimmune encephalitis with autoantibodies against the Ranvier paranode and juxtaparanode, respectively, and extends beyond neurological autoimmunity as well. Although IgG1 autoantibody-mediated neurological disorders can also respond well to rituximab induction therapy in combination with an autoantibody titer drop, remission tends to be less long-lasting and cases where titers are refractory tend to occur more often than in IgG4 autoimmunity. Moreover, presence of GC-like structures in the thymus of myasthenic patients with predominantly IgG1 autoantibodies against the acetylcholine receptor and in ovarian teratomas of autoimmune encephalitis patients with predominantly IgG1 autoantibodies against the N‐methyl‐d‐aspartate receptor (NMDAR) confers increased the ability to generate LLPCs. Here, we review available information on the short-and long-lived nature of ASCs in IgG1 and IgG4 autoantibody-mediated neurological disorders and highlight common mechanisms as well as differences, all of which can inform therapeutic strategies and personalized medical approaches.
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Affiliation(s)
- C Zografou
- Institute of Neuropathology, University of Zurich, Zurich, Switzerland
| | - A G Vakrakou
- First Department of Neurology, National and Kapodistrian University of Athens Medical School, Athens, Greece
| | - P Stathopoulos
- First Department of Neurology, National and Kapodistrian University of Athens Medical School, Athens, Greece
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10
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Myasthenia Gravis: Epidemiology, Pathophysiology and Clinical Manifestations. J Clin Med 2021; 10:jcm10112235. [PMID: 34064035 PMCID: PMC8196750 DOI: 10.3390/jcm10112235] [Citation(s) in RCA: 111] [Impact Index Per Article: 37.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Revised: 05/17/2021] [Accepted: 05/17/2021] [Indexed: 12/12/2022] Open
Abstract
Myasthenia gravis (MG) is an autoimmune neurological disorder characterized by defective transmission at the neuromuscular junction. The incidence of the disease is 4.1 to 30 cases per million person-years, and the prevalence rate ranges from 150 to 200 cases per million. MG is considered a classic example of antibody-mediated autoimmune disease. Most patients with MG have autoantibodies against the acetylcholine receptors (AChRs). Less commonly identified autoantibodies include those targeted to muscle-specific kinase (MuSK), low-density lipoprotein receptor-related protein 4 (Lrp4), and agrin. These autoantibodies disrupt cholinergic transmission between nerve terminals and muscle fibers by causing downregulation, destruction, functional blocking of AChRs, or disrupting the clustering of AChRs in the postsynaptic membrane. The core clinical manifestation of MG is fatigable muscle weakness, which may affect ocular, bulbar, respiratory and limb muscles. Clinical manifestations vary according to the type of autoantibody, and whether a thymoma is present.
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Jiang R, Hoehn KB, Lee CS, Pham MC, Homer RJ, Detterbeck FC, Aban I, Jacobson L, Vincent A, Nowak RJ, Kaminski HJ, Kleinstein SH, O'Connor KC. Thymus-derived B cell clones persist in the circulation after thymectomy in myasthenia gravis. Proc Natl Acad Sci U S A 2020; 117:30649-30660. [PMID: 33199596 PMCID: PMC7720237 DOI: 10.1073/pnas.2007206117] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Myasthenia gravis (MG) is a neuromuscular, autoimmune disease caused by autoantibodies that target postsynaptic proteins, primarily the acetylcholine receptor (AChR) and inhibit signaling at the neuromuscular junction. The majority of patients under 50 y with AChR autoantibody MG have thymic lymphofollicular hyperplasia. The MG thymus is a reservoir of plasma cells that secrete disease-causing AChR autoantibodies and although thymectomy improves clinical scores, many patients fail to achieve complete stable remission without additional immunosuppressive treatments. We speculate that thymus-associated B cells and plasma cells persist in the circulation after thymectomy and that their persistence could explain incomplete responses to resection. We studied patients enrolled in a randomized clinical trial and used complementary modalities of B cell repertoire sequencing to characterize the thymus B cell repertoire and identify B cell clones that resided in the thymus and circulation before and 12 mo after thymectomy. Thymus-associated B cell clones were detected in the circulation by both mRNA-based and genomic DNA-based sequencing. These antigen-experienced B cells persisted in the circulation after thymectomy. Many circulating thymus-associated B cell clones were inferred to have originated and initially matured in the thymus before emigration from the thymus to the circulation. The persistence of thymus-associated B cells correlated with less favorable changes in clinical symptom measures, steroid dose required to manage symptoms, and marginal changes in AChR autoantibody titer. This investigation indicates that the diminished clinical response to thymectomy is related to persistent circulating thymus-associated B cell clones.
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Affiliation(s)
- Ruoyi Jiang
- Department of Immunobiology, Yale University School of Medicine, New Haven, CT 06511
| | - Kenneth B Hoehn
- Department of Pathology, Yale University School of Medicine, New Haven, CT 06511
| | - Casey S Lee
- Department of Neurology, Yale University School of Medicine, New Haven, CT 06511
| | - Minh C Pham
- Department of Immunobiology, Yale University School of Medicine, New Haven, CT 06511
| | - Robert J Homer
- Department of Pathology, Yale University School of Medicine, New Haven, CT 06511
- Pathology & Laboratory Medicine Service, VA CT Health Care System, West Haven, CT 06516
| | - Frank C Detterbeck
- Department of Surgery, Yale University School of Medicine, New Haven, CT 06511
| | - Inmaculada Aban
- Department of Biostatistics, University of Alabama, Birmingham, AL 35294
| | - Leslie Jacobson
- Nuffield Department of Clinical Neurosciences, John Radcliffe Hospital, University of Oxford, OX1 2JD Oxford, United Kingdom
| | - Angela Vincent
- Nuffield Department of Clinical Neurosciences, John Radcliffe Hospital, University of Oxford, OX1 2JD Oxford, United Kingdom
| | - Richard J Nowak
- Department of Neurology, Yale University School of Medicine, New Haven, CT 06511
| | - Henry J Kaminski
- Department of Neurology, The George Washington University, Washington, DC 20052
| | - Steven H Kleinstein
- Department of Immunobiology, Yale University School of Medicine, New Haven, CT 06511;
- Department of Pathology, Yale University School of Medicine, New Haven, CT 06511
- Interdepartmental Program in Computational Biology & Bioinformatics, Yale University, New Haven, CT 06511
| | - Kevin C O'Connor
- Department of Immunobiology, Yale University School of Medicine, New Haven, CT 06511;
- Department of Neurology, Yale University School of Medicine, New Haven, CT 06511
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12
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Lazaridis K, Tzartos SJ. Myasthenia Gravis: Autoantibody Specificities and Their Role in MG Management. Front Neurol 2020; 11:596981. [PMID: 33329350 PMCID: PMC7734299 DOI: 10.3389/fneur.2020.596981] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Accepted: 10/30/2020] [Indexed: 12/11/2022] Open
Abstract
Myasthenia gravis (MG) is the most common autoimmune disorder affecting the neuromuscular junction, characterized by skeletal muscle weakness and fatigability. It is caused by autoantibodies targeting proteins of the neuromuscular junction; ~85% of MG patients have autoantibodies against the muscle acetylcholine receptor (AChR-MG), whereas about 5% of MG patients have autoantibodies against the muscle specific kinase (MuSK-MG). In the remaining about 10% of patients no autoantibodies can be found with the classical diagnostics for AChR and MuSK antibodies (seronegative MG, SN-MG). Since serological tests are relatively easy and non-invasive for disease diagnosis, the improvement of methods for the detection of known autoantibodies or the discovery of novel autoantibody specificities to diminish SN-MG and to facilitate differential diagnosis of similar diseases, is crucial. Radioimmunoprecipitation assays (RIPA) are the staple for MG antibody detection, but over the past years, using cell-based assays (CBAs) or improved highly sensitive RIPAs, it has been possible to detect autoantibodies in previously SN-MG patients. This led to the identification of more patients with antibodies to the classical antigens AChR and MuSK and to the third MG autoantigen, the low-density lipoprotein receptor-related protein 4 (LRP4), while antibodies against other extracellular or intracellular targets, such as agrin, Kv1.4 potassium channels, collagen Q, titin, the ryanodine receptor and cortactin have been found in some MG patients. Since the autoantigen targeted determines in part the clinical manifestations, prognosis and response to treatment, serological tests are not only indispensable for initial diagnosis, but also for monitoring treatment efficacy. Importantly, knowing the autoantibody profile of MG patients could allow for more efficient personalized therapeutic approaches. Significant progress has been made over the past years toward the development of antigen-specific therapies, targeting only the specific immune cells or autoantibodies involved in the autoimmune response. In this review, we will present the progress made toward the development of novel sensitive autoantibody detection assays, the identification of new MG autoantigens, and the implications for improved antigen-specific therapeutics. These advancements increase our understanding of MG pathology and improve patient quality of life by providing faster, more accurate diagnosis and better disease management.
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Affiliation(s)
| | - Socrates J Tzartos
- Tzartos NeuroDiagnostics, Athens, Greece.,Department of Neurobiology, Hellenic Pasteur Institute, Athens, Greece
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13
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Fan W, Liang C, Ou M, Zou T, Sun F, Zhou H, Cui L. MicroRNA-146a Is a Wide-Reaching Neuroinflammatory Regulator and Potential Treatment Target in Neurological Diseases. Front Mol Neurosci 2020; 13:90. [PMID: 32581706 PMCID: PMC7291868 DOI: 10.3389/fnmol.2020.00090] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Accepted: 04/29/2020] [Indexed: 12/12/2022] Open
Abstract
Progressive functional deterioration and loss of neurons underlies neurological diseases and constitutes an important cause of disability and death worldwide. The causes of various types of neurological diseases often share several critical nerve-related cellular mechanisms and pathological features, particularly the neuroinflammatory response in the nervous system. A rapidly growing body of evidence indicates that various microRNAs play pivotal roles in these processes in neurological diseases and might be viable therapeutic targets. Among these microRNAs, microRNA-146a (miR-146a) stands out due to the rapid increase in recent literature on its mechanistic involvement in neurological diseases. In this review, we summarize and highlight the critical role of miR-146a in neurological diseases. MiR-146a polymorphisms are associated with the risk of neurological disease. Alterations in miR-146a expression levels are crucial events in the pathogenesis of numerous neurological diseases that are spatially and temporally diverse. Additionally, the target genes of miR-146a are involved in the regulation of pathophysiological processes in neurological diseases, particularly the neuroinflammatory response. In summary, miR-146a mainly plays a critical role in neuroinflammation during the progression of neurological diseases and might be a prospective biomarker and therapeutic target. Understanding the mechanisms by which miR-146a affects the neuroinflammatory response in different neurological injuries, different cell types, and even different stages of certain neurological diseases will pave the way for its use as a therapeutic target in neurodegenerative diseases.
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Affiliation(s)
- Weihao Fan
- Guangdong Key Laboratory of Age-Related Cardiac and Cerebral Diseases, Affiliated Hospital of Guangdong Medical University, Zhanjiang, China.,Department of Neurology, Affiliated Hospital of Guangdong Medical University, Zhanjiang, China
| | - Chunmei Liang
- Guangdong Key Laboratory of Age-Related Cardiac and Cerebral Diseases, Affiliated Hospital of Guangdong Medical University, Zhanjiang, China
| | - Mingqian Ou
- Guangdong Key Laboratory of Age-Related Cardiac and Cerebral Diseases, Affiliated Hospital of Guangdong Medical University, Zhanjiang, China.,Department of Neurology, Affiliated Hospital of Guangdong Medical University, Zhanjiang, China
| | - Ting Zou
- Guangdong Key Laboratory of Age-Related Cardiac and Cerebral Diseases, Affiliated Hospital of Guangdong Medical University, Zhanjiang, China.,Department of Neurology, Affiliated Hospital of Guangdong Medical University, Zhanjiang, China
| | - Furong Sun
- Guangdong Key Laboratory of Age-Related Cardiac and Cerebral Diseases, Affiliated Hospital of Guangdong Medical University, Zhanjiang, China.,Department of Neurology, Affiliated Hospital of Guangdong Medical University, Zhanjiang, China
| | - Haihong Zhou
- Guangdong Key Laboratory of Age-Related Cardiac and Cerebral Diseases, Affiliated Hospital of Guangdong Medical University, Zhanjiang, China.,Department of Neurology, Affiliated Hospital of Guangdong Medical University, Zhanjiang, China
| | - Lili Cui
- Guangdong Key Laboratory of Age-Related Cardiac and Cerebral Diseases, Affiliated Hospital of Guangdong Medical University, Zhanjiang, China
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14
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Fichtner ML, Jiang R, Bourke A, Nowak RJ, O'Connor KC. Autoimmune Pathology in Myasthenia Gravis Disease Subtypes Is Governed by Divergent Mechanisms of Immunopathology. Front Immunol 2020; 11:776. [PMID: 32547535 PMCID: PMC7274207 DOI: 10.3389/fimmu.2020.00776] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Accepted: 04/06/2020] [Indexed: 12/13/2022] Open
Abstract
Myasthenia gravis (MG) is a prototypical autoantibody mediated disease. The autoantibodies in MG target structures within the neuromuscular junction (NMJ), thus affecting neuromuscular transmission. The major disease subtypes of autoimmune MG are defined by their antigenic target. The most common target of pathogenic autoantibodies in MG is the nicotinic acetylcholine receptor (AChR), followed by muscle-specific kinase (MuSK) and lipoprotein receptor-related protein 4 (LRP4). MG patients present with similar symptoms independent of the underlying subtype of disease, while the immunopathology is remarkably distinct. Here we highlight these distinct immune mechanisms that describe both the B cell- and autoantibody-mediated pathogenesis by comparing AChR and MuSK MG subtypes. In our discussion of the AChR subtype, we focus on the role of long-lived plasma cells in the production of pathogenic autoantibodies, the IgG1 subclass mediated pathology, and contributions of complement. The similarities underlying the immunopathology of AChR MG and neuromyelitis optica (NMO) are highlighted. In contrast, MuSK MG is caused by autoantibody production by short-lived plasmablasts. MuSK MG autoantibodies are mainly of the IgG4 subclass which can undergo Fab-arm exchange (FAE), a process unique to this subclass. In FAE IgG4, molecules can dissociate into two halves and recombine with other half IgG4 molecules resulting in bispecific antibodies. Similarities between MuSK MG and other IgG4-mediated autoimmune diseases, including pemphigus vulgaris (PV) and chronic inflammatory demyelinating polyneuropathy (CIDP), are highlighted. Finally, the immunological distinctions are emphasized through presentation of biological therapeutics that provide clinical benefit depending on the MG disease subtype.
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Affiliation(s)
- Miriam L Fichtner
- Department of Neurology, School of Medicine, Yale University, New Haven, CT, United States.,Department of Immunobiology, School of Medicine, Yale University, New Haven, CT, United States
| | - Ruoyi Jiang
- Department of Immunobiology, School of Medicine, Yale University, New Haven, CT, United States
| | - Aoibh Bourke
- Trinity Hall, University of Cambridge, Cambridge, United Kingdom
| | - Richard J Nowak
- Department of Neurology, School of Medicine, Yale University, New Haven, CT, United States
| | - Kevin C O'Connor
- Department of Neurology, School of Medicine, Yale University, New Haven, CT, United States.,Department of Immunobiology, School of Medicine, Yale University, New Haven, CT, United States
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15
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Lazaridis K, Tzartos SJ. Autoantibody Specificities in Myasthenia Gravis; Implications for Improved Diagnostics and Therapeutics. Front Immunol 2020; 11:212. [PMID: 32117321 PMCID: PMC7033452 DOI: 10.3389/fimmu.2020.00212] [Citation(s) in RCA: 111] [Impact Index Per Article: 27.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2019] [Accepted: 01/27/2020] [Indexed: 12/13/2022] Open
Abstract
Myasthenia gravis (MG) is an autoimmune disease characterized by muscle weakness and fatiguability of skeletal muscles. It is an antibody-mediated disease, caused by autoantibodies targeting neuromuscular junction proteins. In the majority of patients (~85%) antibodies against the muscle acetylcholine receptor (AChR) are detected, while in 6% antibodies against the muscle-specific kinase (MuSK) are detected. In ~10% of MG patients no autoantibodies can be found with the classical diagnostics for AChR and MuSK antibodies (seronegative MG, SN-MG), making the improvement of methods for the detection of known autoantibodies or the discovery of novel antigenic targets imperative. Over the past years, using cell-based assays or improved highly sensitive immunoprecipitation assays, it has been possible to detect autoantibodies in previously SN-MG patients, including the identification of the low-density lipoprotein receptor-related protein 4 (LRP4) as a third MG autoantigen, as well as AChR and MuSK antibodies undetectable by conventional methods. Furthermore, antibodies against other extracellular or intracellular targets, such as titin, the ryanodine receptor, agrin, collagen Q, Kv1.4 potassium channels and cortactin have been found in some MG patients, which can be useful biomarkers. In addition to the improvement of diagnosis, the identification of the patients' autoantibody specificity is important for their stratification into respective subgroups, which can differ in terms of clinical manifestations, prognosis and most importantly their response to therapies. The knowledge of the autoantibody profile of MG patients would allow for a therapeutic strategy tailored to their MG subgroup. This is becoming especially relevant as there is increasing progress toward the development of antigen-specific therapies, targeting only the specific autoantibodies or immune cells involved in the autoimmune response, such as antigen-specific immunoadsorption, which have shown promising results. We will herein review the advances made by us and others toward development of more sensitive detection methods and the identification of new antibody targets in MG, and discuss their significance in MG diagnosis and therapy. Overall, the development of novel autoantibody assays is aiding in the more accurate diagnosis and classification of MG patients, supporting the development of advanced therapeutics and ultimately the improvement of disease management and patient quality of life.
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Affiliation(s)
| | - Socrates J Tzartos
- Department of Neurobiology, Hellenic Pasteur Institute, Athens, Greece.,Tzartos NeuroDiagnostics, Athens, Greece
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16
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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: 80] [Impact Index Per Article: 16.0] [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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17
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Li QR, Ni WP, Lei NJ, Yang JY, Xuan XY, Liu PP, Gong GM, Yan F, Feng YS, Zhao R, Du Y. The overexpression of Fra1 disorders the inflammatory cytokine secretion by mTEC of myasthenia gravis thymus. Scand J Immunol 2018; 88:e12676. [PMID: 29807388 DOI: 10.1111/sji.12676] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Accepted: 05/22/2018] [Indexed: 12/01/2022]
Abstract
The thymus of a myasthenia gravis (MG) patient is often accompanied by and effected with follicular hyperplasia. Inflammatory cytokines in thymus induce the formation of germinal centres (GC). MG thymic inflammatory cytokines are predominantly secreted by stromal cells. Our previous studies revealed that the expression level of the Fra1 protein, which is a Fos member of the activator protein 1 transcription factors (AP-1), was higher in the MG thymus compared with that of the normal thymus. Based on that, we demonstrated that Fra1 was mainly expressed in medulla thymic epithelial cells (mTECs) and that the rate of Fra1 positive mTECs in the MG thymus was higher than normal. In vitro, we found that the expression of CCL-5, CCL-19 and CCL-21 could be regulated by Fra1 in mTEC and that IL-1β, IL-6, IL-8 and ICAM1 were downregulated in the Fra1 overexpression group and upregulated in the Fra1 knock-down group. Meanwhile, we detected that the expression levels of suppressor of cytokine signalling 3 (SOCS3) were significantly upregulated along with the overexpression of Fra1. Hence, we considered that the overexpression of Fra1 disrupted inflammatory cytokine secretion by mTEC in the MG thymus and that STAT3 and SOCS3 were strongly involved in this process.
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Affiliation(s)
- Q-R Li
- Department of Immunology, School of Basic Medical, Zhengzhou University, Zhengzhou, China
| | - W-P Ni
- Department of Immunology, School of Basic Medical, Zhengzhou University, Zhengzhou, China
| | - N-J Lei
- Department of Immunology, School of Basic Medical, Zhengzhou University, Zhengzhou, China
| | - J-Y Yang
- College of Veterinary Medicine, North West Agriculture and Forestry University, Zhengzhou, China
| | - X-Y Xuan
- Department of Immunology, School of Basic Medical, Zhengzhou University, Zhengzhou, China
| | - P-P Liu
- Department of Immunology, School of Basic Medical, Zhengzhou University, Zhengzhou, China
| | - G-M Gong
- Department of Immunology, School of Basic Medical, Zhengzhou University, Zhengzhou, China
| | - F Yan
- Department of Immunology, School of Basic Medical, Zhengzhou University, Zhengzhou, China
| | - Y-S Feng
- Department of Immunology, School of Basic Medical, Zhengzhou University, Zhengzhou, China
| | - R Zhao
- Department of Immunology, School of Basic Medical, Zhengzhou University, Zhengzhou, China
| | - Y Du
- Department of Immunology, School of Basic Medical, Zhengzhou University, Zhengzhou, China
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18
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Khan H, Marya, Amin S, Kamal MA, Patel S. Flavonoids as acetylcholinesterase inhibitors: Current therapeutic standing and future prospects. Biomed Pharmacother 2018; 101:860-870. [PMID: 29635895 DOI: 10.1016/j.biopha.2018.03.007] [Citation(s) in RCA: 140] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Revised: 03/04/2018] [Accepted: 03/05/2018] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND Acetylcholinesterase (AChE), a serine hydrolase, is primarily responsible for the termination of signal transmission in the cholinergic system, owing to its outstanding hydrolyzing potential. Its substrate acetylcholine (ACh), is a neurotransmitter of the cholinergic system, with a predominant effect on motor neurons involved in memory formation. So, by decreasing the activity of this enzyme by employment of specific inhibitors, a number of motor neuron disorders such as myasthenia gravis, glaucoma, Lewy body dementia, and Alzheimer's disease, among others, can be treated. However, the current-available AChE inhibitors have several limitations in terms of efficacy, therapeutic range, and safety. SCOPE AND APPROACH Primarily due to the non-compliance of current therapies, new, effective and safe inhibitors are being searched for, especially those which act through multiple receptor sites, but do not elicit undesirable effects. In this regard, the evaluation of phytochemicals such as flavonoids, can be a rational approach. The therapeutic potential of flavonoids has already been recognized agaisnt several ailments. This review deals with various plant-derived flavonoids, their preclinical potential as AChE inhibitors, in established assays, possible mechanisms of action, and structural activity relationship (SAR). RESULTS AND CONCLUSIONS Subsequently, a number of plant-derived flavonoids with outstanding efficacy and potency as AChE inhibitors, the mechanistic, their safety profiles, and pharmacokinetic attributes have been discussed. Through derivatization of these reported flavonoids, some limitation in efficacy or pharmacokinetic parameters can be addressed. The selected flavonoids ought to be tested in clinical studies to discover new neuro-therapeutic candidates.
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Affiliation(s)
- Haroon Khan
- Department of Pharmacy, Abdul Wali Khan University, Mardan, 23200, Pakistan.
| | - Marya
- Department of Pharmacy, Abdul Wali Khan University, Mardan, 23200, Pakistan
| | - Surriya Amin
- Department of Botany, Islamia College Peshawar, Pakistan
| | - Mohammad Amjad Kamal
- King Fahd Medical Research Center, King Abdulaziz University, Saudi Arabia; Enzymoics, 7 Peterlee Place, Hebersham, NSW, 2770, Australia; Novel Global Community Educational Foundation, Australia
| | - Seema Patel
- Bioinformatics and Medical Informatics Research Center, San Diego State University, San Diego, CA, 92182, USA.
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Cron MA, Maillard S, Villegas J, Truffault F, Sudres M, Dragin N, Berrih-Aknin S, Le Panse R. Thymus involvement in early-onset myasthenia gravis. Ann N Y Acad Sci 2017; 1412:137-145. [DOI: 10.1111/nyas.13519] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2017] [Revised: 09/05/2017] [Accepted: 09/12/2017] [Indexed: 12/21/2022]
Affiliation(s)
- Mélanie A. Cron
- INSERM U974; Paris France
- UPMC Sorbonne Universités; Paris France
- AIM; Institut de myologie; Paris France
| | - Solène Maillard
- INSERM U974; Paris France
- UPMC Sorbonne Universités; Paris France
- AIM; Institut de myologie; Paris France
| | - José Villegas
- INSERM U974; Paris France
- UPMC Sorbonne Universités; Paris France
- AIM; Institut de myologie; Paris France
| | - Frédérique Truffault
- INSERM U974; Paris France
- UPMC Sorbonne Universités; Paris France
- AIM; Institut de myologie; Paris France
| | - Muriel Sudres
- INSERM U974; Paris France
- UPMC Sorbonne Universités; Paris France
- AIM; Institut de myologie; Paris France
| | - Nadine Dragin
- INSERM U974; Paris France
- UPMC Sorbonne Universités; Paris France
- AIM; Institut de myologie; Paris France
| | - Sonia Berrih-Aknin
- INSERM U974; Paris France
- UPMC Sorbonne Universités; Paris France
- AIM; Institut de myologie; Paris France
| | - Rozen Le Panse
- INSERM U974; Paris France
- UPMC Sorbonne Universités; Paris France
- AIM; Institut de myologie; Paris France
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20
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Characterization of an anti-fetal AChR monoclonal antibody isolated from a myasthenia gravis patient. Sci Rep 2017; 7:14426. [PMID: 29089519 PMCID: PMC5663942 DOI: 10.1038/s41598-017-14350-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2017] [Accepted: 10/10/2017] [Indexed: 11/24/2022] Open
Abstract
We report here the sequence and functional characterization of a recombinantly expressed autoantibody (mAb 131) previously isolated from a myasthenia gravis patient by immortalization of thymic B cells using Epstein-Barr virus and TLR9 activation. The antibody is characterized by a high degree of somatic mutations as well as a 6 amino acid insertion within the VHCDR2. The recombinant mAb 131 is specific for the γ-subunit of the fetal AChR to which it bound with sub-nanomolar apparent affinity, and detected the presence of fetal AChR on a number of rhabdomyosarcoma cell lines. Mab 131 blocked one of the two α-bungarotoxin binding sites on the fetal AChR, and partially blocked the binding of an antibody (mAb 637) to the α-subunit of the AChR, suggesting that both antibodies bind at or near one ACh binding site at the α/γ subunit interface. However, mAb 131 did not reduce fetal AChR ion channel currents in electrophysiological experiments. These results indicate that mAb 131, although generated from an MG patient, is unlikely to be pathogenic and may make it a potentially useful reagent for studies of myasthenia gravis, rhabdomyosarcoma and arthrogryposis multiplex congenita which can be caused by fetal-specific AChR-blocking autoantibodies.
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21
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Analysis of peripheral B cells and autoantibodies against the anti-nicotinic acetylcholine receptor derived from patients with myasthenia gravis using single-cell manipulation tools. PLoS One 2017; 12:e0185976. [PMID: 29040265 PMCID: PMC5645109 DOI: 10.1371/journal.pone.0185976] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2016] [Accepted: 09/23/2017] [Indexed: 11/23/2022] Open
Abstract
The majority of patients with myasthenia gravis (MG), an organ-specific autoimmune disease, harbor autoantibodies that attack the nicotinic acetylcholine receptor (nAChR-Abs) at the neuromuscular junction of skeletal muscles, resulting in muscle weakness. Single cell manipulation technologies coupled with genetic engineering are very powerful tools to examine T cell and B cell repertoires and the dynamics of adaptive immunity. These tools have been utilized to develop mAbs in parallel with hybridomas, phage display technologies and B-cell immortalization. By applying a single cell technology and novel high-throughput cell-based binding assays, we identified peripheral B cells that produce pathogenic nAChR-Abs in patients with MG. Although anti-nAChR antibodies produced by individual peripheral B cells generally exhibited low binding affinity for the α-subunit of the nAChR and great sequence diversity, a small fraction of these antibodies bound with high affinity to native-structured nAChRs on cell surfaces. B12L, one such Ab isolated here, competed with a rat Ab (mAb35) for binding to the human nAChR and thus considered to recognize the main immunogenic region (MIR). By evaluating the Ab in in vitro cell-based assays and an in vivo rat passive transfer model, B12L was found to act as a pathogenic Ab in rodents and presumably in humans.These findings suggest that B cells in peripheral blood may impact MG pathogenicity. Our methodology can be applied not only to validate pathogenic Abs as molecular target of MG treatment, but also to discover and analyze Ab production systems in other human diseases.
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22
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Ayyar BV, Atassi MZ. Development of humanized scFv antibody fragment(s) that targets and blocks specific HLA alleles linked to myasthenia gravis. Appl Microbiol Biotechnol 2017; 101:8165-8179. [DOI: 10.1007/s00253-017-8557-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2017] [Revised: 09/25/2017] [Accepted: 09/27/2017] [Indexed: 01/13/2023]
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Yi JS, Guptill JT, Stathopoulos P, Nowak RJ, O'Connor KC. B cells in the pathophysiology of myasthenia gravis. Muscle Nerve 2017; 57:172-184. [PMID: 28940642 DOI: 10.1002/mus.25973] [Citation(s) in RCA: 73] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/07/2017] [Indexed: 12/21/2022]
Abstract
Myasthenia gravis (MG) is an archetypal autoimmune disease. The pathology is characterized by autoantibodies to the acetylcholine receptor (AChR) in most patients or to muscle-specific tyrosine kinase (MuSK) in others and to a growing number of other postsynaptic proteins in smaller subsets. A decrease in the number of functional AChRs or functional interruption of the AChR within the muscle end plate of the neuromuscular junction is caused by pathogenic autoantibodies. Although the molecular immunology underpinning the pathology is well understood, much remains to be learned about the cellular immunology contributing to the production of autoantibodies. This Review documents research concerning the immunopathology of MG, bringing together evidence principally from human studies with an emphasis on the role of adaptive immunity and B cells in particular. Proposed mechanisms for autoimmunity, which take into account that different types of MG may incorporate divergent immunopathology, are offered. Muscle Nerve 57: 172-184, 2018.
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Affiliation(s)
- John S Yi
- Division of Surgical Sciences, Department of Surgery, Duke University Medical Center, Durham, North Carolina, USA
| | - Jeffrey T Guptill
- Department of Neurology, Neuromuscular Section, Duke University Medical Center, Durham, North Carolina, USA
| | - Panos Stathopoulos
- Department of Neurology, Yale School of Medicine, Room 353J, 300 George Street, New Haven, Connecticut, 06511, USA
| | - Richard J Nowak
- Department of Neurology, Yale School of Medicine, Room 353J, 300 George Street, New Haven, Connecticut, 06511, USA
| | - Kevin C O'Connor
- Department of Neurology, Yale School of Medicine, Room 353J, 300 George Street, New Haven, Connecticut, 06511, USA
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Gies V, Guffroy A, Korganow AS. [Thymic B cells: not simple bystanders of T cell lymphopoiesis]. Med Sci (Paris) 2017; 33:771-778. [PMID: 28945568 DOI: 10.1051/medsci/20173308023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The thymus is the central site for the differentiation and selection of T cells. It has been known for decades that B lymphocytes reside in the thymus, but little attention has been paid to this unique population. Thymic B cells are mainly located in the medulla and at the cortico-medullary junction. They develop intrathymically, do not recirculate and harbor a distinct phenotype in comparison to peripheral B cells. Furthermore, because of their activated phenotype and their precise histological localization, they have been suspected to play a role in the selection of self-reactive T cells. But it is only during this last decade that murine and human studies have highlighted their functions, such as antigen-presenting cells shaping the T cell repertoire. These works have demonstrated the major role of thymic B cells in the immune system.
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Affiliation(s)
- Vincent Gies
- CNRS UPR 3572, Immunopathologie et chimie thérapeutique, Laboratoire d'Excellence Médalis, Institut de biologie moléculaire et cellulaire (IBMC), 67000 Strasbourg, France. Service d'immunologie clinique et de médecine interne, Centre national de référence des maladies auto-immunes rares, Hôpitaux universitaires de Strasbourg, 67091 Strasbourg, France
| | - Aurélien Guffroy
- CNRS UPR 3572, Immunopathologie et chimie thérapeutique, Laboratoire d'Excellence Médalis, Institut de biologie moléculaire et cellulaire (IBMC), 67000 Strasbourg, France. Service d'immunologie clinique et de médecine interne, Centre national de référence des maladies auto-immunes rares, Hôpitaux universitaires de Strasbourg, 67091 Strasbourg, France
| | - Anne-Sophie Korganow
- CNRS UPR 3572, Immunopathologie et chimie thérapeutique, Laboratoire d'Excellence Médalis, Institut de biologie moléculaire et cellulaire (IBMC), 67000 Strasbourg, France. Service d'immunologie clinique et de médecine interne, Centre national de référence des maladies auto-immunes rares, Hôpitaux universitaires de Strasbourg, 67091 Strasbourg, France
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25
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Robinet M, Villeret B, Maillard S, Cron MA, Berrih-Aknin S, Le Panse R. Use of Toll-Like Receptor Agonists to Induce Ectopic Lymphoid Structures in Myasthenia Gravis Mouse Models. Front Immunol 2017; 8:1029. [PMID: 28970832 PMCID: PMC5609563 DOI: 10.3389/fimmu.2017.01029] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Accepted: 08/09/2017] [Indexed: 12/21/2022] Open
Abstract
Myasthenia gravis (MG) is an autoimmune disease mediated by autoantibodies against the acetylcholine receptor (AChR) at the neuromuscular junction. MG symptoms are characterized by muscle weaknesses. The thymus of MG patients is very often abnormal and possesses all the characteristics of tertiary lymphoid organs such as neoangiogenesis processes, overexpression of inflammatory cytokines and chemokines, and infiltration of B lymphocytes leading to ectopic germinal center (GC) development. We previously demonstrated that injections of mice with polyinosinic–polycytidylic acid [Poly(I:C)], a synthetic double-stranded RNA mimicking viral infection, induce thymic changes and trigger MG symptoms. Upon Poly(I:C) injections, we observed increased thymic expressions of α-AChR, interferon-β and chemokines such as CXCL13 and CCL21 leading to B-cell recruitment. However, these changes were only transient. In order to develop an experimental MG model associated with thymic GCs, we used Poly(I:C) in the classical experimental autoimmune MG model induced by immunizations with purified AChR emulsified in complete Freund’s adjuvant. We observed that Poly(I:C) strongly favored the development of MG as almost all mice displayed MG symptoms. Nevertheless, we did not observe any ectopic GC development. We next challenged mice with Poly(I:C) together with other toll-like receptor (TLR) agonists known to be involved in GC development and that are overexpressed in MG thymuses. Imiquimod and CpG oligodeoxynucleotides that activate TLR7 and TLR9, respectively, did not induce thymic changes. In contrast, lipopolysaccharide that activates TLR4 potentiated Poly(I:C) effects and induced a significant expression of CXCL13 mRNA in the thymus associated with a higher recruitment of B cells that induced over time thymic B-lymphoid structures. Altogether, these data suggest that tertiary lymphoid genesis in MG thymus could result from a combined activation of TLR signaling pathways.
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Affiliation(s)
- Marieke Robinet
- INSERM U974, Paris, France.,UPMC Sorbonne Universités, Paris, France.,AIM, Institut de myologie, Paris, France
| | - Bérengère Villeret
- INSERM U974, Paris, France.,UPMC Sorbonne Universités, Paris, France.,AIM, Institut de myologie, Paris, France
| | - Solène Maillard
- INSERM U974, Paris, France.,UPMC Sorbonne Universités, Paris, France.,AIM, Institut de myologie, Paris, France
| | - Mélanie A Cron
- INSERM U974, Paris, France.,UPMC Sorbonne Universités, Paris, France.,AIM, Institut de myologie, Paris, France
| | - Sonia Berrih-Aknin
- INSERM U974, Paris, France.,UPMC Sorbonne Universités, Paris, France.,AIM, Institut de myologie, Paris, France
| | - Rozen Le Panse
- INSERM U974, Paris, France.,UPMC Sorbonne Universités, Paris, France.,AIM, Institut de myologie, Paris, France
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26
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Danikowski KM, Jayaraman S, Prabhakar BS. Regulatory T cells in multiple sclerosis and myasthenia gravis. J Neuroinflammation 2017; 14:117. [PMID: 28599652 PMCID: PMC5466736 DOI: 10.1186/s12974-017-0892-8] [Citation(s) in RCA: 207] [Impact Index Per Article: 29.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Accepted: 05/29/2017] [Indexed: 01/09/2023] Open
Abstract
Multiple sclerosis (MS) is a chronic debilitating disease of the central nervous system primarily mediated by T lymphocytes with specificity to neuronal antigens in genetically susceptible individuals. On the other hand, myasthenia gravis (MG) primarily involves destruction of the neuromuscular junction by antibodies specific to the acetylcholine receptor. Both autoimmune diseases are thought to result from loss of self-tolerance, which allows for the development and function of autoreactive lymphocytes. Although the mechanisms underlying compromised self-tolerance in these and other autoimmune diseases have not been fully elucidated, one possibility is numerical, functional, and/or migratory deficits in T regulatory cells (Tregs). Tregs are thought to play a critical role in the maintenance of peripheral immune tolerance. It is believed that Tregs function by suppressing the effector CD4+ T cell subsets that mediate autoimmune responses. Dysregulation of suppressive and migratory markers on Tregs have been linked to the pathogenesis of both MS and MG. For example, genetic abnormalities have been found in Treg suppressive markers CTLA-4 and CD25, while others have shown a decreased expression of FoxP3 and IL-10. Furthermore, elevated levels of pro-inflammatory cytokines such as IL-6, IL-17, and IFN-γ secreted by T effectors have been noted in MS and MG patients. This review provides several strategies of treatment which have been shown to be effective or are proposed as potential therapies to restore the function of various Treg subsets including Tr1, iTr35, nTregs, and iTregs. Strategies focusing on enhancing the Treg function find importance in cytokines TGF-β, IDO, interleukins 10, 27, and 35, and ligands Jagged-1 and OX40L. Likewise, strategies which affect Treg migration involve chemokines CCL17 and CXCL11. In pre-clinical animal models of experimental autoimmune encephalomyelitis (EAE) and experimental autoimmune myasthenia gravis (EAMG), several strategies have been shown to ameliorate the disease and thus appear promising for treating patients with MS or MG.
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Affiliation(s)
- K M Danikowski
- Department of Microbiology and Immunology, University of Illinois at Chicago, Chicago, IL, 60612, USA
| | - S Jayaraman
- Department of Microbiology and Immunology, University of Illinois at Chicago, Chicago, IL, 60612, USA
| | - B S Prabhakar
- Department of Microbiology and Immunology, University of Illinois at Chicago, Chicago, IL, 60612, USA.
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27
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Hinge-deleted IgG4 blocker therapy for acetylcholine receptor myasthenia gravis in rhesus monkeys. Sci Rep 2017; 7:992. [PMID: 28428630 PMCID: PMC5430546 DOI: 10.1038/s41598-017-01019-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2016] [Accepted: 03/28/2017] [Indexed: 11/08/2022] Open
Abstract
Autoantibodies against ion channels are the cause of numerous neurologic autoimmune disorders. Frequently, such pathogenic autoantibodies have a restricted epitope-specificity. In such cases, competing antibody formats devoid of pathogenic effector functions (blocker antibodies) have the potential to treat disease by displacing autoantibodies from their target. Here, we have used a model of the neuromuscular autoimmune disease myasthenia gravis in rhesus monkeys (Macaca mulatta) to test the therapeutic potential of a new blocker antibody: MG was induced by passive transfer of pathogenic acetylcholine receptor-specific monoclonal antibody IgG1-637. The effect of the blocker antibody (IgG4Δhinge-637, the hinge-deleted IgG4 version of IgG1-637) was assessed using decrement measurements and single-fiber electromyography. Three daily doses of 1.7 mg/kg IgG1-637 (cumulative dose 5 mg/kg) induced impairment of neuromuscular transmission, as demonstrated by significantly increased jitter, synaptic transmission failures (blockings) and a decrease in the amplitude of the compound muscle action potentials during repeated stimulations (decrement), without showing overt symptoms of muscle weakness. Treatment with three daily doses of 10 mg/kg IgG4Δhinge-637 significantly reduced the IgG1-637-induced increase in jitter, blockings and decrement. Together, these results represent proof-of principle data for therapy of acetylcholine receptor-myasthenia gravis with a monovalent antibody format that blocks binding of pathogenic autoantibodies.
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28
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Vander Heiden JA, Stathopoulos P, Zhou JQ, Chen L, Gilbert TJ, Bolen CR, Barohn RJ, Dimachkie MM, Ciafaloni E, Broering TJ, Vigneault F, Nowak RJ, Kleinstein SH, O'Connor KC. Dysregulation of B Cell Repertoire Formation in Myasthenia Gravis Patients Revealed through Deep Sequencing. THE JOURNAL OF IMMUNOLOGY 2017; 198:1460-1473. [PMID: 28087666 DOI: 10.4049/jimmunol.1601415] [Citation(s) in RCA: 67] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2016] [Accepted: 12/13/2016] [Indexed: 01/14/2023]
Abstract
Myasthenia gravis (MG) is a prototypical B cell-mediated autoimmune disease affecting 20-50 people per 100,000. The majority of patients fall into two clinically distinguishable types based on whether they produce autoantibodies targeting the acetylcholine receptor (AChR-MG) or muscle specific kinase (MuSK-MG). The autoantibodies are pathogenic, but whether their generation is associated with broader defects in the B cell repertoire is unknown. To address this question, we performed deep sequencing of the BCR repertoire of AChR-MG, MuSK-MG, and healthy subjects to generate ∼518,000 unique VH and VL sequences from sorted naive and memory B cell populations. AChR-MG and MuSK-MG subjects displayed distinct gene segment usage biases in both VH and VL sequences within the naive and memory compartments. The memory compartment of AChR-MG was further characterized by reduced positive selection of somatic mutations in the VH CDR and altered VH CDR3 physicochemical properties. The VL repertoire of MuSK-MG was specifically characterized by reduced V-J segment distance in recombined sequences, suggesting diminished VL receptor editing during B cell development. Our results identify large-scale abnormalities in both the naive and memory B cell repertoires. Particular abnormalities were unique to either AChR-MG or MuSK-MG, indicating that the repertoires reflect the distinct properties of the subtypes. These repertoire abnormalities are consistent with previously observed defects in B cell tolerance checkpoints in MG, thereby offering additional insight regarding the impact of tolerance defects on peripheral autoimmune repertoires. These collective findings point toward a deformed B cell repertoire as a fundamental component of MG.
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Affiliation(s)
- Jason A Vander Heiden
- Interdepartmental Program in Computational Biology and Bioinformatics, Yale University, New Haven, CT 06511
| | | | - Julian Q Zhou
- Interdepartmental Program in Computational Biology and Bioinformatics, Yale University, New Haven, CT 06511
| | - Luan Chen
- Interdepartmental Program in Computational Biology and Bioinformatics, Yale University, New Haven, CT 06511
| | | | - Christopher R Bolen
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA 94305
| | - Richard J Barohn
- Department of Neurology, University of Kansas Medical Center, Kansas City, KS 66160
| | - Mazen M Dimachkie
- Department of Neurology, University of Kansas Medical Center, Kansas City, KS 66160
| | - Emma Ciafaloni
- Department of Neurology, University of Rochester School of Medicine, Rochester, NY 14642
| | | | | | - Richard J Nowak
- Department of Neurology, Yale School of Medicine, New Haven, CT 06511
| | - Steven H Kleinstein
- Interdepartmental Program in Computational Biology and Bioinformatics, Yale University, New Haven, CT 06511; .,Department of Immunobiology, Yale School of Medicine, New Haven, CT 06511; and.,Department of Pathology, Yale School of Medicine, New Haven, CT 06511
| | - Kevin C O'Connor
- Department of Neurology, Yale School of Medicine, New Haven, CT 06511;
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29
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Fraussen J, de Bock L, Somers V. B cells and antibodies in progressive multiple sclerosis: Contribution to neurodegeneration and progression. Autoimmun Rev 2016; 15:896-9. [DOI: 10.1016/j.autrev.2016.07.008] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2016] [Accepted: 06/08/2016] [Indexed: 01/17/2023]
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30
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Affiliation(s)
- Sonia Berrih-Aknin
- INSERM U974; Paris France
- CNRS FRE3617; Paris France
- Sorbonne University; UPMC Univ Paris 06; Paris France
- AIM; Institute of Myology; Paris France
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31
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Jakubíková M, Piťha J, Marečková H, Týblová M, Nováková I, Schutzner J. Two-year outcome of thymectomy with or without immunosuppressive treatment in nonthymomatous myasthenia gravis and its effect on regulatory T cells. J Neurol Sci 2015; 358:101-6. [PMID: 26320610 DOI: 10.1016/j.jns.2015.08.029] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2015] [Revised: 08/03/2015] [Accepted: 08/18/2015] [Indexed: 01/09/2023]
Abstract
BACKGROUND Myasthenia gravis (MG) is the autoimmune disorder in which the thymus is considered the pathogenic organ. Thymectomy (TE) is a therapeutic option for MG and often ameliorates clinical symptoms. METHODS We evaluated clinical features and outcomes after TE in patients without thymoma and the influence of TE with or without concomitant immunotherapy on the CD4(+)CD25(+) regulatory T cell subpopulation of lymphocytes in peripheral blood in defined followed groups of nonthymomatous MG patients. RESULTS A total of 46 patients with generalized MG who underwent transsternal TE were identified. Neurologic outcomes after TE were favorable for the majority of patients mainly from the group treated with corticosteroids or combined immunosuppressive treatment. TEs with immunosuppressive treatment in MG patients were associated with increased percentages of CD4(+)CD25(+) cells (p<0.001). No significant change in the postoperative levels of CD4(+)CD25(+) cells was observed in thymectomized patients who preoperatively only received pyridostigmine. Also their clinical response to TE after 2 years of follow-up was worst of all followed groups. CONCLUSIONS The exact mechanism by which TE ameliorates symptoms of MG is yet not clear. These observations indicate that increased percentages of CD4(+)CD25(+) T cells in MG may be related to disease stability and that TE and synergistic effect with concomitant, continuing immunotherapy augmented the proportion of CD4(+)CD25(+) T cells. On the basis of our observations TE alone is not enough to increase the number of circulating CD4(+)CD25(+) regulatory T cells and to establish complete stable remission.
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Affiliation(s)
- Michala Jakubíková
- Department of Neurology and Clinical Neuroscience Center, 1st Faculty of Medicine of Charles University and General Teaching Hospital in Prague, Czech Republic.
| | - Jiří Piťha
- Department of Neurology and Clinical Neuroscience Center, 1st Faculty of Medicine of Charles University and General Teaching Hospital in Prague, Czech Republic
| | - Helena Marečková
- Department of Immunology and Microbiology, 1st Faculty of Medicine of Charles University and General Teaching Hospital in Prague, Czech Republic
| | - Michaela Týblová
- Department of Neurology and Clinical Neuroscience Center, 1st Faculty of Medicine of Charles University and General Teaching Hospital in Prague, Czech Republic
| | - Iveta Nováková
- Department of Neurology and Clinical Neuroscience Center, 1st Faculty of Medicine of Charles University and General Teaching Hospital in Prague, Czech Republic
| | - Jan Schutzner
- Third Department of Surgery, 1st Faculty of Medicine of Charles University and University Hospital Motol, Czech Republic
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32
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Jiménez-Dalmaroni MJ, Gerswhin ME, Adamopoulos IE. The critical role of toll-like receptors--From microbial recognition to autoimmunity: A comprehensive review. Autoimmun Rev 2015; 15:1-8. [PMID: 26299984 DOI: 10.1016/j.autrev.2015.08.009] [Citation(s) in RCA: 179] [Impact Index Per Article: 19.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2015] [Accepted: 08/14/2015] [Indexed: 12/13/2022]
Abstract
Toll-like receptors (TLRs) constitute an important mechanism in the activation of innate immune cells including monocytes, macrophages and dendritic cells. Macrophage activation by TLRs is pivotal in the initiation of the rapid expression of pro-inflammatory cytokines TNF, IL-1β and IL-6 while promoting Th17 responses, all of which play critical roles in autoimmunity. Surprisingly, in inflammatory arthritis, activation of specific TLRs can not only induce but also inhibit cellular processes associated with bone destruction. The intercellular and intracellular orchestration of signals from different TLRs, their endogenous or microbial ligands and accessory molecules determine the activating or inhibitory responses. Herein, we review the TLR-mediated activation of innate immune cells in their activation and differentiation to osteoclasts and the capacity of these signals to contribute to bone destruction in arthritis. Detailed understanding of the opposing mechanisms of TLRs in the induction and suppression of cellular processes in arthritis may pave the way to develop novel therapies to treat autoimmunity.
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Affiliation(s)
| | - M Eric Gerswhin
- Department of Internal Medicine, Division of Rheumatology, Allergy and Clinical Immunology, University of California at Davis School of Medicine, Davis, CA, 95616, USA
| | - Iannis E Adamopoulos
- Department of Internal Medicine, Division of Rheumatology, Allergy and Clinical Immunology, University of California at Davis School of Medicine, Davis, CA, 95616, USA; Institute for Pediatric Regenerative Medicine, Shriners Hospitals for Children Northern California, CA, 95817, USA.
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33
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Yamano T, Steinert M, Klein L. Thymic B Cells and Central T Cell Tolerance. Front Immunol 2015; 6:376. [PMID: 26257742 PMCID: PMC4510420 DOI: 10.3389/fimmu.2015.00376] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2015] [Accepted: 07/09/2015] [Indexed: 11/29/2022] Open
Abstract
Central T cell tolerance is believed to be mainly induced by thymic dendritic cells and medullary thymic epithelial cells. The thymus also harbors substantial numbers of B cells. These may arise though intrathymic B lymphopoiesis or immigration from the bloodstream. Importantly, and in contrast to resting “mainstream” B cells in the periphery, thymic B cells display elevated levels of MHC class II and constitutively express CD80. Arguably, their most unexpected feature is the expression of autoimmune regulator. These unique features of thymic B cells result from a licensing process that involves cross-talk with CD4 single-positive T cells and CD40 signaling. Together, these recent findings suggest that B cells play a more prominent role as thymic APCs than previously appreciated.
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Affiliation(s)
- Tomoyoshi Yamano
- Institute for Immunology, Ludwig-Maximilians-University Munich , Munich , Germany
| | - Madlen Steinert
- Institute for Immunology, Ludwig-Maximilians-University Munich , Munich , Germany
| | - Ludger Klein
- Institute for Immunology, Ludwig-Maximilians-University Munich , Munich , Germany
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34
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Lu FT, Yang W, Wang YH, Ma HD, Tang W, Yang JB, Li L, Ansari AA, Lian ZX. Thymic B cells promote thymus-derived regulatory T cell development and proliferation. J Autoimmun 2015; 61:62-72. [PMID: 26071985 DOI: 10.1016/j.jaut.2015.05.008] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2015] [Revised: 05/19/2015] [Accepted: 05/21/2015] [Indexed: 01/10/2023]
Abstract
Thymic CD4(+) FoxP3(+) regulatory T (Treg) cells are critical for the development of immunological tolerance and immune homeostasis and requires contributions of both thymic dendritic and epithelial cells. Although B cells have been reported to be present within the thymus, there has not hitherto been a definition of their role in immune cell development and, in particular, whether or how they contribute to the Treg cellular thymic compartment. Herein, using both phenotypic and functional approaches, we demonstrate that thymic B cells contribute to the maintenance of thymic Treg cells and, using an in vitro culture system, demonstrate that thymic B cells contribute to the size of the thymic Treg compartment via cell-cell MHC II contact and the involvement of two independent co-stimulatory pathways that include interactions between the CD40/CD80/CD86 co-stimulatory molecules. Our data also suggest that thymic B cells promote the generation of thymic Treg cell precursors (pre-Treg cells), but not the conversion of FoxP3(+) Treg cells from pre-Treg cells. In addition, thymic B cells directly promote the proliferation of thymic Treg cells that is MHC II contact dependent with a minimal if any role for co-stimulatory molecules including CD40/CD80/CD86. Both pathways are independent of TGFβ. In conclusion, we rigorously define the critical role of thymic B cells in the development of thymic Treg cells from non-Treg to precursor stage and in the proliferation of mature thymic Treg cells.
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Affiliation(s)
- Fang-Ting Lu
- Liver Immunology Laboratory, Institute of Immunology and The CAS Key Laboratory of Innate Immunity and Chronic Disease, School of Life Sciences and Medical Center, University of Science and Technology of China, Hefei, Anhui 230027, China.
| | - Wei Yang
- Liver Immunology Laboratory, Institute of Immunology and The CAS Key Laboratory of Innate Immunity and Chronic Disease, School of Life Sciences and Medical Center, University of Science and Technology of China, Hefei, Anhui 230027, China.
| | - Yin-Hu Wang
- Liver Immunology Laboratory, Institute of Immunology and The CAS Key Laboratory of Innate Immunity and Chronic Disease, School of Life Sciences and Medical Center, University of Science and Technology of China, Hefei, Anhui 230027, China.
| | - Hong-Di Ma
- Liver Immunology Laboratory, Institute of Immunology and The CAS Key Laboratory of Innate Immunity and Chronic Disease, School of Life Sciences and Medical Center, University of Science and Technology of China, Hefei, Anhui 230027, China.
| | - Wei Tang
- Liver Immunology Laboratory, Institute of Immunology and The CAS Key Laboratory of Innate Immunity and Chronic Disease, School of Life Sciences and Medical Center, University of Science and Technology of China, Hefei, Anhui 230027, China.
| | - Jing-Bo Yang
- Liver Immunology Laboratory, Institute of Immunology and The CAS Key Laboratory of Innate Immunity and Chronic Disease, School of Life Sciences and Medical Center, University of Science and Technology of China, Hefei, Anhui 230027, China.
| | - Liang Li
- Liver Immunology Laboratory, Institute of Immunology and The CAS Key Laboratory of Innate Immunity and Chronic Disease, School of Life Sciences and Medical Center, University of Science and Technology of China, Hefei, Anhui 230027, China.
| | - Aftab A Ansari
- Department of Pathology, Emory University School of Medicine, Atlanta, GA 30322, USA.
| | - Zhe-Xiong Lian
- Liver Immunology Laboratory, Institute of Immunology and The CAS Key Laboratory of Innate Immunity and Chronic Disease, School of Life Sciences and Medical Center, University of Science and Technology of China, Hefei, Anhui 230027, China; Innovation Center for Cell Signaling Network, Hefei National Laboratory for Physical Sciences at Microscale, Hefei, Anhui 230026, China.
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35
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Nogales-Gadea G, Saxena A, Hoffmann C, Hounjet J, Coenen D, Molenaar P, Losen M, Martinez-Martinez P. Generation of Recombinant Human IgG Monoclonal Antibodies from Immortalized Sorted B Cells. J Vis Exp 2015:e52830. [PMID: 26132628 PMCID: PMC4545184 DOI: 10.3791/52830] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Finding new methods for generating human monoclonal antibodies is an active research field that is important for both basic and applied sciences, including the development of immunotherapeutics. However, the techniques to identify and produce such antibodies tend to be arduous and sometimes the heavy and light chain pair of the antibodies are dissociated. Here, we describe a relatively simple, straightforward protocol to produce human recombinant monoclonal antibodies from human peripheral blood mononuclear cells using immortalization with Epstein-Barr Virus (EBV) and Toll-like receptor 9 activation. With an adequate staining, B cells producing antibodies can be isolated for subsequent immortalization and clonal expansion. The antibody transcripts produced by the immortalized B cell clones can be amplified by PCR, sequenced as corresponding heavy and light chain pairs and cloned into immunoglobulin expression vectors. The antibodies obtained with this technique can be powerful tools to study relevant human immune responses, including autoimmunity, and create the basis for new therapeutics.
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Affiliation(s)
- Gisela Nogales-Gadea
- School for Mental Health and Neuroscience, Maastricht University; Department of Neurosciences, Institut d'Investigació Germans Trias i Pujol
| | - Abhishek Saxena
- School for Mental Health and Neuroscience, Maastricht University
| | - Carolin Hoffmann
- School for Mental Health and Neuroscience, Maastricht University
| | - Judith Hounjet
- School for Mental Health and Neuroscience, Maastricht University
| | - Daniëlle Coenen
- School for Mental Health and Neuroscience, Maastricht University
| | - Peter Molenaar
- School for Mental Health and Neuroscience, Maastricht University
| | - Mario Losen
- School for Mental Health and Neuroscience, Maastricht University
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Guidelines for pre-clinical assessment of the acetylcholine receptor--specific passive transfer myasthenia gravis model-Recommendations for methods and experimental designs. Exp Neurol 2015; 270:3-10. [PMID: 25743217 DOI: 10.1016/j.expneurol.2015.02.025] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2014] [Revised: 02/13/2015] [Accepted: 02/17/2015] [Indexed: 11/21/2022]
Abstract
Antibodies against the muscle acetylcholine receptor (AChR) are the most common cause of myasthenia gravis (MG). Passive transfer of AChR antibodies from MG patients into animals reproduces key features of human disease, including antigenic modulation of the AChR, complement-mediated damage of the neuromuscular junction, and muscle weakness. Similarly, AChR antibodies generated by active immunization in experimental autoimmune MG models can subsequently be passively transferred to other animals and induce weakness. The passive transfer model is useful to test therapeutic strategies aimed at the effector mechanism of the autoantibodies. Here we summarize published and unpublished experience using the AChR passive transfer MG model in mice, rats and rhesus monkeys, and give recommendations for the design of preclinical studies in order to facilitate translation of positive and negative results to improve MG therapies.
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Berrih-Aknin S. Myasthenia Gravis: paradox versus paradigm in autoimmunity. J Autoimmun 2014; 52:1-28. [PMID: 24934596 DOI: 10.1016/j.jaut.2014.05.001] [Citation(s) in RCA: 85] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2014] [Accepted: 05/07/2014] [Indexed: 12/12/2022]
Abstract
Myasthenia Gravis (MG) is a paradigm of organ-specific autoimmune disease (AID). It is mediated by antibodies that target the neuromuscular junction. The purpose of this review is to place MG in the general context of autoimmunity, to summarize the common mechanisms between MG and other AIDs, and to describe the specific mechanisms of MG. We have chosen the most common organ-specific AIDs to compare with MG: type 1 diabetes mellitus (T1DM), autoimmune thyroid diseases (AITD), multiple sclerosis (MS), some systemic AIDs (systemic lupus erythematous (SLE), rheumatoid arthritis (RA), Sjogren's syndrome (SS)), as well as inflammatory diseases of the gut and liver (celiac disease (CeD), Crohn's disease (CD), and primary biliary cirrhosis (PBC)). Several features are similar between all AIDs, suggesting that common pathogenic mechanisms lead to their development. In this review, we address the predisposing factors (genetic, epigenetic, hormones, vitamin D, microbiota), the triggering components (infections, drugs) and their interactions with the immune system [1,2]. The dysregulation of the immune system is detailed and includes the role of B cells, Treg cells, Th17 and cytokines. We particularly focused on the role of TNF-α and interferon type I whose role in MG is very analogous to that in several other AIDS. The implication of AIRE, a key factor in central tolerance is also discussed. Finally, if MG is a prototype of AIDS, it has a clear specificity compared to the other AIDS, by the fact that the target organ, the muscle, is not the site of immune infiltration and B cell expansion, but exclusively that of antibody-mediated pathogenic mechanisms. By contrast, the thymus in the early onset subtype frequently undergoes tissue remodeling, resulting in the development of ectopic germinal centers surrounded by high endothelial venules (HEV), as observed in the target organs of many other AIDs.
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Affiliation(s)
- Sonia Berrih-Aknin
- Sorbonne Universités, UPMC Univ Paris 06, Myology Research Center UM76, F-75013 Paris, France; INSERM U974, F-75013 Paris, France; CNRS FRE 3617, F-75013 Paris, France; Institute of Myology, F-75013 Paris, France.
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