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Lee H, Yoo DK, Han J, Kim KH, Noh J, Lee Y, Lee E, Kwon S, Chung J. Optimization of peripheral blood volume for in silico reconstitution of the human B cell receptor repertoire. FEBS Open Bio 2022; 12:1634-1643. [PMID: 35866358 PMCID: PMC9433817 DOI: 10.1002/2211-5463.13467] [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: 06/15/2022] [Revised: 07/08/2022] [Accepted: 07/20/2022] [Indexed: 11/30/2022] Open
Abstract
B cells recognize antigens via membrane‐expressed B‐cell receptors (BCR) and antibodies. Similar human BCR sequences are frequently found at a significantly higher frequency than that theoretically calculated. Patients infected with SARS‐CoV2 and HIV or with autoimmune diseases share very similar BCRs. Therefore, in silico reconstitution of BCR repertoires and identification of stereotypical BCR sequences related to human pathology have diagnostic potential. Furthermore, monitoring changes of clinically significant BCR sequences and isotype conversion has prognostic potential. For BCR repertoire analysis, peripheral blood (PB) is the most convenient source. However, the optimal human PB volume for in silico reconstitution of the BCR repertoire has not been studied in detail. Here, we sampled 5, 10, and 20 mL PB from the left arm and 40 mL PB from the right arm of two volunteers, reconstituted in silico PB BCR repertoires, and compared their composition. In both volunteers, PB sampling over 20 mL resulted in slight increases in functional unique sequences (FUSs) or almost no increase in repertoire diversity. All FUSs with a frequency above 0.08% or 0.03% in the 40 mL PB BCR repertoire were detected even in the 5 mL PB BCR repertoire from each volunteer. FUSs with a higher frequency were more likely to be found in BCR repertoires from reduced PB volume, and those coexisting in two repertoires showed a statistically significant correlation in frequency irrespective of sampled anatomical site. The correlation was more significant in higher‐frequency FUSs. These observations support the potential of BCR repertoire analysis for diagnosis.
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Affiliation(s)
- Hyunho Lee
- Department of Electrical and Computer Engineering, Seoul National University, Seoul, 08826, Korea
| | - Duck Kyun Yoo
- Department of Biochemistry and Molecular Biology, Seoul National University College of Medicine, Seoul, 03080, Korea.,Department of Biomedical Science, Seoul National University College of Medicine, Seoul, 03080, Korea
| | - Jerome Han
- Department of Biochemistry and Molecular Biology, Seoul National University College of Medicine, Seoul, 03080, Korea.,Department of Biomedical Science, Seoul National University College of Medicine, Seoul, 03080, Korea
| | - Ki Hyun Kim
- Department of Biochemistry and Molecular Biology, Seoul National University College of Medicine, Seoul, 03080, Korea.,Cancer Research Institute, Seoul National University College of Medicine, Seoul, 03080, Korea
| | - Jinsung Noh
- Department of Electrical and Computer Engineering, Seoul National University, Seoul, 08826, Korea
| | - Yonghee Lee
- Department of Electrical and Computer Engineering, Seoul National University, Seoul, 08826, Korea
| | - Eunjae Lee
- Department of Biochemistry and Molecular Biology, Seoul National University College of Medicine, Seoul, 03080, Korea.,Department of Biomedical Science, Seoul National University College of Medicine, Seoul, 03080, Korea
| | - Sunghoon Kwon
- Department of Electrical and Computer Engineering, Seoul National University, Seoul, 08826, Korea.,Interdisciplinary Program in Bioengineering, Seoul National University, Seoul, 08826, Korea.,BK21+ Creative Research Engineer Development for IT, Seoul National University, Seoul, 08826, Korea.,Bio-MAX Institute, Seoul National University, Seoul, 08826, Korea
| | - Junho Chung
- Department of Biochemistry and Molecular Biology, Seoul National University College of Medicine, Seoul, 03080, Korea.,Department of Biomedical Science, Seoul National University College of Medicine, Seoul, 03080, Korea.,Cancer Research Institute, Seoul National University College of Medicine, Seoul, 03080, Korea
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Jeon MY, Seok JM, Fujihara K, Kim BJ. Autoantibodies in central nervous system and neuromuscular autoimmune disorders: A narrative review. PRECISION AND FUTURE MEDICINE 2022. [DOI: 10.23838/pfm.2021.00198] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
The discovery of novel autoantibodies in neurological disorders contributes to a better understanding of its pathogenesis, improves the accuracy of diagnosis, and leads to new treatment strategies. Advances in techniques for the screening and detection of autoantibodies have enabled the discovery of new antibodies in the central nervous system (CNS) and neuromuscular diseases. Cell-based assays using live or fixed cells overexpressing target antigens are widely used for autoantibody-based diagnosis in clinical practice. Common pathogenic autoantibodies are unknown in most patients with multiple sclerosis (MS) and chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). Novel pathogenic autoantibodies to aquaporin-4 and myelin oligodendrocyte glycoprotein (MOG) have been identified in neuromyelitis optica spectrum disorder and MOG antibody-associated disease, respectively. These diseases have clinical similarities to MS, but with the discovery of pathogenic autoantibodies, they are now recognized as distinct disease entities. Antibodies to paranodal membrane proteins such as neurofascin-155, contactin‑1, contactin‑associated protein‑1 in CIDP and muscle-specific kinase and low-density lipoprotein receptor–related protein 4 in myasthenia gravis were added to the profiles of autoantibodies in neurological disorders. Despite the relatively low frequency of seropositivity, autoantibody detection is currently essential for the clinical diagnosis of CNS and neuromuscular autoimmune disorders, and differential approaches to seropositive patients will contribute to more personalized medicine. We reviewed recent discoveries of autoantibodies and their clinical implications in CNS and neuromuscular disorders.
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3
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Chia R, Saez-Atienzar S, Murphy N, Chiò A, Blauwendraat C, Roda RH, Tienari PJ, Kaminski HJ, Ricciardi R, Guida M, De Rosa A, Petrucci L, Evoli A, Provenzano C, Drachman DB, Traynor BJ. Identification of genetic risk loci and prioritization of genes and pathways for myasthenia gravis: a genome-wide association study. Proc Natl Acad Sci U S A 2022; 119:e2108672119. [PMID: 35074870 PMCID: PMC8812681 DOI: 10.1073/pnas.2108672119] [Citation(s) in RCA: 48] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Accepted: 11/22/2021] [Indexed: 12/14/2022] Open
Abstract
Myasthenia gravis is a chronic autoimmune disease characterized by autoantibody-mediated interference of signal transmission across the neuromuscular junction. We performed a genome-wide association study (GWAS) involving 1,873 patients diagnosed with acetylcholine receptor antibody-positive myasthenia gravis and 36,370 healthy individuals to identify disease-associated genetic risk loci. Replication of the discovered loci was attempted in an independent cohort from the UK Biobank. We also performed a transcriptome-wide association study (TWAS) using expression data from skeletal muscle, whole blood, and tibial nerve to test the effects of disease-associated polymorphisms on gene expression. We discovered two signals in the genes encoding acetylcholine receptor subunits that are the most common antigenic target of the autoantibodies: a GWAS signal within the cholinergic receptor nicotinic alpha 1 subunit (CHRNA1) gene and a TWAS association with the cholinergic receptor nicotinic beta 1 subunit (CHRNB1) gene in normal skeletal muscle. Two other loci were discovered on 10p14 and 11q21, and the previous association signals at PTPN22, HLA-DQA1/HLA-B, and TNFRSF11A were confirmed. Subgroup analyses demonstrate that early- and late-onset cases have different genetic risk factors. Genetic correlation analysis confirmed a genetic link between myasthenia gravis and other autoimmune diseases, such as hypothyroidism, rheumatoid arthritis, multiple sclerosis, and type 1 diabetes. Finally, we applied Priority Index analysis to identify potentially druggable genes/proteins and pathways. This study provides insight into the genetic architecture underlying myasthenia gravis and demonstrates that genetic factors within the loci encoding acetylcholine receptor subunits contribute to its pathogenesis.
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Affiliation(s)
- Ruth Chia
- Neuromuscular Diseases Research Section, Laboratory of Neurogenetics, National Institute on Aging, Bethesda, MD 20892;
| | - Sara Saez-Atienzar
- Neuromuscular Diseases Research Section, Laboratory of Neurogenetics, National Institute on Aging, Bethesda, MD 20892
| | - Natalie Murphy
- Neuromuscular Diseases Research Section, Laboratory of Neurogenetics, National Institute on Aging, Bethesda, MD 20892
| | - Adriano Chiò
- Rita Levi Montalcini Department of Neuroscience, University of Turin, Turin 10126, Italy
- Institute of Cognitive Sciences and Technologies, Consiglio Nazionale delle Ricerche, Rome 00185, Italy
- Neurology 1, Azienda Ospedaliero Universitaria Città della Salute e della Scienza, Turin 10126, Italy
| | - Cornelis Blauwendraat
- Molecular Genetics Section, Laboratory of Neurogenetics, National Institute on Aging, Bethesda, MD 20892
| | - Ricardo H Roda
- Department of Neurology, Johns Hopkins School of Medicine, Baltimore, MD 21287
| | - Pentti J Tienari
- Department of Neurology, Neurocenter, Helsinki University Hospital, Helsinki FIN-02900, Finland
- Research Program of Translational Immunology, Faculty of Medicine, University of Helsinki, Helsinki FIN-02900, Finland
| | - Henry J Kaminski
- Department of Neurology and Rehabilitation Medicine, George Washington University, Washington, DC 20037
| | - Roberta Ricciardi
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa 56126, Italy
| | - Melania Guida
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa 56126, Italy
| | - Anna De Rosa
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa 56126, Italy
| | - Loredana Petrucci
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa 56126, Italy
| | - Amelia Evoli
- Institute of Neurology, Università Cattolica del Sacro Cuore, Fondazione Policlinico Universitario "A. Gemelli" Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS), Rome 00168, Italy
| | - Carlo Provenzano
- Dipartimento di Medicina e chirurgia traslazionale, Sezione di Patologia generale, Università Cattolica del Sacro Cuore, Fondazione Policlinico Universitario "A. Gemelli" Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS), Rome 00168, Italy
| | - Daniel B Drachman
- Department of Neurology, Johns Hopkins School of Medicine, Baltimore, MD 21287
| | - Bryan J Traynor
- Neuromuscular Diseases Research Section, Laboratory of Neurogenetics, National Institute on Aging, Bethesda, MD 20892
- Department of Neurology, Johns Hopkins School of Medicine, Baltimore, MD 21287
- Reta Lila Weston Institute, UCL Queen Square Institute of Neurology, University College London, London WC1N 1PJ, UK
- National Institute of Neurological Disorders and Stroke, Bethesda, MD 20892
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Urriola N, Spies JM, Blazek K, Lang B, Adelstein S. A Flow Cytometric Assay to Detect Functional Ganglionic Acetylcholine Receptor Antibodies by Immunomodulation in Autoimmune Autonomic Ganglionopathy. Front Immunol 2021; 12:705292. [PMID: 34249013 PMCID: PMC8261233 DOI: 10.3389/fimmu.2021.705292] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Accepted: 06/07/2021] [Indexed: 12/13/2022] Open
Abstract
Autoimmune Autonomic Ganglionopathy (AAG) is an uncommon immune-mediated neurological disease that results in failure of autonomic function and is associated with autoantibodies directed against the ganglionic acetylcholine receptor (gnACHR). The antibodies are routinely detected by immunoprecipitation assays, such as radioimmunoassays (RIA), although these assays do not detect all patients with AAG and may yield false positive results. Autoantibodies against the gnACHR exert pathology by receptor modulation. Flow cytometric analysis is able to determine if this has occurred, in contrast to the assays in current use that rely on immunoprecipitation. Here, we describe the first high-throughput, non-radioactive flow cytometric assay to determine autoantibody mediated gnACHR immunomodulation. Previously identified gnACHR antibody seronegative and seropositive sera samples (RIA confirmed) were blinded and obtained from the Oxford Neuroimmunology group along with samples collected locally from patients with or without AAG. All samples were assessed for the ability to cause gnACHR immunomodulation utilizing the prototypical gnACHR expressing cell line, IMR-32. Decision limits were calculated from healthy controls, and Receiver Operating Characteristic (ROC) curves were constructed after unblinding all samples. One hundred and ninety serum samples were analyzed; all 182 expected negative samples (from healthy controls, autonomic disorders not thought to be AAG, other neurological disorders without autonomic dysfunction and patients with Systemic Lupus Erythematosus) were negative for immunomodulation (<18%), as were the RIA negative AAG and unconfirmed AAG samples. All RIA positive samples displayed significant immunomodulation. There were no false positive or negative samples. There was perfect qualitative concordance as compared to RIA, with an Area Under ROC of 1. Detection of Immunomodulation by flow cytometry for the identification of gnACHR autoantibodies offers excellent concordance with the gnACHR antibody RIA, and overcomes many of the shortcomings of immunoprecipitation assays by directly measuring the pathological effects of these autoantibodies at the cellular level. Further work is needed to determine the correlation between the degree of immunomodulation and disease severity.
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Affiliation(s)
- Nicolás Urriola
- Department of Clinical Immunology and Allergy, Royal Prince Alfred Hospital, Sydney, NSW, Australia.,Faculty of Medicine and Health, The University of Sydney, Sydney, NSW, Australia
| | - Judith M Spies
- Faculty of Medicine and Health, The University of Sydney, Sydney, NSW, Australia.,Department of Neurology, Royal Prince Alfred Hospital, Sydney, NSW, Australia
| | - Katrina Blazek
- Faculty of Medicine and Health, The University of Sydney, Sydney, NSW, Australia.,Centre for Kidney Research, Children's Hospital at Westmead, Sydney, NSW, Australia
| | - Bethan Lang
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom
| | - Stephen Adelstein
- Department of Clinical Immunology and Allergy, Royal Prince Alfred Hospital, Sydney, NSW, Australia.,Faculty of Medicine and Health, The University of Sydney, Sydney, NSW, Australia.,Central Sydney Immunopathology Laboratory, NSW Health Pathology, Sydney, NSW, Australia
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5
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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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6
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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: 112] [Impact Index Per Article: 28.0] [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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Choi J, Kim NH, Park SH, Cho CG, Lee HJ, Kim SU, Park KS. Abnormalities of Otoacoustic Emissions in Myasthenia Gravis: Association With Serological and Electrophysiological Features. Front Neurol 2018; 9:1124. [PMID: 30619074 PMCID: PMC6306561 DOI: 10.3389/fneur.2018.01124] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Accepted: 12/06/2018] [Indexed: 11/16/2022] Open
Abstract
Objective: To investigate whether otoacoustic emissions (OAEs) are impaired in patients with myasthenia gravis (MG) and whether such dysfunction is associated with serological and electrophysiological features of MG. Methods: We tested 15 patients with MG (30 ears) and 10 healthy age- and sex-matched subjects (20 ears) for transiently evoked OAE (TEOAE) and distortion product OAE (DPOAE). Results: Compared with controls, MG patients revealed a significant reduction in the amplitude of TEOAEs (p < 0.05) and DPOAEs at higher frequencies between 2,026 and 4,053 Hz (p < 0.05). In the subgroup analysis, TEOAE and DPOAE amplitudes were significantly lower in the acetylcholine receptor (AChR) antibody-positive group (p < 0.05) as well as in the repetitive nerve stimulation (RNS)-positive (p < 0.05) group. In particular, the OAE alteration significantly correlated with anti-AChR antibody titers. No significant difference of the OAEs was found between thymomatous and non-thymomatous MG or between purely ocular and generalized MG. Conclusions: Our study confirms that OAEs reveal subclinical dysfunction of the cholinergic neurotransmission of cochlear outer hair cells and correlate well with electrophysiological and serological characteristics of MG patients. Our findings imply that the measurement of OAEs might increase the diagnostic accuracy and help to monitor the severity of MG.
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Affiliation(s)
- Jongsuk Choi
- Department of Neurology, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seoul, South Korea
| | - Nam-Hee Kim
- Department of Neurology, Dongguk University Ilsan Hospital, Ilsan, South Korea
| | - Soo-Hyun Park
- Department of Critical Care Neurology, Seoul National University Hospital, Seoul, South Korea
| | - Chang Gun Cho
- Department of Otorhinolaryngology, Dongguk University Ilsan Hospital, Ilsan, South Korea
| | - Hyo-Jeong Lee
- Department of Otorhinolaryngology-Head and Neck Surgery, Hallym University College of Medicine, Chuncheon, South Korea
| | - Sung Un Kim
- Department of Neurology, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seoul, South Korea
| | - Kyung Seok Park
- Department of Neurology, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seoul, South Korea
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Ning J, Li R, Ren J, Zhangsun D, Zhu X, Wu Y, Luo S. Alanine-Scanning Mutagenesis of α-Conotoxin GI Reveals the Residues Crucial for Activity at the Muscle Acetylcholine Receptor. Mar Drugs 2018; 16:md16120507. [PMID: 30551685 PMCID: PMC6315591 DOI: 10.3390/md16120507] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2018] [Revised: 11/25/2018] [Accepted: 12/10/2018] [Indexed: 01/30/2023] Open
Abstract
Recently, the muscle-type nicotinic acetylcholine receptors (nAChRs) have been pursued as a potential target of several diseases, including myogenic disorders, muscle dystrophies and myasthenia gravis, etc. α-conotoxin GI isolated from Conus geographus selectively and potently inhibited the muscle-type nAChRs which can be developed as a tool to study them. Herein, alanine scanning mutagenesis was used to reveal the structure–activity relationship (SAR) between GI and mouse α1β1δε nAChRs. The Pro5, Gly8, Arg9, and Tyr11 were proved to be the critical residues for receptor inhibiting as the alanine (Ala) replacement led to a significant potency loss on mouse α1β1δε nAChR. On the contrary, substituting Asn4, His10 and Ser12 with Ala respectively did not affect its activity. Interestingly, the [E1A] GI analogue exhibited a three-fold potency for mouse α1β1δε nAChR, whereas it obviously decreased potency at rat α9α10 nAChR compared to wildtype GI. Molecular dynamic simulations also suggest that loop2 of GI significantly affects the interaction with α1β1δε nAChR, and Tyr11 of GI is a critical residue binding with three hydrophobic amino acids of the δ subunit, including Leu93, Tyr95 and Leu103. Our research elucidates the interaction of GI and mouse α1β1δε nAChR in detail that will help to develop the novel analogues of GI.
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Affiliation(s)
- Jiong Ning
- Key Laboratory of Tropical Biological Resources, Ministry of Education, Key Lab for Marine Drugs of Haikou, Hainan University, Haikou 570228, Hainan, China.
| | - Rui Li
- Key Laboratory of Tropical Biological Resources, Ministry of Education, Key Lab for Marine Drugs of Haikou, Hainan University, Haikou 570228, Hainan, China.
| | - Jie Ren
- Key Laboratory of Tropical Biological Resources, Ministry of Education, Key Lab for Marine Drugs of Haikou, Hainan University, Haikou 570228, Hainan, China.
| | - Dongting Zhangsun
- Key Laboratory of Tropical Biological Resources, Ministry of Education, Key Lab for Marine Drugs of Haikou, Hainan University, Haikou 570228, Hainan, China.
| | - Xiaopeng Zhu
- Key Laboratory of Tropical Biological Resources, Ministry of Education, Key Lab for Marine Drugs of Haikou, Hainan University, Haikou 570228, Hainan, China.
| | - Yong Wu
- Key Laboratory of Tropical Biological Resources, Ministry of Education, Key Lab for Marine Drugs of Haikou, Hainan University, Haikou 570228, Hainan, China.
| | - Sulan Luo
- Key Laboratory of Tropical Biological Resources, Ministry of Education, Key Lab for Marine Drugs of Haikou, Hainan University, Haikou 570228, Hainan, China.
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Nakane S, Mukaino A, Higuchi O, Watari M, Maeda Y, Yamakawa M, Nakahara K, Takamatsu K, Matsuo H, Ando Y. Autoimmune autonomic ganglionopathy: an update on diagnosis and treatment. Expert Rev Neurother 2018; 18:953-965. [PMID: 30352532 DOI: 10.1080/14737175.2018.1540304] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
INTRODUCTION Autoimmune autonomic ganglionopathy (AAG) is an acquired immune-mediated disorder that leads to autonomic failure. The disorder is associated with autoantibodies to the ganglionic nicotinic acetylcholine receptor (gAChR). We subsequently reported that AAG is associated with an overrepresentation of psychiatric symptoms, sensory disturbance, autoimmune diseases, and endocrine disorders. Area covered: The aim of this review was to describe AAG and highlight its pivotal pathophysiological aspects, clinical features, laboratory examinations, and therapeutic options. Expert commentary: AAG is a complex neuroimmunological disease, these days considered as an autonomic failure with extra-autonomic manifestations (and various limited forms). Further comprehension of the pathophysiology of this disease is required, especially the mechanisms of the extra-autonomic manifestations should be elucidated. There is the possibility that the co-presence of antibodies that were directed against the other subunits in both the central and peripheral nAChRs in the serum of the AAG patients. Some patients improve with immunotherapies such as IVIg and/or corticosteroid and/or plasma exchange. 123I-MIBG myocardial scintigraphy may be a useful tool to monitor the therapeutic effects of immunotherapies.
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Affiliation(s)
- Shunya Nakane
- a Department of Neurology, Graduate School of Medical Sciences , Kumamoto University , Kumamoto , Japan.,b Department of Molecular Neurology and Therapeutics , Kumamoto University Hospital , Kumamoto , Japan
| | - Akihiro Mukaino
- a Department of Neurology, Graduate School of Medical Sciences , Kumamoto University , Kumamoto , Japan.,b Department of Molecular Neurology and Therapeutics , Kumamoto University Hospital , Kumamoto , Japan
| | - Osamu Higuchi
- c Department of Neurology and Clinical Research , Nagasaki Kawatana Medical Center , Nagasaki , Japan
| | - Mari Watari
- a Department of Neurology, Graduate School of Medical Sciences , Kumamoto University , Kumamoto , Japan
| | - Yasuhiro Maeda
- c Department of Neurology and Clinical Research , Nagasaki Kawatana Medical Center , Nagasaki , Japan
| | - Makoto Yamakawa
- a Department of Neurology, Graduate School of Medical Sciences , Kumamoto University , Kumamoto , Japan
| | - Keiichi Nakahara
- a Department of Neurology, Graduate School of Medical Sciences , Kumamoto University , Kumamoto , Japan
| | - Koutaro Takamatsu
- a Department of Neurology, Graduate School of Medical Sciences , Kumamoto University , Kumamoto , Japan
| | - Hidenori Matsuo
- c Department of Neurology and Clinical Research , Nagasaki Kawatana Medical Center , Nagasaki , Japan
| | - Yukio Ando
- a Department of Neurology, Graduate School of Medical Sciences , Kumamoto University , Kumamoto , Japan
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10
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Pan Z, Zhao M, Peng Y, Wang J. Functional divergence analysis of vertebrate neuronal nicotinic acetylcholine receptor subunits. J Biomol Struct Dyn 2018; 37:2938-2948. [PMID: 30044167 DOI: 10.1080/07391102.2018.1500945] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
Nicotinic acetylcholine receptors (nAChRs) are pentamers formed by subunits from a large multigene family and are highly variable in kinetic, electrophysiological and pharmacological properties. Due to the essential roles of nAChRs in many physiological procedures and diversity in function, identifying the function-related sites specific to each subunit is not only necessary to understand the properties of the receptors but also useful to design potential therapeutic compounds that target these macromolecules for treating a series of central neuronal disorders. By conducting a detailed function divergence analysis on nine neuronal nAChR subunits from representative vertebrate species, we revealed the existence of significant functional variation between most subunit pairs. Specifically, 44 unique residues were identified for the α7 subunit, while another 22 residues that were likely responsible for the specific features of other subunits were detected. By mapping these sites onto the 3 D structure of the human α7 subunit, a structure-function relationship profile was revealed. Our results suggested that the functional divergence related sites clustered in the ligand binding domain, the β2-β3 linker close to the N-terminal α-helix, the intracellular linkers between transmembrane domains, and the "transition zone" may have experienced altered evolutionary rates. The former two regions may be potential binding sites for the α7* subtype-specific allosteric modulators, while the latter region is likely to be subtype-specific allosteric modulations of the heteropentameric descendants such as the α4β2* nAChRs. Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Zhenhua Pan
- a School of Biomedical Engineering , Tianjin Medical University , Tianjin , China.,b Tianjin Key Laboratory of Lung Cancer Metastasis and Tumor Microenvironment , Tianjin Lung Cancer Institute, Tianjin Medical University General Hospital , Tianjin , China
| | - Mengwen Zhao
- a School of Biomedical Engineering , Tianjin Medical University , Tianjin , China
| | - Yonglin Peng
- a School of Biomedical Engineering , Tianjin Medical University , Tianjin , China
| | - Ju Wang
- a School of Biomedical Engineering , Tianjin Medical University , Tianjin , China
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Sharma S, Malmeström C, Lindberg C, Meisel S, Schön K, Verolin M, Lycke NY. A Sensitive Method for Detecting Peptide-specific CD4 + T Cell Responses in Peripheral Blood from Patients with Myasthenia Gravis. Front Immunol 2017; 8:1370. [PMID: 29114250 PMCID: PMC5660702 DOI: 10.3389/fimmu.2017.01370] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2017] [Accepted: 10/05/2017] [Indexed: 01/04/2023] Open
Abstract
Myasthenia gravis (MG) is an autoimmune neurological disorder typified by skeletal muscle fatigue and most often production of autoantibodies against the nicotinic acetylcholine receptor (AChR). The present study was undertaken to assess the extent of AChR-peptide recognition in MG patients using co-culturing (DC:TC) of autologous monocyte-derived dendritic cells (moDCs) and highly enriched CD4+ T cells from the blood as compared to the traditional whole peripheral blood mononuclear cell (PBMC) cultures. We found that the DC:TC cultures were highly superior to the PBMC cultures for detection of reactivity toward HLA-DQ/DR-restricted AChR-peptides. In fact, whereas DC:TC cultures identified recognition in all MG patients the PBMC cultures failed to detect responsiveness in around 40% of the patients. Furthermore, reactivity to multiple peptides was evident in DC:TC cultures, while PBMC cultures mostly exhibited reactivity to a single peptide. No healthy control (HC) CD4+ T cells responded to the peptides in either culture system. Interestingly, whereas spontaneous production of IFNγ and IL-17 was observed in the DC:TC cultures from MG patients, recall responses to peptides enhanced IL-10 production in 9/13 MG patients, while little increase in IFNγ and IL-17 was seen. HCs did not produce cytokines to peptide stimulations. We conclude that the DC: TC culture system is significantly more sensitive and better identifies the extent of responsiveness in MG patients to AChR-peptides than traditional PBMC cultures.
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Affiliation(s)
- Sapna Sharma
- Department of Microbiology and Immunology, Institute of Biomedicine, University of Gothenburg, Gothenburg, Sweden
| | - Clas Malmeström
- Laboratory for Clinical Immunology, Sahlgrenska University Hospital, Gothenburg, Sweden.,Department of Neurology, Sahlgrenska University Hospital, Gothenburg, Sweden
| | | | - Sarah Meisel
- Department of Microbiology and Immunology, Institute of Biomedicine, University of Gothenburg, Gothenburg, Sweden
| | - Karin Schön
- Department of Microbiology and Immunology, Institute of Biomedicine, University of Gothenburg, Gothenburg, Sweden
| | | | - Nils Yngve Lycke
- Department of Microbiology and Immunology, Institute of Biomedicine, University of Gothenburg, Gothenburg, Sweden
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12
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Kalra S, Burbelo PD, Bayat A, Ching KH, Thurm A, Iadarola MJ, Swedo SE. No Evidence of Antibodies against GAD65 and Other Specific Antigens in Children with Autism. BBA CLINICAL 2015; 4:81-84. [PMID: 26366376 PMCID: PMC4564997 DOI: 10.1016/j.bbacli.2015.08.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Background The presence of autoantibodies has been proposed as evidence for a role of autoimmunity in autism. This report investigates the prevalence of autoantibodies in children with autism using the luciferase immunoprecipitation systems (LIPS) immunoassay technology. A panel of autoantibody targets against several known and candidate neurological autoantigens, autoimmune-associated autoantigens and viruses was employed. Methods Serological analysis was performed on typically developing children (n = 55), developmentally delayed children without autism (n = 24) and children diagnosed with autism (n = 104). Autoantibodies were measured against glutamic acid decarboxylase-65 (GAD65), a CNS autoantigen proposed to be associated with autism and against Ro52, glial fibrillary acidic protein, tyrosine hydroxylase, aquaporin-4, and gamma-enolase, the mouse mammary tumor virus and the xenotropic murine leukemia virus. Antibody levels and seropositivity prevalence were analyzed for statistically significant differences between the three groups. Results The majority of the children (98%) were seronegative for all targets in the antigen panel. No GAD65 seropositive children were detected in the cohort. Several low level seropositive sera against several of the protein targets were identified in isolated children in each of the three groups, but there was no difference in prevalence. Conclusion Using this panel of antigens and a sensitive, robust assay, no evidence of unusual immunoreactivity was detected in children with autism, providing evidence against a role of autoimmunity against several previously implicated proteins in autism spectrum disorder pathogenesis. General significance The idea that autoantibodies represent an underlying cause or are biomarkers for autism pathophysiology is not supported by this report.
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Affiliation(s)
- Simran Kalra
- Pediatrics and Developmental Branch, National Institutes of Mental Health, National Institutes of Health, Bethesda, MD
| | - Peter D Burbelo
- Dental Clinical Research Core, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD
| | - Ahmad Bayat
- Department of Perioperative Medicine, Clinical Center, National Institutes of Health, Bethesda, MD
| | - Kathryn H Ching
- Department of Perioperative Medicine, Clinical Center, National Institutes of Health, Bethesda, MD
| | - Audrey Thurm
- Pediatrics and Developmental Branch, National Institutes of Mental Health, National Institutes of Health, Bethesda, MD
| | - Michael J Iadarola
- Department of Perioperative Medicine, Clinical Center, National Institutes of Health, Bethesda, MD
| | - Susan E Swedo
- Pediatrics and Developmental Branch, National Institutes of Mental Health, National Institutes of Health, Bethesda, MD
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Nakane S, Higuchi O, Koga M, Kanda T, Murata K, Suzuki T, Kurono H, Kunimoto M, Kaida KI, Mukaino A, Sakai W, Maeda Y, Matsuo H. Clinical features of autoimmune autonomic ganglionopathy and the detection of subunit-specific autoantibodies to the ganglionic acetylcholine receptor in Japanese patients. PLoS One 2015; 10:e0118312. [PMID: 25790156 PMCID: PMC4366081 DOI: 10.1371/journal.pone.0118312] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2014] [Accepted: 01/14/2015] [Indexed: 01/08/2023] Open
Abstract
Autoimmune autonomic ganglionopathy (AAG) is a rare acquired channelopathy that is characterized by pandysautonomia, in which autoantibodies to ganglionic nicotinic acetylcholine receptors (gAChR) may play a central role. Radioimmunoprecipitation (RIP) assays have been used for the sensitive detection of autoantibodies to gAChR in the serum of patients with AAG. Here, we developed luciferase immunoprecipitation systems (LIPS) to diagnose AAG based on IgGs to both the α3 and β4 gAChR subunits in patient serum. We reviewed the serological and clinical data of 50 Japanese patients who were diagnosed with AAG. With the LIPS testing, we detected anti-α3 and -β4 gAChR antibodies in 48% (24/50) of the patients. A gradual mode of onset was more common in the seropositive group than in the seronegative group. Patients with AAG frequently have orthostatic hypotension and upper and lower gastrointestinal tract symptoms, with or without anti-gAChR. The occurrence of autonomic symptoms was not significantly different between the seropositive and seronegative group, with the exception of achalasia in three patients from the seropositive group. In addition, we found a significant overrepresentation of autoimmune diseases in the seropositive group and endocrinological abnormalities as an occasional complication of AAG. Our results demonstrated that the LIPS assay was a useful novel tool for detecting autoantibodies against gAChR in patients with AAG.
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Affiliation(s)
- Shunya Nakane
- Department of Clinical Research, Nagasaki Kawatana Medical Center, Nagasaki, Japan; Department of Neurology, Nagasaki Kawatana Medical Center, Nagasaki, Japan
| | - Osamu Higuchi
- Department of Clinical Research, Nagasaki Kawatana Medical Center, Nagasaki, Japan
| | - Michiaki Koga
- Department of Neurology and Clinical Neuroscience, Yamaguchi University Graduate School of Medicine, Yamaguchi, Japan
| | - Takashi Kanda
- Department of Neurology and Clinical Neuroscience, Yamaguchi University Graduate School of Medicine, Yamaguchi, Japan
| | - Kenya Murata
- Department of Neurology, Wakayama Medical University, Wakayama, Japan
| | - Takashi Suzuki
- Department of Neurology, Joetsu General Hospital, Niigata, Japan
| | - Hiroko Kurono
- Department of Neurology, Saiseikai Kanagawa Prefecture Hospital, Kanagawa, Japan
| | - Masanari Kunimoto
- Department of Neurology, Saiseikai Kanagawa Prefecture Hospital, Kanagawa, Japan
| | - Ken-ichi Kaida
- Division of Neurology, Department of Internal Medicine 3, National Defense Medical College, Saitama, Japan
| | - Akihiro Mukaino
- Department of Clinical Neuroscience and Neurology, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki, Japan
| | - Waka Sakai
- Department of Neurology, Nagasaki Kawatana Medical Center, Nagasaki, Japan
| | - Yasuhiro Maeda
- Department of Neurology, Nagasaki Kawatana Medical Center, Nagasaki, Japan
| | - Hidenori Matsuo
- Department of Neurology, Nagasaki Kawatana Medical Center, Nagasaki, Japan
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Gan L, O'Hanlon TP, Gordon AS, Rider LG, Miller FW, Burbelo PD. Twins discordant for myositis and systemic lupus erythematosus show markedly enriched autoantibodies in the affected twin supporting environmental influences in pathogenesis. BMC Musculoskelet Disord 2014; 15:67. [PMID: 24602337 PMCID: PMC3973849 DOI: 10.1186/1471-2474-15-67] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/06/2014] [Accepted: 02/04/2014] [Indexed: 11/23/2022] Open
Abstract
Background Studies of twin pairs discordant for autoimmune conditions provide a unique opportunity to explore contributing factors triggered by complex gene-environment interactions. Methods In this cross-sectional study, thirty-one monozygotic or dizygotic twin pairs discordant for myositis or systemic lupus erythematosus (SLE), along with matched healthy controls were evaluated for antibodies against a panel of 21 autoantigens. Results Autoantibody profiling revealed that 42% of the affected twins showed significant seropositivity against autoantigens in the panel. In many of these affected twins, but none of healthy controls, there were high levels of autoantibodies detected against two or more autoantigens commonly seen in systemic autoimmune diseases including Ro52, Ro60, RNP-70 K and/or RNP-A. In contrast, only 10% (3/31) of the unaffected twins showed seropositivity and these immunoreactivities were against single autoantigens not seen in systemic autoimmune diseases. While no significant differences in autoantibodies were detected between the affected or unaffected twins against thyroid peroxidase, transglutaminase and several cytokines, 23% of the affected twins with myositis showed autoantibodies against the gastric ATPase. Analysis of the monozygotic twins separately also revealed a higher frequencies of autoantibodies in the affected twins compared to the unaffected twins (P = 0.046). Lastly, clinical analysis of both the affected monozygotic and dizygotic twins revealed that the autoantibody seropositive affected twins had a greater global disease activity score compared to seronegative affected twins (P = 0.019). Conclusion The findings of significantly more autoantibodies in the affected twins with myositis and SLE compared to the unaffected twins are consistent with potential non-genetic factors playing a role in autoantibody production and pathogenesis of these autoimmune disorders.
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Affiliation(s)
| | | | | | | | - Frederick W Miller
- Environmental Autoimmunity Group, National Institute of Environmental Health Sciences, Bethesda, MD, USA.
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Zisimopoulou P, Brenner T, Trakas N, Tzartos SJ. Serological diagnostics in myasthenia gravis based on novel assays and recently identified antigens. Autoimmun Rev 2013; 12:924-30. [PMID: 23537507 DOI: 10.1016/j.autrev.2013.03.002] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/12/2013] [Indexed: 10/27/2022]
Abstract
Myasthenia gravis (MG) is the most common immune-mediated disorder of the neuromuscular junction with a prevalence of 200-300/million population and its study has established paradigms for exploring other antibody-mediated diseases. Most MG patients (~85%) have autoantibodies against the muscle acetylcholine receptor (AChR-MG), whereas about 6% of MG patients have autoantibodies against the muscle specific kinase (MuSK-MG). Until recently no autoantibodies could be detected in the remaining patients (seronegative MG). Probably, the most sensitive assays for the detection of the autoantibodies in MG sera have been the radioimmunoprecipitation assays (RIPA) for both types of MG. However, with recent novel methods, not yet used routinely, it has been shown that the "seronegative" MG group includes patients with low levels of autoantibodies or of low affinity, against the known autoantigens, or even with antibodies to recently identified autoantigens. Since MG is heterogeneous in terms of pathophysiology, depending on the autoantigen targeted and on other factors (e.g. presence of thymoma), the serological tests are crucial in verifying the initial clinical diagnosis, whereas frequent measurement of autoantibody levels is important in monitoring the course of the disease and the efficacy of treatment. In addition, in AChR-MG, autoantibodies against the muscle proteins titin and ryanodin receptor have been identified; these antibodies are useful for the classification of MG, indicating the concomitant presence of thymoma, and as prognostic markers.
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Burbelo PD, Ching KH, Bren KE, Iadarola MJ. Searching for biomarkers: humoral response profiling with luciferase immunoprecipitation systems. Expert Rev Proteomics 2011; 8:309-16. [PMID: 21679112 DOI: 10.1586/epr.11.23] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
B-cell-mediated humoral responses are triggered in many human diseases, including autoimmune diseases, cancer, and neurologic and infectious diseases. However, the full exploitation of the information contained within a patient's antibody repertoire for diagnosis, monitoring and even disease prediction has been limited due to the poor diagnostic performance of many immunoassay formats. We have developed luciferase immunoprecipitation systems (LIPS) that harnesses light-emitting proteins to generate high-definition antibody profiles that are optimal for both diagnostics and biomarker discovery. Here, we describe the results and implications from a range of LIPS-antibody profiling studies performed in our laboratory. These include highly sensitive diagnostics for domestic and global pathogens, insights into infection-related diseases, discovery of new biomarkers for human diseases, subcategorization of symptoms and identification of pathogenic autoantibodies against self-proteins. These investigations highlight the types of humoral response profiles associated with different diseases, provide new information related to disease pathogenesis and offer a framework for incorporating LIPS antibody profiling into global health initiatives and disease monitoring.
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Affiliation(s)
- Peter D Burbelo
- Neurobiology and Pain Therapeutics Section, Laboratory of Sensory Biology, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD 20892, USA
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