Peptide-Purified Anti-N-methyl-D-aspartate Receptor (NMDAR) Autoantibodies Have Inhibitory Effect on Long-Term Synaptic Plasticity

<b>Background/Objectives:</b> Recent studies, typically using patient cerebrospinal fluid (CSF), have suggested that different autoantibodies (Aabs) acting on their respective receptors, may underlie neuropsychiatric disorders. The GluN1 (NR1) subunit of the N-methyl-D-aspartate receptor...

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Main Authors: Charlotte Day, John-Paul Silva, Rebecca Munro, Brice Mullier, Véronique Marie André, Christian Wolff, Gary J. Stephens, Angela Bithell
Format: Article
Language:English
Published: MDPI AG 2024-12-01
Series:Pharmaceuticals
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Online Access:https://www.mdpi.com/1424-8247/17/12/1643
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author Charlotte Day
John-Paul Silva
Rebecca Munro
Brice Mullier
Véronique Marie André
Christian Wolff
Gary J. Stephens
Angela Bithell
author_facet Charlotte Day
John-Paul Silva
Rebecca Munro
Brice Mullier
Véronique Marie André
Christian Wolff
Gary J. Stephens
Angela Bithell
author_sort Charlotte Day
collection DOAJ
description <b>Background/Objectives:</b> Recent studies, typically using patient cerebrospinal fluid (CSF), have suggested that different autoantibodies (Aabs) acting on their respective receptors, may underlie neuropsychiatric disorders. The GluN1 (NR1) subunit of the N-methyl-D-aspartate receptor (NMDAR) has been identified as a target of anti-NMDAR Aabs in a number of central nervous system (CNS) diseases, including encephalitis and autoimmune epilepsy. However, the role or the nature of Aabs responsible for effects on neuronal excitability and synaptic plasticity is yet to be established fully. <b>Methods:</b> Peptide immunisation was used to generate Aabs against selected specific GluN1 extracellular sequences based on patient-derived anti-NMDAR Aabs that have been shown to bind to specific regions within the GluN1 subunit. ‘Protein A’ purification was used to obtain the total IgG, and further peptide purification was used to obtain a greater percentage of NMDAR-target specific IgG Aabs. The binding and specificity of these anti-NMDAR Aabs were determined using a range of methodologies including enzyme-linked immunosorbent assays, immunocytochemistry and immunoblotting. Functional effects were determined using different in vitro electrophysiology techniques: two-electrode voltage-clamps in <i>Xenopus</i> oocytes and measures of long-term potentiation (LTP) in ex vivo hippocampal brain slices using multi-electrode arrays (MEAs). <b>Results:</b> We show that anti-NMDAR Aabs generated from peptide immunisation had specificity for GluN1 immunisation peptides as well as target-specific binding to the native protein. Anti-NMDAR Aabs had no clear effect on isolated NMDARs in an oocyte expression system. However, peptide-purified anti-NMDAR Aabs prevented the induction of LTP at Schaffer collateral-CA1 synapses in ex vivo brain slices, consistent with causing synaptic NMDAR hypofunction at a network level. <b>Conclusions:</b> This work provides a solid basis to address outstanding questions regarding anti-NMDAR Aab mechanisms of action and, potentially, the development of therapies against CNS diseases.
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spelling doaj-art-6cb7b04c8b8c47fa800bd95f2369e4f52025-08-20T02:56:57ZengMDPI AGPharmaceuticals1424-82472024-12-011712164310.3390/ph17121643Peptide-Purified Anti-N-methyl-D-aspartate Receptor (NMDAR) Autoantibodies Have Inhibitory Effect on Long-Term Synaptic PlasticityCharlotte Day0John-Paul Silva1Rebecca Munro2Brice Mullier3Véronique Marie André4Christian Wolff5Gary J. Stephens6Angela Bithell7School of Pharmacy, University of Reading, Whiteknights, Reading RG6 6AJ, UKUCB Pharma, 208 Bath Road, Slough SL1 3WE, UKUCB Pharma, 208 Bath Road, Slough SL1 3WE, UKUCB Pharma, Chemin du Foriest, 1420 Braine l’Alleud, BelgiumUCB Pharma, Chemin du Foriest, 1420 Braine l’Alleud, BelgiumUCB Pharma, Chemin du Foriest, 1420 Braine l’Alleud, BelgiumSchool of Pharmacy, University of Reading, Whiteknights, Reading RG6 6AJ, UKSchool of Pharmacy, University of Reading, Whiteknights, Reading RG6 6AJ, UK<b>Background/Objectives:</b> Recent studies, typically using patient cerebrospinal fluid (CSF), have suggested that different autoantibodies (Aabs) acting on their respective receptors, may underlie neuropsychiatric disorders. The GluN1 (NR1) subunit of the N-methyl-D-aspartate receptor (NMDAR) has been identified as a target of anti-NMDAR Aabs in a number of central nervous system (CNS) diseases, including encephalitis and autoimmune epilepsy. However, the role or the nature of Aabs responsible for effects on neuronal excitability and synaptic plasticity is yet to be established fully. <b>Methods:</b> Peptide immunisation was used to generate Aabs against selected specific GluN1 extracellular sequences based on patient-derived anti-NMDAR Aabs that have been shown to bind to specific regions within the GluN1 subunit. ‘Protein A’ purification was used to obtain the total IgG, and further peptide purification was used to obtain a greater percentage of NMDAR-target specific IgG Aabs. The binding and specificity of these anti-NMDAR Aabs were determined using a range of methodologies including enzyme-linked immunosorbent assays, immunocytochemistry and immunoblotting. Functional effects were determined using different in vitro electrophysiology techniques: two-electrode voltage-clamps in <i>Xenopus</i> oocytes and measures of long-term potentiation (LTP) in ex vivo hippocampal brain slices using multi-electrode arrays (MEAs). <b>Results:</b> We show that anti-NMDAR Aabs generated from peptide immunisation had specificity for GluN1 immunisation peptides as well as target-specific binding to the native protein. Anti-NMDAR Aabs had no clear effect on isolated NMDARs in an oocyte expression system. However, peptide-purified anti-NMDAR Aabs prevented the induction of LTP at Schaffer collateral-CA1 synapses in ex vivo brain slices, consistent with causing synaptic NMDAR hypofunction at a network level. <b>Conclusions:</b> This work provides a solid basis to address outstanding questions regarding anti-NMDAR Aab mechanisms of action and, potentially, the development of therapies against CNS diseases.https://www.mdpi.com/1424-8247/17/12/1643NMDA receptor autoantibodieshippocampal neuronlong-term potentiationmulti-electrode arrays
spellingShingle Charlotte Day
John-Paul Silva
Rebecca Munro
Brice Mullier
Véronique Marie André
Christian Wolff
Gary J. Stephens
Angela Bithell
Peptide-Purified Anti-N-methyl-D-aspartate Receptor (NMDAR) Autoantibodies Have Inhibitory Effect on Long-Term Synaptic Plasticity
Pharmaceuticals
NMDA receptor autoantibodies
hippocampal neuron
long-term potentiation
multi-electrode arrays
title Peptide-Purified Anti-N-methyl-D-aspartate Receptor (NMDAR) Autoantibodies Have Inhibitory Effect on Long-Term Synaptic Plasticity
title_full Peptide-Purified Anti-N-methyl-D-aspartate Receptor (NMDAR) Autoantibodies Have Inhibitory Effect on Long-Term Synaptic Plasticity
title_fullStr Peptide-Purified Anti-N-methyl-D-aspartate Receptor (NMDAR) Autoantibodies Have Inhibitory Effect on Long-Term Synaptic Plasticity
title_full_unstemmed Peptide-Purified Anti-N-methyl-D-aspartate Receptor (NMDAR) Autoantibodies Have Inhibitory Effect on Long-Term Synaptic Plasticity
title_short Peptide-Purified Anti-N-methyl-D-aspartate Receptor (NMDAR) Autoantibodies Have Inhibitory Effect on Long-Term Synaptic Plasticity
title_sort peptide purified anti n methyl d aspartate receptor nmdar autoantibodies have inhibitory effect on long term synaptic plasticity
topic NMDA receptor autoantibodies
hippocampal neuron
long-term potentiation
multi-electrode arrays
url https://www.mdpi.com/1424-8247/17/12/1643
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