Disrupted callosal connectivity underlies long-lasting sensory-motor deficits in an NMDA receptor antibody encephalitis mouse model

• Text
• PDF

Abstract

NMDA receptor mediated autoimmune encephalitis (NMDAR-AE) frequently results in persistent sensory-motor deficits, especially in children, yet the underlying mechanisms remain unclear. This study investigated the long- term effects of exposure to a patient-derived GluN1-specific monoclonal antibody (mAb) during a critical developmental period (from postnatal day 3 to day 12) in mice. We observed long-lasting sensory-motor deficits characteristic of NMDAR-AE, along with permanent changes in callosal axons within the primary somatosensory cortex (S1) in adulthood, including increased terminal branch complexity. This complexity was associated with paroxysmal recruitment of neurons in S1 in response to callosal stimulation. Particularly during complex motor tasks, mAb3-treated mice exhibited significantly reduced inter-hemispheric functional connectivity between S1 regions, consistent with pronounced sensory-motor behavioral deficits. These findings suggest that transient exposure to anti-GluN1 mAb during a critical developmental window may lead to irreversible morphological and functional changes in callosal axons, which could significantly impair sensory-motor integration and contribute to long-lasting sensory-motor deficits. Our study establishes a new model of NMDAR-AE and identifies novel cellular and network-level mechanisms underlying persistent sensory-motor deficits in this context. These insights lay the foundation for future research into molecular mechanisms and the development of targeted therapeutic interventions.

Authors

Jing Zhou, Ariele L. Greenfield, Rita P. Loudermilk, Christopher M. Bartley, Chun Chen, Xiumin Chen, Morgane A.H. Leroux, Yujun Lu, Deanna Necula, Thomas T. Ngo, Baouyen T. Tran, Patrick S. Honma, Kelli Lauderdale, Chao Zhao, Xiaoyuan Zhou, Hong Wang, Roger A. Nicoll, Cong Wang, Jeanne T. Paz, Jorge J. Palop, Michael R. Wilson, Samuel J. Pleasure

Apex1 safeguards genomic stability to ensure a cytopathic T cell fate in autoimmune disease models

• Text
• PDF

Abstract

T cells have a remarkable capacity to clonally expand, a process that is intricately linked to their effector activities. As vigorously proliferating T cell also incur substantial DNA lesions, how the dividing T cells safeguard their genomic integrity to allow the generation of T effector cells remains largely unknown. Here we report the identification of the apurinic/apyrimidinic endonuclease-1 (Apex1) as an indispensable molecule for the induction of cytopathic T effectors in mouse models. We demonstrate that conditional deletion of Apex1 in T cells results in a remarkable accumulation of baseless DNA sites in the genome of proliferating T cells, which further leads to genomic instability and apoptotic cell death. Consequently, Apex1-deleted T cells fail to acquire any effector features after activation and fail to mediate autoimmune diseases and allergic tissue damages. Detailed mutational analyses pinpoint the importance of its endonuclease domain in the generation of T effector cells. We provide further evidence that inhibiting the base repair activities of Apex1 with chemical inhibitors similarly abrogates the induction of autoimmune diseases. Collectively, our study suggests that Apex1 serves as a gatekeeper for the generation of cytopathic T cells and that therapeutically targeting Apex1 may have important clinical implications in the treatment of autoimmune diseases.

Authors

Xiang Xiao, Yong Du, Si Sun, Xiaojun Su, Junji Xing, Guangchuan Wang, Steven M. Elzein, Dawei Zou, Laurie J. Minze, Zhuyun Mao, Rafik M. Ghobrial, Ashton A. Connor, Wenhao Chen, Zhiqiang Zhang, Xian C. Li

PINK1 is a target of T cell responses in Parkinson's disease

• Text
• PDF

Abstract

Parkinson’s disease (PD) is the second most prevalent neurodegenerative disorder. While there is no curative treatment, the immune system's involvement with autoimmune T cells that recognize the protein alpha-synuclein (α-syn) in a subset of individuals suggests new areas for therapeutic strategies. As not all patients with PD have T cells specific for α-syn, we explored additional autoantigenic targets of T cells in PD. We generated 15-mer peptides spanning several PD-related proteins implicated in PD pathology, including Glucosylceramidase Beta 1 (GBA), Superoxide dismutase 1 (SOD1), PTEN Induced Kinase 1 (PINK1), Parkin RBR E3 Ubiquitin Protein Ligase (parkin), Oxoglutarate Dehydrogenase (OGDH), and Leucine Rich Repeat Kinase 2 (LRRK2). Cytokine production (IFNγ, IL-5, IL-10) against these proteins was measured using a fluorospot assay and PBMCs from patients with PD and age-matched healthy controls. We identified PINK1, a regulator of mitochondrial stability, as an autoantigen targeted by T cells, as well as its unique epitopes, and their HLA restriction. The PINK1-specific T cell reactivity revealed sex-based differences as it was predominantly found in male patients with PD, which may contribute to the heterogeneity of PD. Identifying and characterizing PINK1 and other autoinflammatory targets may lead to antigen-specific diagnostics, progression markers, and/or novel therapeutic strategies for PD.

Authors

Gregory P. Williams, Antoine Freuchet, Tanner Michaelis, April Frazier, Ngan K. Tran, João Rodrigues Lima-Junior, Elizabeth J. Phillips, Simon A. Mallal, Irene Litvan, Jennifer G. Goldman, Roy N. Alcalay, John Sidney, David Sulzer, Alessandro Sette, Cecilia S. Lindestam Arlehamn

Estimation of prevalence of autoimmune diseases in the United States using electronic health record data

• Text
• PDF

Abstract

BACKGROUND. Previous epidemiologic studies of autoimmune diseases in the United States (US) have included a limited number of diseases or used meta-analyses that rely on different data collection methods and analyses for each disease. METHODS. To estimate the prevalence of autoimmune diseases in the US, we used electronic health record data from six large medical systems in the US. We developed a software program using common methodology to compute the estimated prevalence of autoimmune diseases alone and in aggregate that can be readily used by other investigators to replicate or modify the analysis over time. RESULTS. Our findings indicate that over 15 million people, or 4.6% of the US population, have been diagnosed with at least one autoimmune disease from January 1, 2011, to June 1, 2022, and 34% of those are diagnosed with more than one autoimmune disease. As expected, females (63% of those with autoimmune disease) were almost twice as likely as males to be diagnosed with an autoimmune disease. We identified the top 20 autoimmune diseases based on prevalence and according to sex and age. CONCLUSION. Thus, we provide, for the first time, a large-scale prevalence estimate of autoimmune disease in the US by sex and age. FUNDING. Autoimmune Registry Inc., the National Heart Lung and Blood Institute, the National Center for Advancing Translational Sciences, the Intramural Research Program of the National Institute of Environmental Health Sciences.

Authors

Aaron H. Abend, Ingrid He, Neil Bahroos, Stratos Christianakis, Ashley B. Crew, Leanna M. Wise, Gloria P. Lipori, Xing He, Shawn N. Murphy, Christopher D. Herrick, Jagannadha Avasarala, Mark G. Weiner, Jacob S. Zelko, Erica Matute-Arcos, Mark Abajian, Philip R.O. Payne, Albert M. Lai, Heath A. Davis, Asher A. Hoberg, Chris E. Ortman, Amit D. Gode, Bradley W. Taylor, Kristen I. Osinski, Damian N. Di Florio, Noel R. Rose, Frederick W. Miller, George C. Tsokos, DeLisa Fairweather

Cathelicidin antimicrobial peptide expression in neutrophils and neurons antagonistically modulates neuroinflammation

• Text
• PDF

Abstract

Multiple sclerosis (MS) is an autoimmune disease that affects the central nervous system (CNS), the pathophysiology of which remains unclear and for which there is no definitive cure. Antimicrobial peptides (AMPs) are immunomodulatory molecules expressed in various tissues, including the CNS. Here, we investigated whether the cathelicidin-related AMP (CRAMP) modulated the development of experimental autoimmune encephalomyelitis (EAE), a mouse model of MS. We showed that, at early stage, CNS-recruited neutrophils produced neutrophil extracellular traps (NETs) rich in CRAMP that was required for EAE initiation. NET-associated CRAMP stimulated IL-6 production by dendritic cells via the cGAS/STING pathway, thereby promoting encephalitogenic Th17 response. However, at a later disease stage, neurons also expressed CRAMP that reduced EAE severity. Camp knockdown in neurons led to disease exacerbation, while local injection of CRAMP1–39 at the peak of EAE promoted disease remission. In vitro, CRAMP1–39 regulated the activation of microglia and astrocytes through the formyl peptide receptor (FPR)2. Finally, administration of butyrate, a gut microbiota-derived metabolite, stimulated the expression of neural CRAMP via the free fatty acids receptors (FFAR)2/3, and prevented EAE. This study shows that CRAMP produced by different cell types have opposing effects on neuroinflammation, offering therapeutic opportunities for MS and other neuroinflammatory disorders.

Authors

Subash Chand Verma, Emmanuelle Enée, Kanchanadevi Manasse, Feriel Rebhi, Axelle Penc, David Romeo-Guitart, Cuc Bui Thi, Matthias Titeux, Franck Oury, Simon Fillatreau, Roland Liblau, Julien Diana

Reduced thymic IL-4 impairs negative T cell selection in nonobese diabetic mice

• Text
• PDF

Abstract

Type 1 diabetes (T1D) develops spontaneously despite functional antigen presentation machinery in the thymus and a perceptible central tolerance process. We found that intrathymic enrichment with IL-4 fine tunes signaling through the IL-4/IL-13 heteroreceptor (HR) in early thymic progenitors (ETPs), augments negative selection of self-reactive T cells, sustains a diverse T cell repertoire devoid of clones expressing disease-associated T cell receptor (TCR) genes, and protects the nonobese diabetic (NOD) mouse from T1D. Indeed, optimal IL-4 activates STAT transcription factors to program ETP fate decision toward CD11c+CD8α+ dendritic cells (DCs) agile in negative T cell selection and clonal deletion of diabetogenic T cells. However, due to diminished invariant natural killer T (iNKT) 2 cell frequency in the NOD thymus, IL-4 is as suboptimal level, metering STAT activation to program ETP fate decision toward the T cell lineage leading to diminished negative selection, a clonally restricted TCR repertoire, and manifestation of spontaneous T1D. These insights uncover yet another interplay by which IL-4 affects T1D.

Authors

Alexis N. Cattin-Roy, Kimberly G. Laffey, Luan B. Le, Adam G. Schrum, Habib Zaghouani

Endogenous antigens shape the transcriptome and TCR repertoire in an autoimmune arthritis model

• Text
• PDF

Abstract

The development of pathogenic autoreactive CD4+ T cells, particularly in the context of impaired signaling, remains poorly understood. Unraveling how defective signaling pathways contribute to their activation and persistence is crucial for identifying new therapeutic targets. We profiled a highly arthritogenic subset of naïve CD4+ T cells using bulk and single-cell RNA and TCR sequencing from SKG mice, which develop CD4+ T cell mediated autoimmune arthritis driven by a hypomorphic mutation in Zap70—a key TCR signaling kinase. Despite impaired signaling, these cells exhibit heightened expression of T cell activation and cytokine signaling genes, but diminished expression of a subset of tolerogenic markers (Izumo1r, Tnfrsf9, Cd5, S100a11) compared to wild-type cells. The arthritogenic cells show an enrichment for TCR variable beta (Vβ) chains targeting superantigens from the endogenous mouse mammary tumor virus (MMTV) but exhibit diminished induction of tolerogenic markers following peripheral antigen encounter, contrasting with the robust induction of negative regulators seen in wild-type cells. In arthritic joints, cells expressing superantigen-reactive Vβs expand alongside detectable MMTV proviruses. Antiretroviral treatment and superantigen-reactive T cell depletion curtail SKG arthritis, suggesting that endogenous retroviruses disrupt peripheral tolerance and promote the activation and differentiation of self-reactive CD4+ T cells into pathogenic effector cells.

Authors

Elizabeth E. McCarthy, Steven Yu, Noah Perlmutter, Yuka Nakao, Ryota Naito, Charles Lin, Vivienne Riekher, Joe DeRisi, Chun Jimmie Ye, Arthur Weiss, Judith F. Ashouri

Accumulation of Epstein-Barr virus–induced cross-reactive immune responses is associated with multiple sclerosis

• Text
• PDF

Abstract

Authors

Hannes Vietzen, Laura M. Kühner, Sarah M. Berger, Philippe L. Furlano, Gabriel Bsteh, Thomas Berger, Paulus Rommer, Elisabeth Puchhammer-Stöckl

Autoinflammation in patients with leukocytic CBL loss of heterozygosity is caused by constitutive ERK-mediated monocyte activation

• Text
• PDF

Abstract

Patients heterozygous for germline CBL loss-of-function (LOF) variants can develop myeloid malignancy, autoinflammation, or both, if some or all of their leukocytes become homozygous for these variants through somatic loss of heterozygosity (LOH) via uniparental isodisomy. We observed an upregulation of the inflammatory gene expression signature in whole blood from these patients, mimicking monogenic inborn errors underlying autoinflammation. Remarkably, these patients had constitutively activated monocytes that secreted 10 to 100 times more inflammatory cytokines than those of healthy individuals and CBL LOF heterozygotes without LOH. CBL-LOH hematopoietic stem and progenitor cells (HSPCs) outgrew the other cells, accounting for the persistence of peripheral monocytes homozygous for the CBL LOF variant. ERK pathway activation was required for the excessive production of cytokines by both resting and stimulated CBL-LOF monocytes, as shown in monocytic cell lines. Finally, we found that about 1 in 10,000 individuals in the UK Biobank were heterozygous for CBL LOF variants and that these carriers were at high risk of hematological and inflammatory conditions.

Authors

Jonathan Bohlen, Ivan Bagarić, Taja Vatovec, Masato Ogishi, Syed F. Ahmed, Axel Cederholm, Lori Buetow, Steicy Sobrino, Corentin Le Floc’h, Carlos A. Arango-Franco, Luis Seabra, Marine Michelet, Federica Barzaghi, Davide Leardini, Francesco Saettini, Francesca Vendemini, Francesco Baccelli, Albert Catala, Eleonora Gambineri, Marinella Veltroni, Yurena Aguilar de la Red, Gillian I. Rice, Filippo Consonni, Laureline Berteloot, Laetitia Largeaud, Francesca Conti, Cécile Roullion, Cécile Masson, Boris Bessot, Yoann Seeleuthner, Tom Le Voyer, Darawan Rinchai, Jérémie Rosain, Anna-Lena Neehus, Lucia Erazo-Borrás, Hailun Li, Zarah Janda, En-Jui Cho, Edoardo Muratore, Camille Soudée, Candice Lainé, Eric Delabesse, Claire Goulvestre, Cindy S. Ma, Anne Puel, Stuart G. Tangye, Isabelle André, Christine Bole-Feysot, Laurent Abel, Miriam Erlacher, Shen-Ying Zhang, Vivien Béziat, Chantal Lagresle-Peyrou, Emmanuelle Six, Marlène Pasquet, Laia Alsina, Alessandro Aiuti, Peng Zhang, Yanick J. Crow, Nils Landegren, Riccardo Masetti, Danny T. Huang, Jean-Laurent Casanova, Jacinta Bustamante

HLA A*24:02–restricted T cell receptors cross-recognize bacterial and preproinsulin peptides in type 1 diabetes

• Text
• PDF

Abstract

CD8+ T cells destroy insulin-producing pancreatic β cells in type 1 diabetes through HLA class I–restricted presentation of self-antigens. Combinatorial peptide library screening was used to produce a preferred peptide recognition landscape for a patient-derived T cell receptor (TCR) that recognized the preproinsulin-derived (PPI-derived) peptide sequence LWMRLLPLL in the context of disease risk allele HLA A*24:02. Data were used to generate a strong superagonist peptide, enabling production of an autoimmune HLA A*24:02–peptide–TCR structure by crystal seeding. TCR binding to the PPI epitope was strongly focused on peptide residues Arg4 and Leu5, with more flexibility at other positions, allowing the TCR to strongly engage many peptides derived from pathogenic bacteria. We confirmed an epitope from Klebsiella that was recognized by PPI-reactive T cells from 3 of 3 HLA A*24:02+ patients. Remarkably, the same epitope selected T cells from 7 of 8 HLA A*24+ healthy donors that cross-reacted with PPI, leading to recognition and killing of HLA A*24:02+ cells expressing PPI. These data provide a mechanism by which molecular mimicry between pathogen and self-antigens could have resulted in the breaking of self-tolerance to initiate disease.

Authors

Garry Dolton, Anna Bulek, Aaron Wall, Hannah Thomas, Jade R. Hopkins, Cristina Rius, Sarah A.E. Galloway, Thomas Whalley, Li Rong Tan, Théo Morin, Nader Omidvar, Anna Fuller, Katie Topley, Md Samiul Hasan, Shikha Jain, Nirupa D’Souza, Thomas Hodges-Hoyland, the TIRID Consortium, Owen B. Spiller, Deborah Kronenberg-Versteeg, Barbara Szomolay, Hugo A. van den Berg, Lucy C. Jones, Mark Peakman, David K. Cole, Pierre J. Rizkallah, Andrew K. Sewell