RESUMEN
Antibodies can block immune receptor engagement or trigger the receptor machinery to initiate signaling. We hypothesized that antibody agonists trigger signaling by sterically excluding large receptor-type protein tyrosine phosphatases (RPTPs) such as CD45 from sites of receptor engagement. An agonist targeting the costimulatory receptor CD28 produced signals that depended on antibody immobilization and were sensitive to the sizes of the receptor, the RPTPs, and the antibody itself. Although both the agonist and a non-agonistic anti-CD28 antibody locally excluded CD45, the agonistic antibody was more effective. An anti-PD-1 antibody that bound membrane proximally excluded CD45, triggered Src homology 2 domain-containing phosphatase 2 recruitment, and suppressed systemic lupus erythematosus and delayed-type hypersensitivity in experimental models. Paradoxically, nivolumab and pembrolizumab, anti-PD-1-blocking antibodies used clinically, also excluded CD45 and were agonistic in certain settings. Reducing these agonistic effects using antibody engineering improved PD-1 blockade. These findings establish a framework for developing new and improved therapies for autoimmunity and cancer.
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Proteínas Tirosina Fosfatasas , Transducción de Señal , Proteínas Tirosina Fosfatasas/metabolismo , Antígenos CD28 , Receptores InmunológicosRESUMEN
Multiple sclerosis (MS) is a neuro-inflammatory and neurodegenerative disease that is most prevalent in Northern Europe. Although it is known that inherited risk for MS is located within or in close proximity to immune-related genes, it is unknown when, where and how this genetic risk originated1. Here, by using a large ancient genome dataset from the Mesolithic period to the Bronze Age2, along with new Medieval and post-Medieval genomes, we show that the genetic risk for MS rose among pastoralists from the Pontic steppe and was brought into Europe by the Yamnaya-related migration approximately 5,000 years ago. We further show that these MS-associated immunogenetic variants underwent positive selection both within the steppe population and later in Europe, probably driven by pathogenic challenges coinciding with changes in diet, lifestyle and population density. This study highlights the critical importance of the Neolithic period and Bronze Age as determinants of modern immune responses and their subsequent effect on the risk of developing MS in a changing environment.
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Predisposición Genética a la Enfermedad , Genoma Humano , Pradera , Esclerosis Múltiple , Humanos , Conjuntos de Datos como Asunto , Dieta/etnología , Dieta/historia , Europa (Continente)/etnología , Predisposición Genética a la Enfermedad/historia , Genética Médica , Historia del Siglo XV , Historia Antigua , Historia Medieval , Migración Humana/historia , Estilo de Vida/etnología , Estilo de Vida/historia , Esclerosis Múltiple/genética , Esclerosis Múltiple/historia , Esclerosis Múltiple/inmunología , Enfermedades Neurodegenerativas/genética , Enfermedades Neurodegenerativas/historia , Enfermedades Neurodegenerativas/inmunología , Densidad de PoblaciónRESUMEN
JAK inhibitors impact multiple cytokine pathways simultaneously, enabling high efficacy in treating complex diseases such as cancers and immune-mediated disorders. However, their broad reach also poses safety concerns, which have fuelled a demand for increasingly selective JAK inhibitors. Deucravacitinib, a first-in-class allosteric TYK2 inhibitor, represents a remarkable advancement in the field. Rather than competing at kinase domain catalytic sites as classical JAK1-3 inhibitors, deucravacitinib targets the regulatory pseudokinase domain of TYK2. It strikingly mirrors the functional effect of an evolutionary conserved naturally occurring TYK2 variant, P1104A, known to protect against multiple autoimmune diseases yet provide sufficient TYK2-mediated cytokine signalling required to prevent immune deficiency. The unprecedentedly high functional selectivity and efficacy-safety profile of deucravacitinib, initially demonstrated in psoriasis, combined with genetic support, and promising outcomes in early SLE clinical trials make this inhibitor ripe for exploration in other autoimmune diseases for which better, safe, and efficacious treatments are urgently needed.
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Enfermedades Autoinmunes , Inhibidores de las Cinasas Janus , Psoriasis , Humanos , Inhibidores de las Cinasas Janus/farmacología , Inhibidores de las Cinasas Janus/uso terapéutico , TYK2 Quinasa/genética , Enfermedades Autoinmunes/tratamiento farmacológico , Citocinas , Psoriasis/tratamiento farmacológico , Janus Quinasa 1/genética , Janus Quinasa 1/metabolismoRESUMEN
BACKGROUND AND OBJECTIVES: Acute inflammatory CNS diseases include neuromyelitis optica spectrum disorders (NMOSDs) and myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD). Both MOGAD and acute disseminated encephalomyelitis (ADEM) have been reported after vaccination. Consequently, the mass SARS-CoV-2 vaccination program could result in increased rates of these conditions. We described the features of patients presenting with new acute CNS demyelination resembling NMOSDs or MOGAD within 8 weeks of SARS-CoV-2 vaccination. METHODS: The study included a prospective case series of patients referred to highly specialized NMOSD services in the UK from the introduction of SARS-CoV-2 vaccination program up to May 2022. Twenty-five patients presented with new optic neuritis (ON) and/or transverse myelitis (TM) ± other CNS inflammation within 8 weeks of vaccination with either AstraZeneca (ChAdOx1S) or Pfizer (BNT162b2) vaccines. Their clinical records and paraclinical investigations including MRI scans were reviewed. Serologic testing for antibodies to myelin oligodendrocyte glycoprotein (MOG) and aquaporin 4 (AQP4) was performed using live cell-based assays. Patients' outcomes were graded good, moderate, or poor based on the last clinical assessment. RESULTS: Of 25 patients identified (median age 38 years, 14 female), 12 (48%) had MOG antibodies (MOGIgG+), 2 (8%) had aquaporin 4 antibodies (AQP4IgG+), and 11 (44%) had neither. Twelve of 14 (86%) antibody-positive patients received the ChAdOx1S vaccine. MOGIgG+ patients presented most commonly with TM (10/12, 83%), frequently in combination with ADEM-like brain/brainstem lesions (6/12, 50%). Transverse myelitis was longitudinally extensive in 7 of the 10 patients. A peak in new MOGAD cases in Spring 2021 was attributable to postvaccine cases. Both AQP4IgG+ patients presented with brain lesions and TM. Four of 6 (67%) seronegative ChAdOx1S recipients experienced longitudinally extensive TM (LETM) compared with 1 of 5 (20%) of the BNT162b2 group, and facial nerve inflammation was reported only in ChAdOx1S recipients (2/5, 40%). Guillain-Barre syndrome was confirmed in 1 seronegative ChAdOx1S recipient and suspected in another. DISCUSSION: ChAdOx1S was associated with 12/14 antibody-positive cases, the majority MOGAD. MOGAD patients presented atypically, only 2 with isolated ON (1 after BNT162b2 vaccine) but with frequent ADEM-like brain lesions and LETM. Within the seronegative group, phenotypic differences were observed between ChAdOx1S and BNT162b2 recipients. These observations might support a causative role of the ChAdOx1S vaccine in inflammatory CNS disease and particularly MOGAD. Further study of this cohort could provide insights into vaccine-associated immunopathology.
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COVID-19 , Encefalomielitis Aguda Diseminada , Mielitis Transversa , Neuromielitis Óptica , Neuritis Óptica , Femenino , Humanos , Glicoproteína Mielina-Oligodendrócito , Acuaporina 4 , Mielitis Transversa/etiología , Vacunas contra la COVID-19/efectos adversos , SARS-CoV-2 , Vacuna BNT162 , COVID-19/prevención & control , Sistema Nervioso Central , Encefalomielitis Aguda Diseminada/etiología , Vacunación/efectos adversos , InflamaciónRESUMEN
Fetal growth restriction (FGR) affects 5-10% of pregnancies, and can have serious consequences for both mother and child. Prevention and treatment are limited because FGR pathogenesis is poorly understood. Genetic studies implicate KIR and HLA genes in FGR, however, linkage disequilibrium, genetic influence from both parents, and challenges with investigating human pregnancies make the risk alleles and their functional effects difficult to map. Here, we demonstrate that the interaction between the maternal KIR2DL1, expressed on uterine natural killer (NK) cells, and the paternally inherited HLA-C*0501, expressed on fetal trophoblast cells, leads to FGR in a humanized mouse model. We show that the KIR2DL1 and C*0501 interaction leads to pathogenic uterine arterial remodeling and modulation of uterine NK cell function. This initial effect cascades to altered transcriptional expression and intercellular communication at the maternal-fetal interface. These findings provide mechanistic insight into specific FGR risk alleles, and provide avenues of prevention and treatment.
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Retardo del Crecimiento Fetal , Trofoblastos , Animales , Comunicación Celular/genética , Femenino , Retardo del Crecimiento Fetal/genética , Retardo del Crecimiento Fetal/metabolismo , Feto/metabolismo , Antígenos HLA-C/genética , Antígenos HLA-C/metabolismo , Ratones , Embarazo , Trofoblastos/metabolismoRESUMEN
Progressive multiple sclerosis (MS) is characterized by unrelenting neurodegeneration, which causes cumulative disability and is refractory to current treatments. Drug development to prevent disease progression is an urgent clinical need yet is constrained by an incomplete understanding of its complex pathogenesis. Using spatial transcriptomics and proteomics on fresh-frozen human MS brain tissue, we identified multicellular mechanisms of progressive MS pathogenesis and traced their origin in relation to spatially distributed stages of neurodegeneration. By resolving ligand-receptor interactions in local microenvironments, we discovered defunct trophic and anti-inflammatory intercellular communications within areas of early neuronal decline. Proteins associated with neuronal damage in patient samples showed mechanistic concordance with published in vivo knockdown and central nervous system (CNS) disease models, supporting their causal role and value as potential therapeutic targets in progressive MS. Our findings provide a new framework for drug development strategies, rooted in an understanding of the complex cellular and signaling dynamics in human diseased tissue that facilitate this debilitating disease.
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Enfermedades del Sistema Nervioso Central , Esclerosis Múltiple , Enfermedades del Sistema Nervioso Central/complicaciones , Progresión de la Enfermedad , Humanos , Esclerosis Múltiple/patología , Neuronas/metabolismo , ProteómicaRESUMEN
Our incomplete understanding of the causes and pathways involved in the onset and progression of multiple sclerosis (MS) limits our ability to effectively treat this complex neurological disease. Recent studies explore the role of immune cells at different stages of MS and how they interact with cells of the central nervous system (CNS). The findings presented here begin to question the exclusivity of an antigen-specific cause and highlight how seemingly distinct immune cell types can share common functions that drive disease. Innovative techniques further expose new disease-associated immune cell populations and reinforce how environmental context is critical to their phenotype and subsequent role in disease. Importantly, the differentiation of immune cells into a pathogenic state is potentially reversible through therapeutic manipulation. As such, understanding the mechanisms that provide plasticity to causal cell types is likely key to uncoupling these disease processes and may identify novel therapeutic targets that replace the need for cell ablation.
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Esclerosis Múltiple , Humanos , FenotipoRESUMEN
BACKGROUND: Multiple sclerosis (MS), an autoimmune disease of the central nervous system (CNS), can be suppressed in its early stages but eventually becomes clinically progressive and unresponsive to therapy. Here, we investigate whether the therapeutic resistance of progressive MS can be attributed to chronic immune cell accumulation behind the blood-brain barrier (BBB). METHODS: We systematically track CNS-homing immune cells in the peripheral blood of 31 MS patients and 31 matched healthy individuals in an integrated analysis of 497,705 single-cell transcriptomes and 355,433 surface protein profiles from 71 samples. Through spatial RNA sequencing, we localize these cells in post mortem brain tissue of 6 progressive MS patients contrasted against 4 control brains (20 samples, 85,000 spot transcriptomes). FINDINGS: We identify a specific pathogenic CD161+/lymphotoxin beta (LTB)+ T cell population that resides in brains of progressive MS patients. Intriguingly, our data suggest that the colonization of the CNS by these T cells may begin earlier in the disease course, as they can be mobilized to the blood by usage of the integrin-blocking antibody natalizumab in relapsing-remitting MS patients. CONCLUSIONS: As a consequence, we lay the groundwork for a therapeutic strategy to deplete CNS-homing T cells before they can fuel treatment-resistant progression. FUNDING: This study was supported by funding from the University Medical Center Hamburg-Eppendorf, the Stifterverband für die Deutsche Wissenschaft, the OAK Foundation, Medical Research Council UK, and Wellcome.
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Esclerosis Múltiple Crónica Progresiva , Esclerosis Múltiple Recurrente-Remitente , Esclerosis Múltiple , Sistema Nervioso Central/patología , Humanos , Esclerosis Múltiple/tratamiento farmacológico , Esclerosis Múltiple Crónica Progresiva/tratamiento farmacológico , Esclerosis Múltiple Recurrente-Remitente/tratamiento farmacológico , Natalizumab/uso terapéutico , Linfocitos T/patologíaRESUMEN
Mixed lineage kinase domain-like (MLKL) is the main executor of necroptosis, an inflammatory form of programmed cell death. Necroptosis is implicated in combating infections, but also in contributing to numerous other clinical conditions, including cardiovascular diseases and neurodegenerative disorders. Inhibition of necroptosis is therefore of therapeutic interest. Here we report two siblings both of whom over the course of 35 years developed a similar progressive, neurodegenerative spectrum disorder characterized by paresis, ataxia and dysarthria. Magnetic resonance imaging of their central nervous system (CNS) revealed severe global cerebral volume loss and atrophy of the cerebellum and brainstem. These brothers are homozygous for a rare haplotype identified by whole genome sequencing carrying a frameshift variant in MLKL, as well as an in-frame deletion of one amino acid in the adjacent fatty acid 2-hydroxylase (FA2H) gene. Functional studies of patient-derived primary cells demonstrated that the variant in MLKL leads to a deficiency of MLKL protein resulting in impairment of necroptosis. Conversely, shotgun lipidomic analysis of the variant in FA2H shows no impact on either the abundance or the enzymatic activity of the encoded hydroxylase. To our knowledge, this is the first report of complete necroptosis deficiency in humans. The findings may suggest that impaired necroptosis is a novel mechanism of neurodegeneration, promoting a disorder that shares some clinical features with primary progressive multiple sclerosis (PPMS) and other neurodegenerative diseases. Importantly, the necroptotic deficiency does not cause symptoms outside the nervous system, nor does it confer susceptibility to infections. Given the current interest in pharmacological inhibition of necroptosis by targeting MLKL and its associated pathways, this strategy should be developed with caution, with careful consideration of the possible development of adverse neurological effects.
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Apoptosis/genética , Necroptosis/genética , Enfermedades Neurodegenerativas/patología , Proteínas Quinasas/deficiencia , Animales , Apoptosis/fisiología , Humanos , Quinasas Quinasa Quinasa PAM/genética , Quinasas Quinasa Quinasa PAM/metabolismo , Enfermedades Neurodegenerativas/genética , Enfermedades Neurodegenerativas/metabolismo , Fosforilación , Proteínas Quinasas/metabolismo , Proteína Serina-Treonina Quinasas de Interacción con Receptores/metabolismoRESUMEN
Expression of HLA-C varies widely across individuals in an allele-specific manner. This variation in expression can influence efficacy of the immune response, as shown for infectious and autoimmune diseases. MicroRNA binding partially influences differential HLA-C expression, but the additional contributing factors have remained undetermined. Here we use functional and structural analyses to demonstrate that HLA-C expression is modulated not just at the RNA level, but also at the protein level. Specifically, we show that variation in exons 2 and 3, which encode the α1/α2 domains, drives differential expression of HLA-C allomorphs at the cell surface by influencing the structure of the peptide-binding cleft and the diversity of peptides bound by the HLA-C molecules. Together with a phylogenetic analysis, these results highlight the diversity and long-term balancing selection of regulatory factors that modulate HLA-C expression.
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Antígenos HLA-C/química , Antígenos HLA-C/genética , Alelos , Animales , Exones , Regulación de la Expresión Génica , Variación Genética , Antígenos HLA-C/metabolismo , Humanos , Mamíferos/clasificación , Mamíferos/genética , Pan troglodytes , Péptidos/química , Péptidos/genética , Péptidos/metabolismo , Filogenia , Regiones Promotoras Genéticas , Unión ProteicaRESUMEN
Thousands of genetic variants have been identified, which contribute to the development of complex diseases, but determining how to elucidate their biological consequences for translation into clinical benefit is challenging. Conflicting evidence regarding the functional impact of genetic variants in the tyrosine kinase 2 (TYK2) gene, which is differentially associated with common autoimmune diseases, currently obscures the potential of TYK2 as a therapeutic target. We aimed to resolve this conflict by performing genetic meta-analysis across disorders; subsequent molecular, cellular, in vivo, and structural functional follow-up; and epidemiological studies. Our data revealed a protective homozygous effect that defined a signaling optimum between autoimmunity and immunodeficiency and identified TYK2 as a potential drug target for certain common autoimmune disorders.
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Enfermedades Autoinmunes/genética , Estudios de Asociación Genética , TYK2 Quinasa/genética , Animales , Autoinmunidad , Linfocitos T CD4-Positivos/citología , Citocinas/metabolismo , Epigénesis Genética , Femenino , Variación Genética , Genómica , Genotipo , Células HEK293 , Homocigoto , Humanos , Sistema Inmunológico , Janus Quinasa 2/química , Leucocitos Mononucleares/citología , Masculino , Ratones , Mutación Missense , Fenotipo , Polimorfismo de Nucleótido Simple , Conformación Proteica , Sitios de Carácter Cuantitativo , Recombinación Genética , Análisis de Secuencia de ARN , Transducción de Señal , TranscriptomaRESUMEN
OBJECTIVE: To identify target antigens presented by human leukocyte antigen (HLA)-A*02:01 to the myelin-reactive human T-cell receptor (TCR) 2D1, which was originally isolated from a CD8+ T-cell clone recognizing proteolipid protein (PLP) in the context of HLA-A*03:01, we employed a new antigen search technology. METHODS: We used our recently developed antigen search technology that employs plasmid-encoded combinatorial peptide libraries and a highly sensitive single cell detection system to identify endogenous candidate peptides of mice and human origin. We validated candidate antigens by independent T-cell assays using synthetic peptides and refolded HLA:peptide complexes. A molecular model of HLA-A*02:01:peptide complexes was obtained by molecular dynamics simulations. RESULTS: We identified one peptide from glycerolphosphatidylcholine phosphodiesterase 1, which is identical in mice and humans and originates from a protein that is expressed in many cell types. When bound to HLA-A*02:01, this peptide cross-stimulates the PLP-reactive HLA-A3-restricted TCR 2D1. Investigation of molecular details revealed that the peptide length plays a crucial role in its capacity to bind HLA-A*02:01 and to activate TCR 2D1. Molecular modeling illustrated the 3D structures of activating HLA:peptide complexes. CONCLUSIONS: Our results show that our antigen search technology allows us to identify new candidate antigens of a presumably pathogenic, autoreactive, human CD8+ T-cell-derived TCR. They further illustrate how this TCR, which recognizes a myelin peptide bound to HLA-A*03:01, may cross-react with an unrelated peptide presented by the protective HLA class I allele HLA-A*02:01.
RESUMEN
Recent findings indicate a pathogenic involvement of IL-17-producing CD8(+) T cells in multiple sclerosis (MS). IL-17 production has been attributed to a subset of CD8(+) T cells that belong to the mucosal-associated invariant T (MAIT) cell population. Here, we report a reduction of CD8(+) MAIT cells in the blood of MS patients compared with healthy individuals, which significantly correlated with IL-18 serum levels in MS patients. In vitro stimulation of peripheral blood mononuclear cells from healthy individuals and MS patients with IL-18 specifically activated CD8(+) MAIT cells. Moreover, IL-18 together with T-cell receptor stimulation induced, specifically on CD8(+) MAIT cells, an upregulation of the integrin very late antigen-4 that is essential for the infiltration of CD8(+) T cells into the CNS. Notably, we were able to identify CD8(+) MAIT cells in MS brain lesions by immunohistochemistry while they were almost absent in the cerebrospinal fluid (CSF). In summary, our findings indicate that an IL-18-driven activation of CD8(+) MAIT cells contributes to their CNS infiltration in MS, in turn leading to reduced CD8(+) MAIT-cell frequencies in the blood. Therefore, CD8(+) MAIT cells seem to play a role in the innate arm of immunopathology in MS.
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Linfocitos T CD8-positivos/inmunología , Interleucina-18/sangre , Esclerosis Múltiple/inmunología , Subgrupos de Linfocitos T/inmunología , Quimiotaxis de Leucocito , Citometría de Flujo , Humanos , Inmunohistoquímica , Activación de Linfocitos/inmunología , Esclerosis Múltiple/sangre , Esclerosis Múltiple/patologíaRESUMEN
Although there has been much success in identifying genetic variants associated with common diseases using genome-wide association studies (GWAS), it has been difficult to demonstrate which variants are causal and what role they have in disease. Moreover, the modest contribution that these variants make to disease risk has raised questions regarding their medical relevance. Here we have investigated a single nucleotide polymorphism (SNP) in the TNFRSF1A gene, that encodes tumour necrosis factor receptor 1 (TNFR1), which was discovered through GWAS to be associated with multiple sclerosis (MS), but not with other autoimmune conditions such as rheumatoid arthritis, psoriasis and Crohn's disease. By analysing MS GWAS data in conjunction with the 1000 Genomes Project data we provide genetic evidence that strongly implicates this SNP, rs1800693, as the causal variant in the TNFRSF1A region. We further substantiate this through functional studies showing that the MS risk allele directs expression of a novel, soluble form of TNFR1 that can block TNF. Importantly, TNF-blocking drugs can promote onset or exacerbation of MS, but they have proven highly efficacious in the treatment of autoimmune diseases for which there is no association with rs1800693. This indicates that the clinical experience with these drugs parallels the disease association of rs1800693, and that the MS-associated TNFR1 variant mimics the effect of TNF-blocking drugs. Hence, our study demonstrates that clinical practice can be informed by comparing GWAS across common autoimmune diseases and by investigating the functional consequences of the disease-associated genetic variation.
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Predisposición Genética a la Enfermedad/genética , Esclerosis Múltiple/inducido químicamente , Esclerosis Múltiple/genética , Polimorfismo de Nucleótido Simple/genética , Receptores Tipo I de Factores de Necrosis Tumoral/genética , Factor de Necrosis Tumoral alfa/antagonistas & inhibidores , Alelos , Exones/genética , Genoma Humano/genética , Estudio de Asociación del Genoma Completo , Genómica , Genotipo , Humanos , Esclerosis Múltiple/tratamiento farmacológico , Empalme del ARN/genética , Receptores Tipo I de Factores de Necrosis Tumoral/análisis , Receptores Tipo I de Factores de Necrosis Tumoral/metabolismo , Solubilidad , Factor de Necrosis Tumoral alfa/metabolismo , Reino UnidoRESUMEN
Multiple sclerosis (MS) is a disabling autoimmune disease of the central nervous system, which affects approximately 0.1% of the population with variable degrees of severity. Disease susceptibility is jointly determined by genetic predisposition and environmental contribution. However, as only a handful of genetic risk factors have been investigated beyond initial genome-wide association studies and environmental factors are largely unidentified, the exact mechanism of how these associations interact remains speculative. Our current understanding of this complex and heterogeneous disease has been advanced by experimental data obtained from animal modeling, with particular focus on the mouse MS model, experimental autoimmune encephalomyelitis. Manipulation of the mouse genome to study genetic risk factors has largely proved informative, but it also has limitations. Integration effects of transgene insertion, gene copy number, and expression variation, as well as differences in regulatory elements between mouse and human, are some of the hurdles faced when using such models to understand human gene variants in mice. Furthermore, as the list of MS disease-associated genetic variants continues to increase, so does the demand to find new approaches to study them. A new generation of humanized mice aims to tighten the gap between mouse and human, such that MS-associated genetic variants can be modeled more physiologically and systematically.
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Modelos Animales de Enfermedad , Ratones , Esclerosis Múltiple/genética , Animales , Ambiente , Estudios de Asociación Genética , Antígenos HLA/genética , Antígenos HLA/inmunología , Humanos , Ratones/genética , Esclerosis Múltiple/inmunologíaRESUMEN
Although there is growing evidence for a role of excess intracellular cations, particularly calcium ions, in neuronal and glial cell injury in multiple sclerosis, as well as in non-inflammatory neurological conditions, the molecular mechanisms involved are not fully determined. We previously showed that the acid-sensing ion channel 1 which, when activated under the acidotic tissue conditions found in inflammatory lesions opens to allow influx of sodium and calcium ions, contributes to axonal injury in experimental autoimmune encephalomyelitis, an animal model of multiple sclerosis. However, the extent and cellular distribution of acid-sensing ion channel 1 expression in neurons and glia in inflammatory lesions is unknown and, crucially, acid-sensing ion channel 1 expression has not been determined in multiple sclerosis lesions. Here we studied acute and chronic experimental autoimmune encephalomyelitis and multiple sclerosis spinal cord and optic nerve tissues to describe in detail the distribution of acid-sensing ion channel 1 and its relationship with neuronal and glial damage. We also tested the effects of amiloride treatment on tissue damage in the mouse models. We found that acid-sensing ion channel 1 was upregulated in axons and oligodendrocytes within lesions from mice with acute experimental autoimmune encephalomyelitis and from patients with active multiple sclerosis. The expression of acid-sensing ion channel 1 was associated with axonal damage as indicated by co-localization with the axonal injury marker beta amyloid precursor protein. Moreover, blocking acid-sensing ion channel 1 with amiloride protected both myelin and neurons from damage in the acute model, and when given either at disease onset or, more clinically relevant, at first relapse, ameliorated disability in mice with chronic-relapsing experimental autoimmune encephalomyelitis. Together these findings suggest that blockade of acid-sensing ion channel 1 has the potential to provide both neuro- and myelo-protective benefits in multiple sclerosis.
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Axones/metabolismo , Enfermedades Desmielinizantes/metabolismo , Encefalomielitis Autoinmune Experimental/metabolismo , Esclerosis Múltiple/tratamiento farmacológico , Esclerosis Múltiple/metabolismo , Proteínas del Tejido Nervioso/biosíntesis , Canales de Sodio/biosíntesis , Canales Iónicos Sensibles al Ácido , Anciano , Amilorida/farmacología , Amilorida/uso terapéutico , Animales , Axones/efectos de los fármacos , Axones/patología , Técnicas de Cultivo de Célula , Enfermedades Desmielinizantes/tratamiento farmacológico , Enfermedades Desmielinizantes/prevención & control , Encefalomielitis Autoinmune Experimental/tratamiento farmacológico , Encefalomielitis Autoinmune Experimental/patología , Femenino , Humanos , Ratones , Ratones Endogámicos C57BL , Persona de Mediana Edad , Esclerosis Múltiple/patología , Proteínas del Tejido Nervioso/antagonistas & inhibidores , Fármacos Neuroprotectores/farmacología , Fármacos Neuroprotectores/uso terapéutico , Oligodendroglía/metabolismo , Nervio Óptico/efectos de los fármacos , Nervio Óptico/metabolismo , Nervio Óptico/patología , Médula Espinal/efectos de los fármacos , Médula Espinal/metabolismo , Médula Espinal/patología , Regulación hacia ArribaRESUMEN
Anti-CD20 monoclonal antibodies (mAbs) are classified into type I (rituximab-like) or type II (tositumomab-like) based on their ability to redistribute CD20 molecules in the plasma membrane and activate various effector functions. To compare type I and II mAbs directly in vivo and maximize Fc effector function, we selected and engineered mAbs with the same mouse IgG(2)a isotype and assessed their B-cell depleting activity in human CD20 transgenic mice. Despite being the same isotype, having similar affinity, opsonizing activity for phagocytosis, and in vivo half-life, the type II mAb tositumomab (B1) provided substantially longer depletion of B cells from the peripheral blood compared with the type I mAb rituximab (Rit m2a), and 1F5. This difference was also evident within the secondary lymphoid organs, in particular, the spleen. Failure to engage complement did not explain the efficacy of the type II reagents because type I mAbs mutated in the Fc domain (K322A) to prevent C1q binding still did not display equivalent efficacy. These results give support for the use of type II CD20 mAbs in human B-cell diseases.
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Anticuerpos Monoclonales/farmacología , Citotoxicidad Celular Dependiente de Anticuerpos/inmunología , Antígenos CD20/inmunología , Antineoplásicos/farmacología , Activación de Complemento/efectos de los fármacos , Depleción Linfocítica/métodos , Animales , Anticuerpos Monoclonales/genética , Anticuerpos Monoclonales/inmunología , Anticuerpos Monoclonales/metabolismo , Anticuerpos Monoclonales de Origen Murino , Citotoxicidad Celular Dependiente de Anticuerpos/genética , Antígenos CD20/metabolismo , Antineoplásicos/inmunología , Antineoplásicos/metabolismo , Activación de Complemento/genética , Activación de Complemento/inmunología , Complemento C1q/inmunología , Complemento C1q/metabolismo , Evaluación Preclínica de Medicamentos/métodos , Humanos , Regiones Constantes de Inmunoglobulina/genética , Regiones Constantes de Inmunoglobulina/inmunología , Mutación Missense , Unión Proteica/genética , Unión Proteica/inmunología , Receptores de IgG/genética , Receptores de IgG/inmunología , RituximabRESUMEN
Activation of invariant NK T (iNKT) cells with the glycolipid alpha-galactosylceramide promotes CD8(+) cytotoxic T cell responses, a property that has been used to enhance the efficacy of antitumor vaccines. Using chimeric mice, we now show that the adjuvant properties of iNKT cells require that CD40 triggering and Ag presentation to CD8(+) T cells occur on the same APCs. We demonstrate that injection of alpha-galactosylceramide triggers CD70 expression on splenic T cell zone dendritic cells and that this is dependent on CD40 signaling. Importantly, we show that blocking the interaction between CD70 and CD27, its costimulatory receptor on T cells, abrogates the ability of iNKT cells to promote a CD8(+) T cell response and abolishes the efficacy of alpha-GalCer as an adjuvant for antitumor vaccines. These results define a key role for CD70 in linking the innate response of iNKT cells to the activation of CD8(+) T cells.