RESUMEN
Circulating autoantibodies (AB) of different immunoglobulin classes (IgM, IgA, and IgG), directed against the obligatory N-methyl-D-aspartate-receptor subunit NR1 (NMDAR1-AB), belong to the mammalian autoimmune repertoire, and appear with age-dependently high seroprevalence across health and disease. Upon access to the brain, they can exert NMDAR-antagonistic/ketamine-like actions. Still unanswered key questions, addressed here, are conditions of NMDAR1-AB formation/boosting, intraindividual persistence/course in serum over time, and (patho)physiological significance of NMDAR1-AB in modulating neuropsychiatric phenotypes. We demonstrate in a translational fashion from mouse to human that (1) serum NMDAR1-AB fluctuate upon long-term observation, independent of blood-brain barrier (BBB) perturbation; (2) a standardized small brain lesion in juvenile mice leads to increased NMDAR1-AB seroprevalence (IgM + IgG), together with enhanced Ig-class diversity; (3) CTLA4 (immune-checkpoint) genotypes, previously found associated with autoimmune disease, predispose to serum NMDAR1-AB in humans; (4) finally, pursuing our prior findings of an early increase in NMDAR1-AB seroprevalence in human migrants, which implicated chronic life stress as inducer, we independently replicate these results with prospectively recruited refugee minors. Most importantly, we here provide the first experimental evidence in mice of chronic life stress promoting serum NMDAR1-AB (IgA). Strikingly, stress-induced depressive-like behavior in mice and depression/anxiety in humans are reduced in NMDAR1-AB carriers with compromised BBB where NMDAR1-AB can readily reach the brain. To conclude, NMDAR1-AB may have a role as endogenous NMDAR antagonists, formed or boosted under various circumstances, ranging from genetic predisposition to, e.g., tumors, infection, brain injury, and stress, altogether increasing over lifetime, and exerting a spectrum of possible effects, also including beneficial functions.
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Autoanticuerpos , Lesiones Encefálicas , Animales , Barrera Hematoencefálica , Ratones , Receptores de N-Metil-D-Aspartato , Estudios Seroepidemiológicos , Estrés PsicológicoRESUMEN
BACKGROUND: The current standard in the serologic diagnosis of autoimmune bullous diseases (AIBD) is a multistep procedure sequentially applying different assays. In contrast, the BIOCHIP Mosaic technology combines multiple substrates for parallel analysis by indirect immunofluorescence. METHODS: Sera from 749 consecutive, prospectively recruited patients with direct immunofluorescence-positive AIBD from 13 international study centers were analyzed independently and blinded by using (1) a BIOCHIP Mosaic including primate esophagus, salt-split skin, rat bladder, monkey liver, monkey liver with serosa, recombinant BP180 NC16A, and gliadin GAF3X, as well as HEK293 cells expressing recombinant desmoglein 1, desmoglein 3, type VII collagen, and BP230 C-terminus and (2) the conventional multistep approach of the Department of Dermatology, University of Lübeck. RESULTS: In 731 of 749 sera (97.6%), specific autoantibodies could be detected with the BIOCHIP Mosaic, similar to the conventional procedure (725 cases, 96.8%). The Cohen κ for both serologic approaches ranged from 0.84 to 1.00. In 6.5% of sera, differences between the 2 approaches occurred and were mainly attributed to autoantigen fragments not present on the BIOCHIP Mosaic. LIMITATIONS: Laminin 332 and laminin γ1 are not represented on the BIOCHIP Mosaic. CONCLUSIONS: The BIOCHIP Mosaic is a standardized time- and serum-saving approach that further facilitates the serologic diagnosis of AIBD.
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Enfermedades Autoinmunes/diagnóstico , Penfigoide Ampolloso/diagnóstico , Penfigoide Ampolloso/inmunología , Pénfigo/diagnóstico , Pénfigo/inmunología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Enfermedades Autoinmunes/sangre , Niño , Femenino , Técnica del Anticuerpo Fluorescente Indirecta/métodos , Humanos , Masculino , Persona de Mediana Edad , Penfigoide Ampolloso/sangre , Pénfigo/sangre , Estudios Prospectivos , Adulto JovenRESUMEN
TMEM106B is a major risk factor for frontotemporal lobar degeneration with TDP-43 pathology. TMEM106B localizes to lysosomes, but its function remains unclear. We show that TMEM106B knockdown in primary neurons affects lysosomal trafficking and blunts dendritic arborization. We identify microtubule-associated protein 6 (MAP6) as novel interacting protein for TMEM106B. MAP6 over-expression inhibits dendritic branching similar to TMEM106B knockdown. MAP6 knockdown fully rescues the dendritic phenotype of TMEM106B knockdown, supporting a functional interaction between TMEM106B and MAP6. Live imaging reveals that TMEM106B knockdown and MAP6 overexpression strongly increase retrograde transport of lysosomes in dendrites. Downregulation of MAP6 in TMEM106B knockdown neurons restores the balance of anterograde and retrograde lysosomal transport and thereby prevents loss of dendrites. To strengthen the link, we enhanced anterograde lysosomal transport by expressing dominant-negative Rab7-interacting lysosomal protein (RILP), which also rescues the dendrite loss in TMEM106B knockdown neurons. Thus, TMEM106B/MAP6 interaction is crucial for controlling dendritic trafficking of lysosomes, presumably by acting as a molecular brake for retrograde transport. Lysosomal misrouting may promote neurodegeneration in patients with TMEM106B risk variants.
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Dendritas/metabolismo , Lisosomas/metabolismo , Proteínas de la Membrana/metabolismo , Proteínas Asociadas a Microtúbulos/metabolismo , Proteínas del Tejido Nervioso/metabolismo , Animales , Línea Celular , Expresión Génica , Técnicas de Silenciamiento del Gen , Humanos , Mapeo de Interacción de Proteínas , RatasRESUMEN
Translation of the expanded (ggggcc)n repeat in C9orf72 patients with amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) causes abundant poly-GA inclusions. To elucidate their role in pathogenesis, we generated transgenic mice expressing codon-modified (GA)149 conjugated with cyan fluorescent protein (CFP). Transgenic mice progressively developed poly-GA inclusions predominantly in motoneurons and interneurons of the spinal cord and brain stem and in deep cerebellar nuclei. Poly-GA co-aggregated with p62, Rad23b and the newly identified Mlf2, in both mouse and patient samples. Consistent with the expression pattern, 4-month-old transgenic mice showed abnormal gait and progressive balance impairment, but showed normal hippocampus-dependent learning and memory. Apart from microglia activation we detected phosphorylated TDP-43 but no neuronal loss. Thus, poly-GA triggers behavioral deficits through inflammation and protein sequestration that likely contribute to the prodromal symptoms and disease progression of C9orf72 patients.
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Proteína C9orf72/genética , Enfermedades del Sistema Nervioso Central/fisiopatología , Expansión de las Repeticiones de ADN/genética , Cuerpos de Inclusión/patología , Médula Espinal/patología , Animales , Tronco Encefálico/metabolismo , Tronco Encefálico/patología , Proteína C9orf72/metabolismo , Proteínas de Unión al Calcio/metabolismo , Citocinas/metabolismo , Embrión de Mamíferos , Regulación de la Expresión Génica/genética , Hipocampo/citología , Humanos , Cuerpos de Inclusión/genética , Inflamación/genética , Inflamación/patología , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Neuroglía/efectos de los fármacos , Neuroglía/metabolismo , Neuroglía/patología , Neuronas/patología , Proteínas Nucleares/metabolismo , Desempeño PsicomotorRESUMEN
Autoantibodies against the 3 desmocollin (Dsc; Dsc1-Dsc3) isoforms have been described in different pemphigus variants. Here, we developed state-of-the-art detection systems for serum anti-Dsc1, Dsc2 and Dsc1 IgG and IgA. These assays were applied in 5 different cohorts including pemphigus vulgaris (PV) patients with compatible direct immunofluorescence (IF) microscopy but no reactivity against desmogleins 1 and 3 (n = 24) and sera from patients with autoimmune blistering diseases with positive direct IF microscopy taken at the time of diagnosis (n = 749). We found that detection of anti-Dsc serum reactivity is not helpful in the routine diagnosis of PV, pemphigus foliaceus and paraneoplastic pemphigus but may be valuable in pemphigus vegetans.
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Desmocolinas/inmunología , Pénfigo/diagnóstico , Pénfigo/inmunología , Autoanticuerpos/sangre , Estudios de Cohortes , Células HEK293 , Humanos , Pénfigo/sangreRESUMEN
OBJECTIVE: Antibodies to cell surface central nervous system proteins help to diagnose conditions which often respond to immunotherapies. The assessment of antibody assays needs to reflect their clinical utility. We report the results of a multicentre study of aquaporin (AQP) 4 antibody (AQP4-Ab) assays in neuromyelitis optica spectrum disorders (NMOSD). METHODS: Coded samples from patients with neuromyelitis optica (NMO) or NMOSD (101) and controls (92) were tested at 15 European diagnostic centres using 21 assays including live (n=3) or fixed cell-based assays (n=10), flow cytometry (n=4), immunohistochemistry (n=3) and ELISA (n=1). RESULTS: Results of tests on 92 controls identified 12assays as highly specific (0-1 false-positive results). 32 samples from 50 (64%) NMO sera and 34 from 51 (67%) NMOSD sera were positive on at least two of the 12 highly specific assays, leaving 35 patients with seronegative NMO/spectrum disorder (SD). On the basis of a combination of clinical phenotype and the highly specific assays, 66 AQP4-Ab seropositive samples were used to establish the sensitivities (51.5-100%) of all 21 assays. The specificities (85.8-100%) were based on 92 control samples and 35 seronegative NMO/SD patient samples. CONCLUSIONS: The cell-based assays were most sensitive and specific overall, but immunohistochemistry or flow cytometry could be equally accurate in specialist centres. Since patients with AQP4-Ab negative NMO/SD require different management, the use of both appropriate control samples and defined seronegative NMOSD samples is essential to evaluate these assays in a clinically meaningful way. The process described here can be applied to the evaluation of other antibody assays in the newly evolving field of autoimmune neurology.
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Acuaporina 4/sangre , Autoanticuerpos/sangre , Neuromielitis Óptica/sangre , Acuaporina 4/inmunología , Autoanticuerpos/inmunología , Ensayo de Inmunoadsorción Enzimática/métodos , Humanos , Inmunohistoquímica/métodos , Neuromielitis Óptica/inmunología , Sensibilidad y EspecificidadRESUMEN
BACKGROUND AND PURPOSE: Recently, we reported high seroprevalence (age-dependent up to >19%) of N-methyl-d-aspartate-receptor subunit NR1 (NMDAR1) autoantibodies in both healthy and neuropsychiatrically ill subjects (N=4236). Neuropsychiatric syndrome relevance was restricted to individuals with compromised blood-brain barrier, for example, apolipoprotein E4 (APOE4) carrier status, both clinically and experimentally. We now hypothesized that these autoantibodies may upon stroke be protective in individuals with hitherto intact blood-brain barrier, but harmful for subjects with chronically compromised blood-brain barrier. METHODS: Of 464 patients admitted with acute ischemic stroke in the middle cerebral artery territory, blood for NMDAR1 autoantibody measurements and APOE4 carrier status as indicator of a preexisting leaky blood-brain barrier was collected within 3 to 5 hours after stroke. Evolution of lesion size (delta day 7-1) in diffusion-weighted magnetic resonance imaging was primary outcome parameter. In subgroups, NMDAR1 autoantibody measurements were repeated on days 2 and 7. RESULTS: Of all 464 patients, 21.6% were NMDAR1 autoantibody-positive (immunoglobulin M, A, or G) and 21% were APOE4 carriers. Patients with magnetic resonance imaging data available on days 1 and 7 (N=384) were divided into 4 groups according to NMDAR1 autoantibody and APOE4 status. Groups were comparable in all stroke-relevant presenting characteristics. The autoantibody+/APOE4- group had a smaller mean delta lesion size compared with the autoantibody-/APOE4- group, suggesting a protective effect of circulating NMDAR1 autoantibodies. In contrast, the autoantibody+/APOE4+ group had the largest mean delta lesion area. NMDAR1 autoantibody serum titers dropped on day 2 and remounted by day 7. CONCLUSIONS: Dependent on blood-brain barrier integrity before an acute ischemic brain injury, preexisting NMDAR1 autoantibodies seem to be beneficial or detrimental.
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Autoanticuerpos/análisis , Isquemia Encefálica/patología , Receptores de N-Metil-D-Aspartato/inmunología , Accidente Cerebrovascular/patología , Anciano , Anciano de 80 o más Años , Apolipoproteína E4/genética , Barrera Hematoencefálica/inmunología , Barrera Hematoencefálica/patología , Progresión de la Enfermedad , Femenino , Heterocigoto , Humanos , Infarto de la Arteria Cerebral Media/patología , Hemorragias Intracraneales/etiología , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Estudios Seroepidemiológicos , Resultado del TratamientoRESUMEN
OBJECTIVE: We previously reported an unexpectedly high seroprevalence (~10%) of N-methyl-D-aspartate-receptor subunit-NR1 (NMDAR1) autoantibodies (AB) in healthy and neuropsychiatrically ill subjects (N = 2,817). This finding challenges an unambiguous causal relationship of serum AB with brain disease. To test whether similar results would be obtained for other brain antigen-directed AB previously connected with pathological conditions, we systematically screened serum samples of 4,236 individuals. METHODS: Serum samples of healthy (n = 1,703) versus neuropsychiatrically ill subjects (schizophrenia, affective disorders, stroke, Parkinson disease, amyotrophic lateral sclerosis, personality disorder; total n = 2,533) were tested. For analysis based on indirect immunofluorescence, we used biochip mosaics of frozen brain sections (rat, monkey) and transfected HEK293 cells expressing respective recombinant target antigens. RESULTS: Seroprevalence of all screened AB was comparable in healthy and ill individuals. None of them, however, reached the abundance of NMDAR1 AB (again ~10%; immunoglobulin [Ig] G ~1%). Appreciable frequency was noted for AB against amphiphysin (2.0%), ARHGAP26 (1.3%), CASPR2 (0.9%), MOG (0.8%), GAD65 (0.5%), Ma2 (0.5%), Yo (0.4%), and Ma1 (0.4%), with titers and Ig class distribution similar among groups. All other AB were found in ≤0.1% of individuals (anti-AMPAR-1/2, AQP4, CV2, Tr/DNER, DPPX-IF1, GABAR-B1/B2, GAD67, GLRA1b, GRM1, GRM5, Hu, LGl1, recoverin, Ri, ZIC4). The predominant Ig class depended on antigen location, with intracellular epitopes predisposing to IgG (chi-square = 218.91, p = 2.8 × 10(-48) ). INTERPRETATION: To conclude, the brain antigen-directed AB tested here are comparably detectable in healthy subjects and the disease groups studied here, thus questioning an upfront pathological role of these serum AB.
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Autoanticuerpos/sangre , Trastornos Mentales/sangre , Trastornos Mentales/epidemiología , Enfermedades del Sistema Nervioso/sangre , Enfermedades del Sistema Nervioso/epidemiología , Adulto , Anciano , Animales , Autoanticuerpos/biosíntesis , Femenino , Alemania/epidemiología , Células HEK293 , Haplorrinos , Humanos , Masculino , Tamizaje Masivo , Trastornos Mentales/inmunología , Persona de Mediana Edad , Enfermedades del Sistema Nervioso/inmunología , Ratas , Receptores de N-Metil-D-Aspartato/inmunología , Valores de Referencia , Estudios SeroepidemiológicosRESUMEN
A massive expansion of a GGGGCC repeat upstream of the C9orf72 coding region is the most common known cause of amyotrophic lateral sclerosis and frontotemporal dementia. Despite its intronic localization and lack of a canonical start codon, both strands are translated into aggregating dipeptide repeat (DPR) proteins: poly-GA, poly-GP, poly-GR, poly-PR and poly-PA. To address conflicting findings on the predominant toxicity of the different DPR species in model systems, we compared the expression pattern of the DPR proteins in rat primary neurons and postmortem brain and spinal cord of C9orf72 mutation patients. Only poly-GA overexpression closely mimicked the p62-positive neuronal cytoplasmic inclusions commonly observed for all DPR proteins in patients. In contrast, overexpressed poly-GR and poly-PR formed nucleolar p62-negative inclusions. In patients, most of the less common neuronal intranuclear DPR inclusions were para-nucleolar and p62 positive. Neuronal nucleoli in C9orf72 cases showed normal size and morphology regardless of the presence of poly-GR and poly-PR inclusions arguing against widespread nucleolar stress, reported in cellular models. Colocalization of para-nucleolar DPR inclusions with heterochromatin and a marker of transcriptional repression (H3K9me2) indicates a link to gene transcription. In contrast, we detected numerous intranuclear DPR inclusions not associated with nucleolar structures in ependymal and subependymal cells. In patients, neuronal inclusions of poly-GR, poly-GP and the poly-GA interacting protein Unc119 were less abundant than poly-GA inclusions, but showed similar regional and subcellular distribution. Regardless of neurodegeneration, all inclusions were most abundant in neocortex, hippocampus and thalamus, with few inclusions in brain stem and spinal cord. In the granular cell layer of the cerebellum, poly-GA and Unc119 inclusions were significantly more abundant in cases with FTLD than in cases with MND and FTLD/MND. Poly-PR inclusions were rare throughout the brain but significantly more abundant in the CA3/4 region of FTLD cases than in MND cases. Thus, although DPR distribution is not correlated with neurodegeneration spatially, it correlates with neuropathological subtypes.
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Expansión de las Repeticiones de ADN , Silenciador del Gen , Proteínas/genética , Proteínas/metabolismo , Proteínas Adaptadoras Transductoras de Señales/metabolismo , Adulto , Anciano , Animales , Encéfalo/metabolismo , Encéfalo/patología , Proteína C9orf72 , Nucléolo Celular/metabolismo , Nucléolo Celular/patología , Estudios de Cohortes , Degeneración Lobar Frontotemporal/complicaciones , Degeneración Lobar Frontotemporal/genética , Degeneración Lobar Frontotemporal/metabolismo , Degeneración Lobar Frontotemporal/patología , Humanos , Cuerpos de Inclusión/metabolismo , Cuerpos de Inclusión/patología , Persona de Mediana Edad , Enfermedad de la Neurona Motora/complicaciones , Enfermedad de la Neurona Motora/genética , Enfermedad de la Neurona Motora/metabolismo , Enfermedad de la Neurona Motora/patología , Neuroglía/metabolismo , Neuroglía/patología , Neuronas/metabolismo , Neuronas/patología , Ratas , Médula Espinal/metabolismo , Médula Espinal/patologíaRESUMEN
As a result of an error during digital processing of Figure 1a for publication, one of the immunofluorescence panels (GA175-GFP Nucleolin staining) was accidentally strongly altered in contrast and brightness. The corrected version of the figure is shown below. The authors apologize for any confusion caused by this error. In the published article, the collaborators from the two institutions, German Consortium for Frontotemporal Lobar Degeneration and Bavarian Brain Banking Alliance, were incorrectly listed in article note. These names have been relocated to the Appendix section in the article now.Figure 1a and the collaborators list have been amended in the published article.
RESUMEN
Hexanucleotide repeat expansion in C9orf72 is the most common pathogenic mutation in patients with amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration (FTLD). Despite the lack of an ATG start codon, the repeat expansion is translated in all reading frames into dipeptide repeat (DPR) proteins, which form insoluble, ubiquitinated, p62-positive aggregates that are most abundant in the cerebral cortex and cerebellum. To specifically analyze DPR toxicity and aggregation, we expressed DPR proteins from synthetic genes containing a start codon but lacking extensive GGGGCC repeats. Poly-Gly-Ala (GA) formed p62-positive cytoplasmic aggregates, inhibited dendritic arborization and induced apoptosis in primary neurons. Quantitative mass spectrometry analysis to identify poly-GA co-aggregating proteins revealed a significant enrichment of proteins of the ubiquitin-proteasome system. Among the other interacting proteins, we identified the transport factor Unc119, which has been previously linked to neuromuscular and axonal function, as a poly-GA co-aggregating protein. Strikingly, the levels of soluble Unc119 are strongly reduced upon poly-GA expression in neurons, suggesting a loss of function mechanism. Similar to poly-GA expression, Unc119 knockdown inhibits dendritic branching and causes neurotoxicity. Unc119 overexpression partially rescues poly-GA toxicity suggesting that poly-GA expression causes Unc119 loss of function. In C9orf72 patients, Unc119 is detectable in 9.5 % of GA inclusions in the frontal cortex, but only in 1.6 % of GA inclusions in the cerebellum, an area largely spared of neurodegeneration. A fraction of neurons with Unc119 inclusions shows loss of cytosolic staining. Poly-GA-induced Unc119 loss of function may thereby contribute to selective vulnerability of neurons with DPR protein inclusions in the pathogenesis of C9orf72 FTLD/ALS.
Asunto(s)
Proteínas Adaptadoras Transductoras de Señales/metabolismo , Esclerosis Amiotrófica Lateral/metabolismo , Dipéptidos/metabolismo , Degeneración Lobar Frontotemporal/metabolismo , Proteínas de Unión al ARN/química , Proteínas de Unión al ARN/metabolismo , Esclerosis Amiotrófica Lateral/genética , Esclerosis Amiotrófica Lateral/patología , Animales , Caspasas/metabolismo , Células Cultivadas , Corteza Cerebral/citología , Expansión de las Repeticiones de ADN/genética , Expansión de las Repeticiones de ADN/fisiología , Proteínas de Unión al ADN/metabolismo , Dipéptidos/genética , Dipéptidos/farmacología , Degeneración Lobar Frontotemporal/genética , Degeneración Lobar Frontotemporal/patología , Regulación de la Expresión Génica/efectos de los fármacos , Regulación de la Expresión Génica/genética , Proteínas Fluorescentes Verdes/genética , Proteínas Fluorescentes Verdes/metabolismo , Células HEK293 , Humanos , Proteínas Asociadas a Microtúbulos/metabolismo , Proteínas de Unión al ARN/genética , Ratas , Transfección , Ubiquitina/metabolismoRESUMEN
Autoimmune diseases are rare, but their incidence has increased over the past decades. Interestingly, the co-occurrence of autoimmune diseases is well documented; however, data on the presence of more than one specific autoantibody in healthy individuals are not available. Here, we investigated the prevalence of several autoantibodies in a cohort of over 6000 healthy persons. While individual autoantibodies were rarely detected (i.e. ranging from 0.3% for ANCA to 4.6% for anti-TPO), the cumulative prevalence of the tested autoantibodies was as high as 10%. Furthermore, our results demonstrate co-occurrence of ANA with specific autoantibodies that target TPO, CCP and Dsg1/3, while ANCA and autoantibodies to PCA and BP180/BP230 were not more frequent in ANA-positive compared to ANA-negative samples. This indicates that shared and independent mechanisms influence loss of tolerance to distinct sets of self-antigens.
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Autoanticuerpos/sangre , Enfermedades Autoinmunes/inmunología , Donantes de Sangre , Adolescente , Adulto , Anciano , Anticuerpos Anticitoplasma de Neutrófilos/inmunología , Anticuerpos Antinucleares/inmunología , Estudios de Cohortes , Femenino , Humanos , Masculino , Persona de Mediana Edad , Prevalencia , Adulto JovenRESUMEN
A subset of amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration (FTLD) patients present pathological redistribution and aggregation of the nuclear protein fused in sarcoma (FUS) in the cytoplasm. Although FUS associates with the spliceosomal complex, no endogenous neuronal splicing targets have been identified. Here we identify Tau mRNA as a physiological splicing target of FUS. In mouse brain, FUS directly binds to Tau pre-mRNA, and knockdown of FUS in hippocampal neurons leads to preferential inclusion of Tau exons 3 and 10. FUS knockdown causes significant growth cone enlargement and disorganization reminiscent of Tau loss of function. These findings suggest that disturbed cytoskeletal function and enhanced expression of the neurodegeneration-associated Tau exon 10 might contribute to FTLD/ALS with FUS inclusions.
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Degeneración Nerviosa/genética , Degeneración Nerviosa/patología , Empalme del ARN/genética , Proteínas de Unión al ARN/metabolismo , Proteínas tau/genética , Animales , Axones/metabolismo , Citoesqueleto/metabolismo , Exones/genética , Técnicas de Silenciamiento del Gen , Genes Reporteros , Conos de Crecimiento/metabolismo , Células HEK293 , Humanos , Ratones , Fenotipo , Unión Proteica , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Precursores del ARN/metabolismo , ARN Mensajero/genética , ARN Mensajero/metabolismo , Ratas , Proteínas tau/metabolismoRESUMEN
Affiliations: In the published publication [...].
RESUMEN
The rise of cancer immunotherapy has been a milestone in clinical oncology. Above all, immune checkpoint inhibitor treatment (ICI) with monoclonal antibodies targeting programmed cell death protein 1 (PD-1), programmed cell death-ligand 1 (PD-L1), and cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) has improved survival rates for an increasing number of malignancies. However, despite the clinical benefits, ICI-related autoimmunity has become a significant cause of non-relapse-related morbidity and mortality. Neurological immune-related adverse events (irAE-n) are particularly severe toxicities with a high risk for chronic illness, long-term steroid dependency, and early ICI treatment termination. While the clinical characteristics of irAE-n are well described, little is known about underlying immune mechanisms and potential biomarkers. Recently, high frequencies of neuronal autoantibodies in patients with irAE-n have been reported, however, their clinical relevance is unclear. Here, we present a dataset on neuronal autoantibody profiles in ICI-treated cancer patients with and without irAE-n, which was generated to investigate the potential role of neuronal autoantibodies in ICI-induced autoimmunity. Between September 2017 and January 2022 serum samples of 29 cancer patients with irAE-n post-ICI treatment) and 44 cancer control patients without high-grade immune-related adverse events (irAEs, n = 44 pre- and post-ICI treatment) were collected and tested for a large panel of brain-reactive and neuromuscular autoantibodies using indirect immunofluorescence and immunoblot assays. Prevalence of autoantibodies was compared between the groups and correlated with clinical characteristics such as outcome and irAE-n manifestation. These data represent the first systematic comparison of neuronal autoantibody profiles between ICI-treated cancer patients with and without irAE-n, providing valuable information for both researchers and clinicians. In the future, this dataset may be valuable for meta-analyses on the prevalence of neuronal autoantibodies in cancer patients.
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Massive GGGGCC repeat expansion in the first intron of the gene C9orf72 is the most common known cause of familial frontotemporal lobar degeneration (FTLD) and amyotrophic lateral sclerosis (ALS). Despite its intronic localization and lack of an ATG start codon, the repeat region is translated in all three reading frames into aggregating dipeptide-repeat (DPR) proteins, poly-(Gly-Ala), poly-(Gly-Pro) and poly-(Gly-Arg). We took an antibody-based approach to further validate the translation of DPR proteins. To test whether the antisense repeat RNA transcript is also translated, we raised antibodies against the predicted products, poly-(Ala-Pro) and poly-(Pro-Arg). Both antibodies stained p62-positive neuronal cytoplasmic inclusions throughout the cerebellum and hippocampus indicating that not only sense but also antisense strand repeats are translated into DPR proteins in the absence of ATG start codons. Protein products of both strands co-aggregate suggesting concurrent translation of both strands. Moreover, an antibody targeting the putative carboxyl terminus of DPR proteins can detect inclusion pathology in C9orf72 repeat expansion carriers suggesting that the non-ATG translation continues through the entire repeat and beyond. A highly sensitive monoclonal antibody against poly-(Gly-Arg), visualized abundant inclusion pathology in all cortical regions and some inclusions also in motoneurons. Together, our data show that the GGGGCC repeat is bidirectionally translated into five distinct DPR proteins that co-aggregate in the characteristic p62-positive TDP-43 negative inclusions found in FTLD/ALS cases with C9orf72 repeat expansion. Novel monoclonal antibodies against poly-(Gly-Arg) will facilitate pathological diagnosis of C9orf72 FTLD/ALS.
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Esclerosis Amiotrófica Lateral/diagnóstico , Encéfalo/metabolismo , Degeneración Lobar Frontotemporal/diagnóstico , Proteínas/genética , Esclerosis Amiotrófica Lateral/genética , Esclerosis Amiotrófica Lateral/metabolismo , Proteína C9orf72 , Expansión de las Repeticiones de ADN , Degeneración Lobar Frontotemporal/genética , Degeneración Lobar Frontotemporal/metabolismo , Humanos , Biosíntesis de Proteínas , Proteínas/metabolismoRESUMEN
Autoantibodies against soluble liver antigen (SLA) are specific markers for autoimmune hepatitis (AIH) type 1. In contrast to the determination of other AIH-associated autoantibodies by indirect immunofluorescence assay (IFA), detection of anti-SLA relied up to now on ELISA or immunoblot based on bacterially expressed recombinant protein. In order to develop a complementary IFA substrate, SLA isoform 1 was recombinantly produced in the human cell line HEK293 and controlled by a rabbit hyperimmune serum against SLA. The recombinant cells were used in IFA (RC-IFA) to analyze sera from 20 AIH patients with anti-SLA positivity predetermined by ELISA together with 80 controls (20 anti-SLA negative AIH, 15 primary biliary cirrhosis, 15 HCV, and 30 healthy blood donors). Using RC-IFA, anti-SLA was detected in all ELISA positive AIH sera but in none of the controls. Furthermore, a cytosolic fraction of HEK293 containing SLA was able to neutralize the autoantibodies in all positive sera in a dose-dependent manner. HEK293 cells expressing SLA are a valid substrate for the serodiagnosis of AIH relevant autoantibodies by IFA. In concert with cryosections of primate liver, rat kidney, rat liver, rat stomach, and HEp-2 cells, they enable the parallel determination of all autoantibodies associated with autoimmune liver diseases.
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Autoanticuerpos/sangre , Autoantígenos/metabolismo , Técnica del Anticuerpo Fluorescente Indirecta/métodos , Hepatitis Autoinmune/diagnóstico , Isoformas de Proteínas/metabolismo , Animales , Autoantígenos/genética , Autoantígenos/inmunología , Biomarcadores/metabolismo , Clonación Molecular , Células HEK293 , Hepatitis Autoinmune/inmunología , Humanos , Isoformas de Proteínas/genética , Isoformas de Proteínas/inmunología , Conejos , Ratas , Transgenes/genéticaRESUMEN
(1) Background: Homer-3 antibodies are associated with cerebellar disease ranging from subacute degeneration to cerebellitis. However, cognitive impairment associated with Homer-3 autoantibodies has not been reported until now. (2) Methods: in retrospect, we systematically studied clinical, cranial magnetic resonance imaging (cMRI), electroencephalography (EEG) and lumbar puncture data, including neural autoantibodies of a clinical case. (3) Results: we describe the case of a 56-year-old woman presenting with amnestic mild cognitive impairment in association with serum and CSF detection of Homer-3 autoantibodies and a depressive syndrome. cMRI revealed cerebellar atrophy. CSF analysis showed elevated ptau181 protein. Applying the criteria for an autoimmune psychiatric syndrome revealed a plausible autoimmune basis for the mild cognitive impairment. (4) Discussions: our case report demonstrates an amnestic mild cognitive impairment and depressive symptoms associated with Homer-3 autoantibodies as a novel feature of Homer-3 antibody-related disease. We also propose that cognitive dysfunction might result from impaired AMPAR signaling in the hippocampus induced by Homer-3 antibodies, which will have to be verified in further research.
RESUMEN
Background: Autoantibody-associated psychiatric disorders are a new terrain that is currently underrepresented considering immunopsychiatry's potential importance for therapeutic aspects. The aim of our research was thus to present initial pilot data on the long-term clinical course of our patients in an outpatient clinic specializing in autoantibody-associated psychiatric disorders. Methods: Thirty-seven patients were examined clinically in our outpatient clinic at regular intervals over a 1.5-year period. We collected clinical data on their demographics, psychopathology, and cognition, and magnetic resonance imaging (MRI) and cerebrospinal fluid (CSF) data as well as the status of neural autoantibodies in blood and/or serum. Results: Our main finding was that affective, psychotic, and cognitive symptoms did not change significantly over the 1.5-year period, thus revealing no progression. We divided the entire cohort of autoantibody-positive patients (n = 32) into subgroups consisting of patients with dementia (n = 14), mild cognitive impairment (MCI) (n = 7), psychotic disorders (n = 6), and a CSF profile of Alzheimer's disease (n = 6). Relying on established classification schemes, we identified the following percentages in our autoantibody-positive cohort: 28% with autoimmune encephalitis, 15% with autoimmune psychosis, and 63% with autoimmune psychiatric syndromes. Discussion: These initial pilot results suggest that autoantibody-associated diseases do not show a significantly progressive course in the long-term and are often characterized by impaired verbal memory recall when cognitive impairment progresses to dementia. These initial data need to be verified in larger cohorts. We believe that this pilot study underscores the importance of promoting such a specialized outpatient clinic to better characterize various aspects of autoantibody-mediated psychiatric disorders.
RESUMEN
BACKGROUND: Metabotropic glutamate receptors type 5 (mGluR5) play a central role in persistent forms of synaptic plasticity and memory formation. Antibodies to mGluR5 have been reported to be clinically associated with memory impairment. Here, we report on a patient with persistent amnestic cognitive impairment in a single cognitive domain after resolution of mGluR5-associated encephalitis. METHODS: We report on the clinical data of a patient in our Department of Psychiatry and Psychotherapy who underwent several diagnostic investigations including a detailed neuropsychological examination, magnetic resonance imaging, and cerebrospinal fluid analysis involving the determination of neural autoantibodies. RESULTS: A 54-year-old woman presented to our memory clinic with pleocytosis 4 months after remission of probable anti-mGluR5-mediated encephalitis, revealing initial pleocytosis and serum proof of anti-mGluR5 autoantibodies (1:32). A neuropsychological examination revealed mild cognitive impairment in verbal memory encoding and recall. The patient received immunotherapy with corticosteroids, and a subsequent cerebrospinal fluid analysis 1.5 months after the onset of encephalitis confirmed no further signs of inflammation. CONCLUSIONS: Our results suggest that although immunotherapy resulted in the remission of anti-mGluR5 encephalitis, a verbal memory encoding and recall dysfunction persisted. It remains unclear whether the reason for the persistent verbal memory impairment is attributable to insufficiently long immunotherapy or initially ineffective immunotherapy. Because mGluR5 plays an essential role in persistent synaptic plasticity in the hippocampus, it is tempting to speculate that the mGluR5 antibody-antigen complex could lead to persistent cognitive dysfunction, still present after the acute CNS inflammation stage of encephalitis.