RESUMO
BACKGROUND: Vitamin D (VitD) affects the risk of multiple sclerosis (MS), but the impact on disease activity is controversial. We assessed whether VitD is associated with the No-Evidence of Disease Activity-3 (NEDA-3) status at 2 years from disease-modifying treatment (DMT) start, and whether this association is causal or the result of confounding factors. Furthermore, we explored if a genetic predisposition to higher VitD levels affects the risk of disease activity. METHODS: 230 untreated relapsing-remitting MS patients underwent serum 25-OH-vitamin-D measurement, and the association between seasonally adjusted VitD and disease activity was tested. Modelling a Polygenic Risk Score from a Genome-Wide Association Study on ~400 000 individuals, we studied the impact of genetic predisposition to higher VitD on the NEDA-3 status in 1408 independent MS patients. Two-sample Mendelian randomisation (MR) was used to assess causality. RESULTS: Lower baseline VitD was associated with decreased probability of NEDA-3 at 2 years (p=0.019). Particularly, VitD levels <20 ng/mL conferred an over twofold risk of disease activity (OR 2.36, 95% CI 1.30 to 3.88, p=0.0037). Genetic predisposition to higher VitD levels was associated with delayed age at MS onset (p=0.018) and with a higher probability of NEDA-3 status (p=0.034). MR confirmed causality between VitD and the risk of disease activity (p=0.041). CONCLUSIONS: VitD levels before DMT start affect the risk of disease activity in MS. Genetic predisposition to higher VitD levels confers a lower risk of disease activity and is associated with delayed MS onset. Our work prompts future prospective studies regarding VitD supplementation and lifestyle interventions to hamper disease activity in MS.
RESUMO
OBJECTIVE: Multiple sclerosis (MS) has a complex pathobiology, with genetic and environmental factors being crucial players. Understanding the mechanisms underlying heterogeneity in disease activity is crucial for tailored treatment. We explored the impact of DNA methylation, a key mechanism in the genetics-environment interplay, on disease activity in MS. METHODS: Peripheral immune methylome profiling using Illumina Infinium MethylationEPIC BeadChips was conducted on 249 untreated relapsing-remitting MS patients, sampled at the start of disease-modifying treatment (DMT). A differential methylation analysis compared patients with evidence of disease activity (EDA) to those with no evidence of disease activity (NEDA) over 2 years from DMT start. Utilizing causal inference testing (CIT) and Mendelian randomization (MR), we sought to elucidate the relationships between DNA methylation, gene expression, genetic variation, and disease activity. RESULTS: Four differentially methylated regions (DMRs) were identified between EDA and NEDA. Examining the influence of single nucleotide polymorphisms (SNPs), 923 variants were found to account for the observed differences in the 4 DMRs. Importantly, 3 out of the 923 SNPs, affecting DNA methylation in a DMR linked to the anti-Mullerian hormone (AMH) gene, were associated with disease activity risk in an independent cohort of 1,408 MS patients. CIT and MR demonstrated that DNA methylation in AMH acts as a mediator for the genetic risk of disease activity. INTERPRETATION: This study uncovered a novel molecular pathway implicating the interaction between DNA methylation and genetic variation in the risk of disease activity in MS, emphasizing the role of sex hormones, particularly the AMH, in MS pathobiology. ANN NEUROL 2024;96:289-301.
Assuntos
Hormônio Antimülleriano , Metilação de DNA , Esclerose Múltipla Recidivante-Remitente , Polimorfismo de Nucleotídeo Único , Humanos , Metilação de DNA/genética , Feminino , Masculino , Adulto , Hormônio Antimülleriano/genética , Hormônio Antimülleriano/sangue , Polimorfismo de Nucleotídeo Único/genética , Pessoa de Meia-Idade , Esclerose Múltipla Recidivante-Remitente/genética , Análise da Randomização Mendeliana , Esclerose Múltipla/genéticaRESUMO
BACKGROUND: The glycoprotein CD226 plays a key role in regulating immune cell function. Soluble CD226 (sCD226) is increased in sera of patients with several chronic inflammatory diseases but its levels in neuroinflammatory diseases such as multiple sclerosis (MS) are unknown. OBJECTIVE: To investigate the presence and functional implications of sCD226 in persons with multiple sclerosis (pwMS) and other neurological diseases. METHODS: The mechanisms of sCD226 production were first investigated by analyzing CD226 surface expression levels and supernatants of CD3/CD226-coactivated T cells. The role of sCD226 on dendritic cell maturation was evaluated. The concentration of sCD226 in the sera from healthy donors (HD), pwMS, neuromyelitis optica (NMO), and Alzheimer's disease (AD) was measured. RESULTS: CD3/CD226-costimulation induced CD226 shedding. Addition of sCD226 to dendritic cells during their maturation led to an increased production of the pro-inflammatory cytokine interleukin (IL)-23. We observed a significant increase in sCD226 in sera from pwMS and NMO compared to HD and AD. In MS, levels were increased in both relapsing-remitting multiple sclerosis (RRMS) and secondary-progressive multiple sclerosis (SPMS) compared to clinically isolated syndrome (CIS). CONCLUSION: Our data suggest that T-cell activation leads to release of sCD226 that could promote inflammation and raises the possibility of using sCD226 as a biomarker for neuroinflammation.
Assuntos
Antígenos de Diferenciação de Linfócitos T , Células Dendríticas , Esclerose Múltipla , Neuromielite Óptica , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Doença de Alzheimer/sangue , Doença de Alzheimer/imunologia , Antígenos de Diferenciação de Linfócitos T/sangue , Biomarcadores/sangue , Células Dendríticas/imunologia , Esclerose Múltipla/sangue , Esclerose Múltipla/imunologia , Neuromielite Óptica/sangue , Neuromielite Óptica/imunologia , Linfócitos T/imunologia , Idoso de 80 Anos ou maisRESUMO
INTRODUCTION: Natalizumab, a therapy for relapsing-remitting multiple sclerosis (RRMS), is associated with a risk of progressive multifocal leukoencephalopathy (PML). Over the last several years, practitioners have used off-label extended interval dosing (EID) of natalizumab to reduce PML risk, despite the absence of a large-scale efficacy evaluation. METHODS: We conducted a retrospective, multicenter cohort study among adults with RRMS receiving stable standard interval dosing (SID), defined as a ≥ 12-month consecutive period of ≥ 11 natalizumab infusions/year in France. We compared the 12-month risk difference of remaining relapse-free (primary endpoint) between patients who switched to EID (≤ 9 natalizumab infusions) and those who remained on SID, with a noninferiority margin of - 11%. We used propensity score methods such as inverse probability treatment weighting (IPTW) and 1:1 propensity score matching (PSM). Secondary endpoints were annualized relapse rate, disease progression, and safety. RESULTS: Baseline characteristics were similar between patients receiving EID (n = 147) and SID (n = 156). The proportion of relapse-free patients 12 months postbaseline was 142/147 in the EID (96.6%) and 144/156 in the SID group (92.3%); risk difference (95% CI) 4.3% (- 1.3 to 9.8%); p < 0.001 for non-inferiority. There were no significant differences between relapse rates (0.043 vs. 0.083 per year, respectively; p = 0.14) or Expanded Disability Status Scale mean scores (2.43 vs. 2.72, respectively; p = 0.18); anti-JC virus index values were similar (p = 0.23); and no instances of PML were reported. The comparisons using IPTW (n = 306) and PSM (n = 204) were consistent. CONCLUSION: These results support the pertinence of using an EID strategy for RRMS patients treated with natalizumab. CLINICAL TRIALS: gov identifier (NCT04580381).
RESUMO
A personalized approach is strongly advocated for treatment selection in Multiple Sclerosis patients due to the high number of available drugs. Machine learning methods proved to be valuable tools in the context of precision medicine. In the present work, we applied machine learning methods to identify a combined clinical and genetic signature of response to fingolimod that could support the prediction of drug response. Two cohorts of fingolimod-treated patients from Italy and France were enrolled and divided into training, validation, and test set. Random forest training and robust feature selection were performed in the first two sets respectively, and the independent test set was used to evaluate model performance. A genetic-only model and a combined clinical-genetic model were obtained. Overall, 381 patients were classified according to the NEDA-3 criterion at 2 years; we identified a genetic model, including 123 SNPs, that was able to predict fingolimod response with an AUROC= 0.65 in the independent test set. When combining clinical data, the model accuracy increased to an AUROC= 0.71. Integrating clinical and genetic data by means of machine learning methods can help in the prediction of response to fingolimod, even though further studies are required to definitely extend this approach to clinical applications.
RESUMO
Epstein-Barr virus (EBV) infection precedes multiple sclerosis (MS) pathology and cross-reactive antibodies might link EBV infection to CNS autoimmunity. As an altered anti-EBV T cell reaction was suggested in MS, we queried peripheral blood T cell receptor ß chain (TCRß) repertoires of 1,395 MS patients, 887 controls, and 35 monozygotic, MS-discordant twin pairs for multimer-confirmed, viral antigen-specific TCRß sequences. We detected more MHC-I-restricted EBV-specific TCRß sequences in MS patients. Differences in genetics or upbringing could be excluded by validation in monozygotic twin pairs discordant for MS. Anti-VLA-4 treatment amplified this observation, while interferon ß- or anti-CD20 treatment did not modulate EBV-specific T cell occurrence. In healthy individuals, EBV-specific CD8+ T cells were of an effector-memory phenotype in peripheral blood and cerebrospinal fluid. In MS patients, cerebrospinal fluid also contained EBV-specific central-memory CD8+ T cells, suggesting recent priming. Therefore, MS is not only preceded by EBV infection, but also associated with broader EBV-specific TCR repertoires, consistent with an ongoing anti-EBV immune reaction in MS.
Assuntos
Infecções por Vírus Epstein-Barr , Esclerose Múltipla , Linfócitos T CD8-Positivos , Infecções por Vírus Epstein-Barr/complicações , Herpesvirus Humano 4 , Humanos , Receptores de Antígenos de Linfócitos T alfa-beta/genéticaRESUMO
OBJECTIVES: The study aimed to assess the potential for serum neurofilament light chain (NFL) levels to predict the risk of progressive multifocal leukoencephalopathy (PML) in natalizumab (NTZ)-treated patients with multiple sclerosis (MS) and to discriminate PML from MS relapses. METHODS: NFL levels were measured with single molecule array (Simoa) in 4 cohorts: (1) a prospective cohort of patients with MS who developed PML under NTZ therapy (pre-PML) and non-PML NTZ-treated patients (NTZ-ctr); (2) a cohort of patients whose blood was collected during PML; (3) an independent cohort of non-PML NTZ-treated patients with serum NFL determinations at 2 years (replication cohort); and (4) a cohort of patients whose blood was collected during exacerbations. RESULTS: Serum NFL levels were significantly increased after 2 years of NTZ treatment in pre-PML patients compared with NTZ-ctr. The prognostic performance of serum NFL levels to predict PML development at 2 years was similar in the NTZ-ctr group and replication cohort. Serum NFL levels also distinguished PML from MS relapses and were 8-fold higher during PML compared with relapses. CONCLUSIONS: These results support the use of serum NFL levels in clinical practice to identify patients with relapsing-remitting MS at higher PML risk and to differentiate PML from clinical relapses in NTZ-treated patients. CLASSIFICATION OF EVIDENCE: This study provides Class I evidence that serum NFL levels can identify NTZ-treated patients with MS who will develop PML with a sensitivity of 67% and specificity of 80%.
Assuntos
Fatores Imunológicos/administração & dosagem , Leucoencefalopatia Multifocal Progressiva/sangue , Leucoencefalopatia Multifocal Progressiva/diagnóstico , Esclerose Múltipla/sangue , Esclerose Múltipla/diagnóstico , Esclerose Múltipla/tratamento farmacológico , Natalizumab/administração & dosagem , Proteínas de Neurofilamentos/sangue , Adulto , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Esclerose Múltipla Recidivante-Remitente/sangue , Esclerose Múltipla Recidivante-Remitente/diagnóstico , Esclerose Múltipla Recidivante-Remitente/tratamento farmacológico , Prognóstico , Sensibilidade e Especificidade , Adulto JovemRESUMO
BACKGROUND: There are few head-to-head studies to compare highly active treatments in multiple sclerosis (MS). OBJECTIVE: The aim of this study was to compare the effectiveness between natalizumab (NTZ) and fingolimod (FTY) in active relapsing-remitting MS. METHOD: Best Escalation STrategy in Multiple Sclerosis (BEST-MS) is a multicentric, prospective study with a 12-month follow-up including patients with active MS. Treatment choice was at the discretion of physician. Clinical and magnetic resonance imaging (MRI) data were collected at baseline and at 12 months. The primary outcome was the proportion of patients reaching no evidence of disease activity (NEDA) at 12 months. Secondary outcomes included annualized relapse rate and MRI activity. RESULTS: A total of 223 patients were included (NTZ: 109 and FTY: 114). Treatment groups were well balanced at baseline. Proportion of NEDA patients was 47.8% in NTZ group versus 30.4% in FTY group (p = 0.015). This superiority was driven by annualized relapse rate and MRI activity. In the multivariate analysis, treatment group was the only factor associated with NEDA at 12 months with a lower probability in FTY group (odds ratio (OR) = 0.49, p = 0.029). CONCLUSION: BEST-MS is a prospective study that compared head-to-head the effectiveness of NTZ and FTY in active relapsing-remitting MS. Our results suggest a superiority of NTZ over FTY.
Assuntos
Cloridrato de Fingolimode , Esclerose Múltipla , Cloridrato de Fingolimode/uso terapêutico , Humanos , Natalizumab/uso terapêutico , Recidiva Local de Neoplasia , Estudos ProspectivosRESUMO
Multiple sclerosis (MS) disease risk is associated with reduced sun-exposure. This study assessed the relationship between measures of sun exposure (vitamin D [vitD], latitude) and MS severity in the setting of two multicenter cohort studies (nNationMS = 946, nBIONAT = 990). Additionally, effect-modification by medication and photosensitivity-associated MC1R variants was assessed. High serum vitD was associated with a reduced MS severity score (MSSS), reduced risk for relapses, and lower disability accumulation over time. Low latitude was associated with higher vitD, lower MSSS, fewer gadolinium-enhancing lesions, and lower disability accumulation. The association of latitude with disability was lacking in IFN-ß-treated patients. In carriers of MC1R:rs1805008(T), who reported increased sensitivity toward sunlight, lower latitude was associated with higher MRI activity, whereas for noncarriers there was less MRI activity at lower latitudes. In a further exploratory approach, the effect of ultraviolet (UV)-phototherapy on the transcriptome of immune cells of MS patients was assessed using samples from an earlier study. Phototherapy induced a vitD and type I IFN signature that was most apparent in monocytes but that could also be detected in B and T cells. In summary, our study suggests beneficial effects of sun exposure on established MS, as demonstrated by a correlative network between the three factors: Latitude, vitD, and disease severity. However, sun exposure might be detrimental for photosensitive patients. Furthermore, a direct induction of type I IFNs through sun exposure could be another mechanism of UV-mediated immune-modulation in MS.
Assuntos
Monócitos/efeitos da radiação , Esclerose Múltipla/sangue , Esclerose Múltipla/imunologia , Receptor Tipo 1 de Melanocortina/genética , Transcriptoma/efeitos da radiação , Vitamina D/sangue , Linfócitos B/efeitos da radiação , Estudos de Coortes , Feminino , Variação Genética , Genótipo , Humanos , Interferon beta/farmacologia , Interferon beta/uso terapêutico , Masculino , Pessoa de Meia-Idade , Monócitos/metabolismo , Esclerose Múltipla/patologia , Esclerose Múltipla/radioterapia , Fenótipo , Fototerapia , Recidiva , Índice de Gravidade de Doença , Luz Solar , Linfócitos T/metabolismo , Linfócitos T/efeitos da radiação , Transcriptoma/genéticaAssuntos
Fatores Imunológicos/uso terapêutico , Selectina L/sangue , Leucoencefalopatia Multifocal Progressiva/sangue , Leucoencefalopatia Multifocal Progressiva/tratamento farmacológico , Natalizumab/uso terapêutico , Biomarcadores/sangue , Estudos de Coortes , Esquema de Medicação , Humanos , Leucoencefalopatia Multifocal Progressiva/diagnóstico , Estudos Prospectivos , Reprodutibilidade dos TestesRESUMO
Interference with immune cell proliferation represents a successful treatment strategy in T cell-mediated autoimmune diseases such as rheumatoid arthritis and multiple sclerosis (MS). One prominent example is pharmacological inhibition of dihydroorotate dehydrogenase (DHODH), which mediates de novo pyrimidine synthesis in actively proliferating T and B lymphocytes. Within the TERIDYNAMIC clinical study, we observed that the DHODH inhibitor teriflunomide caused selective changes in T cell subset composition and T cell receptor repertoire diversity in patients with relapsing-remitting MS (RRMS). In a preclinical antigen-specific setup, DHODH inhibition preferentially suppressed the proliferation of high-affinity T cells. Mechanistically, DHODH inhibition interferes with oxidative phosphorylation (OXPHOS) and aerobic glycolysis in activated T cells via functional inhibition of complex III of the respiratory chain. The affinity-dependent effects of DHODH inhibition were closely linked to differences in T cell metabolism. High-affinity T cells preferentially use OXPHOS during early activation, which explains their increased susceptibility toward DHODH inhibition. In a mouse model of MS, DHODH inhibitory treatment resulted in preferential inhibition of high-affinity autoreactive T cell clones. Compared to T cells from healthy controls, T cells from patients with RRMS exhibited increased OXPHOS and glycolysis, which were reduced with teriflunomide treatment. Together, these data point to a mechanism of action where DHODH inhibition corrects metabolic disturbances in T cells, which primarily affects profoundly metabolically active high-affinity T cell clones. Hence, DHODH inhibition may promote recovery of an altered T cell receptor repertoire in autoimmunity.
Assuntos
Crotonatos/uso terapêutico , Mitocôndrias/metabolismo , Esclerose Múltipla/tratamento farmacológico , Esclerose Múltipla/imunologia , Linfócitos T/imunologia , Toluidinas/uso terapêutico , Aerobiose/efeitos dos fármacos , Animais , Proliferação de Células/efeitos dos fármacos , Respiração Celular/efeitos dos fármacos , Crotonatos/farmacologia , Di-Hidro-Orotato Desidrogenase , Complexo III da Cadeia de Transporte de Elétrons/metabolismo , Metabolismo Energético/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos dos fármacos , Glicólise/efeitos dos fármacos , Humanos , Hidroxibutiratos , Ativação Linfocitária/efeitos dos fármacos , Subpopulações de Linfócitos/efeitos dos fármacos , Subpopulações de Linfócitos/imunologia , Mitocôndrias/efeitos dos fármacos , Esclerose Múltipla/genética , Esclerose Múltipla/patologia , Esclerose Múltipla Recidivante-Remitente/imunologia , Nitrilas , Fosforilação Oxidativa/efeitos dos fármacos , Oxirredutases atuantes sobre Doadores de Grupo CH-CH/antagonistas & inibidores , Oxirredutases atuantes sobre Doadores de Grupo CH-CH/metabolismo , Receptores de Antígenos de Linfócitos T/metabolismo , Linfócitos T/efeitos dos fármacos , Toluidinas/farmacologiaRESUMO
Paraneoplastic neurological disorders result from an autoimmune response against neural self-antigens that are ectopically expressed in neoplastic cells. In paraneoplastic disorders associated to autoantibodies against intracellular proteins, such as paraneoplastic cerebellar degeneration (PCD), current data point to a major role of cell-mediated immunity. In an animal model, in which a neo-self-antigen was expressed in both Purkinje neurons and implanted breast tumor cells, immune checkpoint blockade led to complete tumor control at the expense of cerebellum infiltration by T cells and Purkinje neuron loss, thereby mimicking PCD. Here, we identify 2 potential therapeutic targets expressed by cerebellum-infiltrating T cells in this model, namely α4 integrin and IFN-γ. Mice with PCD were treated with anti-α4 integrin antibodies or neutralizing anti-IFN-γ antibodies at the onset of neurological signs. Although blocking α4 integrin had little or no impact on disease development, treatment using the anti-IFN-γ antibody led to almost complete protection from PCD. These findings strongly suggest that the production of IFN-γ by cerebellum-invading T cells plays a major role in Purkinje neuron death. Our successful preclinical use of neutralizing anti-IFN-γ antibody for the treatment of PCD offers a potentially new therapeutic opportunity for cancer patients at the onset of paraneoplastic neurological disorders.
Assuntos
Interferon gama/antagonistas & inibidores , Neoplasias Mamárias Experimentais/complicações , Degeneração Paraneoplásica Cerebelar/tratamento farmacológico , Células de Purkinje/patologia , Linfócitos T/efeitos dos fármacos , Animais , Antígenos de Neoplasias/imunologia , Autoanticorpos/imunologia , Autoantígenos/imunologia , Linhagem Celular Tumoral/transplante , Feminino , Integrina alfa4/antagonistas & inibidores , Integrina alfa4/imunologia , Integrina alfa4/metabolismo , Interferon gama/imunologia , Interferon gama/metabolismo , Neoplasias Mamárias Experimentais/imunologia , Camundongos , Camundongos Knockout , Degeneração Paraneoplásica Cerebelar/imunologia , Degeneração Paraneoplásica Cerebelar/patologia , Células de Purkinje/imunologia , Células de Purkinje/metabolismo , Linfócitos T/imunologia , Linfócitos T/metabolismoRESUMO
Unexpected high disease activity (UHDA) after Fingolimod withdrawal has recently become a controversial concern for physicians. Here, we report the case of a patient with severe exacerbation of MS after switching from Fingolimod to Alemtuzumab treatment. This UHDA despite profound lymphopenia raised the question of the management of sequential use of biotherapies such as Fingolimod and Alemtuzumab in MS.
Assuntos
Alemtuzumab/efeitos adversos , Antineoplásicos Imunológicos/efeitos adversos , Substituição de Medicamentos/efeitos adversos , Cloridrato de Fingolimode/uso terapêutico , Imunossupressores/uso terapêutico , Esclerose Múltipla/tratamento farmacológico , Feminino , Humanos , Imageamento por Ressonância Magnética , Pessoa de Meia-Idade , Esclerose Múltipla/diagnóstico por imagem , Esclerose Múltipla/epidemiologiaRESUMO
OBJECTIVE: To identify biomarkers associated with the development of progressive multifocal leukoencephalopathy (PML) in multiple sclerosis (MS) patients treated with natalizumab (NTZ). METHODS: Relapsing-remitting MS patients who developed PML under NTZ therapy (pre-PML) and non-PML NTZ-treated patients (NTZ-ctr) were included in the study. Cryopreserved peripheral blood mononuclear cells and serum samples collected at baseline, at 1- and 2-year treated time points, and during PML were analyzed for gene expression by RNA sequencing and for serum protein levels by Luminex and enzyme-linked immunosorbent assays, respectively. RESULTS: Among top differentially expressed genes in the RNA sequencing between pre-PML and NTZ-ctr patients, pathway analysis revealed a high representation of genes belonging to the following categories: proangiogenic factors (MMP9, VEGFA), chemokines (CXCL1, CXCL5, IL8, CCL2), cytokines (IL1B, IFNG), and plasminogen- and coagulation-related molecules (SERPINB2, PLAU, PLAUR, TFPI, THBD). Serum protein levels for these candidates were measured in a 2-step manner in a screening cohort and a validation cohort of pre-PML and NTZ-ctr patients. Only matrix metalloproteinase 9 (MMP9) was validated; in pre-PML patients, MMP9 protein levels were significantly reduced at baseline compared with NTZ-ctr patients, and levels remained lower at later time points during NTZ treatment. INTERPRETATION: The results from this study suggest that the proangiogenic factor MMP9 may play a role as a biomarker associated with the development of PML in MS patients treated with NTZ. Ann Neurol 2017;82:186-195.
Assuntos
Leucoencefalopatia Multifocal Progressiva/induzido quimicamente , Metaloproteinase 9 da Matriz/sangue , Esclerose Múltipla Recidivante-Remitente/sangue , Esclerose Múltipla Recidivante-Remitente/tratamento farmacológico , Natalizumab/efeitos adversos , Natalizumab/uso terapêutico , Biomarcadores/sangue , Proteínas Sanguíneas/biossíntese , Expressão Gênica/efeitos dos fármacos , Humanos , Fatores Imunológicos/sangue , Leucoencefalopatia Multifocal Progressiva/sangue , Leucoencefalopatia Multifocal Progressiva/complicações , Metaloproteinase 9 da Matriz/biossíntese , Esclerose Múltipla Recidivante-Remitente/complicações , Fator A de Crescimento do Endotélio Vascular/biossíntese , Fator A de Crescimento do Endotélio Vascular/sangueRESUMO
Paraneoplastic neurological disorders (PNDs) are rare human autoimmune diseases that mostly affect the central nervous system (CNS). They are triggered by an efficient immune response against a neural self-antigen that is ectopically expressed in neoplastic tumors. Due to this shared antigenic expression, the immune system reacts not only to tumor cells but also to neural cells resulting in neurological damage. Growing data point to a major role of cell-mediated immunity in PNDs associated to autoantibodies against intracellular proteins. However, its precise contribution in the pathogenesis remains unclear. In this context, our study aimed at investigating the impact of anti-tumor cellular immune responses in the development of PND. To this end, we developed an animal model mimicking PND. We used a tumor cell line expressing the hemagglutinin (HA) of influenza virus to induce an anti-tumor response in CamK-HA mice, which express HA in CNS neurons. To promote and track the T cell response against the HA antigen, naïve HA-specific CD8+ and/or CD4+ T cells, originating from TCR-transgenic animals, were transferred into these mice. We demonstrate that HA-expressing tumors, but not control tumors, induce in vivo activation, proliferation and differentiation of naïve HA-specific CD4+ and CD8+ T cells into effector cells. Moreover, both T cell subsets were needed to control tumor growth and induce CNS inflammation in CamK-HA mice. Thus, this new mouse model provides further insight into the cellular mechanisms whereby a potent anti-tumor immunity triggers a cancer-associated autoimmune disease, and may therefore help to develop new therapeutic strategies against PND.
Assuntos
Fatores Imunológicos/efeitos adversos , Selectina L/sangue , Leucoencefalopatia Multifocal Progressiva/sangue , Leucoencefalopatia Multifocal Progressiva/etiologia , Esclerose Múltipla/tratamento farmacológico , Natalizumab/efeitos adversos , Biomarcadores/sangue , Seguimentos , Humanos , Leucócitos Mononucleares/metabolismo , Leucoencefalopatia Multifocal Progressiva/diagnóstico , Prognóstico , Estudos Prospectivos , Sensibilidade e EspecificidadeRESUMO
Narcolepsy with cataplexy is a rare and severe sleep disorder caused by the destruction of orexinergic neurons in the lateral hypothalamus. The genetic and environmental factors associated with narcolepsy, together with serologic data, collectively point to an autoimmune origin. The current animal models of narcolepsy, based on either disruption of the orexinergic neurotransmission or neurons, do not allow study of the potential autoimmune etiology. Here, we sought to generate a mouse model that allows deciphering of the immune mechanisms leading to orexin(+) neuron loss and narcolepsy development. We generated mice expressing the hemagglutinin (HA) as a "neo-self-antigen" specifically in hypothalamic orexin(+) neurons (called Orex-HA), which were transferred with effector neo-self-antigen-specific T cells to assess whether an autoimmune process could be at play in narcolepsy. Given the tight association of narcolepsy with the human leukocyte antigen (HLA) HLA-DQB1*06:02 allele, we first tested the pathogenic contribution of CD4 Th1 cells. Although these T cells readily infiltrated the hypothalamus and triggered local inflammation, they did not elicit the loss of orexin(+) neurons or clinical manifestations of narcolepsy. In contrast, the transfer of cytotoxic CD8 T cells (CTLs) led to both T-cell infiltration and specific destruction of orexin(+) neurons. This phenotype was further aggravated upon repeated injections of CTLs. In situ, CTLs interacted directly with MHC class I-expressing orexin(+) neurons, resulting in cytolytic granule polarization toward neurons. Finally, drastic neuronal loss caused manifestations mimicking human narcolepsy, such as cataplexy and sleep attacks. This work demonstrates the potential role of CTLs as final effectors of the immunopathological process in narcolepsy.