Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 108
Filtrar
1.
Parkinsonism Relat Disord ; 122: 106080, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38508903

RESUMO

The hypothesis that neurodegenerative diseases are proteinopathies due to toxic effect of different underlying proteins, such as amyloid-beta and 3+4R-tau in Alzheimer's disease (AD) and alpha-synuclein in Parkinson's disease (PD), while still controversial is supported by several studies in the literature. This has led to conduct clinical trials attempting to reduce the load of these allegedly toxic proteins by immunotherapy, mostly but not solely based on antibodies against these proteins. Already completed clinical trials have ranged from initially negative results to recently partial positive outcomes, specifically for anti-amyloid antibodies in AD but also albeit to lesser degree for anti-synuclein antibodies in PD. Currently, there are several ongoing clinical trials in degenerative parkinsonisms with anti-synuclein approaches in PD and multiple system atrophy (MSA), as well as with anti-tau antibodies in 4R-tauopathies such as progressive supranuclear palsy (PSP). While it can be argued that expectations that part of these clinical trials will be positive can be hope or hype, it is reasonable to consider the future possibility of "cocktail" combination of different antibodies after the available experimental evidence of cross-talk between these proteins and neuropathological evidence of coexistence of these proteinopathies more frequently than expected by chance. Moreover, such "cocktail" approaches are widespread and accepted common practice in other fields such as oncology, and the complexity of neurodegenerative parkinsonisms makes reasonable the option for testing and eventually applying such combined approaches, should these prove useful separately, in the setting of patients with evidence of underlying concomitant proteinopathies, for example through biomarkers.


Assuntos
Imunoterapia , alfa-Sinucleína , Proteínas tau , Humanos , alfa-Sinucleína/imunologia , Imunoterapia/métodos , Proteínas tau/imunologia , Animais , Doença de Parkinson/terapia , Doença de Parkinson/imunologia , Doença de Parkinson/tratamento farmacológico
2.
J Biol Chem ; 300(4): 107163, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38484799

RESUMO

The use of variable domain of the heavy-chain of the heavy-chain-only antibodies (VHHs) as disease-modifying biomolecules in neurodegenerative disorders holds promises, including targeting of aggregation-sensitive proteins. Exploitation of their clinical values depends however on the capacity to deliver VHHs with optimal physico-chemical properties for their specific context of use. We described previously a VHH with high therapeutic potential in a family of neurodegenerative diseases called tauopathies. The activity of this promising parent VHH named Z70 relies on its binding within the central region of the tau protein. Accordingly, we carried out random mutagenesis followed by yeast two-hybrid screening to obtain optimized variants. The VHHs selected from this initial screen targeted the same epitope as VHH Z70 as shown using NMR spectroscopy and had indeed improved binding affinities according to dissociation constant values obtained by surface plasmon resonance spectroscopy. The improved affinities can be partially rationalized based on three-dimensional structures and NMR data of three complexes consisting of an optimized VHH and a peptide containing the tau epitope. Interestingly, the ability of the VHH variants to inhibit tau aggregation and seeding could not be predicted from their affinity alone. We indeed showed that the in vitro and in cellulo VHH stabilities are other limiting key factors to their efficacy. Our results demonstrate that only a complete pipeline of experiments, here described, permits a rational selection of optimized VHH variants, resulting in the selection of VHH variants with higher affinities and/or acting against tau seeding in cell models.


Assuntos
Proteínas Intrinsicamente Desordenadas , Anticorpos de Domínio Único , Proteínas tau , Humanos , Epitopos/química , Epitopos/imunologia , Proteínas Intrinsicamente Desordenadas/química , Proteínas Intrinsicamente Desordenadas/imunologia , Peptídeos/química , Peptídeos/imunologia , Anticorpos de Domínio Único/química , Anticorpos de Domínio Único/genética , Anticorpos de Domínio Único/imunologia , Proteínas tau/química , Proteínas tau/imunologia
3.
Adv Neurobiol ; 32: 3-53, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37480458

RESUMO

Sleep deprivation induces amyloid beta peptide and phosphorylated tau deposits in the brain and cerebrospinal fluid together with altered serotonin metabolism. Thus, it is likely that sleep deprivation is one of the predisposing factors in precipitating Alzheimer's disease (AD) brain pathology. Our previous studies indicate significant brain pathology following sleep deprivation or AD. Keeping these views in consideration in this review, nanodelivery of monoclonal antibodies to amyloid beta peptide (AßP), phosphorylated tau (p-tau), and tumor necrosis factor alpha (TNF-α) in sleep deprivation-induced AD is discussed based on our own investigations. Our results suggest that nanowired delivery of monoclonal antibodies to AßP with p-tau and TNF-α induces superior neuroprotection in AD caused by sleep deprivation, not reported earlier.


Assuntos
Doença de Alzheimer , Humanos , Doença de Alzheimer/tratamento farmacológico , Peptídeos beta-Amiloides/imunologia , Anticorpos Monoclonais , Encéfalo , Neuroproteção , Privação do Sono , Fator de Necrose Tumoral alfa/imunologia , Sistemas de Liberação de Fármacos por Nanopartículas/química , Sistemas de Liberação de Fármacos por Nanopartículas/farmacologia , Proteínas tau/imunologia
4.
Front Immunol ; 12: 644213, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33796111

RESUMO

Monomeric C-reactive protein (mCRP) is now accepted as having a key role in modulating inflammation and in particular, has been strongly associated with atherosclerotic arterial plaque progression and instability and neuroinflammation after stroke where a build-up of the mCRP protein within the brain parenchyma appears to be connected to vascular damage, neurodegenerative pathophysiology and possibly Alzheimer's Disease (AD) and dementia. Here, using immunohistochemical analysis, we wanted to confirm mCRP localization and overall distribution within a cohort of AD patients showing evidence of previous infarction and then focus on its co-localization with inflammatory active regions in order to provide further evidence of its functional and direct impact. We showed that mCRP was particularly seen in large amounts within brain vessels of all sizes and that the immediate micro-environment surrounding these had become laden with mCRP positive cells and extra cellular matrix. This suggested possible leakage and transport into the local tissue. The mCRP-positive regions were almost always associated with neurodegenerative, damaged tissue as hallmarked by co-positivity with pTau and ß-amyloid staining. Where this occurred, cells with the morphology of neurons, macrophages and glia, as well as smaller microvessels became mCRP-positive in regions staining for the inflammatory markers CD68 (macrophage), interleukin-1 beta (IL-1ß) and nuclear factor kappa B (NFκB), showing evidence of a perpetuation of inflammation. Positive staining for mCRP was seen even in distant hypothalamic regions. In conclusion, brain injury or inflammatory neurodegenerative processes are strongly associated with mCRP localization within the tissue and given our knowledge of its biological properties, it is likely that this protein plays a direct role in promoting tissue damage and supporting progression of AD after injury.


Assuntos
Doença de Alzheimer , Encéfalo , Proteína C-Reativa , Células Endoteliais , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/imunologia , Doença de Alzheimer/metabolismo , Doença de Alzheimer/patologia , Peptídeos beta-Amiloides/imunologia , Peptídeos beta-Amiloides/metabolismo , Biomarcadores/metabolismo , Encéfalo/irrigação sanguínea , Encéfalo/imunologia , Encéfalo/metabolismo , Encéfalo/patologia , Proteína C-Reativa/imunologia , Proteína C-Reativa/metabolismo , Células Endoteliais/imunologia , Células Endoteliais/metabolismo , Células Endoteliais/patologia , Feminino , Humanos , Imuno-Histoquímica , Inflamação/imunologia , Inflamação/metabolismo , Inflamação/patologia , Interleucina-1beta/imunologia , Interleucina-1beta/metabolismo , Macrófagos/imunologia , Macrófagos/metabolismo , Macrófagos/patologia , Masculino , Proteínas tau/imunologia , Proteínas tau/metabolismo
5.
Ann Clin Transl Neurol ; 8(2): 491-497, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33410601

RESUMO

The contributors to persistent cognitive impairment and hippocampal atrophy in leucine-rich glioma-inactivated 1 antibody encephalitis (LGI1) patients are unknown. We evaluated whether tau neuropathology measured with [18 F]flortaucipir PET neuroimaging associated with persistent cognitive impairment and hippocampal atrophy in four recovering LGI1 patients (3 men; median age, 67 [37-88] years). Imaging findings in cases were compared with those observed in age- and gender-similar cognitively normal individuals (n = 124) and individuals with early-symptomatic Alzheimer disease (n = 11). Elevated [18 F]flortaucipir retention was observed in the two LGI1 patients with hippocampal atrophy and persistent cognitive impairment, including one with autopsy-confirmed Alzheimer disease. Tau neuropathology may associate with cognitive complaints and hippocampal atrophy in recovering LGI1 patients.


Assuntos
Encéfalo/diagnóstico por imagem , Encéfalo/patologia , Carbolinas/metabolismo , Encefalite/imunologia , Peptídeos e Proteínas de Sinalização Intracelular/imunologia , Neuroimagem/métodos , Tomografia por Emissão de Pósitrons/métodos , Proteínas tau/imunologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/patologia , Autoanticorpos , Disfunção Cognitiva , Encefalite/patologia , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Proteínas tau/metabolismo
6.
Med Chem ; 16(8): 1007-1021, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31702507

RESUMO

Alzheimer's disease (AD) is the most prevalent neurodegenerative disorder, with approximately 29 million older people suffering from this disease worldwide. This number is expected to become triple by 2050. AD is a complex and multifactorial neurodegenerative condition, characterized by complex pathology including oxidative stress, formation of aggregates of amyloid and tau, enhanced immune responses, metal deposition and disturbances in cholinesterase enzymes. There is no effective pharmacological treatment for combating the disease to date. The ineffectiveness of current pharmacological interventions in AD has led scientists to search for more safe and effective alternative therapeutic agents. Thus, natural products have become an important avenue for drug discovery in AD research. In this regard, polyphenols are natural products that have been shown to be effective in the modulation of the type of neurodegenerative changes seen in AD, suggesting a possible therapeutic role. The present review focuses on the chemistry of polyphenols, clinical studies for evaluating polyphenols as effective alternatives in AD treatment, cellular and molecular aspects of polyphenols in improving cognitive deficits and the current challenges and futuristic approaches to use polyphenols as safe and effective therapeutic agents in AD treatment.


Assuntos
Doença de Alzheimer/tratamento farmacológico , Fármacos Neuroprotetores/farmacologia , Polifenóis/farmacologia , Doença de Alzheimer/imunologia , Doença de Alzheimer/metabolismo , Peptídeos beta-Amiloides/antagonistas & inibidores , Peptídeos beta-Amiloides/imunologia , Peptídeos beta-Amiloides/metabolismo , Humanos , Fármacos Neuroprotetores/química , Estresse Oxidativo/efeitos dos fármacos , Polifenóis/química , Agregados Proteicos/efeitos dos fármacos , Agregação Patológica de Proteínas/tratamento farmacológico , Agregação Patológica de Proteínas/imunologia , Proteínas tau/antagonistas & inibidores , Proteínas tau/imunologia , Proteínas tau/metabolismo
7.
J Immunol ; 203(1): 84-92, 2019 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-31085590

RESUMO

Tau protein is found to be aggregated and hyperphosphorylated (p-tau) in many neurologic disorders, including Parkinson disease (PD) and related parkinsonisms, Alzheimer disease, traumatic brain injury, and even in normal aging. Although not known to produce autoimmune responses, we hypothesized that the appearance of aggregated tau and p-tau with disease could activate the immune system. We thus compared T cell responses to tau and p-tau-derived peptides between PD patients, age-matched healthy controls, and young healthy controls (<35 y old; who are less likely to have high levels of tau aggregates). All groups exhibited CD4+ T cell responses to tau-derived peptides, which were associated with secretion of IFN-γ, IL-5, and/or IL-4. The PD and control participants exhibited a similar magnitude and breadth of responses. Some tau-derived epitopes, consisting of both unmodified and p-tau residues, were more highly represented in PD participants. These results were verified in an independent set of PD and control donors (either age-matched or young controls). Thus, T cells recognizing tau epitopes escape central and peripheral tolerance in relatively high numbers, and the magnitude and nature of these responses are not modulated by age or PD disease.


Assuntos
Linfócitos T CD4-Positivos/imunologia , Peptídeos/imunologia , Proteínas tau/imunologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Autoimunidade , Células Cultivadas , Seleção Clonal Mediada por Antígeno , Feminino , Humanos , Tolerância Imunológica , Masculino , Pessoa de Meia-Idade , Fosforilação , Agregação Patológica de Proteínas , Especificidade do Receptor de Antígeno de Linfócitos T , Adulto Jovem
8.
Prog Brain Res ; 245: 145-200, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30961867

RESUMO

Alzheimer's disease (AD) is estimated to be afflicting over 55 millions of individual worldwide in 2018-19 for which no suitable clinical therapeutic measures have been developed so far. Thus, there is an urgent need to explore novel therapeutic strategies using nanodelivery of drugs and agents either alone or in combination for superior neuroprotection in AD and enhanced quality of life of the affected individuals. There are reports that AD is often associated with diminished neurotrophic factors and neprilysin together with enhancement of phosphorylated Tau (p-Tau) within the brain and in the cerebrospinal fluid (CSF). Thus, studies aiming to enhance neurotrophic factors and neprilysin together with neutralizing p-Tau within the central nervous system (CNS) may alleviate brain pathology in AD. In this review these strategies are discussed using nanotechnological approaches largely based on our own investigations in relation to current literature in the field.


Assuntos
Doença de Alzheimer/tratamento farmacológico , Doença de Alzheimer/metabolismo , Aminoácidos/administração & dosagem , Anticorpos/administração & dosagem , Nanomedicina/métodos , Nanofios/uso terapêutico , Neprilisina/administração & dosagem , Fármacos Neuroprotetores/administração & dosagem , Proteínas tau/imunologia , Animais , Humanos
9.
EBioMedicine ; 42: 157-173, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30910484

RESUMO

BACKGROUND: Bringing antibodies from pre-clinical studies to human trials requires humanization, but this process may alter properties that are crucial for efficacy. Since pathological tau protein is primarily intraneuronal in Alzheimer's disease, the most efficacious antibodies should work both intra- and extracellularly. Thus, changes which impact uptake or antibody binding will affect antibody efficacy. METHODS: Initially, we examined four tau mouse monoclonal antibodies with naturally differing charges. We quantified their neuronal uptake, and efficacy in preventing toxicity and pathological seeding induced by human-derived pathological tau. Later, we generated a human chimeric 4E6 (h4E6), an antibody with well documented efficacy in multiple tauopathy models. We compared the uptake and efficacy of unmodified and chimeric antibodies in neuronal and differentiated neuroblastoma cultures. Further, we analyzed tau binding using ELISA assays. FINDINGS: Neuronal uptake of tau antibodies and their efficacy strongly depends on antibody charge. Additionally, their ability to prevent tau toxicity and seeding of tau pathology does not necessarily go together. Particularly, chimerization of 4E6 increased its charge from 6.5 to 9.6, which blocked its uptake into human and mouse cells. Furthermore, h4E6 had altered binding characteristics despite intact binding sites, compared to the mouse antibody. Importantly, these changes in uptake and binding substantially decreased its efficacy in preventing tau toxicity, although under certain conditions it did prevent pathological seeding of tau. CONCLUSIONS: These results indicate that efficacy of chimeric/humanized tau antibodies should be thoroughly characterized prior to clinical trials, which may require further engineering to maintain or improve their therapeutic potential. FUND: National Institutes of Health (NS077239, AG032611, R24OD18340, R24OD018339 and RR027990, Alzheimer's Association (2016-NIRG-397228) and Blas Frangione Foundation.


Assuntos
Anticorpos Monoclonais/farmacologia , Proteínas tau/antagonistas & inibidores , Animais , Anticorpos Monoclonais/química , Anticorpos Monoclonais/imunologia , Anticorpos Monoclonais Humanizados/imunologia , Anticorpos Monoclonais Humanizados/farmacologia , Transporte Biológico , Biomarcadores , Modelos Animais de Doenças , Humanos , Imuno-Histoquímica , Camundongos , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Agregados Proteicos , Agregação Patológica de Proteínas/metabolismo , Ligação Proteica , Multimerização Proteica , Relação Estrutura-Atividade , Tauopatias/tratamento farmacológico , Tauopatias/metabolismo , Proteínas tau/imunologia
10.
J Mol Biol ; 431(9): 1818-1829, 2019 04 19.
Artigo em Inglês | MEDLINE | ID: mdl-30763568

RESUMO

Amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) are neurodegenerative disorders with clear similarities regarding their clinical, genetic and pathological features. Both are progressive, lethal disorders, with no current curative treatment available. Several genes that correlated with ALS and FTD are implicated in the same molecular pathways. Strikingly, many of these genes are not exclusively expressed in neurons, but also in glial cells, suggesting a multicellular pathogenesis. Moreover, chronic inflammation is a common feature observed in ALS and FTD, indicating an essential role of microglia, the resident immune cells of the central nervous system, in disease development and progression. In this review, we will provide a comprehensive overview of the implications of microglia in ALS and FTD. Specifically, we will focus on the role of impaired phagocytosis and increased inflammatory responses and their impact on microglial function. Several genes associated with the disorders can directly be linked to microglial activation, phagocytosis and neuroinflammation. Other genes associated with the disorders are implicated in biological pathways involved in protein degradation and autophagy. In general such mutations have been shown to cause abnormal protein accumulation and impaired autophagy. These impairments have previously been linked to affect the innate immune system in the central nervous system through inappropriate activation of microglia and neuroinflammation, highlighted in this review. Although it has been well established that microglia play essential roles in neurodegenerative disorders, the precise underlying mechanisms remain to be elucidated.


Assuntos
Esclerose Lateral Amiotrófica/imunologia , Autofagia/imunologia , Demência Frontotemporal/imunologia , Regulação da Expressão Gênica/imunologia , Microglia/imunologia , Esclerose Lateral Amiotrófica/genética , Esclerose Lateral Amiotrófica/patologia , Animais , Autofagia/genética , Proteína C9orf72/genética , Proteína C9orf72/imunologia , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/imunologia , Modelos Animais de Doenças , Progressão da Doença , Demência Frontotemporal/genética , Demência Frontotemporal/patologia , Humanos , Imunidade Inata , Glicoproteínas de Membrana/genética , Glicoproteínas de Membrana/imunologia , Camundongos , Microglia/patologia , Proteína FUS de Ligação a RNA/genética , Proteína FUS de Ligação a RNA/imunologia , Receptores Imunológicos/genética , Receptores Imunológicos/imunologia , Superóxido Dismutase-1/genética , Superóxido Dismutase-1/imunologia , Proteínas tau/genética , Proteínas tau/imunologia
11.
J Neurosci Methods ; 319: 60-68, 2019 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-30278184

RESUMO

BACKGROUND: Early stages of Alzheimer's disease (AD) are characterized by high phosphorylation of microtubule-associated protein tau, which may result from the downregulation of protein phosphatases. NEW METHOD: In order to model phosphatase downregulation and analyze its effect on tau aggregation in vitro, we treated neuroblastoma SH-SY5Y cells with okadaic acid (OA), a protein phosphatase inhibitor, and examined high molecular weight phospho-tau species. RESULTS AND COMPARISON WITH EXISTING METHODS: OA treatment led to the appearance of heat-stable protein species with apparent molecular weight around 100 kDa, which were immunoreactive to anti-tau antibodies against phosphorylated Ser202 and Ser396. As these high molecular weight tau-immunoreactive proteins (HMW-TIPs) corresponded to the predicted size of two tau monomers, we considered the possibility that they represent phosphorylation-induced tau oligomers. We attempted to dissociate HMW-TIPs by urea and guanidine, as well as by alkaline phosphatase treatment, but HMW-TIPs were stable under all conditions tested. These characteristics resemble properties of certain sodium dodecyl sulfate (SDS)-resistant tau oligomers from AD brains. The absence of HMW-TIPs detection by anti-total tau antibodies Tau46, CP27 and Tau13 may be a consequence of epitope masking and protein truncation. Alternatively, HMW-TIPs may represent previously unreported phosphoproteins cross-reacting with tau. CONCLUSIONS: Taken together, our data provide a novel characterization of an OA-based cell culture model in which OA induces the appearance of HMW-TIPs. These findings have implications for further studies of tau under the conditions of protein phosphatase downregulation, aiming to explain mechanisms involved in early events leading to AD.


Assuntos
Doença de Alzheimer/enzimologia , Inibidores Enzimáticos/administração & dosagem , Modelos Biológicos , Ácido Okadáico/administração & dosagem , Fosfoproteínas Fosfatases/metabolismo , Proteínas tau/metabolismo , Anticorpos , Linhagem Celular Tumoral , Humanos , Fosfoproteínas Fosfatases/antagonistas & inibidores , Fosforilação , Ensaio de Radioimunoprecipitação , Proteínas tau/imunologia
12.
ACS Sens ; 4(1): 161-169, 2019 01 25.
Artigo em Inglês | MEDLINE | ID: mdl-30582808

RESUMO

A noninvasive, highly sensitive universal immunosensor platform for protein-based biomarker detection is described in this Article. A neutral charged sensing environment is constructed by an antibody with an oppositely charged amino acid as surface charge neutralizer. By adjusting the pH condition of the testing environment, this neutral charged immunosensor (NCI) directly utilizes the electrostatic charges of the analyte for quantification of circulating protein markers, achieving a wide dynamic range covering through the whole picomole level. Comparing with previous studies on electrostatic charges characterization, this NCI demonstrates its capability to analyze not only the negatively charged biomolecules but also positively charged analytes. We applied this NCI for the detection of HE4 antigen with a detection limit at 2.5 pM and Tau antigen with a detection limit at 0.968 pM, demonstrating the high-sensitivity property of this platform. Furthermore, this NCI possesses a simple fabrication method (less than 2 h) and a short testing turnaround time (less than 30 min), providing an excellent potential for further clinical point-of-care applications.


Assuntos
Proteína 2 do Domínio Central WAP de Quatro Dissulfetos/análise , Proteínas tau/sangue , Anticorpos Imobilizados/imunologia , Biomarcadores Tumorais/sangue , Biomarcadores Tumorais/imunologia , Complexos de Coordenação/química , Técnicas Eletroquímicas/instrumentação , Técnicas Eletroquímicas/métodos , Eletrodos , Ouro/química , Humanos , Concentração de Íons de Hidrogênio , Imunoensaio/instrumentação , Imunoensaio/métodos , Limite de Detecção , Oxirredução , Peptídeos/química , Ácido Poliglutâmico/química , Proteína 2 do Domínio Central WAP de Quatro Dissulfetos/imunologia , Proteínas tau/imunologia
13.
J Exp Med ; 215(9): 2235-2245, 2018 09 03.
Artigo em Inglês | MEDLINE | ID: mdl-30082275

RESUMO

Alzheimer's disease (AD) is an age-associated neurodegenerative disease characterized by amyloidosis, tauopathy, and activation of microglia, the brain resident innate immune cells. We show that a RiboTag translational profiling approach can bypass biases due to cellular enrichment/cell sorting. Using this approach in models of amyloidosis, tauopathy, and aging, we revealed a common set of alterations and identified a central APOE-driven network that converged on CCL3 and CCL4 across all conditions. Notably, aged females demonstrated a significant exacerbation of many of these shared transcripts in this APOE network, revealing a potential mechanism for increased AD susceptibility in females. This study has broad implications for microglial transcriptomic approaches and provides new insights into microglial pathways associated with different pathological aspects of aging and AD.


Assuntos
Envelhecimento/imunologia , Doença de Alzheimer/imunologia , Amiloide/imunologia , Apolipoproteínas E/imunologia , Microglia/imunologia , Proteínas tau/imunologia , Envelhecimento/genética , Envelhecimento/patologia , Doença de Alzheimer/genética , Doença de Alzheimer/patologia , Amiloide/genética , Amiloidose/genética , Amiloidose/imunologia , Amiloidose/patologia , Animais , Apolipoproteínas E/genética , Quimiocina CCL3/genética , Quimiocina CCL3/imunologia , Quimiocina CCL4/genética , Quimiocina CCL4/imunologia , Modelos Animais de Doenças , Feminino , Masculino , Camundongos , Camundongos Transgênicos , Microglia/patologia , Transdução de Sinais/genética , Transdução de Sinais/imunologia , Proteínas tau/genética
14.
Acta Neuropathol Commun ; 6(1): 82, 2018 08 22.
Artigo em Inglês | MEDLINE | ID: mdl-30134961

RESUMO

Tau, the main component of the neurofibrillary tangles (NFTs), is an attractive target for immunotherapy in Alzheimer's disease (AD) and other tauopathies. MC1/Alz50 are currently the only antibodies targeting a disease-specific conformational modification of tau. Passive immunization experiments using intra-peritoneal injections have previously shown that MC1 is effective at reducing tau pathology in the forebrain of tau transgenic JNPL3 mice. In order to reach a long-term and sustained brain delivery, and avoid multiple injection protocols, we tested the efficacy of the single-chain variable fragment of MC1 (scFv-MC1) to reduce tau pathology in the same animal model, with focus on brain regional differences. ScFv-MC1 was cloned into an AAV delivery system and was directly injected into the hippocampus of adult JNPL3 mice. Specific promoters were employed to selectively target neurons or astrocytes for scFv-MC1 expression. ScFv-MC1 was able to decrease soluble, oligomeric and insoluble tau species, in our model. The effect was evident in the cortex, hippocampus and hindbrain. The astrocytic machinery appeared more efficient than the neuronal, with significant reduction of pathology in areas distant from the site of injection. To our knowledge, this is the first evidence that an anti-tau conformational scFv antibody, delivered directly into the mouse adult brain, is able to reduce pathological tau, providing further insight into the nature of immunotherapy strategies.


Assuntos
Anticorpos/farmacologia , Encéfalo/efeitos dos fármacos , Tauopatias/imunologia , Tauopatias/terapia , Proteínas tau/imunologia , Proteínas tau/metabolismo , Análise de Variância , Animais , Anticorpos/sangue , Complexo Antígeno-Anticorpo , Astrócitos/efeitos dos fármacos , Astrócitos/metabolismo , Astrócitos/patologia , Encéfalo/metabolismo , Encéfalo/patologia , Dependovirus , Modelos Animais de Doenças , Feminino , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Células HEK293 , Humanos , Cadeias Pesadas de Imunoglobulinas/genética , Cadeias Pesadas de Imunoglobulinas/metabolismo , Cadeias Leves de Imunoglobulina/genética , Cadeias Leves de Imunoglobulina/metabolismo , Camundongos , Camundongos Transgênicos , Mutação/genética , Proteínas do Tecido Nervoso/metabolismo , Parvovirinae/genética , Conformação Proteica/efeitos dos fármacos , Tauopatias/genética , Proteínas tau/genética
15.
Acta Neuropathol ; 136(1): 69-87, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29934874

RESUMO

Alzheimer's disease (AD) is the most common form of dementia in the elderly affecting more than 5 million people in the U.S. AD is characterized by the accumulation of ß-amyloid (Aß) and Tau in the brain, and is manifested by severe impairments in memory and cognition. Therefore, removing tau pathology has become one of the main therapeutic goals for the treatment of AD. Tau (tubulin-associated unit) is a major neuronal cytoskeletal protein found in the CNS encoded by the gene MAPT. Alternative splicing generates two major isoforms of tau containing either 3 or 4 repeat (R) segments. These 3R or 4RTau species are differentially expressed in neurodegenerative diseases. Previous studies have been focused on reducing Tau accumulation with antibodies against total Tau, 4RTau or phosphorylated isoforms. Here, we developed a brain penetrating, single chain antibody that specifically recognizes a pathogenic 3RTau. This single chain antibody was modified by the addition of a fragment of the apoB protein to facilitate trafficking into the brain, once in the CNS these antibody fragments reduced the accumulation of 3RTau and related deficits in a transgenic mouse model of tauopathy. NMR studies showed that the single chain antibody recognized an epitope at aa 40-62 of 3RTau. This single chain antibody reduced 3RTau transmission and facilitated the clearance of Tau via the endosomal-lysosomal pathway. Together, these results suggest that targeting 3RTau with highly specific, brain penetrating, single chain antibodies might be of potential value for the treatment of tauopathies such as Pick's Disease.


Assuntos
Doença de Alzheimer/tratamento farmacológico , Expansão das Repetições de DNA/genética , Doença de Pick/tratamento farmacológico , Anticorpos de Cadeia Única/uso terapêutico , Proteínas tau/genética , Proteínas tau/imunologia , Doença de Alzheimer/genética , Doença de Alzheimer/patologia , Animais , Apolipoproteínas B/metabolismo , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Linhagem Celular Transformada , Técnicas de Cocultura , Modelos Animais de Doenças , Comportamento Exploratório/efeitos dos fármacos , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Proteínas Associadas aos Microtúbulos/metabolismo , Neuroblastoma/patologia , Fosforilação , Doença de Pick/genética , Doença de Pick/patologia , Transporte Proteico/efeitos dos fármacos , Transporte Proteico/genética , Proteínas rab5 de Ligação ao GTP/metabolismo , Proteínas tau/metabolismo
16.
Front Immunol ; 9: 672, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29686672

RESUMO

The post-injury inflammatory response is a key mediator in long-term recovery from traumatic brain injury (TBI). Moreover, the immune response to TBI, mediated by microglia and macrophages, is influenced by existing brain pathology and by secondary immune challenges. For example, recent evidence shows that the presence of beta-amyloid and phosphorylated tau protein, two hallmark features of AD that increase during normal aging, substantially alter the macrophage response to TBI. Additional data demonstrate that post-injury microglia are "primed" and become hyper-reactive following a subsequent acute immune challenge thereby worsening recovery. These alterations may increase the incidence of neuropsychiatric complications after TBI and may also increase the frequency of neurodegenerative pathology. Therefore, the purpose of this review is to summarize experimental studies examining the relationship between TBI and development of AD-like pathology with an emphasis on the acute and chronic microglial and macrophage response following injury. Furthermore, studies will be highlighted that examine the degree to which beta-amyloid and tau accumulation as well as pre- and post-injury immune stressors influence outcome after TBI. Collectively, the studies described in this review suggest that the brain's immune response to injury is a key mediator in recovery, and if compromised by previous, coincident, or subsequent immune stressors, post-injury pathology and behavioral recovery will be altered.


Assuntos
Doença de Alzheimer/imunologia , Lesões Encefálicas Traumáticas/imunologia , Envelhecimento/imunologia , Proteínas Amiloidogênicas/imunologia , Animais , Humanos , Inflamação/imunologia , Macrófagos/imunologia , Proteínas tau/imunologia
17.
Sci Rep ; 8(1): 6209, 2018 04 18.
Artigo em Inglês | MEDLINE | ID: mdl-29670132

RESUMO

Tau antibodies have shown therapeutic potential for Alzheimer's disease and several are in clinical trials. As a microtubule-associated protein, tau relies on dynamic phosphorylation for its normal functions. In tauopathies, it becomes hyperphosphorylated and aggregates into toxic assemblies, which collectively lead to neurodegeneration. Of the phospho-epitopes, the region around Ser396 has received particular attention because of its prominence and stability in tauopathies. Here we report the first structure of a monoclonal tau antibody in complex with the pathologically important phospho-Ser396 residue. Its binding region reveals tau residues Tyr394 to phospho-Ser396 stabilized in a ß-strand conformation that is coordinated by a phospho-specific antigen binding site. These details highlight a molecular switch that defines this prominent conformation of tau and ways to target it. Overall, the structure of the antibody-antigen complex clarifies why certain phosphorylation sites in tau are more closely linked to neurodegeneration than others.


Assuntos
Anticorpos Monoclonais/química , Modelos Moleculares , Conformação Proteica , Proteínas tau/química , Doença de Alzheimer , Motivos de Aminoácidos , Sequência de Aminoácidos , Anticorpos Monoclonais/imunologia , Anticorpos Monoclonais/metabolismo , Especificidade de Anticorpos/imunologia , Sítios de Ligação , Epitopos/química , Epitopos/imunologia , Epitopos/metabolismo , Humanos , Fragmentos Fab das Imunoglobulinas/química , Fragmentos Fab das Imunoglobulinas/imunologia , Peptídeos/química , Peptídeos/imunologia , Fosforilação , Ligação Proteica , Relação Estrutura-Atividade , Proteínas tau/imunologia , Proteínas tau/metabolismo
18.
Nat Commun ; 8(1): 1000, 2017 10 17.
Artigo em Inglês | MEDLINE | ID: mdl-29042562

RESUMO

Traumatic brain injury (TBI) is characterized by acute neurological dysfunction and associated with the development of chronic traumatic encephalopathy (CTE) and Alzheimer's disease. We previously showed that cis phosphorylated tau (cis P-tau), but not the trans form, contributes to tau pathology and functional impairment in an animal model of severe TBI. Here we found that in human samples obtained post TBI due to a variety of causes, cis P-tau is induced in cortical axons and cerebrospinal fluid and positively correlates with axonal injury and clinical outcome. Using mouse models of severe or repetitive TBI, we showed that cis P-tau elimination with a specific neutralizing antibody administered immediately or at delayed time points after injury, attenuates the development of neuropathology and brain dysfunction during acute and chronic phases including CTE-like pathology and dysfunction after repetitive TBI. Thus, cis P-tau contributes to short-term and long-term sequelae after TBI, but is effectively neutralized by cis antibody treatment.Induction of the cis form of phosphorylated tau (cis P-tau) has previously been shown to occur in animal models of traumatic brain injury (TBI), and blocking this form of tau using antibody was beneficial in a rodent model of severe TBI. Here the authors show that cis P-tau induction is a feature of several different forms of TBI in humans, and that administration of cis P-tau targeting antibody to rodents reduces or delays pathological features of TBI.


Assuntos
Lesões Encefálicas/fisiopatologia , Encéfalo/fisiopatologia , Modelos Animais de Doenças , Proteínas tau/líquido cefalorraquidiano , Adolescente , Adulto , Idoso , Animais , Anticorpos Neutralizantes/imunologia , Anticorpos Neutralizantes/farmacologia , Axônios/metabolismo , Axônios/patologia , Encéfalo/efeitos dos fármacos , Encéfalo/patologia , Lesões Encefálicas/líquido cefalorraquidiano , Lesões Encefálicas/tratamento farmacológico , Linhagem Celular Tumoral , Feminino , Humanos , Masculino , Camundongos Endogâmicos C57BL , Pessoa de Meia-Idade , Atividade Motora/efeitos dos fármacos , Fosforilação , Adulto Jovem , Proteínas tau/imunologia , Proteínas tau/metabolismo
19.
Acta Neuropathol Commun ; 5(1): 58, 2017 07 31.
Artigo em Inglês | MEDLINE | ID: mdl-28760159

RESUMO

Tauopathies are a group of neurodegenerative disorders, including Alzheimer's disease, defined by the presence of brain pathological inclusions comprised of abnormally aggregated and highly phosphorylated tau protein. The abundance of brain tau aggregates correlates with disease severity and select phospho-tau epitopes increase at early stages of disease. We generated and characterized a series of novel monoclonal antibodies directed to tau phosphorylated at several of these phospho-epitopes, including Ser396/Ser404, Ser404 and Thr205. We also generated phosphorylation independent antibodies against amino acid residues 193-211. We show that most of these antibodies are highly specific for tau and strongly recognize pathological inclusions in human brains and in a transgenic mouse model of tauopathy. They also reveal epitope-specific differences in the biochemical properties of Alzheimer's disease sarkosyl-insoluble tau. These new reagents will be useful for investigating the progression of tau pathology and further as tools to target the cellular transmission of tau pathology.


Assuntos
Anticorpos Monoclonais , Epitopos , Proteínas tau/imunologia , Doença de Alzheimer/metabolismo , Doença de Alzheimer/patologia , Animais , Encéfalo/metabolismo , Encéfalo/patologia , Linhagem Celular Tumoral , Modelos Animais de Doenças , Feminino , Humanos , Hibridomas/metabolismo , Imuno-Histoquímica , Camundongos Endogâmicos BALB C , Camundongos Transgênicos , Mutação , Fosforilação , Proteínas Recombinantes/metabolismo , Proteínas tau/deficiência , Proteínas tau/genética
20.
J Exp Med ; 214(5): 1227-1238, 2017 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-28416651

RESUMO

Tauopathies are characterized by the progressive accumulation of hyperphosphorylated, aggregated forms of tau. Our laboratory has previously demonstrated that passive immunization with an anti-tau antibody, HJ8.5, decreased accumulation of pathological tau in a human P301S tau-expressing transgenic (P301S-tg) mouse model of frontotemporal dementia/tauopathy. To investigate whether the Fc domain of HJ8.5 is required for the therapeutic effect, we engineered single-chain variable fragments (scFvs) derived from HJ8.5 with variable linker lengths, all specific to human tau. Based on different binding properties, we selected two anti-tau scFvs and tested their efficacy in vivo by adeno-associated virus-mediated gene transfer to the brain of P301S-tg mice. The scFvs significantly reduced levels of hyperphosphorylated, aggregated tau in brain tissue of P301S-tg mice, associated with a decrease in detergent-soluble tau species. Interestingly, these mice showed substantial levels of scFvs in the cerebrospinal fluid without significant effects on total extracellular tau levels. Therefore, our study provides a novel strategy for anti-tau immunotherapeutics that potentially limits a detrimental proinflammatory response.


Assuntos
Anticorpos de Cadeia Única/imunologia , Tauopatias/imunologia , Proteínas tau/imunologia , Animais , Encéfalo/metabolismo , Dependovirus/genética , Modelos Animais de Doenças , Feminino , Técnicas de Transferência de Genes , Hipocampo/metabolismo , Masculino , Camundongos , Camundongos Transgênicos , Anticorpos de Cadeia Única/genética , Anticorpos de Cadeia Única/fisiologia , Tauopatias/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA