α-synuclein vaccination prevents the accumulation of parkinson disease-like pathologic inclusions in striatum in association with regulatory T cell recruitment in a rat model (original) (raw)
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Journal of Pre-Clinical and Clinical Research
Introduction. It has been established that changes in the levels of a-synuclein (ASN) are associated with Parkinson's disease (PD). The progression of PD is characterized by immune response and inflammation, especially the activation of the microglia. Activated microglia cells release potentially cytotoxic substances, such as pro-inflammatory cytokines, caspases as well as neuroprotective molecules such as neurotrophins. Objective. We examined the potential role of recombinant ASN monomers as a major pathogenic factor causing inflammatory responses in the central nervous system. Methods. Mice were bilaterally infused with human ASN monomers into the striatum (ST) or substantia nigra pars compacta (SNpc) (single treatment was 4μg/structure, 8μg per brain) and decapitated after 1, 4 or 12 weeks post injection. The changes in the level of neurotrophins, receptor for neurotrophins, marker of microglia and adhesion molecules in ST were evaluated using Real-Time PCR. The analysis of morphological changes of T lymphocytes was performed by immunohistochemical staining. Results. In our study, we reported a CD4+ T-cell infiltration to the CNS following ASN delivery to ST or SNpc. We observed a slight effect of ASN on the expression of intercellular adhesion molecule 1 (ICAM-1) and vascular cell adhesion molecule 1 (VCAM-1). The present study demonstrated an increase in the expression of the glial cell-derived neurotrophic factor (GDNF), brain-derived neurotrophic factor (BDNF), neurotrophin-3 (NT-3) and receptors of nerve growth factor (NGF)-TrkA, receptor of BDNF-TrkB, receptor of NT-3-TrkC, following the administration of ASN into ST. Conclusion. Our research provides further evidence for the involvement of ASN in the inflammatory response in the CNS.
Journal of Neuroinflammation, 2016
Background: Passive and active immunization with α-synuclein has been shown to be neuroprotective in animal models of Parkinson's disease. We have previously shown that vaccination with α-synuclein, long before α-synucleininduced brain pathology, prevents striatal degeneration by inducing regulatory T cell infiltration in parenchyma and antibody deposition on α-synuclein overexpressing neurons. However, the effect of peripheral α-synuclein on the immune system is unknown, as are the mechanistic changes induced in the CD4 T cell population during successful neuroprotective animal studies. We have studied the changes induced by vaccination with α-synuclein in the CD4 T cell pool and its impact on brain microglia to understand the immune mechanisms behind successful vaccination strategies in Parkinson's disease animal models. Methods: Mice were immunized with WT or nitrated α-synuclein at a dose equivalent to the one used in our previous successful vaccination strategy and at a higher dose to determine potential dose-dependent effects. Animals were re-vaccinated 4 weeks after and sacrificed 5 days later. These studies were conducted in naive animals in the absence of human α-synuclein expression. Results: The CD4 T cell response was modulated by α-synuclein in a dose-dependent manner, in particular the regulatory T cell population. Low-dose α-synuclein induced expansion of naive (Foxp3 + CCR6-CD127lo/ neg) and dopamine receptor type D3+ regulatory T cells, as well as an increase in Stat5 protein levels. On the other hand, high dose promoted activation of regulatory T cells (Foxp3CCR6 + CD127lo/neg), which were dopamine receptor D2+D3-, and induced up-regulation of Stat5 and production of anti-α-synuclein antibodies. These effects were specific to the variant of α-synuclein used as the pathology-associated nitrated form induced distinct effects at both doses. The changes observed in the periphery after vaccination with low-dose α-synuclein correlated with an increase in CD154+, CD103+, and CD54+ microglia and the reduction of CD200R+ microglia. This resulted in the induction of a polarized tolerogenic microglia population that was CD200R-CD54CD103CD172a+ (82 % of total microglia). Conclusions: We have shown for the first time the mechanisms behind α-synuclein vaccination and, importantly, how we can modulate microglia's phenotype by regulating the CD4 T cell pool, thus shedding invaluable light on the design of neuroimmunoregulatory therapies for Parkinson's disease.
Neurochemical Research
The aim of the study was to examine the Braak's hypothesis to explain the spreading and distribution of the neuropathological changes observed in the course of Parkinson's disease among ascending neuroanatomical regions. We investigated the neurotransmitter levels (monoamines and amino acid concentration) as well as tyrosine hydroxylase (TH) and transglutaminase-2 (TG2) mRNA expression in the mouse striata (ST) after intracerebral α-synuclein (ASN) administration into gigantocellular reticular nucleus (Gi). Male C57BL/10 Tar mice were used in this study. ASN was administrated by stereotactic injection into Gi area (4 μl; 1 μg/μl) and mice were decapitated after 1, 4 or 12 weeks post injection. The neurotransmitters concentration in ST were evaluated using HPLC detection. TH and TG2 mRNA expression were examined by Real-Time PCR method. At 4 and 12 weeks after ASN administration we observed decrease of DA concentration in ST relative to control groups and we found a significantly higher concentration one of the DA metabolites-DOPAC. At these time points, we also noticed the increase in DA turnover determined as DOPAC/DA ratio. Additionally, at 4 and 12 weeks after ASN injection we noted decreasing of TH mRNA expression. Our findings corresponds with the Braak's theory about the presence of the first neuropathological changes within brainstem and then with time affecting higher neuroanatomical regions. These results obtained after administration of ASN monomers to the Gi area may be useful to explain the pathogenesis of Parkinson's disease.
Background: α-Synuclein (α-syn) is the predominant protein in Lewy-body inclusions, which are pathological hallmarks of α-synucleinopathies, such as Parkinson’s disease (PD) and multiple system atrophy (MSA). Other hallmarks include activation of microglia, elevation of pro-inflammatory cytokines, as well as the activation of T and B cells. These immune changes point towards a dysregulation of both the innate and the adaptive immune system. T cells have been shown to recognize epitopes derived from α-syn and altered populations of T cells have been found in PD and MSA patients, providing evidence that these cells can be key to the pathogenesis of the disease. Objective: To study the role of the adaptive immune system with respect to α-syn pathology. Methods: We injected human α-syn preformed fibrils (PFFs) into the striatum of immunocompromised mice (NSG) and assessed accumulation of phosphorylated α-syn pathology, proteinase K-resistant α-syn pathology and microgliosis in the stria...
Nigral damage and dopaminergic hypofunction in mesencephalon-immunized guinea pigs
Annals of Neurology, 1992
To support a potential role for immune mechanisms in the destruction of substantia nigra (SN) neurons, guinea pigs were immunized with bovine mesencephalon containing SN neurons. After immunization no clinical signs of basal ganglia dysfunction appeared. However, pathological examination revealed evidence of neuronal damage in the SN in 8 of 17 guinea pigs immunized with bovine mesencephalon. No nigral pathology was noted in animals immunized with spinal cord gray matter or Freund's adjuvant alone. Accompanying the SN damage in mesencephalon-immunized guinea pigs was a 25% decrease in tyrosine hydroxylase activity in the SN and a 27% decrease in dopamine content in the striatum. Deposits of IgG were detected by immunohistochemical techniques in sections of SN from mesencephalon-immunized guinea pigs and in sections of human SN after exposure to serum from mesencephalon-immunized guinea pigs. These data document the antigenicity of SN and suggest the possibility that immune mechanisms can contribute to basal ganglia pathology.
ASN NEURO, 2013
The role of neuroinflammation and the adaptive immune system in PD (Parkinson's disease) has been the subject of intense investigation in recent years, both in animal models of parkinsonism and in post-mortem PD brains. However, how these processes relate to and modulate α-syn (α-synuclein) pathology and microglia activation is still poorly understood. Specifically, how the peripheral immune system interacts, regulates and/or is induced by neuroinflammatory processes taking place during PD is still undetermined. We present herein a comprehensive review of the features and impact that neuroinflamation has on neurodegeneration in different animal models of nigral cell death, how this neuroinflammation relates to microglia activation and the way microglia respond to α-syn in vivo. We also discuss a possible role for the peripheral immune system in animal models of parkinsonism, how these findings relate to the state of microglia activation observed in these animal models and how these findings compare with what has been observed in humans with PD. Together, the available data points to the need for development of dual therapeutic strategies that modulate r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r 1 To whom correspondence should be addressed (email malu.tansey@emory.edu and mrr@biomekemi.au.dk).
Editorial Immunology and the Central Nervous System
2013
1 Department of Biochemistry and Molecular Biology, Institute of Neuroscience and School of Medicine, Universitat Autonoma de Barcelona, Campus de Bellaterra, Cerdanyola del Valles, Barcelona, Spain 2 School of Food Science and Environmental Health, Dublin Institute of Technology, Dublin, Ireland 3 Centers for Disease Control and Prevention (CDC), Atlanta, GA, USA 4 Immunotherapeutics BU, GlaxoSmithKline Vaccines, Laval, QC, Canada
PloS one, 2013
The discovery of the involvement of alpha-synuclein (α-syn) in Parkinson's disease (PD) pathogenesis has resulted in the development and use of viral vector-mediated α-syn overexpression rodent models. The goal of these series of experiments was to characterize the neurodegeneration and functional deficits resulting from injection of recombinant adeno-associated virus (rAAV) serotype 2/5-expressing human wildtype α-syn in the rat substantia nigra (SN). Rats were unilaterally injected into two sites in the SN with either rAAV2/5-expressing green fluorescent protein (GFP, 1.2 x 10 13 ) or varying titers (2.2 x 10 12 , 1.0 x 10 13 , 5.9 x 10 13 , or 1.0 x 10 14 ) of rAAV2/5-α-syn. Cohorts of rats were euthanized 4, 8, or 12 weeks following vector injection. The severity of tyrosine hydroxylase immunoreactive (THir) neuron death in the SN pars compacta (SNpc) was dependent on vector titer. An identical magnitude of nigrostriatal degeneration (60-70% SNpc THir neuron degeneration and 40-50% loss of striatal TH expression) was observed four weeks following 1.0 x 10 14 titer rAAV2/5-α-syn injection and 8 weeks following 1.0 x 10 13 titer rAAV2/5-α-syn injection. THir neuron degeneration was relatively uniform throughout the rostral-caudal axis of the SNpc. Despite equivalent nigrostriatal degeneration between the 1.0 x 10 13 and 1.0 x 10 14 rAAV2/5-α-syn groups, functional impairment in the cylinder test and the adjusting steps task was only observed in rats with the longer 8 week duration of α-syn expression. Motor impairment in the cylinder task was highly correlated to striatal TH loss. Further, 8 weeks following 5.9 x 10 13 rAAV2/5-α-syn injection deficits in ultrasonic vocalizations were observed. In conclusion, our rAAV2/5-αsyn overexpression model demonstrates robust nigrostriatal α-syn overexpression, induces significant nigrostriatal degeneration that is both vector and duration dependent and under specific parameters can result in motor impairment that directly relates to the level of striatal TH denervation.