Alpha-synuclein (α-Syn) plays a pivotal role in the pathophysiology of Parkinson's disease (PD), which can partly be modulated by innate and adaptive immune functions, and vice versa. Here, naturally ...occurring α-Syn autoantibodies (α-Syn-nAbs) may be effective against α-Syn pathoetiology and may serve as a PD biomarker. However, serum and cerebrospinal fluid α-Syn-nAbs levels still lack consistent evidence as required for a reliable PD biomarker. Serum and cerebrospinal fluid α-Syn-nAbs levels of 66 PD patients and 69 healthy controls were assessed using a validated ELISA assay. Moreover, potential sources of error variance including unspecific ELISA background signals, free serum hemoglobin concentrations, α-Syn plate coating procedures, and differences in α-Syn-nAbs standards, were investigated. PD patients and controls did not differ in serum (p = .49) nor cerebrospinal fluid (p = .29) α-Syn-nAbs levels. Interestingly, free serum hemoglobin concentrations were negatively correlated with α-Syn-nAbs levels in controls (Spearman ρ = -.41, p<.001), but not in PD patients (ρ = .16, p = .21). ELISA α-Syn plate coating procedures impacted inter-assay variability (same day coating: 8-16%; coating on different days: 16-58%). α-Syn-nAbs standards from different purification batches differed regarding optical density measured in ELISAs suggesting differences in α-Syn affinity. While α-Syn-nAbs levels may represent a potential PD biomarker, several methodological issues have to be considered to increase reproducibility of α-Syn-nAbs findings. Further studies using standardized protocols minimizing sources of error variance may be necessary to establish a reliable PD α-Syn-nAbs biomarker.
Alzheimer's disease (AD) is diagnosed based upon medical history, neuropsychiatric examination, cerebrospinal fluid analysis, extensive laboratory analyses and cerebral imaging. Diagnosis is time ...consuming and labour intensive. Parkinson's disease (PD) is mainly diagnosed on clinical grounds.
The primary aim of this study was to differentiate patients suffering from AD, PD and healthy controls by investigating exhaled air with the electronic nose technique. After demonstrating a difference between the three groups the secondary aim was the identification of specific substances responsible for the difference(s) using ion mobility spectroscopy. Thirdly we analysed whether amyloid beta (Aβ) in exhaled breath was causative for the observed differences between patients suffering from AD and healthy controls.
We employed novel pulmonary diagnostic tools (electronic nose device/ion-mobility spectrometry) for the identification of patients with neurodegenerative diseases. Specifically, we analysed breath pattern differences in exhaled air of patients with AD, those with PD and healthy controls using the electronic nose device (eNose). Using ion mobility spectrometry (IMS), we identified the compounds responsible for the observed differences in breath patterns. We applied ELISA technique to measure Aβ in exhaled breath condensates.
The eNose was able to differentiate between AD, PD and HC correctly. Using IMS, we identified markers that could be used to differentiate healthy controls from patients with AD and PD with an accuracy of 94%. In addition, patients suffering from PD were identified with sensitivity and specificity of 100%. Altogether, 3 AD patients out of 53 participants were misclassified. Although we found Aβ in exhaled breath condensate from both AD and healthy controls, no significant differences between groups were detected.
These data may open a new field in the diagnosis of neurodegenerative disease such as Alzheimer's disease and Parkinson's disease. Further research is required to evaluate the significance of these pulmonary findings with respect to the pathophysiology of neurodegenerative disorders.
Abnormal aggregation of proteins induces neuronal cell loss in neurodegenerative disorders such as Alzheimer's Disease, Creutzfeldt-Jakob Disease and Parkinson's Disease. Specific stimuli initialize ...conformational changes in physiological proteins, causing intra- or extracellular protein aggregation. We and other groups have identified naturally occurring autoantibodies (nAbs) as part of the human antibody pool that are able to prevent peptide fibrillation. These nAbs show a rescue effect following exposure of toxic aggregates on neurons, and they support microglial uptake of aggregated peptides.
Identification of a putative common epitope among the relevant proteins β-Amyloid, α-Synuclein and Prion Protein for the respective nAbs.
Binding affinity between the aforementioned proteins and nAbs was tested by Dot Blot, ELISA and SPR-technology. Furthermore, the functionality of the protein-nAbs-complexes was studied in Thioflavin-T assays and microglial uptake experiments to study dependent inhibition of protein aggregation and enhancement of Fcγ mediated uptake by microglial cells.
β-Amyloid and Prion Protein fragment showed considerable binding affinity and functional efficacy for all applied nAbs. Thereby, no significant difference within the different nAbs was detected. In contrast, α-Synuclein was bound exclusively by nAbs-α-Synuclein, which was reproduced in all binding studies. Surprisingly, functional assays with α-Synuclein revealed no significant effect of nAbs in comparison to IVIg treatment. However, all applied nAbs as well as IVIg show a minimal functionality on the microglial uptake of α-Synuclein.
nAbs-Aβ, nAbs-PrP possibly display comparable affinity to the same structural epitope within Aβ and PrP106-126 A117V whereas the epitope recognized by nAbs-α-Syn is only present in α-Syn. The structural similarity of Aβ and PrP fragment promotes the outline for an efficient antibody for the treatment of several neurodegenerative disorders and extend the functional characteristics of the investigated nAbs.
There is extensive evidence that accumulation of mononuclear phagocytes including microglial cells, monocytes, and macrophages at sites of β-amyloid (Aβ) deposition in the brain is an important ...pathological feature of Alzheimer’s disease (AD) and related animal models, and the concentration of these cells clustered around Aβ deposits is several folds higher than in neighboring areas of the brain 1–5. Microglial cells phagocytose and clear debris, pathogens, and toxins, but they can also be activated to produce inflammatory cytokines, chemokines, and neurotoxins 6. Over the past decade, the roles of microglial cells in AD have begun to be clarified, and we proposed that these cells play a dichotomous role in the pathogenesis of AD 4, 6–11. Microglial cells are able to clear soluble and fibrillar Aβ, but continued interactions of these cells with Aβ can lead to an inflammatory response resulting in neurotoxicity. Inflammasomes are inducible high molecular weight protein complexes that are involved in many inflammatory pathological processes. Recently, Aβ was found to activate the NLRP3 inflammasome in microglial cells in vitro and in vivo thereby defining a novel pathway that could lead to progression of AD 12–14. In this manuscript, we review possible steps leading to Aβ-induced inflammasome activation and discuss how this could contribute to the pathogenesis of AD.
Treating patients who have cancer with vaccines that stimulate a targeted immune response is conceptually appealing, but cancer vaccine trials have not been successful in late-stage patients with ...treatment-refractory tumours
. We are testing melanoma FixVac (BNT111)-an intravenously administered liposomal RNA (RNA-LPX) vaccine, which targets four non-mutated, tumour-associated antigens that are prevalent in melanoma-in an ongoing, first-in-human, dose-escalation phase I trial in patients with advanced melanoma (Lipo-MERIT trial, ClinicalTrials.gov identifier NCT02410733). We report here data from an exploratory interim analysis that show that melanoma FixVac, alone or in combination with blockade of the checkpoint inhibitor PD1, mediates durable objective responses in checkpoint-inhibitor (CPI)-experienced patients with unresectable melanoma. Clinical responses are accompanied by the induction of strong CD4
and CD8
T cell immunity against the vaccine antigens. The antigen-specific cytotoxic T-cell responses in some responders reach magnitudes typically reported for adoptive T-cell therapy, and are durable. Our findings indicate that RNA-LPX vaccination is a potent immunotherapy in patients with CPI-experienced melanoma, and suggest the general utility of non-mutant shared tumour antigens as targets for cancer vaccination.
In the central nervous system (CNS), insulin‐like growth factor 1 (IGF‐1) regulates myelination by oligodendrocyte (ODC) precursor cells and shows anti‐apoptotic properties in neuronal cells in ...different in vitro and in vivo systems. Previous work also suggests that IGF‐1 protects ODCs from cell death and enhances remyelination in models of toxin‐induced and autoimmune demyelination. However, since evidence remains controversial, the therapeutic potential of IGF‐1 in demyelinating CNS conditions is unclear. To finally shed light on the function of IGF1‐signaling for ODCs, we deleted insulin‐like growth factor 1 receptor (IGF1R) specifically in mature ODCs of the mouse. We found that ODC survival and myelin status were unaffected by the absence of IGF1R until 15 months of age, indicating that IGF‐1 signaling does not play a major role in post‐mitotic ODCs during homeostasis. Notably, the absence of IGF1R did neither affect ODC survival nor myelin status upon cuprizone intoxication or induction of experimental autoimmune encephalomyelitis (EAE), models for toxic and autoimmune demyelination, respectively. Surprisingly, however, the absence of IGF1R from ODCs protected against clinical neuroinflammation in the EAE model. Together, our data indicate that IGF‐1 signaling is not required for the function and survival of mature ODCs in steady‐state and disease.
Main Points
Absence of insulin‐like growth factor 1 receptor from mature oligodendrocytes:
does not impair their survival and myelin maintenance.
does not affect cuprizone‐induced toxic demyelination.
ameliorates experimental autoimmune encephalomyelitis.
In this article, we review the current knowledge on pathological and physiological autoantibodies directed toward structures in the central nervous system (CNS) with an emphasis on their regulation ...and origin. Pathological autoantibodies in the CNS that are associated with autoimmunity often lead to severe neurological deficits via inflammatory processes such as encephalitis. In some instances, however, autoantibodies function as a marker for diagnostic purposes without contributing to the pathological process and/or disease progression. The existence of naturally occurring physiological autoantibodies has been known for a long time, and their role in maintaining homeostasis is well established. Within the brain, naturally occurring autoantibodies targeting aggregated proteins have been detected and might be promising candidates for new therapeutic approaches for neurodegenerative disorders. Further evidence has demonstrated the existence of naturally occurring antibodies targeting antigens on neurons and oligodendrocytes that promote axonal outgrowth and remyelination. The numerous actions of physiological autoantibodies as well as their regulation and origin are summarized in this review.
Background Abnormal aggregation of proteins induces neuronal cell loss in neurodegenerative disorders such as Alzheimer's Disease, Creutzfeldt-Jakob Disease and Parkinson's Disease. Specific stimuli ...initialize conformational changes in physiological proteins, causing intra- or extracellular protein aggregation. We and other groups have identified naturally occurring autoantibodies (nAbs) as part of the human antibody pool that are able to prevent peptide fibrillation. These nAbs show a rescue effect following exposure of toxic aggregates on neurons, and they support microglial uptake of aggregated peptides. Objective Identification of a putative common epitope among the relevant proteins beta-Amyloid, alpha-Synuclein and Prion Protein for the respective nAbs. Material and methods Binding affinity between the aforementioned proteins and nAbs was tested by Dot Blot, ELISA and SPR-technology. Furthermore, the functionality of the protein-nAbs-complexes was studied in Thioflavin-T assays and microglial uptake experiments to study dependent inhibition of protein aggregation and enhancement of Fcgamma mediated uptake by microglial cells. Results beta-Amyloid and Prion Protein fragment showed considerable binding affinity and functional efficacy for all applied nAbs. Thereby, no significant difference within the different nAbs was detected. In contrast, alpha-Synuclein was bound exclusively by nAbs-alpha-Synuclein, which was reproduced in all binding studies. Surprisingly, functional assays with alpha-Synuclein revealed no significant effect of nAbs in comparison to IVIg treatment. However, all applied nAbs as well as IVIg show a minimal functionality on the microglial uptake of alpha-Synuclein. Conclusion nAbs-Abeta, nAbs-PrP possibly display comparable affinity to the same structural epitope within Abeta and PrP106-126 A117V whereas the epitope recognized by nAbs-alpha-Syn is only present in alpha-Syn. The structural similarity of Abeta and PrP fragment promotes the outline for an efficient antibody for the treatment of several neurodegenerative disorders and extend the functional characteristics of the investigated nAbs.
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