ABSTRACT
The pathological misfolding and aggregation of soluble α-synuclein into toxic oligomers and insoluble amyloid fibrils causes Parkinson's disease, a progressive age-related neurodegenerative disease for which there is no cure. HET-s is a soluble fungal protein that can form assembled amyloid fibrils in its prion state. We engineered HET-s(218-298) to form four different fibrillar vaccine candidates, each displaying a specific conformational epitope present on the surface of α-synuclein fibrils. Vaccination with these four vaccine candidates prolonged the survival of immunized TgM83+/- mice challenged with α-synuclein fibrils by 8% when injected into the brain to model brain-first Parkinson's disease or by 21% and 22% when injected into the peritoneum or gut wall, respectively, to model body-first Parkinson's disease. Antibodies from fully immunized mice recognized α-synuclein fibrils and brain homogenates from patients with Parkinson's disease, dementia with Lewy bodies and multiple system atrophy. Conformation-specific vaccines that mimic epitopes present only on the surface of pathological fibrils but not on soluble monomers, hold great promise for protection against Parkinson's disease, related synucleinopathies and other amyloidogenic protein misfolding disorders.
Subject(s)
Mice, Transgenic , Parkinson Disease , alpha-Synuclein , Animals , Parkinson Disease/immunology , Parkinson Disease/pathology , Mice , alpha-Synuclein/immunology , alpha-Synuclein/metabolism , Humans , Amyloid/immunology , Amyloid/metabolism , Vaccination , Fungal Proteins/immunology , Brain/pathology , Brain/metabolism , Brain/immunology , Female , Mice, Inbred C57BLABSTRACT
Biotinylation is probably the most frequent and practically useful modification of molecules to facilitate selective and highly affine binding to (strept)avidin for immobilization, enrichment, and purification for further (bio)chemical or (bio)physical investigations. We present a protecting-group-free synthesis of a branched biotin bis-azide that enables dual-payload late-stage functionalization with arbitrary alkynes via click chemistry. Utility of the chassis is briefly showcased on the example of a valuable Pittsburgh B analogue, which binds pathological protein aggregates, commonly found in neurodegenerative diseases.
Subject(s)
Alkynes , Biotin , Biotinylation , Click Chemistry , Molecular Structure , Biotin/chemistry , Alkynes/chemistry , Thiazoles/chemistry , Thiazoles/chemical synthesis , Azides/chemistryABSTRACT
Misfolded and aggregated α-synuclein is a neuropathological hallmark of Parkinson's disease (PD). Thus, α-synuclein aggregates are regarded as a biomarker for the development of diagnostic assays. Quantification of α-synuclein aggregates in body fluids is challenging, and requires highly sensitive and specific assays. Recent studies suggest that α-synuclein aggregates may be shed into stool. We used surface-based fluorescence intensity distribution analysis (sFIDA) to detect and quantify single particles of α-synuclein aggregates in stool of 94 PD patients, 72 isolated rapid eye movement sleep behavior disorder (iRBD) patients, and 51 healthy controls. We measured significantly elevated concentrations of α-synuclein aggregates in stool of iRBD patients versus those of controls (p = 0.024) or PD patients (p < 0.001). Our results show that α-synuclein aggregates are excreted in stool and can be measured using the sFIDA assay, which could support the diagnosis of prodromal synucleinopathies.