Rational design of structure-based vaccines targeting misfolded alpha-synuclein conformers of Parkinson's disease and related disorders

Flores-Fernandez, J. M.; Pesch, V.; Sriraman, A.; Chimal-Juarez, E.; Amidian, S.; Wang, X.; Reithofer, S.; Ma, L.; Tamgueney, G.; Wille, H.

doi:10.1101/2023.06.30.547254

bioRxiv · 10.1101/2023.06.30.547254

Rational design of structure-based vaccines targeting misfolded alpha-synuclein conformers of Parkinson's disease and related disorders

Flores-Fernandez, J. M.·Pesch, V.·Sriraman, A.·Chimal-Juarez, E.·Amidian, S.·Wang, X.·Reithofer, S.·Ma, L.·Tamgueney, G.·Wille, H.

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Abstract

BackgroundSynucleinopathies, including Parkinsons disease, multiple system atrophy, and dementia with Lewy bodies, are neurodegenerative disorders caused by the accumulation of misfolded alpha-synuclein protein. Developing effective vaccines against synucleinopathies has been challenging due to the difficulty of stimulating an immune-specific response against alpha-synuclein, conferring neuroprotection without causing harmful autoimmune reactions, and selectively targeting only pathological forms of alpha-synuclein. Previous attempts using linear peptides and epitopes without control of the antigen structure for immunization failed in clinical trials. The immune system was unable to distinguish between the native alpha-synuclein and its amyloid form. ResultsThe prion domain of the fungal HET-s protein was selected as a scaffold to introduce select epitopes from the surface of alpha-synuclein fibrils. Four vaccine candidates were generated by introducing specific amino acid substitutions onto the surface of the scaffold protein in regions that showed structural similarity to alpha-synuclein fibril structures. Each vaccine candidate had unique amino acid substitutions that imitated a specific epitope from alpha-synuclein amyloid fibrils. The approach successfully mimicked the stacking of the parallel in-register beta-sheet structure seen in alpha-synuclein fibrils as the vaccine candidates were found to be structurally stable and self-assembling into the desired conformations. All vaccine candidates induced substantial levels of IgG antibodies that recognized pathological alpha-synuclein fibrils derived from a synucleinopathy mouse model. Furthermore, the resulting anti-sera recognized pathological alpha-synuclein aggregates in brain lysates from patients who died from dementia with Lewy bodies, multiple system atrophy, or Parkinsons disease, but did not recognize linear alpha-synuclein peptides. Each vaccine candidate induced a unique pattern of reactivity toward alpha-synuclein aggregates contained in distinct disease pathologies. ConclusionsThis new approach, based on the rational design of vaccines using the secondary and tertiary structure of alpha-synuclein amyloid fibrils and strict control over the exposed antigen structure used for immunization, as well as the ability to mimic aggregated alpha-synuclein, provides a promising avenue towards developing effective vaccines against alpha-synuclein fibrils, which may be crucial for the prevention and treatment of synucleinopathies.

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Flores-Fernandez, J. M., Pesch, V., Sriraman, A., Chimal-Juarez, E., Amidian, S., Wang, X., Reithofer, S., Ma, L., Tamgueney, G., Wille, H.. 2023-06-30. Rational design of structure-based vaccines targeting misfolded alpha-synuclein conformers of Parkinson's disease and related disorders. https://doi.org/10.1101/2023.06.30.547254

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