α-Synuclein fibril-specific nanobody reduces prion-like α-synuclein spreading in mice

Butler et al. selected disulfide bond-free nanobodies to target alpha-synuclein fibrils. Nanobody PFFNB2 was shown to disaggregate alpha-synuclein fibrils in vitro and inhibit alpha-synuclein pathology development in neuron cultures and mouse models. Pathogenic alpha-synuclein (alpha-syn) is a prion-like protein that drives the pathogenesis of Lewy Body Dementia (LBD) and Parkinson's Disease (PD). To target pathogenic alpha-syn preformed fibrils (PFF), here we designed extracellular disulfide bond-free synthetic nanobody libraries in yeast. Following selection, we identified a nanobody, PFFNB2, that can specifically recognize alpha-syn PFF over alpha-syn monomers. PFFNB2 cannot inhibit the aggregation of alpha-syn monomer, but can significantly dissociate alpha-syn fibrils. Furthermore, adeno-associated virus (AAV)-encoding EGFP fused to PFFNB2 (AAV-EGFP-PFFNB2) can inhibit PFF-induced alpha-syn serine 129 phosphorylation (pS129) in mouse primary cortical neurons, and prevent alpha-syn pathology spreading to the cortex in the transgenic mice expressing human wild type (WT) alpha-syn by intrastriatal-PFF injection. The pS129 immunoreactivity is negatively correlated with the expression of AAV-EGFP-PFFNB2. In conclusion, PFFNB2 holds a promise for mechanistic exploration and therapeutic development in alpha-syn-related pathogenesis.

Automated summary

Butler et al. selected disulfide bond-free nanobodies to target alpha-synuclein fibrils. Nanobody PFFNB2 was shown to disaggregate alpha-synuclein fibrils in vitro and inhibit alpha-synuclein pathology development in neuron cultures and mouse models.