MJF-14 proximity ligation assay detects early non-inclusion alpha-synuclein pathology with enhanced specificity and sensitivity
Nanna Møller Jensen, YuHong Fu, Cristine Betzer, Hongyun Li, Sara Elfarrash, Ali H. Shaib, Donatus Krah, Zagorka Vitic, Lasse Reimer, Hjalte Gram, Vladimir L. Buchman, Mark Denham, Silvio O. Rizzoli, Glenda M. Halliday, Poul Henning Jensen
Abstract
α-Synuclein proximity ligation assay (PLA) has proved a sensitive technique for detection of non-Lewy body α-synuclein aggregate pathology. Here, we describe the MJF-14 PLA, a new PLA towards aggregated α-synuclein with unprecedented specificity, using the aggregate-selective α-synuclein antibody MJFR-14-6-4-2 (hereafter MJF-14). Signal in the assay correlates with α-synuclein aggregation in cell culture and human neurons, induced by α-synuclein overexpression or pre-formed fibrils. Co-labelling of MJF-14 PLA and pS129-α-synuclein immunofluorescence in post-mortem cases of dementia with Lewy bodies shows that while the MJF-14 PLA reveals extensive non-inclusion pathology, it is not sensitive towards pS129-α-synuclein-positive Lewy bodies. In Parkinson's disease brain, direct comparison of PLA and immunohistochemistry with the MJF-14 antibody shows widespread α-synuclein pathology preceding the formation of conventional Lewy pathology. In conclusion, we introduce an improved α-synuclein aggregate PLA to uncover abundant non-inclusion pathology, which deserves future validation with brain bank resources and in different synucleinopathies.