Neutralization of pathogenic PC-OxPL by AAV-delivered scFv as a therapeutic strategy for amyotrophic lateral...

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disorder defined by progressive motor neuron loss and TDP-43 proteinopathy, yet the upstream drivers of this pathology remain unclear. Oxidized phosphatidylcholines (PC-OxPL) have emerged as potent inducers of proteinopathy in the central nervous system (CNS), but their role in ALS has not been systematically explored. We identify a distinct PC-OxPL signature in the cerebrospinal fluid (CSF) of patients with sporadic ALS (sALS) and show that apolipoprotein E (apoE)-containing particles are the primary PC-OxPL carriers in this compartment. In human iPSC-derived motor neurons, PC-OxPL exposure triggered disease-relevant transcriptional alterations and TDP-43 pathology, establishing PC-OxPL as a mediator of ALS-like neurodegeneration in vitro. To counteract this toxicity, we engineered an Adeno-Associated Virus (AAV)-delivered single-chain antibody fragment (scFv), PC-OxPL-VecTab, targeting PC-OxPL neoepitopes. PC-OxPL-VecTab neutralized PC-OxPL-induced neurotoxicity, reduced TDP-43 aggregation, and prevented motor neuron death and behavioral deficits in a sALS CSF transfer mouse model. Intrathecal delivery of PC-OxPL-VecTab in minipigs achieved broad CNS biodistribution and transgene expression, supporting the feasibility of CNS delivery. These findings position PC-OxPL as a mechanistic contributor to ALS pathogenesis and establish PC-OxPL-VecTab as a therapeutic strategy for ALS with potential broader applicability to disorders associated with PC-OxPL accumulation.