Engineered autophagy receptors administered with extracellular vesicles eliminate pathological Tau and TDP-43

In neurodegenerative diseases such as frontotemporal dementia and amyotrophic lateral sclerosis, pathological forms of proteins such as Tau and TDP-43 accumulate within large heterogeneous inclusions inside cells. Current strategies to eliminate such aberrant protein species in patients encounter three main challenges: crossing the blood-brain barrier and plasma membrane, specifically recognizing pathological forms of proteins, and engaging mechanisms to eliminate large entities. Here we fuse LC3A, a central protein in the recruitment of substrates into autophagosomes, to cytoplasm-stable antibodies. These engineered autophagy receptors, targeting Tau or TDP-43, are delivered using small extracellular vesicles and reduce pathology in models, including Tau P301S adult primary mouse neurons, TDP-43^G298S iPSC-derived motor neurons and after intravenous injection in Tau P301S mice. Similarly, adeno-associated-virus-mediated delivery in TDP-43^ΔNLS mice enhances clearance of pathological TDP-43. This targeted degradation strategy allows delivery into the brain while capitalizing on the specificity of antibodies and the ability of autophagy to degrade large intracellular entities.