TY - JOUR TI - Phagocytic glia are obligatory intermediates in transmission of mutant huntingtin aggregates across neuronal synapses AU - Donnelly, Kirby M AU - DeLorenzo, Olivia R AU - Zaya, Aprem DA AU - Pisano, Gabrielle E AU - Thu, Wint M AU - Luo, Liqun AU - Kopito, Ron R AU - Panning Pearce, Margaret M A2 - Bellen, Hugo J A2 - Westbrook, Gary L VL - 9 PY - 2020 DA - 2020/05/28 SP - e58499 C1 - eLife 2020;9:e58499 DO - 10.7554/eLife.58499 UR - https://doi.org/10.7554/eLife.58499 AB - Emerging evidence supports the hypothesis that pathogenic protein aggregates associated with neurodegenerative diseases spread from cell to cell through the brain in a manner akin to infectious prions. Here, we show that mutant huntingtin (mHtt) aggregates associated with Huntington disease transfer anterogradely from presynaptic to postsynaptic neurons in the adult Drosophila olfactory system. Trans-synaptic transmission of mHtt aggregates is inversely correlated with neuronal activity and blocked by inhibiting caspases in presynaptic neurons, implicating synaptic dysfunction and cell death in aggregate spreading. Remarkably, mHtt aggregate transmission across synapses requires the glial scavenger receptor Draper and involves a transient visit to the glial cytoplasm, indicating that phagocytic glia act as obligatory intermediates in aggregate spreading between synaptically-connected neurons. These findings expand our understanding of phagocytic glia as double-edged players in neurodegeneration—by clearing neurotoxic protein aggregates, but also providing an opportunity for prion-like seeds to evade phagolysosomal degradation and propagate further in the brain. KW - huntingtin KW - prion-like KW - neurodegeneration KW - phagocytic glia KW - Draper KW - protein aggregate JF - eLife SN - 2050-084X PB - eLife Sciences Publications, Ltd ER -