Pio, T.; Bettaiah, M.; Zhao, R.; Wariyar, S. S.; Mouhi, S.; Hill, E. J.; Sloan, S. A.; Brain Organoid Hub, ; Andersen, J.

Oligodendrocytes play essential roles in central nervous system development and homeostasis, and their dysfunction is a hallmark of numerous neurological disorders. However, human in vitro systems that support oligodendrocyte lineage progression while enabling the study of disease-relevant states remain limited. Here, we establish human spinal cord organoids (hSpO) and cortico-motor assembloids as platforms to model oligodendrocyte development, neuron-glia interactions, and cytokine-induced dysfunction. We show that hSpO generate oligodendrocyte lineage populations that transcriptionally resemble those found in the developing human spinal cord, and oligodendrocyte progenitor cells that exhibit physiologically-relevant functional properties, including migration and monosynaptic input from neurons. Exposure of assembloids to pro-inflammatory cytokines induces transcriptional changes across the oligodendrocyte lineage, characterized by altered lineage progression and acquisition of disease-associated gene expression programs that mirror signatures observed in multiple sclerosis patient tissue. Together, this work establishes hSpO and assembloids as in vitro systems for studying oligodendrocyte lineage development and disease-associated states in a human multi-cellular context.