Modeling neurotropic virus infection with functional human neural spheroids as a platform for high-throughput...

Neurotropic arboviruses pose significant threats to human health due to their ability to infect the central nervous system (CNS). Despite the significant impact on public health, mechanisms underlying neuropathogenesis remains poorly understood, and the development of effective antivirals has been hampered by the lack of predictive, high-throughput (HT) infection platforms that can replicate in vivo disease features to drive early drug discovery. To address this gap, we developed a human-based, HT-compatible, functional viral disease neural spheroid model assembled from human induced pluripotent stem cell (hiPSC)-differentiated neurons and astrocytes as a platform for studying virus infection and the development of HT screening (HTS)-compatible assays for drug discovery. Here, we investigated eight high impact species belonging to either the Bunyaviricetes class or Togaviridae family and evaluated infectability on neural spheroids, followed by characterization of neural activity dysregulation and induced disease. We found that neural spheroids support productive infection, with virus- and time-dependent changes in disease profiles. Transcriptomic changes induced by two representative members, LACV and CHIKV, revealed a highly pro-inflammatory response in LACV infected spheroids whereas CHIKV-infection induced neurodegenerative profiles. Finally, we evaluated antiviral and anti-neural dysfunction activity of interferon-alpha as well as tested the small molecule gemcitabine against CHIKV as a proof-of-concept for HT antiviral compound screening. Together, our data establishes the viral-neural spheroids as a valuable platform that supports productive infection by high impact neurotropic viruses, and this platform can be used to both investigate viral pathogenesis and support therapeutics discovery and development.