Downregulation of Neurodevelopmental Gene Expression in iPSC-Derived Cerebral Organoids Upon Infection by Human Cytomegalovirus

Human cytomegalovirus (HCMV) is a beta herpesvirus that, upon congenital infection, can cause severe birth defects including vision and hearing loss, microcephaly, and seizures. Currently, no approved treatment options exist for in utero infections. We previously demonstrated that HCMV infection decreases calcium signaling responses and alters neuronal differentiation in induced pluripotent stem cell (iPSC) derived neural progenitor cells (NPCs). Here we aimed to determine the impact of infection on the transcriptome in developing human neurons using iPSC-derived 3-dimensional cerebral organoids. We infected iPSC-derived cerebral organoids with HCMV encoding eGFP and sorted cell populations based on GFP signal strength. Significant transcriptional downregulation was observed including in key neurodevelopmental gene pathways in both the GFP (+) and intermediate groups. Interestingly, the GFP (-) group also showed downregulation of the same targets indicating a mismatch between GFP expression and viral infection. Using a modified HCMV virus destabilizing IE 1 and 2 proteins, we still observed significant downregulation of neurodevelopmental gene expression in infected neural progenitor cells. Together, these data indicate that IE viral proteins are not the main drivers of neurodevelopmental gene dysregulation in HCMV infected neural tissues suggesting therapeutically targeting IE gene expression is insufficient to restore neural differentiation and function.