Human cytomegalovirus (CMV) infections can cause severe neurological complications, particularly in newborns and immunocompromised patients. Children affected with congenital CMV infection may develop long-term neurological damage and intellectual disabilities. Currently, postnatal antiviral therapies are limited and there are no prenatal options available. Research on antivirals against congenital CMV infections is, at least partly, restricted due to the lack of physiologically relevant models and the use of lab-adapted CMV strains with limited clinical relevance. In this study, we evaluated the toxicity and antiviral efficacy of three FDA-approved anti-CMV drugs against two CMV strains, a clinical and a lab-adapted strain, using two human induced pluripotent stem cell (iPSC-)derived central nervous system models, viz. neural progenitor cells (NPCs) and dorsal forebrain regionalized neural organoids (RNOs). We found iPSC line-dependent differences in antiviral toxicity. We observed that antiviral treatment restored NPCs and RNOs gene expression after CMV infection and reduced CMV copy numbers. Infection of NPCs and RNOs with the clinical CMV strain, but not with the lab-adapted strain, led to an impaired expression of cortical development markers. Our findings highlight the value of using physiologically relevant human models and clinical CMV strains to understand the neuropathogenesis of congenital CMV and to test therapeutic strategies.

Enterovirus A71 (EV-A71) and enterovirus D68 (EV-D68) are recognised as causative agents of severe neurological complications, including acute flaccid myelitis (AFM). However, the molecular mechanisms underlying the neurovirulence and effects on neuromuscular integrity remain poorly understood. Here, we employed human induced pluripotent stem cell-derived neuromuscular organoids (NMOs) to investigate the cellular tropism and pathogenic effects of EV-A71 and EV-D68 in a human-relevant context. Both viruses infected neuronal populations within NMOs, with EV-A71 exhibiting higher levels of viral replication than EV-D68. Transcriptomic analysis revealed downregulation of neuronal and muscular gene networks following infection. EV-A71 preferentially suppressed neuronal pathways, while both viruses exerted comparable effects on muscle-associated gene expression. These transcriptional changes highlighted alterations in pathways governing neuronal and muscle function and communication, prompting examination of synaptic vesicle machinery components. At the protein level, both viruses were associated with sporadic cleavage of the neuronal SNARE protein synaptosomal-associated protein 25 (SNAP25). In addition, infection with either virus increased cleaved caspase-3 levels, consistent with activation of apoptotic signalling. Together, these findings indicate virus-specific downstream effects and establish NMOs as a robust platform for dissecting enterovirus–host interactions relevant to AFM.