Effect of antivirals on clinical and lab-adapted human cytomegalovirus strains using induced pluripotent stem cell-derived human neural models.

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.