Neurodevelopmental disorders have been increasingly associated with maternal immune activation (MIA) during pregnancy, particularly in response to viral infections. However, the impact of human respiratory syncytial virus (hRSV) infection during gestation on offspring neurodevelopment remains poorly understood. This study aimed to characterize hRSV-induced MIA and evaluate its effects on fetal brain development and offspring behavior using a murine model. Pregnant mice were infected with hRSV at gestational day 14, and tissues were analyzed at day 19. Infection induced pulmonary inflammation, evidenced by increased neutrophil infiltration, and viral replication was detected in maternal lungs and placental tissue, but not in fetal organs. Placental infection was associated with increased decidual immune cells and a shift toward a pro-inflammatory cytokine profile, including elevated IL-6, TNF-α, IFN-γ, and IL-1β, along with decreased IL-10 and IFN-λ. Increased levels of IL-6, TNF-α, and IL-4 were also detected in maternal serum and fetal brains, suggesting vertical transfer of cytokines. Additionally, reduced brain-derived neurotrophic factor levels and altered expression of tight junction-related genes were observed in fetal brains. Behavioral analyses revealed that offspring of infected dams exhibited impaired short-term memory and altered anxiety-like and repetitive behaviors, which persisted or intensified with age. These findings demonstrate that maternal hRSV infection induces MIA, disrupts the fetal neuroimmune environment, and leads to long-term behavioral alterations in offspring, highlighting hRSV as a potential risk factor for neurodevelopmental disorders.
Muñoz et al. (Wed,) studied this question.