Maternal viral infection causes global alterations in porcine fetal microglia

Significance Mental health disorders account for approximately 14% of the worldwide burden of disease and affect people of all age groups and socioeconomic statuses. Prenatal exposure to maternal infection increases the risk of developing certain mental health disorders, most notably schizophrenia and autism. Maternally derived cytokines, up-regulated during infection, may lead to an aberrant proinflammatory and phagocytic shift in fetal microglia, the resident immune cells of the brain. As these cells perform essential processes that aid in the highly orchestrated progression of brain development, modifications in their prenatal phenotype could be detrimental. Using swine, a highly translatable animal model, we show that fetal microglia activity is globally altered by maternal infection, a finding that could have far-reaching implications for neuropsychiatric disorders.