Maternal immune activation induces IL-6-dependent alterations in cytokine and gene expression profiles in the offspring

Infection in pregnant women is associated with increased risk for autism and schizophrenia in the offspring. In a mouse model of this risk factor, activation of the maternal immune system sets in motion a cascade of molecular events that ultimately result in autism- and schizophrenia-related behaviors in offspring. The finding that interleukin-6 (IL-6) is a crucial mediator of these effects led us to examine the mechanism by which this cytokine influences fetal development in vivo. We find that maternal immune activation (MIA) with a viral mimic, synthetic double-stranded RNA (poly(I:C)), increases IL-6 mRNA as well as maternally derived IL-6 protein in the placenta.