The activation of a particular immune response in pregnant mice causes changes in the brain structure of the mouse offspring and causes behavioral changes similar to those exhibited in humans with autism spectrum disorder (ASD), according to a new study spearheaded by University of Massachusetts researchers. Furthermore, this immune response mirrors what occurs with certain viral infections during human pregnancy, which supports past human studies that have shown correlations between maternal viral infections during pregnancy and an increased risk of autism in the baby.
The study found that an increase in the production of the interleukin-17a cytokine, which stems from a specific group of helper T cells (Th17), is the mechanism that led to the inflammatory immune response in the mother that caused ASD symptoms in the offspring including repetitive behavior and abnormal communication. However, blocking the action of Th17 cells restored normal structure and function to the brains of the mouse offspring.
"Blocking the function of Th17 cells and IL-17a in the maternal womb by using antibodies and other genetic techniques completely restored normal behavior and brain structure in the affected offspring," Jun Huh, co-author of the study, said in a press release.
"The study also showed that a therapeutic treatment with antibodies blocking IL-17a corrected certain behavioral abnormalities, suggesting Th17 cells, as well as the specific proteins they produce, may be candidate therapeutic targets in efforts to prevent autism in the children of susceptible mothers," he added.
Further research will need to be conducted in order to determine if these results can be replicated in humans and if Th17 cells serve the same function in human mothers.
"To our knowledge, this is the first study to identify a specific population of immune cells that may have a direct role in causing behaviors linked to autism," said Dan Littman, another co-author of the study, adding that the current results stem only from viral infections and are in no way connected to vaccinations.
The findings are set to be published in the journal Science.
