PASADENA, Calif.Scientists at the California Institute of Technology (Caltech) pioneered the study of the link between irregularities in the immune system and neurodevelopmental disorders such as autism a decade ago. Since then, studies of postmortem brains and of individuals with autism, as well as epidemiological studies, have supported the correlation between alterations in the immune system and autism spectrum disorder.
What has remained unanswered, however, is whether the immune changes play a causative role in the development of the disease or are merely a side effect. Now a new Caltech study suggests that specific changes in an overactive immune system can indeed contribute to autism-like behaviors in mice, and that in some cases, this activation can be related to what a developing fetus experiences in the womb.
The results appear in a paper this week in the Proceedings of the National Academy of Sciences (PNAS).
"We have long suspected that the immune system plays a role in the development of autism spectrum disorder," says Paul Patterson, the Anne P. and Benjamin F. Biaggini Professor of Biological Sciences at Caltech, who led the work. "In our studies of a mouse model based on an environmental risk factor for autism, we find that the immune system of the mother is a key factor in the eventual abnormal behaviors in the offspring."
The first step in the work was establishing a mouse model that tied the autism-related behaviors together with immune changes. Several large epidemiological studiesincluding one that involved tracking the medical history of every person born in Denmark between 1980 and 2005have found a correlation between viral infection during the first trimester of a mother's pregnancy and a higher risk for autism spectrum disorder in her child. To model this in mice, the researchers injected pregnant mothers with a viral mimic that triggered the same type of immune response a viral infection
|Contact: Deborah Williams-Hedges|
California Institute of Technology