https://www.autismspeaks.org/science/science-news/study-may-shed-light-autism-and-brain-inflammation
“We’re starting to understand how the peripheral immune system can affect brain function and behavior,” says neuroscientist Anthony Filiano, who is leading the study at the University of Virginia, Charlottesville....
Dr. Filiano designed a study that built on earlier research in both mice and people. Previous mouse studies have shown that maternal inflammation during pregnancy can result in offspring with brain inflammation and autism-like behaviors. Along these lines, several studies looking at medical records have shown that mothers who have infections and/or signs of inflammation during pregnancy are more likely to have children who develop autism spectrum disorder (ASD). In addition, studies have found signs of inflammation in the brains of those affected by ASD.
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In his new study, Dr. Filiano is using a line of mice genetically engineered to lack T cells. His team has noted three important abnormalities in these mice:
*The T-cell deficient mice spent less time socializing with other mice.
*Their microglia (brain immune cells) were in an “activated,” or inflammatory, state.
* Brain regions associated with social behavior in the mice showed signs of abnormal hyperconnectivity. Indirectly, this suggests that the microglia failed to perform their task of pruning excess connections between brain cells.
Restoring normal behavior
Working with the T-cell deficient mice, the researchers next showed that they could restore normal social behavior with a transplant of T cells from ordinary mice.
These early findings suggest that T cells and microglia work together to support healthy brain development, Dr. Filiano says. “We think the T cells are doing this by producing signaling molecules such as interleukin 4, which can pass into the brain.”