Today at Neuroscience 2015 in Chicago, researchers reported on a new study supporting the idea that certain antibodies in a woman’s bloodstream can interfere with prenatal brain development in ways that predispose a child to autism. The results raise interest in identifying and blocking such antibodies in pregnant women.
Antibodies are proteins that bind to foreign invaders such as viruses and bacteria to mark them for destruction by the immune system. But sometimes they bind to healthy cells to cause an autoimmune, or “self-destructive,” reaction.
Previous research has associated some cases of autism spectrum disorder (ASD) with maternal antibodies that interfere with prenatal brain development. (See diagram above, courtesy Pediatric Bioscience.)
In the new study, researchers isolated several such antibodies from mothers of children affected by autism. Then they injected them into pregnant mice.
"We found that male offspring but not female offspring exposed in utero to one particular antibody showed structural abnormalities in the developing brain," says lead author Lior Brimberg, of the Feinstein Institute for Medical Research, in Manhasset, New York. "As adults, those male mice displayed behavioral abnormalities reminiscent of ASD." These included repetitive behaviors, learning inflexibility and reduced sociability.
The clear male versus female effect in mice is in line with autism’s little-understood sex disparity in people: Autism affects nearly five times as many boys and men as girls and women.
The researchers further studied the antibody and found that it attacks a cell-membrane protein that’s key to healthy brain-cell function. This dovetails with still other human and animal studies that have linked autism to mutations in the gene that produces this same brain-cell protein.
"This approach allows identification of potential ASD-inducing antibodies and could lead to the development of reagents [medicines] that block these antibodies and prevent the occurrence of this subtype of ASD," Dr. Brimberg says. It also advances understanding of at least one of the pathways by which autism develops.
The study was funded by the Simons Foundation, the U.S. Department of Defense and the Brain & Behavior Research Foundation.
See all our Neuroscience 2015 coverage here.
For more on maternal antibodies and autism, also see