Anxiety is a common symptom of autism spectrum disorder (ASD), a spectrum of neurological disorders that impair social skills and verbal communication. Anxiety may stem from a faulty immune system, according to a new study in mice conducted by researchers at China’s Zhejiang University. While previous research has explored the idea that immune cells influence the brain and behavior, the new study is notable for connecting the immune system’s role in anxiety to overproduction of a molecule called xanthine, as well as immune cells called CD4+ T cells.
The study was led by Jin Jin, a professor of life sciences at Zhejiang. Over the course of eight days, Jin and his colleagues exposed mice to chronic stress by repeatedly shocking their feet. While mice under stress lost the motivation to explore unfamiliar territory, the mice lacking T-cells did not become anxious after experiencing chronic stress, suggesting that those cells play a crucial role in anxiety. The researchers also found that immune cells seem to retain a “memory” of chronic stress. When those cells were transplanted back into mice that lacked T-cells, they began showing anxiety. The results of the study were published in October in the journal Cell.
In addition to studying T-cells, the researchers found that overproduction of the chemical xanthine led to stress, as people mice and people with anxiety showed elevated blood levels of the molecule. According to a report on the study this month by Spectrum News, Jin says has team has found that only a subset of immune cells in anxious mice overproduces xanthine. The researchers are currently working on strategies to block those cells using antibodies as a possible treatment for anxiety.