A quarterly publication of the Autism Research Institute
Spring 2026 | Number 2, Volume 40
A study by researchers in the United States offers new insights into the immune system’s role in autism spectrum disorders (ASD).
The study, by Rachel Moreno and colleagues, focused on regulatory T cells (Tregs), which calm inflammation. Treg levels often are low in individuals with ASD, while levels of inflammatory immune cells often are elevated.
In their investigation, the researchers compared the numbers and types of Tregs in 36 children with ASD and 18 neurotypical controls, and examined gene expression in Tregs to see if there were differences between the two groups. Within the ASD group, they looked for differences between children with and without gastrointestinal (GI) problems.
The researchers detected lower numbers of Tregs in children with ASD, but decreases in specific Treg populations varied depending on whether or not the children had GI problems. Those with both ASD and GI problems had fewer Tregs capable of producing anti-inflammatory proteins, while those with ASD but no GI problems had fewer Tregs capable of dividing after activation.
Compared to Tregs from controls, Tregs from children with ASD had 213 upregulated or downregulated genes. The genes that exhibited increased expression generally play roles in DNA reorganization and repair, energy management, and fat metabolism, while the genes that exhibited reduced expression are primarily involved in energy production.
The researchers also found that in both the ASD group and the control group, children with fewer Tregs tended to have more challenging behaviors. Moreno comments, “These differences in Treg populations may help explain the higher levels of inflammation seen in autism and could be linked to both gastrointestinal problems and certain behavioral traits. This data further supports the idea that the immune system plays an important role in autism in at least some individuals.”
“Altered phenotype and gene expression of regulatory T cells (Tregs) in children with autism, and the relationship with comorbid gastrointestinal symptoms,” Rachel J. Moreno, Destanie Rose, and Paul Ashwood, Journal of Neuroinflammation, February 2026 (free online). Address: Paul Ashwood, MIND Institute, 2825 50th Street, Sacramento, CA 95817, [email protected].
—and—
“Studies tie altered regulatory T cells to autism-related behavior, point to potential therapies,” news release, Lisa Howard, UC Davis, April 2, 2026.
