Scientists Discover New T Cells Linked to Asthma and Other Immune Diseases

A team of researchers led by Yasuhiro Murakawa at the RIKEN Center for Integrative Medical Sciences (IMS), Kyoto University in Japan, and IFOM ETS in Italy has discovered rare helper T cell subtypes associated with immune conditions such as asthma, rheumatoid arthritis, and multiple sclerosis.

Their findings, published in the journal Science, were made possible by a new technique called ReapTEC. This method identified genetic enhancers in these uncommon T cell subtypes that are connected to specific immune diseases.

Helper T cells are a type of white blood cell crucial to the immune system. They recognize pathogens and regulate the immune response. Abnormal T cell function can lead to immune-mediated diseases, where the body mistakenly attacks itself or overreacts to harmless substances.

Within T cells, regions of DNA called enhancers do not code for proteins but enhance the expression of other genes. Variations in these enhancers can affect T cell function. The researchers developed ReapTEC to find connections between these enhancers and immune diseases.

After analyzing about a million human T cells, they identified several rare T cell types and almost 63,000 active bidirectional enhancers. By combining their data with genome-wide association studies (GWAS), they found that genetic variants for immune diseases were often located within these enhancers.

They identified 606 enhancers related to 18 immune-mediated diseases and some of the genes targeted by these enhancers. For example, an enhancer related to inflammatory bowel disease triggered the IL7R gene.

“In the short-term, we have developed a new genomics method that can be used by researchers around the world,” said Murakawa. “We hope this knowledge will lead to a better understanding of the genetic mechanisms underlying human immune-mediated diseases.”