Nobel Winner’s Team Succeeds in Mass-Producing Tregs, Aims to Tackle Autoimmune Diseases with New Treatment

The Yomiuri Shimbun

15:02 JST, October 25, 2025

A research team led by Nobel Prize winner Shimon Sakaguchi, a specially appointed professor at the University of Osaka, has developed technology to mass-produce regulatory T cells (Tregs), which can be used to treat immune diseases, the team has announced.

Sakaguchi will be awarded the Nobel Prize in Physiology or Medicine this year for the discovery of Tregs.

T cells, a type of immune cell, attack “enemies” like bacteria and viruses that enter the body, but a certain percentage of them become rogue T cells, which mistakenly injure the body and cause inflammation. Tregs have the ability to suppress the activity of rogue T cells. Research is being conducted around the world to use this function to treat such issues as autoimmune diseases, but it has been difficult to produce large numbers of stable Tregs.

The team extracted T cells causing inflammation from the blood of the mice with autoimmune diseases and cultured them for about two weeks using a special method. As a result, they were able to increase the number of T cells and successfully transform many of them into stable Tregs.

When these Tregs were administered to mice with colitis caused by immune abnormalities, the team was able to confirm the worsening of inflammation was suppressed. The effectiveness of the treatment was also confirmed in experiments on mice that had developed inflammation after bone marrow transplants. The 30-day survival rate for mice with this condition was less than 25%, but the figure increased to about 70% among mice that had received Tregs.

“This is the first step toward human application. We would like to use this technology to treat various autoimmune diseases,” Sakaguchi said.

His team plans to conduct clinical trials in the United States as early as next year to administer these Tregs to patients with autoimmune diseases and verify their safety and effectiveness. In Japan, clinical trials are also planned for patients with pemphigus vulgaris, an incurable disease that causes blistering of the skin all over the body due to an overactive immune system.

Kyoto University Prof. Hiroshi Kawamoto, an immunology expert, pointed out that the Tregs created with Sakaguchi’s technology are robust and easy to use in treatment, saying: “This could help build future treatments. It’s time to confirm their effectiveness in humans.”

The University of Osaka announced Wednesday that it had awarded Sakaguchi the title of distinguished honorary professor.