By Michael Irving May 08, 2022 – Type 1 diabetes can be a rare but serious side effect of a cancer treatment that use what are known as immune checkpoint inhibitors. In a new study in mice, researchers in Japan have shown that administering stem cell therapy could help prevent this.
Many types of cancer use a devious trick to defend themselves from the immune system – they trigger a “checkpoint” system that deactivates immune cells that come to attack the tumor. A major form of cancer immunotherapy targets this process, releasing the brakes and allowing the immune system to attack at full power again.
This therapy, which uses immune checkpoint inhibitors, has shown promise in fighting a range of cancers. However, there can be some adverse immunological side effects – colitis is common but treatable, while a very small group of patients can go on to develop type 1 diabetes. This occurs due to a build-up of immune cells in the pancreas, which disrupts insulin production.
In the new study, researchers at Osaka University investigated whether mesenchymal stem cells (MSCs) could help prevent this serious side effect. These specialized stem cells play roles in tissue regeneration and modulation of immune functions.
The team started by inducing diabetes in mice by giving them a purified PD-L1 monoclonal antibody, a commonly used immune checkpoint inhibitor. Some mice were then also treated with MSCs derived from human fat tissue, and the researchers examined the immune cells in their pancreatic secretions.
Of the mice that received just the antibody, 64 percent (or 16 out of 25 animals) developed type 1 diabetes, compared to just 19 percent of mice (or four out of 21) that also received MSCs. There was also significantly reduced build up of T cells and macrophages in the pancreatic islets of MSC-treated mice.
“We found that MSCs effectively prevented this influx of immune cells, thereby avoiding the detrimental effects on pancreatic cells,” said corresponding author Shunbun Kita.
Of course, the treatment is still a long way off ever being used in humans – this was just an early animal test, and a fairly small one at that. Much more work will need to be conducted to investigate the potential for MSCs to help prevent this rare but serious side effect.
The research was published in the journal Diabetologia.
