Treating type 1 diabetes with stem cell replacement therapy 18 February 2022 Are stem cells the future of treatment for people living with type 1 diabetes? A Harvard researcher certainly hopes so. Stem cells are the raw matter from which specialised cells are formed; replacement therapy uses stem cells to generate functional cells that can replace damaged cells. Since the immune system rejects these ‘foreign cells’, immunosuppressants are treatments used to lower the activity of the immune system and prevent cell-rejection. Through their early-stage clinical trials, Vertex Pharmaceuticals found this combination therapy helped reproduce insulin-producing cells in their first human subject. Behind this therapeutic study is Harvard Stem Cell Institute Co-Director and Xander University Professor, Douglas Melton. Melton was prompted to shift his research focus to pancreatic islets (where insulin is produced) after his son was diagnosed with type 1 diabetes at six months old. Ten years later, Melton’s older daughter was also diagnosed with type 1 diabetes. “The first major change in the treatment of type 1 diabetes was probably the discovery of insulin in 1920. Now it’s 100 years later, and if this [stem cell therapy] works, it’s going to change the medical treatment for people with diabetes. Instead of injecting insulin, [people with type 1 diabetes] will get cells that will be their own insulin factories. It’s a new kind of medicine,” Melton said. The idea to use stem cells began almost two decades ago. “When we first started, we had to try to figure out how the islets in a person’s pancreas replenished. Blood, for example, is replenished routinely by a blood stem cell. So, if you give blood at a blood drive, your body makes more blood. But we showed in mice that this isn’t true for pancreatic islets. Once they’re removed or killed, the adult body has no capacity to make new ones.’’ This realisation led to investigating embryonic stem cells and how they could be made into insulin-producing cells, known as ‘beta cells’. Melton anticipated this controversial study to take five years, but it took three times as long. Next, the team hope to find a way to genetically engineer stem cells so they aren’t rejected as foreign bodies. “If we can figure that out, it will help inform our thinking about what genes to change in our stem cell-derived islets so they could go into any person. This would be relevant not just to diabetes, but to any cells you wanted to transplant for liver or even heart transplants. It could mean no longer having to worry about immunosuppression.” Melton’s full interview with The Harvard Gazette can be accessed here. Key Points Vertex Pharmaceuticals announces first breakthrough in type 1 diabetes treatment since the discovery of insulin more than 100 years ago. Led by Professor Douglas Melton, this study is trialling stem cell replacement therapy in combination with immunosuppressive therapy. This combined treatment may offer an alternative to injecting insulin by introducing cells that can reproduce insulin. Next, the researchers are looking at genetically modifying stem cells so they aren’t rejected by the immune system. These findings could eliminate the need for immunosuppressives and could be applied to all procedures involving cell transplants.