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Across the world, people living with type 1 diabetes continue to deal with the daily ups and downs of managing blood glucose levels. Although insulin therapy is lifesaving, it does not replicate the body’s finely tuned glucose regulation. Stem cell therapy for type 1 diabetes is advancing beta cell replacement and gene editing, offering hope for restoring insulin production.
For this reason, researchers have long sought to restore insulin-producing beta cells. The EU-funded ISLET project represents a promising step forward in type 1 diabetes treatment advances. A Horizon 2020 initiative, it brings together expertise in stem cell biology, clinical transplantation, computational science, and lived experience, with the goal of developing stem cell therapies for diabetes that could one day replace those destroyed by the immune system in type 1 diabetes. Importantly, the project also focuses on clinical-grade cell manufacturing to ensure these therapies can be safely and consistently used in humans.
To understand the promise of this research, it helps to look at the key cell types involved. Insulin producing beta cells are found in clusters in the pancreas called islets. These cells “sense” blood glucose levels and release insulin accordingly. In type 1 diabetes, the immune system mistakenly attacks and destroys these beta cells.
Stem cells, on the other hand, are unspecialised cells that can develop into many different cell types. Scientists can guide them in the laboratory to become beta cells through the cell differentiation process – the process by which a general-purpose cell becomes specialised.
There are two main types of stem cells used in research:
This distinction matters. While embryonic stem cells are highly versatile, iPSCs can be created from a person’s own cells, potentially reducing the risk of immune rejection.
To understand the promise of this research, it helps to look at the key cell types involved. This distinction matters. While embryonic stem cells are highly versatile, iPSCs can be created from a person’s own cells.
Within the ISLET project, scientists grow stem cells in controlled laboratory environments. They then introduce specific growth factors and chemical signals that guide these cells to become insulin-producing beta cells. However, producing beta cells in a research setting is only the first step. The real challenge lies in translating this into a therapy.
Mina Brimpari, Scientific Project Manager of the ISLET project, focuses on adapting these laboratory methods into processes that meet Good Manufacturing Practice (GMP) standards. GMP ensures that therapies are produced safely, consistently and at a quality suitable for clinical use. This transition – from laboratory protocols to clinical-grade manufacturing – underpins future human trials.
Alongside advances in stem cell research, CRISPR gene editing technology is opening new possibilities for treating type 1 diabetes.
CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats) is a powerful tool that allows scientists to make precise changes to DNA. In the context of islet cell therapies, CRISPR can be used to:
For example, researchers are exploring ways to “edit” cells so they do not trigger an autoimmune response, which is the underlying cause of type 1 diabetes. This approach could reduce or even remove the need for long-term immunosuppressive therapy.
Although still under investigation, gene editing may help make cell-based therapies more durable and accessible. However, even with these advances, significant practical challenges remain. Despite rapid progress, scientists must ensure that stem cells reliably become fully functional beta cells every time. Even small inconsistencies can affect how the cells respond to glucose. While the differentiation process takes about a month, developing reproducible methods can take years. Another major challenge is scaling cell-based therapies. Producing enough cells for clinical use requires careful optimisation to maintain quality at larger volumes.
These challenges illustrate the complexity of translating scientific breakthroughs into real-world therapies.
Researchers are exploring ways to “edit” cells so they do not trigger an autoimmune response. This approach could reduce or even remove the need for long-term immunosuppressive therapy.
These scientific advances are already being translated into several experimental therapeutic approaches. The ISLET project is part of a broader global effort to develop cell-based therapies for type 1 diabetes. Several approaches are already being explored in clinical and preclinical studies.
Encapsulated islet cell therapies
One approach involves placing engineered islet cells inside protective devices that shield them from the immune system. These encapsulated islet cell therapies aim to avoid immune attack without the need for systemic immunosuppression.
Stem cell-derived islet transplants
Another strategy focuses on transplanting fully developed beta cells. VX-880 stem cell therapy has shown early clinical results, with some participants achieving insulin independence.
Both approaches aim to re-establish physiological insulin production, reducing or potentially eliminating the need for insulin injections.
Gene-edited cell therapies
Some research combines stem cells with gene editing technologies such as CRISPR. Studies published in journals such as Nature Biotechnology and Cell Stem Cell have demonstrated that gene-edited beta cells can evade immune detection in laboratory and animal models. Although these approaches are still being refined, they represent an important step towards long-term solutions.
Scientific innovation alone is not enough. The ISLET project also highlights the importance of including people living with type 1 diabetes in research. Mina Brimpari notes that having a colleague with lived experience brings valuable insight into the daily realities of managing glucose levels. This perspective helps guide research priorities and strengthens team motivation. Collaboration with organisations such as the International Diabetes Federation Europe Region further ensures that research remains aligned with the community’s needs.
As a result, the project reflects a more inclusive model of innovation. One that values both scientific expertise and lived experience.
Some research combines stem cells with gene editing technologies such as CRISPR. Studies published in journals have demonstrated that gene-edited beta cells can evade immune detection.
One of the most widely reported stories comes from Brian Shelton, a participant in a clinical trial of the stem cell–derived islet therapy VX-880.
Shelton was diagnosed with type 1 diabetes at age 12. Before participating in the clinical trial, he had lived with the condition for decades and experienced severe hypoglycaemia unawareness – a condition where warning signs of low blood glucose are reduced or absent.
Following treatment, he achieved insulin independence after cell therapy and near-normal glucose control. He described the impact as “a whole new life… I feel like I’ve been given a second chance.”
As of follow-up reports through 2023, Shelton remained stable with functional insulin production. His experience highlights the potential of stem cell-derived islet therapies to recover natural insulin production, although such outcomes are not yet guaranteed for all participants.
As cell and gene therapies evolve, regulatory systems are adapting. The European Medicines Agency and the US Food and Drug Administration are developing frameworks to assess advanced therapy medicinal products, with progress in fields such as cancer immunotherapy helping pave the way. These essential regulatory pathways ensure that new treatments meet strict standards for safety and effectiveness while enabling innovation to move forward.
Following treatment, he achieved insulin independence after cell therapy and near-normal glucose control.
Looking ahead, researchers hope to see early-phase clinical trials produce meaningful results within the next decade. While challenges remain, progress in stem cell biology, gene editing and manufacturing is accelerating. Each advance brings the field closer to therapies that could restore beta cell function. For people living with type 1 diabetes, this research offers cautious optimism. It signals a shift from managing the condition towards potentially addressing its underlying cause.
For people living with type 1 diabetes, this signals a shift from managing the condition toward addressing its underlying cause.
The ISLET project highlights how science, technology and lived experience can come together to shape future diabetes treatments. While these therapies are not yet widely available, continued progress suggests that restoring insulin-producing cells may one day become part of routine care.
For more information about the ISLET project, visit: https://isletproject.eu/
