Objective
The overall goal of this project is to develop a safer and more specific immune therapy to help treat those who received islet or stem cell therapy and potentially prevent type 1 diabetes (T1D) by protecting insulin‑producing cells from immune attack. To achieve this, the project has the following closely related objectives:
1. Develop safer immune‑calming drugs for T1D
The first objective is to improve a new group of small‑molecule drugs that can calm harmful immune responses without shutting down the immune system in general. These drugs block a specific immune signal (called CD40-CD40L) that is known to drive immune attacks on insulin‑producing cells. Our existing drug candidates will be fine‑tuned so that they • work more effectively at lower doses, • stay in the body long enough to be useful, • can be taken by mouth rather than by injection, and • have a safety profile suitable for long‑term use. This step is essential to move from promising laboratory compounds toward medicines that could realistically be used in patients.
2. Test whether these drugs protect insulin‑producing cells in living systems
The second objective is to confirm that the best drug candidates actually work in living organisms, not just in test tubes. We will test whether these drugs • reduce harmful immune activation, • protect transplanted insulin‑producing cells, • prevent immune cells from invading and damaging these cells, and • maintain normal blood sugar levels in transplant recipients over time. These studies will include both short‑term and long‑term testing to see whether the benefits last after treatment ends.
3. Determine whether immune tolerance can be achieved
A key long‑term objective is to find out whether these drugs can help the immune system learn to tolerate insulin‑producing cells instead of constantly attacking them. Rather than requiring lifelong immune suppression, the goal is to • reset the immune response, • allow transplanted or newly formed insulin‑producing cells to survive, and • reduce or eliminate the need for continuous treatment. Achieving this kind of immune tolerance would represent a major advance for type 1 diabetes treatment and prevention.
Together, these objectives aim to create a new, patient‑friendly immune therapy that • supports islet cell transplantation, • reduces the risk of autoimmune recurrence, and • may eventually help prevent T1D in high‑risk individuals. By focusing on immune-activation specific and orally available small‑molecule drugs, this project seeks to overcome the safety and practicality limitations of current immune‑suppressing treatments.
Background Rationale
Type 1 diabetes (T1D) develops when the immune system mistakenly attacks the body’s own insulin‑producing cells. Once these cells are destroyed, the body can no longer regulate blood sugar on its own. Current treatments replace insulin but do not address the underlying immune problem, which continues for life.
One promising strategy to restore natural insulin production is islet cell transplantation, where new insulin‑producing cells are introduced into the body. Unfortunately, this approach faces major immune challenges. The immune system attacks the transplanted cells since they are foreign, and the original autoimmune process that caused diabetes can return and destroy the new cells, even when standard anti‑rejection drugs are used.
Most existing immune‑suppressing drugs work by broadly weakening the immune system. While this can help protect transplanted cells, it also increases the risk of serious side effects such as infections and cancer. These risks make long‑term use especially problematic, and they are unacceptable for diabetes prevention in people who are otherwise healthy. Because of these limitations, there is a strong need for more precise immune therapies — treatments that calm harmful immune responses without shutting down immune protection overall.
This proposal focuses on a specific immune communication pathway called CD40-CD40L, which plays a key role in activating aggressive immune responses against transplanted islet cells. This pathway is known to be involved both in transplant rejection and in the autoimmune processes that lead to T1D. Blocking this pathway has been shown to protect insulin‑producing cells and, in some cases, help the immune system develop long‑lasting tolerance. There are ongoing promising attempts to block CD40-CD40L using antibody‑based drugs. Although effective, these treatments can cause serious side effects and can be administered only via injection.
The rationale for this project is to take a different approach by developing small‑molecule drugs that block CD40-CD40L. Small molecules are similar to many commonly used medications and offer several advantages, such as • they are less likely to trigger harmful immune reactions, • they can often be taken by mouth rather than by injection, • they are easier to control and discontinue if needed, • they are better suited for long‑term or preventive use. We have already shown that several of these small‑molecule compounds can protect transplanted insulin‑producing cells and delay or prevent diabetes in animal models. In some cases, the immune system remained tolerant even after treatment ended, suggesting the possibility of lasting immune reeducation rather than continuous suppression.
Together, this background supports the central idea of the proposal: that orally available small‑molecule therapies that target a specific immune-activating pathway could overcome key immune barriers to provide long-term function in islet transplant recipients and possibly even it T1D treatment and prevention, while avoiding the risks associated with current immune‑suppressing drugs.
Description of Project
Type 1 diabetes (T1D) is a lifelong disease in which the immune system mistakenly attacks and destroys insulin‑producing cells in the pancreas. One promising treatment approach is islet cell transplantation, where healthy insulin‑producing cells are transplanted into patients. However, two major challenges remain: the immune system often rejects the transplanted cells, and the same autoimmune process that caused diabetes in the first place can return and destroy them. To avoid this, immune suppression medication has to be administered long-term, and all existing treatments are associated with serious side effects.
This project aims to address these problems by developing a new type of immune‑modulating medicine that is more targeted, safer, and easier for patients to take than current treatments. The research focuses on a key immune “communication signal” known as CD40–CD40L. This signal helps activate immune cells and plays an important role in transplant rejection and in the development of autoimmune diseases like type 1 diabetes. Blocking this signal can calm harmful immune responses while leaving much of the immune system intact. Antibodies that block CD40–CD40L are being explored with promising results, but they have disadvantages. As a possible alternative, this project develops small‑molecule drugs — traditional chemical medicines similar to pills many people already take. Small molecules have several advantages: they are less likely to trigger unwanted immune reactions, can often be taken orally, and are easier to use long‑term, which is especially important for chronic diseases and prevention.
We have already discovered several promising small‑molecule compounds that block the CD40–CD40L signal. In laboratory tests and multiple animal models, these compounds: • reduced immune attacks on transplanted insulin‑producing cells, • prolonged survival and function of transplanted islets, • suppressed harmful immune cell infiltration, and • delayed or even prevented the onset of type 1 diabetes in a widely used mouse model. In many cases, the transplanted cells continued working long after treatment was stopped suggesting that the immune system may have learned to tolerate them rather than simply being suppressed. This phenomenon, called immune tolerance, is a major goal in transplantation medicine.
Accordingly, the project has two main goals:
• Improve the drug candidates by fine‑tuning their chemical structure so they work better in the body, last longer, and can be taken by mouth.
• Confirm long‑term effectiveness and safety by testing the best compounds in established animal models of immune activation and islet transplantation.
If successful, this research could lead to a new class of oral medicines that protect transplanted insulin‑producing cells and possibly prevent T1D in people at high risk, without the serious side effects associated with current immune‑suppressing therapies. More broadly, this approach could have implications beyond diabetes, offering a safer way to control harmful immune responses in other autoimmune diseases and transplant settings.
Anticipated Outcome
This project is expected to produce several important outcomes that could significantly advance the treatment and prevention of type 1 diabetes (T1D).
1. Identification of safer, patient‑friendly immune therapies
By the end of the project, we expect to identify one or more promising small‑molecule drugs that safely and effectively calm harmful immune responses linked to islet destruction and T1D onset. These drugs are designed to be more specific than current immune‑suppressing therapies, reducing the risk of serious side effects of long-term therapies such as infections or cancer. Because they are small molecules, they are also expected to be suitable for oral use, making them easier and more practical for patients than biologics such as antibodies.
2. Improved protection of insulin‑producing cells
Another anticipated outcome is strong evidence that these drugs can protect insulin‑producing cells from immune attack. In transplantation models, this means transplanted islet cells should survive longer, function better, and continue producing insulin. This could improve the success and durability of islet cell replacement therapies for people with T1D.
3. Reduced recurrence of autoimmune damage
A major challenge in T1D treatment is that the immune system can continue attacking insulin‑producing cells even after transplantation. The project is expected to show that targeting the CD40-CD40L immune pathway can reduce or prevent this autoimmune recurrence. This would address a key reason why many current transplant approaches fail over time.
4. Evidence for immune tolerance rather than lifelong suppression
One of the most important anticipated outcomes is evidence that short‑term treatment may lead to long‑lasting immune tolerance and avoid the need for life-long immune suppression. Instead of requiring continuous immune suppression, the immune system may learn to accept insulin‑producing cells as normal. If confirmed, this would represent a major shift in how T1D / islet transplantation could be managed moving from lifelong treatment toward immune re‑education.
5. Foundation for prevention strategies
Beyond transplantation, the results are expected to support the idea that immune therapy targeting a specific immune-activation pathway could be used earlier in the disease process. This raises the possibility of preventing or delaying T1D in people who are known to be at high risk, before extensive damage to insulin‑producing cells occurs.
6. Clear path toward clinical development
Finally, the project is expected to generate the scientific and preclinical evidence needed to move these drug candidates closer to human testing. This includes demonstrating effectiveness, safety, and suitability for real‑world use.
Overall impact
Taken together, the anticipated outcomes point toward a future in which T1D treatment is safer, more durable, and more focused on correcting the underlying immune problem instead of only managing blood sugar levels.
Relevance to T1D
Type 1 diabetes (T1D) is caused by a malfunction of the immune system. Instead of protecting the body, immune cells attack and destroy the pancreas’s insulin‑producing cells. Once these cells are lost, people with T1D must rely on lifelong insulin therapy. Even with modern technology, this does not fully restore normal blood sugar control or prevent long‑term complications.
One promising way to treat T1D is islet cell replacement, in which new insulin‑producing cells are transplanted into the patient. However, this approach faces two major immune‑related obstacles. First, the immune system recognizes the transplanted cells as foreign and attacks them. Second, the same autoimmune process that caused T1D in the first place can return and destroy the new cells even when standard anti‑rejection drugs are used.
This proposal targets both problems. It focuses on a specific immune signal, called CD40-CD40L, that acts like an “on switch” for aggressive anti-islet immune responses. This pathway is known to be important in the development of T1D and in immune attacks on transplanted islet cells. By blocking this signal, it may be possible to calm the harmful immune response without shutting down the immune system entirely.
There are several ongoing attempts to block CD40-CD40L using antibody‑based drugs. While effective, these treatments can cause serious side effects and can be administered only via injection. This project takes a different approach by developing small‑molecule drugs — traditional chemical medicines that are typically safer, are less likely to cause immune reactions, and can be taken as pills.
We have already shown that our newly developed small‑molecule compounds can • protect transplanted insulin‑producing cells in animal models, • reduce immune cell invasion into the transplanted tissue, and • delay or prevent the onset of diabetes in a widely used model of autoimmune T1D. Importantly, many treated animals remained diabetes‑free even after treatment stopped, suggesting the immune system may have learned to tolerate the insulin‑producing cells rather than continuously attacking them. Achieving this kind of immune tolerance is a long‑standing goal in T1D research.
If successful, this work could lead to • safer immune therapies to support islet transplantation, • new strategies to prevent T1D in people at high risk, and • reduced reliance on broad immune‑suppressing drugs with serious side effects. Overall, this proposal addresses a core cause of T1D, the immune attack itself and offers a realistic path toward longer‑lasting, safer, and more effective treatments.