Objective
Our data demonstrated that our “intelligent” drugs deliver therapeutic to β cells when injected in vivo. With this project, we will functionally test the efficacy of RNA therapeutics delivered to β cells with our smart nanoparticles to modulate the biology of insulin cells. Specifically, we will:
1) Deliver an mRNA that will express a protein called cyclin D1, which is crucial for cell replication. Typically, insulin-producing cells of adults express low levels of this protein, and this is one of the reasons why the number of β cells does not increase during adulthood. We will transiently upregulate this protein with our intelligent drug. This should induce cell proliferation resulting in increased β cell number and hopefully insulin independence. We will first optimize our nanoplatform to maximize the delivery of the therapeutics to β cells, evaluate whether the beta cell proliferates, and try to reverse diabetes in immunodeficient mice transplanted with few human islets by increasing the number of insulin-producing cells.
2) Instruct beta cells in vivo to a) resist autoimmunity and b) fight back and kill the cells responsible for autoimmune diabetes. To achieve these goals, we will deliver with our smart nanoparticle two therapeutics alone or in combination. The first therapeutic (called Fas-shRNA) will block one of the mechanisms by which immune cells kill insulin-producing cells. The second therapeutic (called Fas-ligand mRNA) will provide β cells with the weapon to destroy the immune cells responsible for Type 1 diabetes but leave the other cells of the immune system (i.e. those that fight the infections) unharmed. We will first test the effect of the two therapeutics on the expression of the relevant proteins, then we will test the therapeutic effect of these two therapeutic used alone or in combination; finally, we will examine the effects of treatment on the immune pancreatic microenvironment
In summary, our goal is to test the efficacy and the safety of two “intelligent” drugs that have the potential to increase the number of insulin producing cells and teach them how to resist autoimmunity. Considering that patients with a long history of type 1 diabetes still have few insulin producing cells, our pro-proliferative and immunomodulatory strategies have the potential to increase their number and block their killing from the immune system. This may result in a “cure” for diabetes by making the patient’s body able to produce sufficient insulin to maintain the normal level of glucose in the blood.
Background Rationale
Type 1 diabetes is an autoimmune disease in which insulin-producing cells (beta cells) are killed by the patient immune system. In the last decades, three important discoveries have been made:
1) Patients with a long history of type 1 diabetes still have functional insulin-producing cells in their body. Unfortunately, these cells are few and thus unable to produce sufficient insulin to keep glucose levels under control.
2) A gene (called cyclinD1) that controls cell replication is poorly expressed on beta cells. Induction of this gene using viruses results in β cell replication and an increased number of insulin producing cells.
3) Proteins called Fas and Fas-Ligand have been discovered to be crucial in controlling what the immune system recognizes as self or as a pathogen. For example, the eye that is considered an immune-privileged site (i.e., is not attacked by the immune system) expresses the protein Fas-ligand and kills those immune cells that could erroneously recognize it as a “pathogen”. Β cells do not express the shield called Fas-Ligand but rather, when inflamed, express the suicide protein Fas. Thus, to make the insulin producing cell resistant and able to fight back the immune system, we need to inhibit the suicide protein Fas and express the shield protein Fas-ligand specifically on β cells.
The problem in translating these discoveries in effective treatment for diabetes is that these genes play an important role in many other tissues and in many cancers. Thus, it is necessary to modulate these genes specifically in β cells and in a temporally defined fashion to have the desired effects on insulin producing cells and no side effects on other tissues and organs. The smart nanoparticles that we developed can do exactly this. A part of the drug called aptamer recognizes the beta cells in vivo and deliver the other part (the lipid nanoparticle carrying the therapeutic) to beta cells allowing the modulation of these genes only inside the beta cells.
Description of Project
This project aims to develop and validate new “intelligent” drugs able to induce the expansion of insulin producing beta cells and to protect them from autoimmunity without undesirable side effects on other tissues or organs. Important progress has been made in understanding the mechanisms that limit beta cell proliferation and protect these cells from autoimmunity. Unfortunately, these mechanisms are also present in other cells and tissues and thus preclude the use of conventional “non-intelligent” drugs. To overcome this problem, we built on the advancement of lipid nanoparticles, similar to the ones that have been used to vaccinate billions of people against COVID19 and made them “smart” by decorating their surface with RNA aptamers specific for β cells. These smart lipid nanoparticles can recognize and deliver their therapeutic cargo to the insulin producing cells in the body. Thus, instead of going to the lymph nodes and promoting an immune response as in the case of the vaccine, our “smart” aptamer decorated lipid nanoparticles can modulate the biology of β cells. We propose to use these nanoparticles to instruct insulin producing cells to proliferate, resist autoimmunity, and kill those immune cells that are responsible for type 1 diabetes. We expect that these drugs will increase the number of cells that produce insulin in our body and make them resistant to autoimmunity with limited of no side effects. We will test these possibilities in mice that spontaneously develop diabetes and in mice that are immunocompromised and transplanted with human islets. Generating the proof of principle on the use of these intelligent drugs will open the door for a new class of safe therapeutics that, by controlling β cell biology in vivo, may lead to tight control of blood glucose concentration and protection from autoimmunity without the need of exogenous insulin, immunosuppressive drugs nor off-target effects on other tissues.
Anticipated Outcome
Based on the research from different groups showing that the modulation of the genes that we are targeting induces beta cell proliferation and protection from autoimmunity and based on our data showing that our smart nanoparticles can modulate these genes specifically on insulin-producing cells in vivo, we anticipate that treatment will increase the number of insulin-producing cells in vivo and provide long term protection against autoimmunity. We anticipate that treatment will be safe because is temporally defined and targeted only to the beta cells. Thus, we anticipate that there will not be any side effects. We do not yet know the extension of the pro-proliferative and immune protective action of our intelligent drugs. Indeed, we do not know yet if targeting cyclin D1 is sufficient to increase beta cell number to a size sufficient to restore glycemic control. We do not know how many treatments are necessary to restore enough β cells, nor we know if additional anti-proliferative genes such as SMAD, and DYRK1A should be targeted to maximize beta cell proliferation. Additionally, we do not know yet if a few short courses of treatment are sufficient to instruct the insulin producing cells to upregulate the FasL shield gene, inhibit the suicide gene Fas, and defend themselves from the immune response for a long time. We cannot exclude that treatment to induce immune protection needs to be periodically repeated. Answering these questions is foremost important before the development of our smart drugs for human use. We will answer to some of these questions with this project that could open the door for a new therapeutic strategy that may cure and not only treat type 1 diabetes.
Relevance to T1D
The main problems toward a cure for type 1 diabetes are that (1) we do not know how to safely stop it and reverse it when it first manifests, and (2) we do not know how to increase the number of insulin producing cells in the body without inducing negative side effect in other tissues. We are proposing to investigate two independent targeted strategies aimed to (i) block the autoimmune attack only on the insulin-producing cells and (ii) increase the number of functional beta cells in patients with T1D. The first strategy has the potential to make diabetes asymptomatic in newly diagnosed patients. In other words, the immune system could be blocked in killing beta cells but still be ready to fight infections and pathogens. This should allow the preservation of most beta cells, drastically reducing the need for artificial insulin. The second strategy, possibly in combination with the first one, should increase the number of insulin producing cells allowing patients with established type 1 diabetes to gradually reduce the dose of insulin needed, hopefully to a level that they do not need it anymore.