eVLP-Mediated Cas9 Delivery for Preventing IBMIR in Islet Transplantation

Area of Science:

• Immunology
• Endocrinology
• Gene Therapy

Background:

• Islet transplantation offers a potential cure for type 1 diabetes by replacing lost insulin-producing beta cells.
• Instant blood-mediated inflammatory reaction (IBMIR) is a major barrier, causing rapid destruction of transplanted islets due to blood contact.
• Tissue factor (TF) and plasminogen activator inhibitor-1 (PAI-1) are key mediators of IBMIR, initiating coagulation and inhibiting fibrinolysis, respectively.

Purpose of the Study:

• To genetically modify rat islets by knocking out TF and PAI-1 genes to mitigate IBMIR.
• To assess the impact of TF and PAI-1 gene knockout on islet viability, functionality, and IBMIR inhibition.
• To evaluate the therapeutic efficacy of modified islets in a mouse model of type 1 diabetes.

Main Methods:

• Utilized an engineered virus-like particle (eVLP)-mediated CRISPR-Cas9 system for targeted gene knockout of TF and PAI-1 in rat islets.
• Confirmed effective gene downregulation without off-target mutations and assessed islet viability and function.
• Transplanted modified islets into streptozotocin-induced diabetic mice and monitored glycemic control and IBMIR markers.

Main Results:

• Successful downregulation of TF and PAI-1 expression in islets without compromising their viability or function.
• Transplanted islets lacking TF and PAI-1 significantly improved glycemic control in diabetic mice.
• Reduced levels of thrombin-antithrombin complex and complement component 3a in recipient mice, confirming IBMIR inhibition.

Conclusions:

• Gene editing of TF and PAI-1 in islets is a viable strategy to prevent IBMIR.
• This approach enhances the therapeutic potential of islet transplantation for type 1 diabetes.
• Targeting TF and PAI-1 offers a promising avenue for improving graft survival and long-term transplant success.