Engineered Tregs as a therapy to Gaucher syndrome

About This Grant

SUMMARY Lysosomal storage diseases (LSDs) are a group of inherited disorders that arise from mutations in genes responsible for encoding lysosomal enzymes or transporters, which are critical for breaking down and exporting complex macromolecules. When these enzymes or transporters fail to function properly, harmful substances accumulate within cells, leading to widespread cellular dysfunction and severe clinical abnormalities. In particular, the sphingolipidoses—a subset of LSDs—cause dysfunction in the breakdown of sphingolipids, essential components of cell membranes and regulators of critical signaling pathways. This disruption not only impairs cell function but also triggers a cascade of damaging effects that can significantly diminish quality of life. Gaucher disease (GD) is the most common sphingolipidosis. It occurs due to a deficiency in the enzyme β- glucocerebrosidase (GCase), leading to the buildup of substrate glucosylceramide (GCs) in macrophages, eventually resulting in various complications. The clinical phenotype is variable, but three clinical forms have been identified: type 1 is the most common and typically causes no neurological damage, whereas types 2 and 3 are characterized by neurological impairment. Once diagnosed, GD typically requires lifetime treatment. Regulatory T cells (Tregs) have a unique ability to cross the blood-brain barrier and to secrete anti-inflammatory factors, making them a promising foundation for new cell-based therapies. Our innovative approach allows Tregs to be engineered to deliver various therapeutic molecules directly to affected tissues and disease sites, offering a promising treatment platform for protein replacement therapies. In this application, we propose to engineer Tregs to secrete and replace GCase levels in the brain and peripheral tissues through the following aims: Aim 1: Generate GCase expression constructs with and without a MOG CAR for expression and lab-scale production testing. Aim 2: Evaluate expression and functional activity of engineered Tregs in vitro. Aim 3: Demonstrate in vivo expression of GCase and preferential localization of GCase -Tregs to the brain and peripheral tissues, local production of GCase, and reduction of GCs in affected tissues. Phase I Milestone: Select lead GCase-Treg product based on its ability to be detected in the brain and peripheral tissues within seven days of injection, and its ability to produce sufficient GCase >5-fold over vector control Tregs) to significantly reduce the levels of GCs in affected tissues. The selected candidate will be developed and advanced through IND-enabling studies in Phase II, including required studies for translation of this therapy into the clinic.