Project Details
Description
ABSTRACT: Enzymopathies are a disturbance of enzyme function, including genetic deficiency or a defect in
specific enzymes. Current treatment methods are insufficient and rely on hematopoietic stem cell transplant
(HSCT) or lifelong enzyme replacement therapy (ERT). ERT can cost hundreds of thousands of dollars per year
and HSCTs are highly precarious, with a subset resulting in death from graft versus host disease or infection
brought on by prolonged immunosuppression. An alternative approach would be to modify a patients more
malleable and accessible cells, such as lymphocytes, to express large quantities of active enzyme and re-infuse
these cells into the patient to produce the lacking enzyme. This excess enzyme can be excreted from engineered
cells in vivo and taken up by endogenous cells, a process termed cross correction. Recently, there has been a
large amount of work on genome engineering of human T cells, typically for cancer immunotherapies. However,
the subsets of T cells that are long-lived are metabolically inactive and not ideal for constant protein production.
Conversely, B cells can generate large amounts of protective antibodies and continue to do so for years after
conversion to long-lived plasma cells. It has been demonstrated that these plasma cells are not merely re-seeded
by memory B cells but instead are the result of becoming long-lived antibody producing cells that do not
proliferate. The fact that B cells can become long lived and inherently have the metabolic activity to generate
large quantities of protein (i.e. antibody) led us to hypothesize that these cells might be an ideal platform for gene
therapy of enzymopathies. To enable the use of engineered B cells for therapy we recently established the use
of CRISPR/Cas9 for gene knock-in and knockout in primary human B cells (Johnson et. al., Sci Rep. 2018 Aug
14;8(1):12144). Now, we will apply these approaches to engineer B cells for the treatment of enzymopathies and
perform preclinical testing. Here, we propose to: 1) optimize expression vectors and integration sites for optimal
expression of therapeutic transgenes in human B cells and 2) perform proof-of-concept studies to use
engineered human B cells to treat enzymopathies. Specifically, we will treat a mouse model of
mucopolysaccharidosis type I (MPS I) on a NOD/SCID/Il2rγ background by transplantation of engineered human
B cells. MPS I is an autosomal recessive lysosomal disease caused by deficiency of alpha-L-iduronidase (IDUA)
enzyme resulting in accumulation of glycosaminoglycan storage material and multi-systemic disease. Affected
individuals suffer from hepatosplenomegaly, corneal clouding, skeletal dysplasias, cardiopulmonary obstruction,
and in the severe form (Hurler syndrome) progressive neurologic impairment. B cells will be engineered to
express a BCR of known antigen specificity transcriptionally linked to IDUA with subsequent immunization to
generate long lived plasma cells in vivo. The studies proposed in this R01 application thus constitute a
comprehensive analysis of the use of engineered B cells to treat enzymopathies with the ultimate goal of treating
enzymopathies in humans.
Status | Active |
---|---|
Effective start/end date | 3/1/20 → 2/28/25 |
Funding
- National Institute of Allergy and Infectious Diseases: $387,500.00
- National Institute of Allergy and Infectious Diseases: $386,667.00
- National Institute of Allergy and Infectious Diseases: $387,500.00
- National Institute of Allergy and Infectious Diseases: $385,000.00
- National Institute of Allergy and Infectious Diseases: $348,750.00
Fingerprint
Explore the research topics touched on by this project. These labels are generated based on the underlying awards/grants. Together they form a unique fingerprint.