Lentiviral Hematopoietic Stem Cell Gene Therapy Rescues Clinical Phenotypes in a Murine Model of Pompe Disease

Giuseppa Piras,Claudia Montiel-Equihua,Yee-Ka Agnes Chan,Slawomir Wantuch,Daniel Stuckey,Derek Burke,Helen Prunty,Rahul Phadke,Darren Chambers,Armando Partida-Gaytan,Diego Leon-Rico,Neelam Panchal,Kathryn Whitmore,Miguel Calero,Sara Benedetti,Giorgia Santilli,Adrian J Thrasher,H Bobby Gaspar

doi:10.1016/j.omtm.2020.07.001

Abstract

Pompe disease is a lysosomal storage disorder caused by malfunctions of the acid alpha-glucosidase (GAA) enzyme with a consequent toxic accumulation of glycogen in cells. Muscle wasting and hypertrophic cardiomyopathy are the most common clinical signs that can lead to cardiac and respiratory failure within the first year of age in the more severe infantile forms. Currently available treatments have significant limitations and are not curative, highlighting a need for the development of alternative therapies. In this study, we investigated the use of a clinically relevant lentiviral vector to deliver systemically GAA through genetic modification of hematopoietic stem and progenitor cells (HSPCs). The overexpression of GAA in human HSPCs did not exert any toxic effect on this cell population, which conserved its stem cell capacity in xenograft experiments. In a murine model of Pompe disease treated at young age, we observed phenotypic correction of heart and muscle function with a significant reduction of glycogen accumulation in tissues after 6 months of treatment. These findings suggest that lentiviral-mediated HSPC gene therapy can be a safe alternative therapy for Pompe disease.

Highlights

Pompe disease (PD; OMIM: 232300) is a rare inherited metabolic disorder resulting from an impaired metabolism of glycogen in cells
Relevant lentiviral vector (LV) for Pompe Disease We generated a self-inactivating LV with a pCCL backbone, which has been widely used in gene therapy clinical trials,[25,26] as a therapeutic vehicle for the expression of a native form of hGAA in hematopoietic stem and progenitor cell (HSPC) and compared the GAA expression under the control of the EFS-1a promoter in the presence or absence of the human b-globin LCR enhancer, as previously described[43] (Figure 1A; LV.LCR-EFS.GAA and LV.EFS.GAA, respectively)
To ensure that the overexpression of hGAA in the HSPCs does not lead to any adverse effects on HSPC function and capability, we investigated the engraftment capacity of LV.LCR-EFS.GAA-transduced hCD34+ cells from a third healthy donors (HDs) in NSG mice

Summary

Introduction

Pompe disease (PD; OMIM: 232300) is a rare inherited metabolic disorder resulting from an impaired metabolism of glycogen in cells. 558 Molecular Therapy: Methods & Clinical Development Vol 18 September 2020 a 2020 The Authors. AVV-mediated gene therapy can trigger antibody or cell-mediated immune responses to transgene or viral capsid,[16,17,18,19,20] as has been observed in clinical trials for hemophilia B21 using AAV, but liver-directed transgene expression has been shown in pre-clinical studies[22] to potentially overcome this safety concern by induction of immune tolerance. AVV-mediated gene therapy remains a promising treatment, the episomal nature of viral persistence results in a dilution effect in replicating cells such as hepatocytes, in younger patients, and thereby increasing safety concerns would arise for multiple dosages in those patients.[18,22,23]

Methods

Results

Conclusion