Gene editing of human hematopoietic stem and progenitor cells
for Friedreich’s ataxia using CRISPR/Cas9 technology
Dr. Celine Rocca 1, Ms. Shi Yanmeng 1, Mr. Jay Sharma 1, Dr. Prashant Mali 1, Dr. Stephanie Cherqui 1
- University of California, San Diego
Our goal is now to develop an autologous HSPC transplantation. To achieve our objective, we are developing
a CRISPR/Cas9 method to remove the GAA expansion in the intron 1 of the frataxin gene in FRDA patient HSPCs.
We first optimized the conditions of in lymphoblasts isolated from FRDA patients and obtained up to 62% of gene
correction. At the mRNA and protein levels, frataxin expression reached the same level than their carrier parents’
cell lines. In addition, using a very sensitive method developed by BIOLOG, we showed that mitochondrial activity
was also improved in corrected cell. We thus moved towards the manufacturing development of the human product
using first CD34+ cells isolated from healthy donor peripheral blood. We successfully gene-corrected 24 to 50%
of the CD34+ cells. The capacity of the gene-modified CD34+ cells to differentiate into the different hematopoietic
lineage cells was tested in vitro by Colony Forming Unit assays and in vivo in NOD scidgamma immunodeficient
mice. Finally, we gene-edited CD34+ cells isolated from FRDA patients reaching-up 55% correction accompanied by
an increased in frataxin expression and normal differentiation in the different hematopoietic lineage cells. With
this study, we are laying the foundations for a future clinical trial for autologous HSPC transplantation for FRDA