Therapy Development by Genome Editing of Hematopoietic Stem Cells

Abstract

Accessibility of hematopoietic stem cells (HSCs) for the manipulation and repopulation of the blood and immune systems has placed them at the forefront of cell and gene therapy development. Recent advances in genome-editing tools, in particular for clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein (Cas) and CRISPR/Cas-derived editing systems, have transformed the gene therapy landscape. Their versatility and the ability to edit genomic sequences and facilitate gene disruption, correction or insertion, have broadened the spectrum of potential gene therapy targets and accelerated the development of potential curative therapies for many rare diseases treatable by transplantation or modification of HSCs. Ongoing developments seek to address efficiency and precision of HSC modification, tolerability of treatment and the distribution and affordability of corresponding therapies. Here, we give an overview of recent progress in the field of HSC genome editing as treatment for inherited disorders and summarize the most significant findings from corresponding preclinical and clinical studies. With emphasis on HSC-based therapies, we also discuss technical hurdles that need to be overcome en route to clinical translation of genome editing and indicate advances that may facilitate routine application beyond the most common disorders.

Correction of Beta-Thalassemia IVS-II-654 Mutation in a Mouse Model Using Prime Editing

“…The current results showed that PE3 successfully installed a therapeutic conversion of GGT > CCC and accordingly ameliorated the hematological and histopathological symptoms in a beta-thalassemia mouse model with the IVS-II-654 mutation. CRISPR/Cas9-derived gene modification, base editing, and prime editing have been utilized for precise gene therapies [ 16 , 18 , 19 , 20 ]. CRISPR/Cas9-mediated gene modification mainly involves homology-directed repair (HDR), NHEJ, microhomology-mediated end joining (MMEJ), and homology-mediated end joining (HMEJ) [ 18 , 20 , 21 ].…”

“…CRISPR/Cas9-derived gene modification, base editing, and prime editing have been utilized for precise gene therapies [ 16 , 18 , 19 , 20 ]. CRISPR/Cas9-mediated gene modification mainly involves homology-directed repair (HDR), NHEJ, microhomology-mediated end joining (MMEJ), and homology-mediated end joining (HMEJ) [ 18 , 20 , 21 ]. We successfully corrected the IVS-II-654 (C > T) mutation in the same mouse model using a Cas9-mediated HMEJ method, and are planning to publish the results elsewhere.…”

A CRISPR view of hematopoietic stem cells: Moving innovative bioengineering into the clinic

“…[95][96][97] Analogous strategies will likely follow for the lymphoid regulator IL7R 86,98 and the other 170 single gene mutations known to impair human hematopoiesis. 99 Due to the life-long persistence of transplanted HSCs, these strategies are potential single-treatment, permanent cures. We expect that this is just the beginning of life-saving CRISPR-edited HSC therapies.…”

“…A few pre‐clinical studies have also demonstrated proof of concept CRISPR‐based therapies to treat severe combined immunodeficiency (SCID) and chronic granulomatous disease (CGD) by targeting IL2RG and CYBB, respectively, in HSCs 95–97 . Analogous strategies will likely follow for the lymphoid regulator IL7R 86,98 and the other 170 single gene mutations known to impair human hematopoiesis 99 . Due to the life‐long persistence of transplanted HSCs, these strategies are potential single‐treatment, permanent cures.…”

Promising Stem Cell therapy in the Management of HIV and AIDS: A Narrative Review

“…Despite the fact that other gene editing techniques exist, CRISPR/Cas9 is the most reliable and efficient proven method for gene rectification. [100][101][102][103] Genome engineering employing CRISPR/Cas has proven to be a strong method for quickly and accurately changing specific genomic sequences. The rise of innovative haematopoiesis research tools to examine the complexity of hematopoietic stem cell (HSC) biology has been fuelled by considerable advancements in CRISPR technology over the last five years.…”