Department of Biotechnology
inStem (Institute for Stem Cell Science and Regenerative Medicine)

Efficient and error-free correction of sickle mutation in human erythroid cells using prime editor-2.

Publication Type

Journal Article

Date of Publication

January 1, 2022

Journal

Frontiers in genome editing

Volume/Issue

4

ISSN

2673-3439

Sickle cell anaemia (SCA) is one of the common autosomal recessive monogenic disorders, caused by a transverse point mutation (GAG > GTG) at the sixth codon of the beta-globin gene, which results in haemolytic anaemia due to the fragile RBCs. Recent progress in genome editing has gained attention for the therapeutic cure for SCA. Direct correction of SCA mutation by homology-directed repair relies on a double-strand break (DSB) at the target site and carries the risk of generating beta-thalassaemic mutations if the editing is not error-free. On the other hand, base editors cannot correct the pathogenic SCA mutation resulting from A > T base transversion. Prime editor (PE), the recently described CRISPR/Cas 9 based gene editing tool that enables precise gene manipulations without DSB and unintended nucleotide changes, is a viable approach for the treatment of SCA. However, the major limitation with the use of prime editing is the lower efficiency especially in human erythroid cell lines and primary cells. To overcome these limitations, we developed a modular lenti-viral based prime editor system and demonstrated its use for the precise modelling of SCA mutation and its subsequent correction in human erythroid cell lines. We achieved highly efficient installation of SCA mutation (up to 72%) and its subsequent correction in human erythroid cells. For the first time, we demonstrated the functional restoration of adult haemoglobin without any unintended nucleotide changes or indel formations using the PE2 system. We also validated that the off-target effects mediated by the PE2 system is very minimal even with very efficient on-target conversion, making it a safe therapeutic option. Taken together, the modular lenti-viral prime editor system developed in this study not only expands the range of cell lines targetable by prime editor but also improves the efficiency considerably, enabling the use of prime editor for myriad molecular, genetic, and translational studies.

Alternate Journal

Front Genome Ed

PubMed ID

36605051

PubMed Central ID

PMC9808041

Authors

Anila George
Nithin Sam Ravi
Kirti Prasad
Lokesh Panigrahi
Sanya Koikkara
Vignesh Rajendiran
Nivedhitha Devaraju
Joshua Paul
Aswin Anand Pai
Yukio Nakamura
Ryo Kurita
Poonkuzhali Balasubramanian
Saravanabhavan Thangavel
Srujan Marepally
Shaji R Velayudhan
Alok Srivastava
Kumarasamypet M Mohankumar