@article {3340, title = {CRISPR/Cas9 Gene Editing of Hematopoietic Stem and Progenitor Cells for Gene Therapy Applications.}, journal = {J Vis Exp}, year = {2022}, month = {2022 08 09}, abstract = {

CRISPR/Cas9 is a highly versatile and efficient gene-editing tool adopted widely to correct various genetic mutations. The feasibility of gene manipulation of hematopoietic stem and progenitor cells (HSPCs) in vitro makes HSPCs an ideal target cell for gene therapy. However, HSPCs moderately lose their engraftment and multilineage repopulation potential in ex vivo culture. In the present study, ideal culture conditions are described that improves HSPC engraftment and generate an increased number of gene-modified cells in vivo. The current report displays optimized in vitro culture conditions, including the type of culture media, unique small molecule cocktail supplementation, cytokine concentration, cell culture plates, and culture density. In addition to that, an optimized HSPC gene-editing procedure, along with the validation of the gene-editing events, are provided. For in vivo validation, the gene-edited HSPCs infusion and post-engraftment analysis in mouse recipients are displayed. The results demonstrated that the culture system increased the frequency of functional HSCs in vitro, resulting in robust engraftment of gene-edited cells in vivo.

}, keywords = {Animals, CRISPR-Cas Systems, Gene Editing, Genetic Therapy, Hematopoietic Stem Cell Transplantation, Hematopoietic Stem Cells, Mice}, issn = {1940-087X}, doi = {10.3791/64064}, author = {Venkatesan, Vigneshwaran and Christopher, Abisha Crystal and Karuppusamy, Karthik V and Babu, Prathibha and Alagiri, Manoj Kumar K and Thangavel, Saravanabhavan} } @article {2545, title = {Genome Engineering of Hematopoietic Stem Cells Using CRISPR/Cas9 System.}, journal = {Methods Mol Biol}, volume = {2429}, year = {2022}, month = {2022}, pages = {307-331}, abstract = {

Ex vivo genetic manipulation of autologous hematopoietic stem and progenitor cells (HSPCs) is a viable strategy for the treatment of hematologic and primary immune disorders. Targeted genome editing of HSPCs using the CRISPR-Cas9 system provides an effective platform to edit the desired genomic locus for therapeutic purposes with minimal off-target effects. In this chapter, we describe the detailed methodology for the CRISPR-Cas9 mediated gene knockout, deletion, addition, and correction in human HSPCs by viral and nonviral approaches. We also present a comprehensive protocol for the analysis of genome modified HSPCs toward the erythroid and megakaryocyte lineage in vitro and the long-term multilineage reconstitution capacity in the recently developed NBSGW mouse model that supports human erythropoiesis.

}, keywords = {Animals, CRISPR-Cas Systems, Gene Editing, Hematopoietic Stem Cell Transplantation, Hematopoietic Stem Cells, Mice, Transplantation, Autologous}, issn = {1940-6029}, doi = {10.1007/978-1-0716-1979-7_20}, author = {Devaraju, Nivedhitha and Rajendiran, Vignesh and Ravi, Nithin Sam and Mohankumar, Kumarasamypet M} } @article {2465, title = {Identification of novel HPFH-like mutations by CRISPR base editing that elevate the expression of fetal hemoglobin.}, journal = {Elife}, volume = {11}, year = {2022}, month = {2022 02 11}, abstract = {

Naturally occurring point mutations in the promoter switch hemoglobin synthesis from defective adult beta-globin to fetal gamma-globin in sickle cell patients with hereditary persistence of fetal hemoglobin (HPFH) and ameliorate the clinical severity. Inspired by this natural phenomenon, we tiled the highly homologous proximal promoters using adenine and cytosine base editors that avoid the generation of large deletions and identified novel regulatory regions including a cluster at the -123 region. Base editing at -123 and -124 bp of promoter induced fetal hemoglobin (HbF) to a higher level than disruption of well-known BCL11A binding site in erythroblasts derived from human CD34+ hematopoietic stem and progenitor cells (HSPC). We further demonstrated in vitro that the introduction of -123T \> C and -124T \> C HPFH-like mutations drives gamma-globin expression by creating a de novo binding site for KLF1. Overall, our findings shed light on so far unknown regulatory elements within the promoter and identified additional targets for therapeutic upregulation of fetal hemoglobin.

}, keywords = {Adenine, Anemia, Sickle Cell, beta-Globins, beta-Thalassemia, Cell Line, Clustered Regularly Interspaced Short Palindromic Repeats, CRISPR-Cas Systems, Cytosine, Fetal Hemoglobin, gamma-Globins, Gene Editing, Hematopoietic Stem Cells, Humans, Point Mutation, Promoter Regions, Genetic}, issn = {2050-084X}, doi = {10.7554/eLife.65421}, author = {Ravi, Nithin Sam and Wienert, Beeke and Wyman, Stacia K and Bell, Henry William and George, Anila and Mahalingam, Gokulnath and Vu, Jonathan T and Prasad, Kirti and Bandlamudi, Bhanu Prasad and Devaraju, Nivedhitha and Rajendiran, Vignesh and Syedbasha, Nazar and Pai, Aswin Anand and Nakamura, Yukio and Kurita, Ryo and Narayanasamy, Muthuraman and Balasubramanian, Poonkuzhali and Thangavel, Saravanabhavan and Marepally, Srujan and Velayudhan, Shaji R and Srivastava, Alok and DeWitt, Mark A and Crossley, Merlin and Corn, Jacob E and Mohankumar, Kumarasamypet M} } @article {1936, title = {Efficient allelic-drive in Drosophila.}, journal = {Nat Commun}, volume = {10}, year = {2019}, month = {2019 04 09}, pages = {1640}, abstract = {

Gene-drive systems developed in several organisms result in super-Mendelian inheritance of transgenic insertions. Here, we generalize this "active genetic" approach to preferentially transmit allelic variants (allelic-drive) resulting from only a single or a few nucleotide alterations. We test two configurations for allelic-drive: one, copy-cutting, in which a non-preferred allele is selectively targeted for Cas9/guide RNA (gRNA) cleavage, and a more general approach, copy-grafting, that permits selective inheritance of a desired allele located in close proximity to\ the gRNA cut site. We also characterize a phenomenon we refer to as lethal-mosaicism that dominantly eliminates NHEJ-induced mutations and favors inheritance of functional cleavage-resistant alleles. These two efficient allelic-drive methods, enhanced by lethal mosaicism and a trans-generational drive process we refer to as "shadow-drive", have broad practical applications in improving health and agriculture and greatly extend the active genetics toolbox.

}, keywords = {Agriculture, Alleles, Animals, Animals, Genetically Modified, CRISPR-Cas Systems, DNA End-Joining Repair, DNA Mutational Analysis, Drosophila, Female, Gene Drive Technology, Gene Editing, Inheritance Patterns, Male, Mosaicism, RNA, Guide}, issn = {2041-1723}, doi = {10.1038/s41467-019-09694-w}, author = {Guichard, Annabel and Haque, Tisha and Bobik, Marketta and Xu, Xiang-Ru S and Klanseck, Carissa and Kushwah, Raja Babu Singh and Berni, Mateus and Kaduskar, Bhagyashree and Gantz, Valentino M and Bier, Ethan} }