Browsing by Author "Mantri, Sruthi"

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    Gene correction for SCID-X1 in long-term hematopoietic stem cells
    (Springer Nature, 2019) Pavel-Dinu, Mara; Wiebking, Volker; Dejene, Beruh T.; Srifa, Waracharee; Mantri, Sruthi; Nicolas, Carmencita E.; Lee, Ciaran; Bao, Gang; Kildebeck, Eric J.; Punjya, Niraj; Sindhu, Camille; Inlay, Matthew A.; Saxena, Nivedita; DeRavin, Suk See; Malech, Harry; Roncarolo, Maria Grazia; Weinberg, Kenneth I.; Porteus, Matthew H.; Bioengineering
    Gene correction in human long-term hematopoietic stem cells (LT-HSCs) could be an effective therapy for monogenic diseases of the blood and immune system. Here we describe an approach for X-linked sSevere cCombined iImmunodeficiency (SCID-X1) using targeted integration of a cDNA into the endogenous start codon to functionally correct disease-causing mutations throughout the gene. Using a CRISPR-Cas9/AAV6 based strategy, we achieve up to 20% targeted integration frequencies in LT-HSCs. As measures of the lack of toxicity we observe no evidence of abnormal hematopoiesis following transplantation and no evidence of off-target mutations using a high-fidelity Cas9 as a ribonucleoprotein complex. We achieve high levels of targeting frequencies (median 45%) in CD34+ HSPCs from six SCID-X1 patients and demonstrate rescue of lymphopoietic defect in a patient derived HSPC population in vitro and in vivo. In sum, our study provides specificity, toxicity and efficacy data supportive of clinical development of genome editing to treat SCID-Xl.
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    Human genome-edited hematopoietic stem cells phenotypically correct Mucopolysaccharidosis type I
    (Springer Nature, 2019) Gomez-Ospina, Natalia; Scharenberg, Samantha G.; Mostrel, Nathalie; Bak, Rasmus O.; Mantri, Sruthi; Quadros, Rolen M.; Gurumurthy, Channabasavaiah B.; Lee, Ciaran; Bao, Gang; Suarez, Carlos J.; Khan, Shaukat; Sawamoto, Kazuki; Tomatsu, Shunji; Raj, Nitin; Attardi, Laura D.; Aurelian, Laure; Porteus, Matthew H.; Bioengineering
    Lysosomal enzyme deficiencies comprise a large group of genetic disorders that generally lack effective treatments. A potential treatment approach is to engineer the patient’s own hematopoietic system to express high levels of the deficient enzyme, thereby correcting the biochemical defect and halting disease progression. Here, we present an efficient ex vivo genome editing approach using CRISPR-Cas9 that targets the lysosomal enzyme iduronidase to the CCR5 safe harbor locus in human CD34+ hematopoietic stem and progenitor cells. The modified cells secrete supra-endogenous enzyme levels, maintain long-term repopulation and multi-lineage differentiation potential, and can improve biochemical and phenotypic abnormalities in an immunocompromised mouse model of Mucopolysaccharidosis type I. These studies provide support for the development of genome-edited CD34+ hematopoietic stem and progenitor cells as a potential treatment for Mucopolysaccharidosis type I. The safe harbor approach constitutes a flexible platform for the expression of lysosomal enzymes making it applicable to other lysosomal storage disorders.