Genetic Engineering and Manufacturing of Hematopoietic Stem Cells

Abstract

The marketing approval of genetically engineered hematopoietic stem cells (HSCs) as the first-line therapy for the treatment of severe combined immunodeficiency due to adenosine deaminase deficiency (ADA-SCID) is a tribute to the substantial progress that has been made regarding HSC engineering in the past decade. Reproducible manufacturing of high-quality, clinical-grade, genetically engineered HSCs is the foundation for broadening the application of this technology. Herein, the current state-of-the-art manufacturing platforms to genetically engineer HSCs as well as the challenges pertaining to production standardization and product characterization are addressed in the context of primary immunodeficiency diseases (PIDs) and other monogenic disorders.

Vectofusin-1 Improves Transduction of Primary Human Cells with Diverse Retroviral and Lentiviral Pseudotypes, Enabling Robust, Automated Closed-System Manufacturing

“…The current gold standard for the ex vivo genetic modification of target cells for these approaches is to use retroviral vector-based gene transfer technologies. 1,2 To enable successful acceptance of these technologies into clinical routine, manufacturing must be simplified and costs must be reduced. 3,4 One of the costlier reagents required for the manufacturing is the viral vector, therefore possible savings could be reached by reducing the viral vector production costs or by increasing the efficiency of viral vector transduction of target cells, thereby reducing the amount of viral vector required.…”

TALEN-mediated functional correction of human iPSC-derived macrophages in context of hereditary pulmonary alveolar proteinosis

“…However, this procedure has to be repeated every 4-8 weeks, is associated with considerable cardiopulmonary risks and severely affects the quality of life of herPAP patients. Allogeneic bone marrow transplantation (allo-BMT) or hematopoietic stem cell based gene therapy, both of which have been used successfully for the treatment of other congenital diseases affecting the lympho-hematopoietic compartment 22 – 24 have proven problematic in herPAP, as the pre-existing lung damage prevents adequate chemo- and radiotherapeutic preconditioning 25 . Recently, however, pulmonary macrophage transplantation has been described as a highly effective therapeutic approach for herPAP in two murine disease models 26 , 27 .…”

Implications of hematopoietic stem cells heterogeneity for gene therapies

“…In the early 1980s the marker CD34 was identified on immature normal human BM cells as well as on leukemic human cells [36]. Indeed, proving the clinical applicability of this marker, data indicated that at least 2 × 106 CD34+ cells per kg recipient's body weight are needed for the engraftment of the transplant, while higher doses can speed up the process particularly for autologous HSCT [16,37]. However, studies showed that CD34 expression on the cell surface is shared by numerous hematopoietic cell types varying from HSCs to multi/oligopotent progenitor cells and lineage-restricted progenitor cells, and can be detected even on non-hematopoietic cells [32,[38][39][40].…”