From stem cells to functional lymphocytes: cell differentiation and gene therapy implementation for RAG-SCID

García Pérez, L. (2021)

Doctoral Thesis

The immune system is a complex mechanism of defence to prevent/limit infections and to guarantee homeostasis and repair. It consists of an interactive network of lymphoid organs, humoral factors and several types of specialized cells that develop from hematopoietic stem cells. In this thesis we gained additional knowledge on normal immune development, with detailed focus on the transcriptional network (Notch, Tcf1, Gata3, Bcl11b) orchestrating T-cell development.
The disruption of normal lymphoid development can lead to severe illnesses known as immunodeficiencies. Severe Combined Immunodeficiency (SCID) is a devastating and fatal immune disorder affecting infants lacking a functional immune system. We focused on developing an efficient and safe gene therapy approach to correct both RAG1 and RAG2 immune defects causing SCID. The successful pre-clinical development together with a favorable safety substantiates the first phase I/II clinical trial worldwide for RAG1-SCID gene therapy.
Additionally, we optimized related protocols by developing novel tools allowing better characterizing the product prior infusion. Lastly, we aimed to reduce the toxicity of the used conditioning regimens for a safer and more efficient allogeneic and autologous gene therapy transplantation outcome.
Altogether, the work described in this thesis moves towards a regular enforcement of gene therapy treatment for immunodeficiencies.

• HSC
• Gene therapy
• RAG
• Immunodeficiency
• T cell
• Conditioning
• Lentivirus
• DNA branched

• All authors: García Pérez, L.
• Supervisor: Staal, F.J.T.
• Co-supervisor: Pike-Overzet, K.
• Committee: Lankester, A.C.; Langerak, A.W.; Andre, I.; Burg, M. van der
• Qualification: Doctor (dr.)
• Awarding Institution: Faculty of Medicine, Leiden University Medical Center (LUMC), Leiden University
• Date: 2021-10-06
• ISBN (print): 9789464214604