Developing a synthetic bone marrow niche for testing novel leukaemia therapies

Doherty-Boyd, William Sebastian (2025) Developing a synthetic bone marrow niche for testing novel leukaemia therapies. PhD thesis, University of Glasgow.

Abstract

Haematopoietic stem cells (HSCs) are responsible for haematopoiesis, the continuous production of blood and immune cells within the bone marrow (BM) niche. The BM niche maintains the stem cell pool and haematopoietic activity with a variety of stimuli. Erroneous haematopoiesis can result in disorders and diseases such as acute myeloid leukaemia (AML). Chimeric antigen receptor (CAR) T-cell therapy has the potential to significantly improve AML patients’ outlook. However, the efficacy of novel therapies is difficult to assess prior to clinical trials. A model BM niche was developed to provide insight into therapies’ efficacies.

The model used mesenchymal stromal cells (MSCs), which support HSCs in the BM niche, as a feeder layer. The MSCs were cultured on a surface coated with poly(ethyl acrylate). This material caused fibronectin, which the surface was also coated with, to assemble in an open conformation. The fibronectin, which was loaded with the osteogenic growth factor bone morphogenic protein 2, directed the phenotype of MSCs cultured on top. A synthetic, peptide-based hydrogel was also layered on top of the MSCs, forming a barrier between MSCs under the gel and HSCs cultured on top of the gel, and acting as a culture interface between the different cell populations. This system promoted a niche-like phenotype in MSCs, which supported HSCs, mimicking the BM niche.

A CAR T-cell therapy which specifically eliminated AML cells was also developed. AML cells lack differentiable surface markers that can be used as CAR T-cell targets without harming healthy myeloid cells. To overcome this, CD33, a myeloid and AML cell surface marker, was disrupted in HSCs. This allowed CD33 to be targeted with CAR T-cells, theoretically eliminating all CD33 expressing cells, including AML cells, while a CD33del population of haematopoietic cells with the potential to repopulate the niche survived. This therapeutic approach was tested in the model BM niche and found to effectively eliminate AML cells, but also affect haematopoietic cells, warranting further research.

The successful modelling of a healthy, diseased, and treated BM niche demonstrated the usefulness of in vitro models for testing novel therapies for BM associated disorders and diseases.

• Item Type: Thesis (PhD)
• Qualification Level: Doctoral
• Subjects: Q Science > QH Natural history > QH301 Biology; Q Science > QH Natural history > QH345 Biochemistry; Q Science > QR Microbiology; R Medicine > R Medicine (General)
• Colleges/Schools: College of Medical Veterinary and Life Sciences > School of Molecular Biosciences
• Supervisor's Name: Dalby, Professor Matthew
• Date of Award: 2025
• Depositing User: Theses Team
• Unique ID: glathesis:2025-85003
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 08 Apr 2025 08:51
• Last Modified: 09 Apr 2025 08:11
• Thesis DOI: 10.5525/gla.thesis.85003
• URI: https://theses.gla.ac.uk/id/eprint/85003

Related URLs

• Article DOI
• Article DOI
• Article DOI