Burke, Christina Lynne;
(2023)
Engineering cellular therapy for rhabdomyosarcoma: Design of CAR T-cells and characterisation of the tumour immune microenvironment.
Doctoral thesis (Ph.D), UCL (University College London).
Abstract
Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma in children and young adults. Despite this, the prognosis remains dismal for patients with high-risk disease, with fewer than 30% achieving cure. The aim of this work was therefore to develop a chimeric antigen receptor (CAR) T-cell immunotherapy for RMS, to serve as a more effective and tolerable treatment option. Six candidate surface target antigens were investigated for targeting with a CAR. Notably, B7-H3 was homogeneously expressed on five of five RMS cell lines and four of four primary RMS samples tested. Five anti-B7-H3 scFv binders generated by collaborators and their derivatives were tested for binding to RMS and reference cell lines, from which candidate CAR T-cells were generated. The CAR “A10” showed significant activity in vitro, achieving between 43.0 and 66.5% specific cell lysis of RMS cell lines after four hours of co-culture in a chromium release cytotoxicity assay. In addition, appreciable inflammatory cytokine secretion was observed against RMS targets in vitro. A second antigen, the foetal acetylcholine receptor (fAChR) was also taken forward for targeting with a CAR. Though highly selective for RMS, a significantly lower inflammatory and cytotoxic response was observed from anti-fAChR CAR T-cells when compared with the anti-B7-H3 CAR. Mechanisms of immunosuppression within the solid tumour microenvironment (TME) may dampen CAR T-cell efficacy. Presented here also is an interrogation of the RMS tumour immune microenvironment using complementary scRNA-seq and Chip Cytometry approaches, the latter being the first multiplex immunofluorescence study performed on RMS. Findings in a preliminary cohort of seven RMS tumours indicate a myeloid cell-dominated TME and absence of T-cell infiltrate, with the exception of paratesticular tumours. The results published herein are ultimately combined to give recommendations for the design of a next-generation CAR for treating RMS, which will be the focus of future studies.
| Type: | Thesis (Doctoral) |
|---|---|
| Qualification: | Ph.D |
| Title: | Engineering cellular therapy for rhabdomyosarcoma: Design of CAR T-cells and characterisation of the tumour immune microenvironment |
| Language: | English |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences > Faculty of Population Health Sciences > UCL GOS Institute of Child Health UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences > Faculty of Population Health Sciences > UCL GOS Institute of Child Health > Developmental Biology and Cancer Dept |
| URI: | https://discovery.ucl.ac.uk/id/eprint/10166961 |
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