Assessment of TWIST1 as an immunotherapeutic target of cancer.
Doctoral thesis, UCL (University College London).
CD8+ T lymphocytes are key mediators of anti-tumour immunity, eliminating tumour cells through the recognition of tumour antigens. Increasing the number of characterised tumour antigens, especially those with highly specific tumour expression, may enable the development of more effective immunotherapy of cancers. TWIST1 is a basic-helix-loop-helix transcription factor (bHLB) with an important role in cell lineage determination and differentiation. It is expressed by a number of carcinomas where it functions as a pro-metastatic oncogene, but is absent or expressed at low levels in normal tissues. The main aim of this study was to investigate whether anti-TWIST1 immune responses could be generated and used to target cancer cells. Two potential HLA-A0201 restricted TWIST1-derived epitopes, SLNEAFAAL and KLAARYIDFL (referred to as SLN and KLA) were identified by in silico prediction methods and their binding to HLA-A*0201 confirmed in vitro. The peptides were assessed for their capacity to induce specific immune responses by generating cytotoxic T lymphocyte (CTL) lines from the peripheral blood of HLA-A2-positive healthy donors. SLN peptide-specific CTLs were detected in 1 out of 5 healthy donors by peptide/MHC class I pentamers and the CTL line generated showed specific cytotoxicity and the release of interferon-γ on recognition of T2 target cells pulsed with SLN. KLA peptide-specific CTLs were not detected in the four healthy HLA-A2-positive donors tested. The immunogenicity of KLA was also assessed by peptide immunisation of HLA-A*0201 transgenic mice and the in vitro stimulation of alloreactive peptide-specific CD8+ T cells from HLA-A2-negative healthy blood donors. CTLs capable of specifically killing T2 cells pulsed with KLA peptide were isolated from an alloreactive CTL bulk line using peptide/HLA-A*0201 pentamer reagents and magnetic cell sorting. The data presented here shows the existence of functional anti-TWIST1 CTL precursors within the autologous and allogeneic HLA-A*0201-restricted T cell repertoires of healthy donors, and therefore merits the further evaluation of SLN and KLA as target epitopes for the treatment of TWIST1+ tumours.
|Title:||Assessment of TWIST1 as an immunotherapeutic target of cancer|
|Open access status:||An open access version is available from UCL Discovery|
|Additional information:||Copyright restricted material has been removed from the e-thesis.|
|UCL classification:||UCL > School of Life and Medical Sciences > Faculty of Population Health Sciences > Institute of Child Health|
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