Development of a mRNA therapeutic vaccine for HPV-ve head and neck squamous cell carcinoma

Abstract

Head and neck squamous cell carcinoma (HNSCC) is ranked as 8th most common cancer in UK, with approximately 12,800 new cases diagnosed every year. The causes primarily relate to carcinogenic exposures, such as alcohol and tobacco consumption, and the infection of human papilloma virus (HPV). Strategies for HNSCC generally involve surgical intervention, radiotherapy, chemotherapy, or the combination of radiation and chemotherapy. Prognosis of HNSCC is highly influenced by HPV status, as HPV-ve HNSCC is associated with a poorer 5-year survival rate of 57.1% compared to HPV+ve HNSCC. Therefore, the exploration of more potent therapeutic approaches is necessary to HPV-ve HNSCC patients. Immunotherapy, designed to boost the patients’ immune response against malignant cells, is one of the revolutions for HNSCC treatment. This thesis aimed to develop a novel therapeutic cancer vaccine targeting HPV-ve HNSCC, with the goal of enhancing antitumour immunity.

Initial investigations focused on evaluating RALA peptide as a delivery system for various nucleic acids. Through physiochemical characterisation and functional assessments, RALA/mRNA nanoparticles (NPs) at an N:P ratio of 9 demonstrated optimal properties and superior protein expression compared to pDNA and saRNA. Building on this, the project identified MAGEA4 as a promising tumour antigen for HPV-ve HNSCC via bioinformatics, and GM-CSF selected as an adjuvant. Both MAGEA4 and GM-CSF encoding mRNAs were synthesised and successfully encapsulated with RALA. The therapeutic efficacy of the RALA/mRNA-MAGEA4 vaccine was subsequently evaluated in a murine model of HPV-ve HNSCC. The vaccine successfully elicited a robust T-cell-mediated immune response, characterised by increased IL-2 and IFN-γ production. This translated into significantly prolonged survival in vaccinated mice. While GM-CSF enhanced the immune response, the therapeutic efficacy remained inconclusive, highlighting its complex dual role in tumour immunity.

This research demonstrated the potential of RALA/mRNA-MAGEA4 NPs as a viable and effective therapeutic cancer vaccine platform for HPV-ve HNSCC. The findings provided insights into non-viral mRNA delivery and antigen selection.

Thesis is embargoes until 31 December 2030.

Date of Award	Dec 2025
Original language	English
Awarding Institution	Queen's University Belfast
Supervisor	Helen McCarthy (Supervisor) & Jonathan Coulter (Supervisor)