Towards the development of HAGE-based vaccines for the treatment of patients with triple negative breast cancers

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Nagarajan, D, 2018. Towards the development of HAGE-based vaccines for the treatment of patients with triple negative breast cancers. PhD, Nottingham Trent University.

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Abstract

Breast cancer is a heterogeneous disease with many subtypes mostly identified based on expressions of oestrogen, progesterone, and/or epidermal growth factor receptors (or) none at all (also known as triple negative breast cancer, TNBC). TNBC account for 15-20% of all breast cancer and is the most aggressive subtype with a higher rate of local and distant metastasis and resistance to therapy which leads to frequent recurrences. TNBC treatment therefore rely mainly on neoadjuvant, surgery and/or radiotherapy. The level of immune infiltrate in TNBC has been linked to a more favourable outcome and lower mutation and neoantigen counts, indicating that an active immune surveillance is ongoing and that these patients might benefit from checkpoint inhibitor therapy. However, patients who did not display high level of immune infiltrate or whose disease and come back after conventional treatment, antigen-specific vaccine might provide a new method of treatment. The design of cancer vaccines need to take into consideration the choice of the antigen to be used in the vaccine (its expression pattern of the antigen by the tumour cells versus normal cells, its importance for the survival of the cancer cell, and its immunogenicity) as well as the delivery and adjuvant used in combination with the antigen. The cancer-testis antigen HAGE (DDX43, CT13) has been shown to be expressed in 43% of patients with TNBC, is not expressed by normal cells of vital organs, is required for the proliferation of cancer cells and is immunogenic. Therefore, patients with HAGE positive tumours might benefit from a HAGE-specific vaccine.

This work has investigated the immunogenicity of two HAGE-derived sequences, has assessed the effect of several adjuvants as well as compared peptide HAGE 30mer versus DNA-HAGE vaccine in the form of Immunobody® and has assessed the anti-tumor efficiency of the best HAGE-derived vaccine. HAGE-derived 24 and 30-amino-acid long peptide using IFA as adjuvant were compared in the HHDII/DR1 transgenic mice. Based on peptide-specific immune responses determined using an IFNγ ELISpot assay, HAGE-30mer vaccine was found to be superior to the 24mer sequence as determined by high number of IFNɣ released against shorter vaccine-derived peptides. Range of adjuvants such as IFA, CpG, IRX-2, were administered either alone or in combination with HAGE 30mer peptide vaccine. The best responses were found to be generated by HAGE 30mer formulations containing IFA+CpG and IFA+IRX-2. Since mode of delivery influences the nature and strength of immune responses, a DNA based vaccine was assessed in this study called Immunobody®. ImmunoBody® encodes a human antibody with antigen inserted within the Complementarity-Determining Regions (CDR). HAGE-Immunobody® generated strong anti-HAGE immune responses, as demonstrated by the significant increase in the number of IFNγ secreting splenocytes. Moreover, splenocytes from vaccinated mice stimulated in vitro could recognise and specifically respond to HAGE+ tumour cells, including MDA-MB-231. This response was both HAGE and T cell-specific. More importantly the tumour growth of B16 cells (knockout for β2microglobulin and transfected with HHDII, HLA-DR1, Luciferin and HAGE constructs) was significantly slowed down by ImmunoBody®-HAGE vaccine. Overall, this work has demonstrated the potential value of HAGE-derived vaccines for the treatment HAGE positive cancers. Future studies will combine the vaccine with immune-checkpoint inhibitors.

Item Type:	Thesis
Creators:	Nagarajan, D.
Date:	2018
Rights:	This work is the intellectual property of the author and may also be owned by the research sponsor(s) and/or Nottingham Trent University. You may copy up to 5% of this work for private study, or personal, non-commercial research. Any re-use of the information contained within this document should be fully referenced, quoting the author, title, university, degree level and pagination. Queries or requests for any other use, or if a more substantial copy is required, should be directed to the owner(s) of the Intellectual Property Rights.
Divisions:	Schools > School of Science and Technology
Record created by:	Linda Sullivan
Date Added:	09 Nov 2018 12:24
Last Modified:	09 Nov 2018 12:24
URI:	https://irep.ntu.ac.uk/id/eprint/34884