iPhAGES Platform Optimization and Applications

Overview

Miniphagemid-mediated Cancer Immunotherapy:

Molecular targeted therapy has emerged as a promising strategy to treat cancer over the last several years. Unlike the broad-spectrum cytotoxic drugs prescribed for conventional chemotherapy, targeted therapy is designed to address specific molecular changes which are unique to a specific cancer type. To develop a successful targeted therapy, many delivery platforms have been investigated to optimize safety, specificity and efficiency. Virus-like particles (VLPs) have demonstrated a robust ability to stimulate potent immune responses and overcome the immunosuppressive state of tumour microenvironment (TME). In addition, filamentous bacteriophage (phage) M13 has been investigated as a safe and efficient delivery vehicle for therapeutic genes and drugs. Phage-based vectors can be engineered to transfer exogenous genetic material to mammalian cells as they have no natural tropism. Combining the advantages of both VLPs and phages, the goal of this project is to construct a hybrid biological platform to specifically deliver DNA encoding VLP-displaying anti-tumour peptides VGE4 to colorectal cancer cells via M13 phage.

This project aims to construct a miniaturized M13 phagemid vector (miniphagemid) to target epidermal growth factor receptor (EGFR) positive cancer cells, as human cancer cells often overexpress EGFR on their cell surfaces. Additionally, the miniphagemid will encode human papillomavirus (HPV) VLPs with an anti-angiogenic peptide surface display. The DNA VLP sequence encoding the L1 capsid gene of HPV-16 with an inserted VGB4 peptide sequence will be cloned into a miniphagemid. This genetically engineered miniphagemid will then be produced in Escherichia coli using a novel non-packaging M13 helper plasmid. The helper plasmid, in addition to complementing phagemid packaging, will allow the display of a cell-specific targeting ligand – the EGF, which will promote specific receptor-mediated endocytosis for efficient phage uptake to a human colorectal carcinoma epithelial cell line (HT-29). The formation of HPV VLP displaying VGB4 in mammalian tumor cells and subsequent release into the extracellular environment will assess the potential of this hybrid delivery system for targeted cancer therapy.