Bacteriophage-guided oncolytic virotherapy, cancer vaccines and immunotherapy.

Abstract

Cancer vaccine development has gained significant importance in combating cancer, a major global cause of death. These vaccines aim to activate the immune system to identify and attack cancer cells by targeting tumour-associated antigens (TAAs) or tumour-specific antigens (TSAs). The use of Transmorphic Phage Adeno-Associated Virus Phage (TPA) presents a promising approach to producing an effective cancer vaccine. TPA was designed based on a hybrid between the M13 phage capsid and the recombinant DNA of the human adeno associated (AAV2) virus. The coat proteins of M13 were designed to display the RGD4C ligand that directs the phage particles to target tumour cells and tumour- associated vasculature through selective binding to αvβ3 and αvβ5 integrin receptors. The present work focuses on investigating the possibility of the targeted RGD4C.TPA vector encoding TSA-like antigens such as the human papilloma virus (HPV) viral antigens E6 and E7 as potential therapeutic cancer vaccine candidates. Fusion DNA sequences of E6 and E7 were cloned in the AAV-based transgene cassette of TPA vector and tested in vitro and in vivo, assessing the transduction efficacy, therapeutic effects, and safety profile in non- HPV-associated tumour-bearing mice including murine B16F1 melanoma and CT26 colon cancer. Then, TPA vector encoding E6 and E7 was studied to determine if it can act as a potential preventive vaccine by measuring both the humoral and cellular immune responses post-immunisation in tumour-free mice, in addition to understanding the vector uptake by antigen-presenting cells. Finally, we assessed the effect of the TPA.E6T2AE7 in preventing HPV-associated TC-1 tumours in tumour-bearing mice. The overall thesis showed that our targeted TPA encoding antigens can act as a dual cancer vaccine, both therapeutic and preventive, effectively, without causing any side effects, highlighting its potential as a safe and effective cancer vaccine candidate, overcoming the issues associated with currently developed vaccines