Alyssa Bogle, University of Guelph

Authors: Alyssa E. Bogle (1), Jacob G.E. Yates (2), Yanlong Pei (1), Melanie M. Goens (1), Khalil Karimi (1), Samuel Workenhe (1), Leonardo Susta (1), Sarah K. Wootton (1) Affiliations: (1) University of Guelph (2) University of Toronto

Expressing & Multiplying

Newcastle Disease virus (NDV) is a nonsegmented, negative sense single-stranded RNA virus in the Paramyxoviridae family. Because NDV is an avian‑restricted pathogen, it demonstrates an excellent safety profile in humans and functions naturally as an oncolytic virus (OV). OVs preferentially replicate in tumor cells while sparing healthy cells, positioning them as a promising therapeutic candidate for several cancers. NDV has demonstrated substantial antitumor potential in multiple clinical settings; however, its efficacy as a monotherapy remains limited, indicating a need for further optimization. One mechanism by which OVs exert antitumor effects is through virus‑induced cell–cell fusion, which generates large syncytia that promote immunogenic cell death and enhance antitumor immune activation. Prior studies have shown that specific point mutations in the NDV fusion (F) and hemagglutinin–neuraminidase (HN) proteins can increase viral fusogenicity and/or intratumoral spread. Building on these findings, we aimed to engineer a highly fusogenic NDV variant to augment its therapeutic efficacy by amplifying both direct oncolysis and downstream immune‑mediated antitumor responses. Mutant viruses with different combinations of F and HN mutations were engineered, and two were selected based on enhanced spread compared to parental NDV. The oncolytic activity of these mutant viruses is being evaluated in seven different tumor cell lines. Mutant viruses that demonstrate enhanced fusion and/or improved oncolytic activity compared to the parental virus will be tested for their therapeutic efficacy and induction of anti-tumor immune responses in the B16F10 murine melanoma model. The findings could guide the development of more potent NDV platforms for cancer immunotherapy.