Salmonella vector creates de novo parvovirus that reduces solid tumors and forms antitumor immune memory

Despite their potential, OVs are cleared after systemic injection and are not effective against internal tumors. When injected intravenously, virus-delivering Salmonella (VDS) is safe and colonizes tumors 50 million times more than clearance organs.

After colonization, VDS invades cancer cells, releases a virus-encoding plasmid, and initiates virion formation. Bacterial delivery of the H-1 parvovirus reduces both hepatocellular and pancreatic tumors, increases survival, and triggers the formation of tumor-specific splenocytes that prevent re-implantation. Treating with VDS increases dendritic cells, infiltration of CD8 T cells, and polarized macrophages.