Bacteriophage-mediated nucleic acid immunisation

Whole bacteriophage V particles, containing reporter genes under the control of the cytomegalovirus promoter (PCMV), have been used as delivery vehicles for nucleic acid immunisation. Following intramuscular injection of mice with V-gt11 containing the gene for hepatitis B surface antigen (HBsAg), anti-HBsAg responses in excess of 150 mIU ml31 were detected. When isolated peritoneal macrophages were incubated with whole V particles containing the gene for green fluorescent protein (GFP) under the control of PCMV, GFP antigen was detected on the macrophage surface 8 h later. Results suggested that direct targeting of antigen-presenting cells by bacteriophage ‘vaccines ’ may occur, leading to enhanced immune responses compared to naked DNA delivery. Bacteriophage DNA vaccines offer several advantages: they do not contain antibiotic resistance genes, they offer a large cloning capacity (V15 kb), the DNA is protected from environmental degradation, they offer the potential for oral delivery, and large-scale production is cheap, easy and extremely rapid