The potential for DNA vaccination against Mannheimia haemolytica using green fluorescent protein gene fusions

Bovine pneumonic pasteurellosis, caused by Mannheimia haemolytica , is a problem which continues to plague the cattle industry. Current vaccines against pasteurellosis are only moderately effective, prompting the investigation of alternative vaccine technologies in an attempt to improve vaccine efficacy. The studies described in this thesis were designed to explore the potential for the development of DNA vaccination against M. haemolytica by targeting several genes whose products are involved in the pathogenesis of M. haemolytica for use in a plasmid-based DNA vaccine. A method for vaccinating rabbits intradermally with plasmid DNA that can result in an immune response is described. Vaccination of rabbits and mice using DNA vaccines containing gene sequences derived from M. haemolytica fused to the amino terminus of the gene for green fluoresence protein (GFP) was attempted, but errors in the formulation of the plasmid sequence used for the experimental vaccine have rendered some of the studies of limited value. However, these studies do demonstrate the successful expression of GFP in cells after transfection with plasmids which contain a large insert of "nonsense" DNA before the GFP sequence. Recent work in the DNA vaccination field using fusion protein vectors including GFP is also discussed.