Genovac was approached by a client who wanted polyclonal antibodies against the human protooncogene RAS GTPase in a rat hostanimal. However, this was a challenge since this intracellular target shares an extremely high amino acid sequence similarity with its rat orthologue, at 98%.
In order to generate the polyclonal antibodies, genetic immunization was used. Here, the protein was routed to the cell surface tostimulate an immune response.
The methods that were used in this project and described in this case study demonstrate the possibility to generate antibodiesagainst a highly conserved, intracellular protein by genetic immunization. Due to immune tolerance, some proteins that are highly conserved between mice and humans are not very immunogenic in mice, making it difficult to generate antibodies using aconventional approach. Our genetic immunization proved to be an effective approach for the generation of antibodies against such a “difficult antigen”.
The client’s request was to generate polyclonals against the human RAS, thus the project terminated at Milestone 2 (generation ofpolyclonal serum) instead of going all the way through to Milestone 4 (generation of monoclonal antibodies).