Generation of high-affinity monoclonal antibodies via genetic immunization

Genetic immunization takes advantage of immunology and DNA-technology to synthesize monoclonal as well as polyclonal antibodies: following subcloning of cDNAs encoding the antigen of interest, animals are ?transfected? with these expression plasmids that in the majority (more than 80% success rate) elicit an immune response.
The methodology, first described in the early 90s, even enables researchers to obtain antibodies directed against proteins that may not be purified recombinantly. Nowadays, genetic immunization is intensively studied with the purpose of establishing this methodology as a new form of vaccination.

Background: To generate antibodies conventional immunization protocols require the isolation and purification of proteins. This is time-consuming and often frustrating due to misfolding of proteins in bacteria. Furthermore, posttranslational modifications are lacking in bacterially expressed proteins. Therefore, mammalian expression systems (e.g. the baculosystem) have been established to obtain modified proteins. However, these systems are even more time consuming. Alternatively, peptides are synthesized and used as antigens. When applying genetic immunization neither proteins nor peptides are delivered to the host. Instead, an expression vector encoding for the protein (or protein fragment) is introduced. Protein synthesis takes place in vivo and elicits an immune response. Genetic immunization holds several advantages over conventional protocols:

  • Proteins are formed in vivo, resulting in production of proteins in their natural conformation and with all possible posttranslational modifications.
  • Furthermore antibodies generated by genetic immunization exhibit a 100 to 1000-fold higher affinity for the antigen compared to conventionally generated antibodies.
  • By immunizing with several expression plasmids encoding for different (associated) proteins, antibodies against multiprotein complexes may be generated.
  • Genetic immunization leads to time and cost savings since isolation and purification of proteins is no longer required.
In summary, genetic immunization is an important innovation for all researchers that rely on antibodies and that lack appropriate tools to perform their research. It is time-saving and meets all criteria for high quality antibodies for research.

Several antibodies generated by genetic immunization are available at IL-13R (Human) antibody, IL-13R (ANTAGONISTIC) (Human) antibody, Granzyme B (Human) antibody, Granzyme K (Human) antibody, Granzyme K (Human) antibody, Granzyme K (Human) antibody, ICOS Ligand (Human) antibody, FAS Ligand (Human) antibody, CEA-CAM1 (Human) antibody, CEA-CAM6 (Human) antibody, FPRL1 (Human) antibody

Source: Garcia J-F et al. Genetic Immunization: A New Monoclonal Antibody for the Detection of BCL-6 Protein in Paraffin Sections. Journal of Histochemistry & Cytochemistry. Vol 54 (1): 31-38. 2006

Bates M K et al. Genetic Immunization for Antibody Generation in Research Animals by Intravenous Delivery for Plasmid DNA. BioTechniques. Vol 40 (2):199-207. 2006

Lohrmann J et al. A Shortcut from Genomics to Drug Development and Therapy. Current Drug Discovery. October 2003: 17-21. 2003