Presentation on DNA Vaccines

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Vaccines • Vaccines are “one of the greatest achievements of modern medicine” • In developed nations, vaccines have almost exterminated polio and smallpox and tightly controlled diseases like hepatitis A and B or typhus • There are three generations of vaccinations • First generation vaccines are either weakened or killed forms of whole organisms • There is a problem with first-gen vaccines: the pathogens can still revert to dangerous forms and cause diseases in immunocompromised vaccine recipients. • Second generation vaccines are specific protein antigens, which are safer, but cannot generate killer T cell responses DNA Vaccines • Third generation of vaccines • Consist of recombinant plasmids that have been transformed to produce one to two proteins form a pathogen • This DNA is injected directly into somatic cells, where, through transcription and translation, the proteins are created. • The proteins are recognized as foreign and processed by the cell and displayed on the cell surface by MHC markers • Here, they raise helper T cell, cytotoxic T cell, and antibody immune responses. Current applications • DNA vaccines have had limited success in clinical trials • A veterinary DNA vaccines for use on horses to protect from West Nile virus has been approved • In June 2006 and August 2007, positive results were announced for vaccines against bird flu and multiple sclerosis, respectively. • The technique still needs to proven conclusively in human testing Use of Plasmid Vectors • Highly active expression vectors elicit the best immune response • Strong viral promoters, such as Rous Sarcoma virus (RSV) or cytomegalovirus (CMV) promoters are most commonly used • The plasmids most commonly used als... ... middle of paper ... ... Cited Continued • Baker, Barbara, et. al. “The N gene of tobacco confers resistance to tobacco mosaic virus in transgenic tomato.”Proceedings of the National Academy of Sciences of the United States93 (1996) 8776–8781. • Feldstein, Paul. Personal interview. July 2008. Fig. 8 Images • Fig. 1: http://www-tc.pbs.org/wgbh/nova/bioterror/images/germ_dna.jpg • Fig 2: http://www.gen.cam.ac.uk/Images/summers/plasmids.jpg • Fig 3:http://www.bio.davidson.edu/people/kabernd/seminar/2002/method/gtwmeth/genegungtw.gif • Fig 6:http://upload.wikimedia.org/wikipedia/commons/d/da/Making_of_a_DNA_vaccine.jpg • Fig. 4: http://en.wikipedia.org/wiki/Image:Antibody.svg • Fig. 5: http://en.wikipedia.org/wiki/Image:Antigen_presentation.jpg • Fig. 7: http://www.ncbi.nlm.nih.gov/ICTVdb/ICTVdB/em_tmv.gif • Fig 8: http://www.technologyreview.com/files/8829/DNAVaccineBG.jpg

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