"Induction of Cytotoxic T Lymphocytes and Antitumor Immunity with DNA Vaccines Expressing Single T Cell Epitopes," by Frank Ciernik, Jay A. Berzofsky, and David P. Carbone explores the uses of the gene gun and how it can induce both humoral and cellular immunity. The paper specifically explores the effects of p53, a tumor repressor which gets its name from its molecular weight( p53 is a protein that has a molecular weight of 53). It is tremendously important because fifty percent of known cancer types stem from a mutation in this gene.
A Brief History of Immunization
Vaccines came about some 200 years ago when Jenner discovered that if someone caught a mild case of cowpox they would not get smallpox.
In 1879, another scientist, Louis Pasteur, accidentally discovered the vaccine for fowl cholera by leaving cultures out in his laboratory. Later, Pasteur went on to develop an effective vaccine for rabies.
The typhoid and cholera vaccines were produced by Wilhelm Kolle in 1896.
The groundwork for tetanus and diptheria toxid vaccines was laid by Emil von Behring and Emile Roux in the early 20th century.
In 1955, the polio vaccine, developed by Jonas Salk, was licensed.
The Contagious and Non-Contagious Infectious Diseases Sourcebook estimates that a vaccine for chickenpox developed by Merrick Sharp Dohme will soon be available.
There are many advantages to using gene immunization rather than protein immunization. For example, it is more effective at inducing cellular and humoral responses than protein. More importantly, it is safer.
By targeting only the desired epitope, this method of immunization avoids the induction of unwanted responses. A current example of an unwelcome response would be enhancing antibodies in HIV patients, which may promote infection. This, of course, needs to be avoided.
Gene immunization also minimizes the chance of the patient developing autoimmunity. Autoimmunity is the condition where the body mounts an immune response against its own cells and tissues. Obviously, this condition, which sometimes occurs with protein immunization is undesirable.
Furthermore, this method is safer than immunizing with a live or attenuated organism because the patient would not become infected with the organism -- for example, polio virus -- one is trying to immunize against. Even with today's technology, a small percentage of people contract polio from the vaccine. This would not happen if they are immunized with the specific CTL epitopes for this disease. Since the whole protein is not present, the patient would not contract the illness.
Genetic immunization is also more effective than protein immunization. In this approach, DNA enters a cell, replicates and produces protein which, in a sense, is similar to what a virus does. Simplistically, this tricks the immune system into believing that the cell is infected with a virus so that T-cells will recognize the cell, immediately divide and...