Gene Gun Mediated Gene Transfer
This page was created as an assignment for Genetically Modified Organisms, an Undergraduate course at Davidson College
This picture Courtesy of Malcolm Campbell at Davidson College
The Gene Gun, also known as the microprojectile approach, was developed in the early 1980’s by Cornell University botanists at the New York State Agricultural Experiment Station in Geneva, N.Y. along with researchers at the Cornell Nanofabrication Facility (Voiland et al, 1999).
How it works
The gun consists of two 6” x 7” x 10” stainless steel chambers connected to a 2HP vacuum pump. The DNA to be delivered is attached to tiny gold or tungsten balls (1 micrometer in diameter). These balls are put onto a disk that is in the inside of the Gene Gun. A blast of helium at 1000 psi sends the disk shooting forward at approximately 1300 feet per second, roughly the same speed as a bullet leaving a rifle. A screen stops the disk and the tiny gold or tungsten balls are launched towards the target cells. The balls breech the cell membrane and release the DNA particles. The Gene Gun utilizes recombinant DNA technology to incorporate the expression of the delivered genes. The genetically altered cells can be used to make plants that include the desired genetic modification in all of their cells (Voiland et al, 1999).
Genetic Vaccination: Genes are introduced into the body using the Gene Gun with the purpose of eliciting an immune response to the proteins expressed by the delivered gene. This method of vaccination may be safer than other methods because only foreign DNA in introduced and not foreign proteins or killed vaccines (Lin et al, 2000).
Suicide Gene Therapy: This application of the Gene Gun has been used in the treatment of Cancer patients. A gene that expresses a toxic protein but has tumor specific promoters is introduced to tumor cells. When the protein is expressed the tumor cell dies. The protein is only toxic to tumor cells because the specific promoters needed for expression are only produced in tumor cells (Lin et al, 2000).
Immunomodulation: This method is also used to fight Cancer. Using the Gene Gun, a protein that will only be expressed in tumor cells but will also elicit an increased immune response are inserted. An increased immune response directed towards tumor cells is obviously a desired effect (Lin et al, 2000).
Genetic Pharmacology: The Gene Gun can be used to introduce genes that will produce proteins that are useful or therapeutic to an organism. Some examples of this may be clotting factors in hematologic disorders or increased production of red blood cells in organisms that are anemic. Sustained expression of the introduced genes is a problem in many cases often requiring multiple administrations (Lin et al, 2000).
A Research Tool: The gene gun can be used to insert promoters that will lead to the expression of certain genes. The effects of the amplification of certain proteins is a valuable way for researchers to study the functions of these proteins (Lin et al, 2000).
For more info on the gene gun click HERE
Campbell, Malcolm "The Helios gene gun by BioRad." 2001 <http://www.bio.davidson.edu/courses/Bio111/genegun.html>
Guttman, C., (2001). Variety of diseases potential targets for skin gene therapy. Dermatology Times 22, 8.
Lin, M., et al, (2000). The gene gun: current applications in cutaneous gene therapy. International Journal of Dermatology 39, 161-170.
Voiland, Michael, McCandless, Linda "Development of the 'gene gun' at Cornell." February 1999 <http://www.nysaes.cornell.edu/>
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© Copyright 2002 Department of Biology, Davidson College, Davidson, NC 28035