Protein Transduction.

The use of protein transduction technology to fight HIV infection is through an elegant "Trojan Horse" mechanism. It involves the transduction of a protein which has been engineered with a target site for HIV protease. Therefore this protein will only become activated in cells containing HIV protease and remains dormant in uninfected cells. Upon activation this target protein turns on a cell suicide pathway. Thus cells infected with HIV are killed specifically and it has been shown experimentally in cell culture that they are killed with a high frequency.

This therapy is also versatile in that the engineered site for HIV protease may be easily modified if drug resistant strains arise. This flexibility differs from current chemically based drugs because resistance, once it arises, often applies to a whole family of similar compounds. Protein transduction based therapies may enable patients to keep ahead of drug resistance. Current protease inhibitors have another drawback in that they do not kill the virus but merely put it in stasis. However, cells containing the virus continue to multiply and have the potential to develop drug resistant strains and will resume production of virus once therapy is discontinued. Alternative mechanisms of HIV-infected cell killing using protein transduction are also being investigated.

To transduce proteins involves the addition of a tag and purification of the tagged proteins. This technique is quite flexible and applicable to numerous targets. There are a large number of potential applications for this technology in basic research and in the treatment of other diseases (eg Hepatitis C and cancer). There is some irony to the application of this technology to HIV treatment in that the tag itself is derived from an HIV protein. Protein transduction, if clinical trials are successful, may yield an AIDS therapy that is much less expensive than current drugs which will be a boon to patients who are unable to afford current treatment regimens and to nations that are being devastated by this disease.

Protein transduction is likely to be employed in basic research to study the underlying mechanisms of aging and it is possible that it may be applied to stave off the aging process. One potential application would be to introduce telomerase into cells using the transduction tag in order to extend the lifespan of cells in which telomeres have become a limiting factor. So look forward to hearing more about protein transduction in the future and look for updates here at immortality.org.

This article is dedicated to my great-aunt Mary Haslam who recently passed away at the age of 90 years. She spent a life teaching and she taught me a love of reading and of learning.