Genetic therapy requires retroviral vectors, which insert the "healthy" genes into the patient's DNA. The virus particles are normally produced at a temperature of 37oC. A team of molecular biologists in Leiden (funded by the NWO's Medical Sciences Division) have developed a method of increasing production of the retroviral vectors by a factor of five or 10. This is done by reducing the temperature to 32oC. The new method makes genetic therapy more effective because the quantity of virus particles used determines the chance of success when inserting the genetic material.

When virus particles are produced at a temperature of 37oC, half of them are broken down within 10 hours. Reducing the temperature to 32oC slows down this process considerably, even though the viruses are produced just as quickly. This means that it is possible to produce far more virus particles. Temperatures above and below 32oC make the particles less stable.

The virus particles contain RNA which in human cells is transcribed into DNA. Inserting correct genetic material into mutated chromosomes offers major possibilities in the treatment of genetic disorders. It also means that cells can be made more resistant to such diseases as cancer and AIDS.

Further information:
Dr. Leonie Kaptein (University Leiden)
T 31-20-617-8753 or 31-71-527-6076
E-mail kaptein@chem.leidenuniv.nl

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Contact: Dr. Leonie Kaptein
kaptein@chem.leidenunvi.nl
31-20-6178753
Netherlands Organization for Scientific Research
18-Jun-1998