Disease-Fighting Molecule Boosts Immune System

Scientists are getting ready to publish the first detailed results of their synthesis of a remarkable molecule that has been shown to improve the immune system's ability to battle disease.

Called QS-21A, it has been used in more than 80 clinical trials of therapeutic vaccines against melanoma, breast cancer, small cell lung cancer, HIV, and malaria. Unlike more recognizable vaccines used to prevent disease, therapeutic vaccines treat disease that already has occurred. QS-21A is added to therapeutic vaccines as an adjuvant, or booster that enhances the vaccine's effects. QS-21A makes vaccines more powerful, and allows some to be effective at lower doses.

QS-21A's effects have been known for 80 years. However, the substance was available previously in limited quantities because it had to be extracted from the bark of a South American tree. In 2005, however, Dr. David Y. Gin and colleagues from the University of Illinois at Urbana-Champaign (USA) synthesized QS-21A. In their latest study, published in the August 30, 2006, issue of the Journal of the American Chemical Society, the researchers provide vital data that should enable researchers to produce analogues, or molecular variants of QS-21A. This study may also help solve the mystery of how QS-21A works, according to Dr. Gin, and why it is so potent. Some of the new analogues could be even be found to be more effective.



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University of Illinois at Urbana-Champaign