Fighting Fungus With Fat
WHEN THE BODY'S IMMUNE system is weakened by AIDS or cancer chemotherapy, normally harmless fungi such as aspergillus (picture) can spread to the lungs and other organs, causing inflammation. Drugs based on a compound called amphotericin-B control fungal infections but cause side effects such as chills and kidney damage. So the Food & Drug Administration recommends their use only for diagnosed fungal infections.
Now, drug companies and research scientists are making important strides against fungal infections. NeXstar Pharmaceuticals Inc. in Boulder, Colo., is selling a drug called AmBisome, which encases amphotericin-B in tiny, synthetic bubbles of fat called liposomes. These keep the drug molecules sealed up until they have time to reach the fungus cells. So less goes a longer way. The FDA has cleared AmBisome for first-line use against suspected fungal infections.
Separately, biologist Gerald Fink, director of the Whitehead Institute for Biomedical Research in Cambridge, Mass., and his colleagues have shed light on the infectious mechanism of Candida albicans, another fungal scourge for AIDS and chemotherapy patients. The fungus' infectiousness depends on a genetic switch that lets it project protein filaments into host cells. In experiments with mice, Fink found a way to deactivate this switch and reduce the fungus' virulence.