NEW YORK, Feb. 5 (UPI) -- U.S. scientists say they have determined how a deadly fungus microbe -- Cryptococcus neoformans -- evades the human immune system and causes disease.
Albert Einstein College of Medicine researchers said their findings may help scientists develop new therapies or vaccines against fungal infections, such as those that occur in AIDS and transplant patients who must take lifelong immunosuppressive therapy.
Scientists have known the capsule surrounding C. neoformans is essential to its ability to cause disease. When the fungus enters a host, the capsule begins to enlarge. "As the capsule grows larger, it reaches a point where immune system scavenger cells, known as macrophages, can't swallow it," said Professor Arturo Casadevall, the study's senior author. "But we didn't understand the mechanism responsible for capsule growth."
The protective capsule is composed of polysaccharides, which are long chains of sugar molecules, or saccharides. The researchers, using a technique called dynamic light scattering, discovered the capsule grows by linking more and more saccharides together at the outer edge of the capsule, forming giant molecules pointing in an outward, or axial, direction.
They said their findings may lead to potential new targets for drug intervention and reveal a new area of investigation into basic polysaccharide biology.
The study appears in the Proceedings of the National Academy of Sciences.
