Scientists discover how deadly fungus protects itselfFebruary 04, 2009Researchers at Albert Einstein College of Medicine of Yeshiva University have discovered how a deadly microbe evades the human immune system and causes disease. The study, published in the journal Proceedings of the National Academy of Sciences (PNAS), may help scientists develop new therapies or vaccines against infections caused by Cryptococcus neoformans. These fungal infections occur most commonly in those with compromised immune systems ─ especially AIDS patients and transplant patients who must take lifelong immunosuppressive therapy. The fungus causes an estimated one million deaths each year worldwide, including some 600,000 in sub-Saharan Africa. The lead author of the study was Susana Frases-Carvajal, Ph.D., a postdoctoral fellow in microbiology & immunology at Einstein. C. neoformans typically enters the body through the lungs and can spread throughout the body, including the brain. The resulting infection, called cryptococcosis, can cause chest pain, dry cough, abdominal swelling, headache, blurred vision, or confusion. The infection can be fatal, especially if not treated with antifungal medications. "It's a horrendous disease, and even with therapy, you often can't get rid of it," says the paper's senior author, Arturo Casadevall, M.D., Ph.D., professor and chair of microbiology & immunology. Scientists have known that 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," says Dr. Casadevall. "But we didn't understand the mechanism responsible for capsule growth." The protective capsule of C. neoformans is composed of polysaccharides, which are long chains of sugar molecules, or saccharides. Using a technique called dynamic light scattering, Dr. Frases and her colleagues found that 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. The findings point to potential new targets for drug intervention and reveal a new area of investigation into basic polysaccharide biology. Polysaccharides are poorly understood, partly because of the difficulty of working with them. "Also, scientists have tended to view polysaccharides as boring molecules that simply grow to a specified length," says Dr. Casadevall. "But this study raises huge questions about polysaccharides," he adds. "For example, how does the organism assemble these molecules, and how does it know how to make molecules that are roughly the same length? We don't know. There appears to be a whole dimension of cellular machinery that we never knew existed." Albert Einstein College of Medicine |
|||||||||||||||||||||
| Related Neoformans Current Events and Neoformans News Articles Fungus Found in Humans Shown To Be Nimble in Mating Game Brown University researchers have determined that Candida albicans, a human fungal pathogen, pursues both same-sex and the more conventional opposite-sex mating. The findings are published in the August 2009 edition of the journal Nature. Einstein scientists treat cancer as an infectious disease -- with promising results Researchers at the Albert Einstein College of Medicine of Yeshiva University have shown for the first time that cancers can be successfully treated by targeting the viruses that cause them. Evidence of same-sex mating in nature: the story of Cryptococcus neoformans Cryptococcus neoformans is a major cause of fungal meningitis in predominantly immunocomprised individuals. This fungus has two mating-types/sexes, and mating typically requires two individuals with opposite mating types. Einstein researchers' discover 'radiation-eating' fungi Scientists have long assumed that fungi exist mainly to decompose matter into chemicals that other organisms can then use. But researchers at the Albert Einstein College of Medicine of Yeshiva University have found evidence that fungi possess a previously undiscovered talent with profound implications: the ability to use radioactivity as an energy source for making food and spurring their growth. Infectious disease researchers develop basis for experimental melanoma treatment While investigating a fungus known to cause an infection in people with AIDS, two grantees of the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health (NIH), unexpectedly discovered a potential strategy for treating metastatic melanoma, one of the deadliest forms of skin cancer. Skeletal Muscle Repairs the Heart; Gray Wolves Maintain the Food Chain in Winter: Press Release from PLoS Biology Heart Repair Gets New Muscle Some organs in the human body deal with injury better than others. A flesh wound or muscle tear might hurt, but, assuming you are otherwise healthy, both will heal. The prognosis for a heart attack, on the other hand, is not so clear-cut. More Neoformans Current Events and Neoformans News Articles |
|||||||||||||||||||||
|
|||||||||||||||||||||
|
|||||||||||||||||||||