PRESS-NEWS.org - Press Release Distribution
PRESS RELEASES DISTRIBUTION

Fungus uses copper detoxification as crafty defense mechanism

2013-03-14
(Press-News.org) DURHAM, NC – A potentially lethal fungal infection appears to gain virulence by being able to anticipate and disarm a hostile immune attack in the lungs, according to findings by researchers at Duke Medicine.

Defense mechanisms used by the fungus Cryptococcus neoformans enable it to lead to fatal meningitis, which is one of the opportunistic infections often associated with death in HIV/AIDS patients, organ transplant recipients, diabetics and other immunosuppressed patients. In describing the complex process of how C. neoformans averts destruction in the lungs of mice, the Duke researchers have opened new options for drug development.

"Very few antifungal drugs are effective, so we need to identify the Achilles' heel of these fungal pathogens," said Dennis J. Thiele, PhD, the George Barth Geller Professor of Pharmacology and Cancer Biology at Duke University. Thiele is senior author of a study published March 13, 2013, in the journal Cell Host & Microbe. "With this research we may be closer to understanding how this fungal pathogen evades death in its host, and hopefully be closer to finding effective treatments."

Found in the environment, C. neoformans spores can be inhaled and cause infection, particularly when people have weakened immune systems. The Centers for Disease Control and Prevention estimates that worldwide, C. neoformans causes 1 million cases of meningitis a year among HIV/AIDS patients, with nearly 625,000 deaths.

Thiele and colleagues focused on the interplay between C. neoformans in the lungs of mice and the host's immune system, which mount an immediate attack against the pathogen.

The immune response is led by macrophages, which circulate in the blood stream and engulf invading microbes to destroy them. The macrophages are essentially tiny torture chambers for pathogens, using hostile conditions and toxic substances to kill invaders.

Among the substances inside the macrophages is copper, a mineral the body needs for normal cognitive function and development, but also known to have antifungal properties. In the face of a pathogenic invasion of fungal spores, the macrophages begin concentrating more copper within their torture chamber as one of the body's antifungal weapons.

The Duke researchers found that lethal strains of C. neoformans have two ways of battling against the toxicity of the copper. First, the pathogen turns on genes that make proteins to protect it from copper toxicity, so even when exposed to the hostile copper environment in the macrophages, it survives.

But a second defense mechanism is also deployed. The fungus, sensing the copper-rich environment, triggers a response that shuts down the host's ability to pump more copper into the macrophages – defusing this weapon in the immune system's arsenal.

"With these two mechanisms, C. neoformans can defend itself by sequestering the copper, and somehow communicate to the host macrophage, commanding that it shut down the copper pumps," Thiele said.

Thiele said studies are now focusing on how antifungal agents might thwart the pathogen's two defense systems. "The detoxification machinery might represent an effective drug target," Thiele said.

### In addition to Thiele, study authors include Chen Ding, Richard A. Festa, Ying-Lien Chen and Joseph Heitman from Duke; Anna Espart and Sílvia Atrian from Universitat de Barcelona, Spain; Òscar Palacios, Jordi Espín and Mercè Capdevila from Universitat Autònoma de Barcelona, Spain.

The work was supported in part by the National Institutes of Health (GM48140-24, 2P30 AI064518-06, AI50438).



ELSE PRESS RELEASES FROM THIS DATE:

Study: Dynamic new software improves care of aging brain

Study: Dynamic new software improves care of aging brain
2013-03-14
INDIANAPOLIS -- Innovative medical records software developed by geriatricians and informaticians from the Regenstrief Institute and the Indiana University Center for Aging Research will provide more personalized health care for older adult patients, a population at significant risk for mental health decline and disorders. A new study published in eGEMs, a peer-reviewed online publication recently launched by the Electronic Data Methods Forum, unveils the enhanced Electronic Medical Record Aging Brain Care Software, an automated decision-support system that enables care ...

Mayo Clinic and Illinois researchers develop new sensor for methylated DNA

2013-03-14
ROCHESTER, Minn. -- Collaborators from Mayo-Illinois Alliance for Technology Based Healthcare have developed a new, single molecule test for detecting methylated DNA. Methylation -- the addition of a methyl group of molecules to a DNA strand -- is one of the ways gene expression is regulated. The findings appear in the current issue of Scientific Reports (Nature Publishing Group). "While nanopores have been studied for genomic sequencing and screening analysis, this new assay can potentially circumvent the need for some of the current processes in evaluating epigenetics-related ...

Researchers divide enzyme to conquer genetic puzzle

2013-03-14
Rice University researchers have found a way to divide and modify enzymes to create what amounts to a genetic logic gate. Biochemist Matthew Bennett and graduate student David Shis created a library of AND gates by mutating a protein from a bacterial virus. The well-understood protein known as T7 RNA polymerase (RNAP) is a strong driver of transcription in cells. Their discovery should help overcome a bottleneck in the development of synthetic gene networks that mimic digital circuitry. These networks could become diagnostic systems that look for signs of disease and, ...

News tips from the journal mBio®, volume 4, issue 1

2013-03-14
Disarming One of the Deadliest Pathogens Francisella tularensis, the cause of tularemia and one of the deadliest respiratory pathogens in existence, is considered a potential biological weapon because it is readily aerosolized and exhibits a high degree of infectivity and lethality in humans. While a live attenuated vaccine strain has been developed, it remains unlicensed because scientists have been unable to understand the basis for its attenuated virulence. In an attempt to find an acceptable live attenuated vaccine strain, researchers from Harvard Medical School ...

Outside the box: UCLA uses brain aneurysm treatment to stop irregular heart rhythms

2013-03-14
For the first time, a UCLA team has used a technique normally employed in treating brain aneurysms to treat severe, life-threatening irregular heart rhythms in two patients. This unique use of the method helped stop ventricular arrhythmias — which cause "electrical storms" — that originated in the septum, the thick muscle that separates the heart's two ventricles. This area is virtually impossible to reach with conventional treatment. The research is published in the February issue of Heart Rhythm, the official journal of the Heart Rhythm Society, and is highlighted ...

College kids who don't drink milk could face serious consequences

2013-03-14
URBANA – College-age kids who don't consume at least three servings of dairy daily are three times more likely to develop metabolic syndrome than those who do, said a new University of Illinois study. "And only one in four young persons in the study was getting the recommended amount of dairy," said Margarita Teran-Garcia, a U of I professor of food science and human nutrition. That alarming finding means that three-fourths of the 18- to 25-year-old college applicants surveyed are at risk for metabolic syndrome, the researcher said. Metabolic syndrome occurs when ...

Particles and fields package integrated on upcoming Mars-bound spacecraft

Particles and fields package integrated on upcoming Mars-bound spacecraft
2013-03-14
The six science instruments that comprise the Particles and Fields Package that will characterize the solar wind and ionosphere of Mars have been integrated aboard NASA's Mars Atmosphere and Volatile EvolutioN (MAVEN) spacecraft. The spacecraft is on track for launch later this year. The Solar Wind Electron Analyzer (SWEA) was the last of the six instruments to be delivered, and was integrated late last week at Lockheed Martin in Littleton, Colo. SWEA measures the properties of electrons at Mars, one electron at a time, and can process up to one million events per second. The ...

NASA sees Cyclone Tim develop in the Coral Sea

NASA sees Cyclone Tim develop in the Coral Sea
2013-03-14
System 96P has been moving through the Coral Sea near northeastern Australia over the last couple of days, and today, March 14, NASA's Aqua satellite captured the storm as it matured into Tropical Storm Tim. The Moderate Resolution Imaging Spectroradiometer (MODIS) instrument aboard NASA's Aqua satellite captured a visible image of Tropical Cyclone Tim in the Coral Sea on March 13, 2013 at 04:05 UTC (12:05 a.m. EDT). The MODIS image showed a large band of thunderstorms wrapping into the center of circulation from the south and east. Cyclone Tim's northeastern quadrant ...

Witnessing starbursts in young galaxies

2013-03-14
On March 13, it was announced the most vigorous bursts of star birth in the cosmos took place much earlier than previously thought - results now published in a set of papers in Nature and the Astrophysical Journal. As these findings are published, three of the scientists at the forefront of this research - including the lead researcher of the latest findings – offered their insights about what this reveals about the history of our universe, and how the Atacama Large Millimeter/submillimeter Array (ALMA) is providing a "zoom lens" into the early universe. This includes ...

People with peanut/tree nut allergies can minimize risk of reactions on airplane flights

2013-03-14
Ann Arbor, Mich. — Few situations can provoke more anxiety for people with peanut or tree-nut allergies than having an allergic reaction while flying on an airplane and being unable to get help. But in a new study, published in the Journal of Allergy and Clinical Immunology-In Practice, researchers found passengers who engaged in eight mitigating factors were less likely to report an allergic reaction. This is the first study to show that in-flight peanut and tree nut allergy is an international problem, says lead author and pediatrician Matthew Greenhawt, M.D., M.B.A., ...

LAST 30 PRESS RELEASES:

Two scientific researchers to receive 2025 Ralph L. Sacco Scholarships for Brain Health

Researchers improve chemical reaction that underpins products from foods to fuels

Texas Tech to develop semiconductor power devices through $6 million grant

Novel genomic screening tool enables precision reverse-engineering of genetic programming in cells

Hot Schrödinger cat states created

How cells repair their power plants

Oxygen is running low in inland waters—and humans are to blame

ACP’s Best Practice Advice addresses use of cannabis, cannabinoids for chronic noncancer pain

Beyond photorespiration: A systematic approach to unlocking enhanced plant productivity

How a small number of mutations can fuel outbreaks of western equine encephalitis virus

Exposure to wildfire smoke linked with worsening mental health conditions

Research uncovers hidden spread of one of the most common hospital-associated infections

Many older adults send their doctors portal messages, but who pays?

Fine particulate matter from 2020 California wildfires and mental health–related emergency department visits

Gender inequity in institutional leadership roles in US academic medical centers

Pancreatic cells ‘remember’ epigenetic precancerous marks without genetic sequence mutations

Rare combination of ovarian tumors found in one patient

AI-driven clinical recommendations may aid physician decision making to improve quality of care

Artificial intelligence has potential to aid physician decisions during virtual urgent care

ACP and Annals of Internal Medicine present breaking scientific news at ACP’s Internal Medicine Meeting 2025

New study reveals polymers with flawed fillers boost heat transfer in plastics

Signs identified that precede sudden arrhythmic death syndrome in young people

Discovery of bacteria's defence against viruses becomes a piece of the puzzle against resistance

Pre-eclampsia is associated with earlier onset and higher incidence of cardiovascular risk factors

Warwick astronomers discover doomed pair of spiralling stars on our cosmic doorstep

Soil conditions significantly increase rainfall in world’s megastorm hotspots

NK cells complexed with bispecific antibody yield high response rates in patients with lymphoma

Planetary health diet and mediterranean diet associated with similar survival and sustainability benefits

Singapore launches national standard to validate antimicrobial disinfectant products

Molecular stool test could improve detection of tuberculosis in adults with HIV

[Press-News.org] Fungus uses copper detoxification as crafty defense mechanism