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See how scientists @OSUWexMed are using glowing cells to spot a growing threat from fungi. Details: http://bit.ly/1aCFk9k  
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Chad Rappleye, Ph.D.


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Glowing Cells Help Spot A Growing Threat

Lung infections from fungi are up, can be dangerous & costly to treat

(COLUMBUS, Ohio) October 2013 – From the mold on a shower curtain, to floor of the gym locker room to the dirt in your back yard, we are exposed to fungi every day.  Most of the time they’re harmless, but lung infections caused by breathing in the spores of the fungus Histoplasma capsulatum are on the rise.

It’s estimated 100,000 people each year develop histoplasmosis and there aren’t many good treatment options.  “Depending on the degree of the infection, treatments can last from a few weeks to even up to a year, and the side effects can be pretty bad,” said Chad Rappleye, PhD, a microbiologist in the Center for Microbial Interface Biology at The Ohio State University Wexner Medical Center.

So, Rappleye has come up with a new approach.  He’s discovered a way to mark the fungal cells, so whenever they grow, they glow.  Using fluorescent light, Rappleye says the fungi turn bright red under the microscope.  This advancement enabled Rappleye and co-workers to identify a new compound that inhibits the growth of Histoplasma cells while they are living inside human cells.  This potential new antifungal drug could lead to a new way to fight the pathogen without harming human cells.

To see how this approach works click the video box to the left.  To read the full press release, “click to read more” link below.

 

 

 

 

 

 

 

NEW DRUG CANDIDATE FOUND FOR FUNGAL LUNG INFECTIONS

COLUMBUS, Ohio – On a molecular level, you have more in common with shower curtain mold or the mushrooms on your pizza than you might think. Humans and fungi share similar proteins, a biological bond that makes curing fungal infections difficult and expensive. Current costs to treat these stubborn infections can top $50,000 per patient, and no new classes of antifungal drugs that treat systemic infections have been introduced for at least 20 years.

Now, researchers at The Ohio State University Wexner Medical Center have discovered a new compound that could be developed as an antifungal drug to treat histoplasmosis and cryptococcosis, two types of fungal infections that are naturally drug-resistant.

Generally, people with weakened immune systems are more likely to develop life-threatening fungal infections. However, the airborne fungus Histoplasma capsulatum, which causes histoplasmosis, can infect healthy people as well.

“Histoplasmosis is an unusual fungal disease because anyone can be infected, not just people with compromised immune systems. Like tuberculosis, Histoplasma infects healthy hosts, attacks their lungs, and can lie dormant in immune cells for years, later causing reactivation disease,” said Chad Rappleye, PhD, a microbiologist in the Center for Microbial Interface Biology at Ohio State’s Wexner Medical Center and in the Department of Microbial Infection and Immunity at Ohio State’s College of Medicine. “So this is an unrecognized public health threat that’s needed better treatment options for some time.”

There are an estimated 100,000 Histoplasma infections each year in the United States. Most are contained by the body’s immune system, but each year a few thousand people will develop chronic or life-threatening histoplasmosis disease requiring hospitalization and antifungal treatment.  The antifungals currently used to treat the infection have undesirable toxic side effects requiring monitoring by a physician and may need to be taken for weeks or months.

Histoplasma is particularly good at avoiding detection by the body’s immune system and surviving the immune response,” said Jessica Edwards, PhD, a postdoctoral researcher at Ohio State University.

Respiratory histoplasmosis manifests with flu-like symptoms, often making diagnosis difficult.  Rappleye says people with histoplasmosis have been mistakenly diagnosed with colds, the flu, and even lung cancer. “It depends on how familiar a physician is with histoplasmosis,” he said. Intrigued by the challenges of finding a new drug that would target the fungus without harming the human host, in 2012, Rappleye received pilot funding from Ohio State’s Center for Clinical and Translational Science (CCTS) and the Public Health Preparedness for Infectious Diseases Program (PHPID).

Rappleye’s team searched a library of commercially-available small molecules used by other investigators to find new antivirals or anticancer drugs. They performed a high-throughput phenotypic screen of 3,600 compounds looking for agents that inhibited fungal, but not human, cells.

To speed the selection process, Rappleye and Edwards engineered Histoplasma cells with a fluorescent protein that made the cells glow red while inside of a living macrophage – the type of mammalian immune cell that Histoplasma attacks and in which it reproduces.

As the number of fungal cells increased inside the macrophage, so did the fluorescence and consequently, the cells would glow brighter.  However, when a macrophage was exposed to an active compound that prevents Histoplasma reproduction, it maintained the same level of brightness.  This allowed the scientists to quickly determine efficacy and toxicity of the drug candidate in a natural environment.

“Not only were we able to visually screen thousands of compounds in just a few weeks, but we were also able to measure the compound’s impact in a real, live host cell,” said Edwards.

The team narrowed down to a primary candidate called 41F5, which is 60 times more toxic to fungal cells than human cells. Their work was recently published in the September Antimicrobial Agents and Chemotherapy.

The team is currently working with Werner Tjarks, PhD, a medicinal chemist at Ohio State, to see if the selectivity and toxicity profile can be enhanced further for additional testing. Rappleye is also working with the Ohio State’s Technology Commercialization Office (TCO) to potentially commercialize the derivatives from 41F5.

“There are people here in the U.S. and around the world suffering from varying degrees of histoplasmosis that need a safer and better treatment option. Our pilot study outcomes and methods are very encouraging, and I’m hopeful that with additional funding from the National Institutes of Health, we’ll be able to keep moving at this accelerated pace,” Rappleye said.

Histoplasma capsulatum spores are found across a broad stretch of the Midwest and southern United States. Experts estimate that 80 percent of people who live in the region have been exposed, and that nearly 10 to 25 percent of all AIDS patients living in these areas will develop a histoplasmosis infection. Once inhaled, the fungal cells can cause symptoms similar to an upper respiratory infection, and disease severity is dependent on how many spores are inhaled. In rare cases, histoplasmosis can cause blindness, joint pain, or life-threatening complications including meningitis and heart problems.

 

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/newmedia/mcp/osunch/2013/oct13/lungfungus/8-Images/1-Photos/01_pointing.jpg
Glowing cells help spot a growing threat
Chad Rappleye, PhD, tracks an active lung infection at The Ohio State University Wexner Medical Center. Rappleye discovered a process in which active fungal infections turn bright red under fluorescent light, making them easier to find. His work could lead to a new class of drugs to treat fungal infections in humans. Details: bit.ly/1aCFk9k
/newmedia/mcp/osunch/2013/oct13/lungfungus/8-Images/1-Photos/02_Close_up.jpg
Looking for effective new therapies for fungal infections
Spotting fungal infections can be hard and treating serious cases can be difficult. Thanks to the work of Chad Rappleye, PhD of The Ohio State University Wexner Medical Center, that could someday change. Rappleye has discovered a way to mark fungal infections so they turn bright red when active. His discovery could lead to a badly needed new class of drugs to fight fungal infections. Details: bit.ly/1aCFk9k
/newmedia/mcp/osunch/2013/oct13/lungfungus/8-Images/1-Photos/03_Microscope_wide.jpg
New drug candidate found for fungal lung infections
Chad Rappleye, PhD, points to the red, glowing cells of an active fungal infection. Rappleye, a researcher at The Ohio State University Wexner Medical Center, says current therapies for treating fungal infections in humans are expensive and often have serious side effects. His technique could lead to a new class of drugs that will help find and stop infections, while doing little or no damage to healthy cells. Details: bit.ly/1aCFk9k
/newmedia/mcp/osunch/2013/oct13/lungfungus/8-Images/1-Photos/04_Screen_foreground.jpg
New technique for tracking fungal infections makes active infections glow
The discovery of a new way to mark fungal infections in humans could lead to new drugs to treat them. Chad Rappleye, PhD, a researcher at The Ohio State University Wexner Medical Center, found a way to make active fungal cells glow bright red when exposed to fluorescent light. That`s important because fungal cells hide inside healthy human cells, so finding and killing them is difficult and costly. Details on the new process here: bit.ly/1aCFk9k
/newmedia/mcp/osunch/2013/oct13/lungfungus/8-Images/1-Photos/05_Posing.jpg
Process allows scientists to track fungal infections in humans. When they grow, they glow
It`s estimated 100,000 people a year develop lung infections from a fungus known as histoplasmosis capsulatum. Anne Unger had an infection that went undiagnosed for years, which spread and nearly cost her the sight in her right eye. Now, researchers at The Ohio State University Wexner Medial Center have developed a new way to spot those infections earlier. Details: bit.ly/1aCFk9k
/newmedia/mcp/osunch/2013/oct13/lungfungus/8-Images/1-Photos/06_Anne_close.jpg
Fungal infections that develop in the lungs can do serious damage in other parts of the body
A fungal lung infection went undiagnosed in Anne Unger for years. It eventually spread and nearly took the sight from her right eye. Experts say 100,000 people get lung infections each year from the histoplasmosis capsulatum fungus, and treating often comes with serious side affects. Researchers at The Ohio State University Wexner Medical Center have found a way to make those infections glow bright red under the microscope, so they can find and possible treat them much sooner and with fewer side effects. Details on their discovery here: bit.ly/1aCFk9k
/newmedia/mcp/osunch/2013/oct13/lungfungus/8-Images/1-Photos/07_Anne_raking.jpg
Histoplasmosis capsulatum, a fungus common in the midwest and south, is often inhaled by humans when soil is disturbed
Disturbing the soil in the midwest and southern US often releases spores into the air of a fungus known as histoplasmosis capsulatum. Most of the time the fungus is harmless, but an estimated 100,000 people a year develop lung infections because of it, and treating those patients can take months and cost $50,000 each. Researchers at The Ohio State University Wexner Medical Center have discovered a new way to find those infections, which could lead to a class of drugs that is safer and cheaper to use. Details: bit.ly/1aCFk9k
/newmedia/mcp/osunch/2013/oct13/lungfungus/8-Images/1-Photos/08_Anne_medium.jpg
Fungal lung infections affect nearly 100,000 people each year, and treating them can be difficult and costly
Anne Unger was one of the tens of thousands of patients each year who battled a serious fungal infection. Starting in her lungs years ago, the infection migrated and nearly cost Anne the vision in her right eye. Finding and treating fungal lung infections can be challenging, but researchers at The Ohio State University Wexner Medical Center have discovered a new technique that makes those infections glow bright red under fluorescent light. Their work could lead to new drugs to treat fungal lung infections, something that hasn`t been seen in medicine for decades. Details: bit.ly/1aCFk9k
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