Crippled Antibiotic Linked to Cystic Fibrosis Infections

Crippled Antibiotic Linked to Cystic Fibrosis Infections -

The people with cystic fibrosis are prone to lung infections killer. However, scientists have attempted to understand how the underlying genetic defect of the disease - a mutated gene that leads to poor transport chloride in and out of cells - favors these infections. Now comes a possible explanation: An antibiotic that normally produces the lung is inactivated in a salty environment. The discovery, published in the current issue of Cell , suggests that the passage somehow the antibiotic back on - or replace it with another that can run into the salty lung fluid - could reduce the number of fatal infections.

Last year, researchers found that certain strains of bacteria are tame in low salt lung fluid of healthy people, but thrive in the salty lung fluid of patients with cystic fibrosis. Now a team led by James Wilson of the Institute for Human Gene Therapy in Philadelphia and Michael Zasloff of Magainin Research Institute in Plymouth Meeting, Pennsylvania, seems to have found what distinguishes these pulmonary fluids apart. They found in human lung cells messenger RNA that helps make a protein called human -defensin, first isolated from the kidney dialysis fluid it a few years ago.

In the presence of poor liquid salt, they found, a synthetic version of the human -defensin was a powerful weapon against a broad spectrum of bacteria, including P. aeruginosa and E. coli , two bugs that afflict people with cystic fibrosis. But when exposed to high levels of salt, human -defensin was virtually powerless. "It helps to fill this gap on how a defect in an ion channel leads to defects in the lungs," says molecular biologist Mark Anderson Magainin institute.

Not everyone is convinced that all people with cystic fibrosis have pulmonary salty liquid. Nevertheless, the experts welcome the conclusion. "It's very exciting," said Charles Bevins of the Cleveland Clinic, who helped isolate -defensins trachea of ​​the cow and the gastrointestinal tract. Bevins said
human -defensin could be used as a medicine to fight against infections of cystic fibrosis lung if researchers are able to modify it to withstand high levels of salt. drugs most likely candidates, he said, are Protegrin, a compound isolated neutrophils pork or microbial peptides called magainins there first isolated 10 years from frog skin, some of which are better than defensins in salt solutions.

Tweet