Scientists from Wake Forest University Baptist Medical Centre have identified a gene that appears to play a critical role in severity of lung disease in people with cystic fibrosis.
After studying nearly 3,000 cystic fibrosis patients, the team found small genetic differences in a gene called IFRD1 linked to lung disease severity.
"This is a good example of researchers with different expertise coming together and using the knowledge gained from mapping the human genome to make discoveries that improve our understanding of cystic fibrosis," Nature magazine quoted Carl Langefeld, Ph.D., a study co-author and Wake Forest University School of Medicine researcher as saying.
"It may also help in the identification of targets for drug development and the development of tools for the earlier diagnosis of individuals with cystic fibrosis who are susceptible to severe lung disease," Langefeld added.
During the analysis, the researchers discovered that the protein encoded by IFRD1 is particularly abundant in a type of white blood cell called neutrophils, and that it regulates their function.
Neutrophils are known to cause inflammatory damage to the airways of people with cystic fibrosis.
"Neutrophils appear to be particularly bad actors in cystic fibrosis," said senior investigator Christopher Karp, M.D., the director of Molecular Immunology at Cincinnati Children's Hospital Medical Centre.
"They are important to the immune system's response to bacterial infection. In cystic fibrosis, however, neutrophilic airway inflammation is dysregulated, eventually destroying the lung," he added.
For understanding the IFRD1's role further, the researchers looked at mice in which the gene was removed. Deleting the gene made evident its role in regulating inflammation and disease.
While the absence resulted in delayed clearance of bacteria from the airway, it also resulted in less inflammation and disease.
While studying the blood samples from healthy human volunteers, the researchers found that the same IFRD1 variations that modified cystic fibrosis lung disease severity also altered neutrophil function in the healthy volunteers.
"It's possible that IFRD1 itself could become a target for treatment, but right now it's a signpost to pathways for further study," Karp said.
"We want to find out what other genes and proteins IFRD1 interacts with, and how this is connected to inflammation in cystic fibrosis lung disease," he added.