A joint research project between the University of North Carolina School of Medicine and North Carolina State University has found a noninvasive method of harvesting lung stem cells and then multiplying the healthy cells. Their discovery could lead to a powerful therapy against several inflammatory lung conditions such as idiopathic pulmonary fibrosis (IPF), chronic obstructive pulmonary disease (COPD), and cystic fibrosis — often-fatal conditions that affect tens of millions of Americans.

In research published in the journal Respiratory Research, the scientists demonstrated that they could harvest lung stem cells from people using a relatively non-invasive, doctor's-office technique. "We snip tiny, seed-sized samples of airway tissue using a bronchoscope," said Jason Lobo, M.D., an assistant professor of medicine at UNC and medical director of lung transplant and interstitial lung disease. "This method involves far less risk to the patient than does a standard, chest-penetrating surgical biopsy of lung tissue."

The harvested cells were then multiplied in the lab to yield enough cells for treatment. When the cells were infused intravenously into mice, they found that most of the cells gathered in the animals' lungs.

"These cells are from the lung, and so in a sense they're happiest, so to speak, living and working in the lung," said co-author Ke Cheng, Ph.D., an associate professor in NCSU's Department of Molecular Biomedical Sciences and the UNC/NCSU Joint Department of Biomedical Engineering.

In a second study using rodents and published in the journal Stem Cells Translational Medicine, the team showed that they could use the same type of lung cell to successfully treat a model of IPF — a chronic, irreversible, and ultimately fatal disease characterized by a progressive decline in lung function.

"The treatment was safe and effective whether the lung spheroid cells were derived from the recipients' own lungs or from the lungs of an unrelated strain of rats," said co-author Jason Lobo, M.D., an assistant professor of medicine at UNC and medical director of lung transplant and interstitial lung disease.

"In other words, even if the donated stem cells were 'foreign,' they did not provoke a harmful immune reaction in the recipient animals, as transplanted tissue normally does.

"This is the first time anyone has generated potentially therapeutic lung stem cells from minimally invasive biopsy specimens," said Lobo.

The researchers believe their work could be applied to a wide range of lung fibrosis diseases. They have been in discussions with the FDA and are preparing an application for an initial clinical trial in patients with IPF.

These diseases of the lung involve the buildup of fibrous, scar-like tissue, typically due to chronic lung inflammation. As this fibrous tissue replaces working lung tissue, the lungs become less able to transfer oxygen to the blood. Patients ultimately are at risk of early death from respiratory failure. In the case of IPF, which has been linked to smoking, most patients live for fewer than five years after diagnosis.

Research presented earlier this year at the European Respiratory Society's Lung Science Conference, found that stem cell therapy using mesenchymal stem cells (MSCs) can reduce the lung inflammation associated with the lung diseases chronic obstructive pulmonary disease (COPD) and cystic fibrosis. The stem cell therapy was used in mice with inflammatory lung disease, which has some of the features of COPD and cystic fibrosis.

Mice were given MSC therapy at four and six weeks. After eight weeks, lung tissue was taken from the mice and compared to mice that hadn't received the treatment. Mice given MSC therapy showed reduced inflammation as well as improvements in lung tissue, suggesting that the treatment may repair damaged tissue.