University of North Carolina Health Care researchers have made strides toward a stem cell treatment for lung diseases such as pulmonary fibrosis, COPD, and cystic fibrosis.
In fact, they are discussing the start of clinical trials with regulatory authorities.
The team discussed its work in two recent studies. One proved that it is possible to isolate lung stem cells with a relatively non-invasive procedure. The other showed that stem cells reduce fibrosis in rats with pulmonary fibrosis.
The first study, in the journal Respiratory Research, was titled “Derivation of therapeutic lung spheroid cells from minimally invasive transbronchial pulmonary biopsies.” The second, in Stem Cells Translational Medicine, was “Safety and Efficacy of Allogeneic Lung Spheroid Cells in a Mismatched Rat Model of Pulmonary Fibrosis.”
“This is the first time anyone has generated potentially therapeutic lung stem cells from minimally invasive biopsy specimens,” Dr. Jason Lobo, director of the university’s lung transplant and interstitial lung disease program, said in a press release. He was co-senior author of both studies.
“We think the properties of these cells make them potentially therapeutic for a wide range of lung fibrosis diseases,” added Dr. Ke Cheng, who led the studies with Lobo. He is an associate professor in North Carolina State University’s Department of Molecular Biomedical Sciences.
The research team had previously homed in on stem and support cells they could isolate from a lung tissue sample and grow in a lab. The tissue formed sphere-like structures in a lab dish, prompting the scientists to call them lung spheroid cells.
In 2015, the team showed that these cells had potent regenerative properties in animals with lung diseases. In fact, the stem cells they cultivated outperformed another type called mesenchymal stem cells.
Their latest project involved gathering lung spheroid cells from patients with various lung diseases. They used a procedure called a transbronchial biopsy that can be done in a doctor’s office.
“We snip tiny, seed-sized samples of airway tissue using a bronchoscope,” Lobo said. “This method involves far less risk to the patient than does a standard, chest-penetrating surgical biopsy of lung tissue.”
From this tiny piece of airway, researchers gathered stem cells, then allowed them to multiply — because stem cell treatments require infusions of millions of such cells.
When they injected the cells intravenously into mice, they discovered that most found their way into 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,” Cheng said.
The team then tested the treatment in rats exposed to a chemical that triggers lung fibrosis. The lung spheroid cells gave rise to healthy lung cells, reducing both inflammation and fibrosis in the animals’ lungs.
“Also, the treatment was safe and effective whether the lung spheroid cells were derived from the recipient’s own lungs or from the lungs of an unrelated strain of rats,” Lobo said. “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.”
The researchers said that in humans their goal would be to use patients’ own stem cells to minimize the risk of immune reactions. But because large quantities of cells are needed, it might be necessary to gather cells from healthy volunteers or organ donation networks as well.
“Our vision is that we will eventually set up a universal cell donor bank,” Cheng said.
The team is in discussions with the U.S. Food and Drug Administration aimed at starting the first human study by year’s end. The first trial would include a small group of pulmonary fibrosis patients. The team also hopes their spheroid stem cell therapy will help patients with other lung diseases.