Researchers from the UNC School of Medicine and North Carolina State University showed that they could harvest and multiply lung stem cells in volumes sufficient for human therapy. In a second study, the team used their cell therapy to treat a model of idiopathic pulmonary fibrosis.
The scientists reported that they are in talks with the FDA to prepare for an initial clinical trial with IPF patients.
“This is the first time anyone has generated potentially therapeutic lung stem cells from minimally invasive biopsy specimens,” co-senior author Dr. Jason Lobo said in prepared remarks.
“We think the properties of these cells make them potentially therapeutic for a wide range of lung fibrosis diseases,” co-senior author Ke Cheng added.
Although there are two therapies indicated for IPF, the drugs don’t halt the progression of the fatal disease. To stop the underlying disease, IPF patients can opt for a lung transplant. But that procedure is risky and necessitates the long-term use of immunosuppressive drugs.
To address these issues, some scientists have turned to stem cell therapies.
Cheng and Lobo focused their efforts on lung spheroid cells. The team previously demonstrated that lung spheroid cells boast regenerative properties when applied to a mouse model of lung fibrosis.
In one study, the researchers found they could harvest lung spheroid cells from patients with lung disease using a transbronchial biopsy, a relatively non-invasive procedure.
“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.”
Then Cheng and his team multiplied lung spheroid cells from these samples into tens of millions of cells – enough to be delivered as a therapy. The scientists observed that when they intravenously infused the therapy into mice, the harvested lung spheroid 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,” Cheng said.
In the team’s second study, they modeled a lung fibrosis condition – on that closely mimicked human IPF – in rats. The team reported healthier lung cells and less inflammation and fibrosis in rats treated with lung spheroid cells compared to rats treated with a placebo.
“Also, 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,” 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.”