Short-term vaping exposure injures deep lung tissue and immunity

Just days of e-cigarette vapor exposure can injure the lungs' most delicate tissue and leave it more vulnerable to viral infection, according to a study led by National Jewish Health researchers and published in JCI Insight.

The research team studied human lung epithelial and endothelial cells, along with precision-cut human lung tissue, all taken from the distal lung - the deep, delicate region where oxygen passes into the bloodstream. They exposed these tissues to e-cigarette vapor alone, and separately tested vapor exposure followed by infection with a respiratory virus, in preclinical models. Within 24 hours, e-cigarette vapor damaged the protective barrier of the distal lung, triggered cellular stress, impaired cells' internal process for clearing damaged components, slowed cell growth and repair, and increased cell death.

Strikingly, signs of lung stress persisted 10 days after just a five-day exposure period ended. The team observed lasting changes in barrier function, tissue remodeling, and Th1 immunity - a branch of the immune system critical to fighting viral infections.

Prior vaping exposure also increased SARS-CoV-2 viral burden and suppressed several antiviral genes following infection.

Our findings suggest that even short-term vaping exposure can initiate injury in the deepest and most delicate regions of the lung. Importantly, some effects persisted after exposure ended and altered the immune response to a subsequent viral infection."

Irina Petrache, MD, senior author, pulmonologist and chief of the Division of Pulmonary, Critical Care and Sleep Medicine, National Jewish Health

The findings, which will need to be confirmed in future studies in people, point to biological mechanisms that may help explain why vaping has been linked to lung injury and greater susceptibility to respiratory infections. The researchers noted that repeated exposure could potentially contribute to chronic lung disease by sustaining cellular injury and disrupting normal repair.