Research Uncovers Why Viral Infections are Worse for People with COPD

New research has identified the cells responsible for exacerbating viral infections in people with chronic obstructive pulmonary disease (COPD) – tissue-resident natural killer (trNK) cells that are abnormally active in people with COPD. When exposed to viral infections in COPD-affected lungs, these trNK cells respond too aggressively and, as a result, fail to produce the necessary cytokine, or signaling protein, to fight the infection.

The findings, discovered by researchers from the Hunter Medical Research Institute and the University of Newcastle in collaboration with Grace Cooper from University of Southampton, were published in the American Journal of Respiratory and Critical Care Medicine.

In the study, mice were exposed to cigarette smoke for 12 weeks to induce COPD-like lung disease, after which their lung trNK cell phenotypes and function were analyzed. That analysis showed that when the natural killer (NK) cells were exposed to viral infections, they became overactive and ultimately stopped working. This overly aggressive immune response meant the NK cells could not produce the necessary signaling protein, or cytokine, and could not fight the infection. 

“Collectively,” researchers concluded, “these results demonstrate that trNK cell function is altered in cigarette smoke-induced disease and suggests that smoke exposure may aberrantly prime trNK cell responsiveness to viral infection. This may contribute to excess inflammation during viral exacerbations of COPD.”

Read the original article in Medical Xpress.