Tissue-Resident Lung Natural Killer Cells in Chronic Obstructive Pulmonary Disease and Viral Infections

The study discusses the role of natural killer (NK) cells in chronic obstructive pulmonary disease (COPD) pathogenesis. The study highlights that peripheral blood NK cells from patients with COPD have lower cytotoxicity than those from smokers without COPD or never-smokers. NK cells from respiratory compartments, including BAL, sputum, and lung tissue, demonstrate increased relative cytotoxicity in COPD. During viral infections, a leading cause of COPD exacerbations, NK cells are crucial to limit initial disease severity but can also exacerbate pathology. The findings suggest that the anatomic location of NK cells must be considered when evaluating their potential involvement, particularly regarding their cytotoxic responses.