The purpose of this study is to determine whether the lungs of individuals with chronic obstructive pulmonary disease (COPD) contain resident memory T lymphocytes that can produce a combination of cytokines that induce the symptoms of an acute exacerbation of COPD (AE-COPD). Specifically, the study will determine cell-surface receptors of lung T cells in comparison with blood T cells from the same subject, and will examine anti-CD3-activated blood or lung T cells for interleukin (IL)-6 and interferon-gamma production in response to IL-18, and for IL-17A production in response to recombinant IL-23.