This study group forms the normal subject control group in an experiment designed to determine whether the alveolar macrophages (AMø) of patients with chronic obstructive pulmonary disease (COPD) show abnormal responsiveness to bacterial and viral products. Specifically, the study will determine the dose-response characteristics of AMø for production of interleukin (IL)-6, IL-18, and IL-23 (pro-inflammatory cytokines) on stimulation by purified lipopolysaccharide, a synthetic lipopeptide (PAM3-Cys), or poly I:C. These stimuli mimic the response to Gram-negative bacteria, Gram-positive bacteria, and RNA viruses, respectively. Results of the AMø from these healthy volunteers will be compared with AMø of COPD patients and smokers (or ex-smokers) with normal pulmonary function; those samples are being obtained during clinically indicated bronchoscopies under a separate consent form.