FIG 5.

Smoking cessation associates with augmented innate nasal mucosal defense against S. aureus. Participants were cleared of endogenous nasal S. aureus and subsequently reinoculated with their own S. aureus strain as described for Fig. 2. Nasal fluids were collected from each participant at day −17 (prior to mupirocin application for clearance of endogenous S. aureus), day −6 (one week after the last mupirocin application), and at days 3, 8, 11, 15 or 16, 22 or 23, and 31 or 32 postinoculation with autologous S. aureus. Fluids were analyzed using Bio-Rad's 27-plex proinflammatory panel, and results are shown for G-CSF (A), IL-1β (B), and the Il-1RA-to-Il-1β ratio (C), where gray circles represent nasal fluids collected from S. aureus-negative noses (n = 34 for smoking, n = 27 for cessation groups) and black circles represent nasal fluids collected from S. aureus-positive noses (n = 100 for smoking, n = 33 for cessation groups). Error bars represent the means and SEM.