Low-Dose Oxygen Enhances Macrophage-Derived Bacterial Clearance following Cigarette Smoke Exposure

Figure 1

Low-dose oxygen is beneficial in CS- and PAO1-exposed mice. (a) Macrophages recovered by BAL from mice exposed to 5 weeks of cigarette smoke followed by 35–40% oxygen or room air for an additional 3 days (-5, by one-way ANOVA). (b–d) Following 5-week CS or room air exposure, mice were exposed to PAO1 bacteria by intratracheal (i.t.) injection and either low-dose oxygen (35–40%) or room air (control), followed by up to 5 days of oxygen or room air exposure. (b) At day 2 after PAO1 exposure, mice were harvested and lung CFUs were quantified (-3, against all other groups by one-way ANOVA, and n.s. compared to both control groups). (c) Among CS-exposed mice, Kaplan-Meier survival curve following i.t. PAO1 exposure (-7 mice, by log-rank Mantel-Cox). (d) Following bronchoalveolar lavage (BAL) on day 2 after PAO1 exposure, total protein was quantified (–4, against all other groups by one-way ANOVA). (e) Following day 2 BAL, total cell count was quantified (–4).

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