Fig. 7

Protective efficiency of vaccine in mice. a The pulmonary bacterial burden after challenge with PAO1 in WT mice and sting^−/− mice (n = 5). b The pulmonary bacterial burden in mice after challenge of clinical isolate W9 (n = 6). c The pulmonary bacterial burden after challenge of PAO1 in COPD model mice vaccinated with XPa. The mice in the COPD + XPa group (n = 7) were prepared to establish COPD before immunization. Mice in the XPa + COPD group (n = 4) were prepared to establish COPD after immunization. The mice in the COPD group (n = 6) were only prepared to establish the COPD model. See “Materials and methods” for detailed experimental processes. d Survival curve of the mice after challenge with PAO1 (n = 8). e and f Survival curves of tlr4^−/−, tlr9^−/− mice after challenge of PAO1 and of tlr4^−/−, tlr9^−/− mice immunized with XPa (n = 5). g, h and i Bodyweight curves throughout the experiment. Data were analyzed using unpaired t-test. Survival curves were compared using a log-rank (Mantel–Cox) test (conservative). *P < 0.05, **P < 0.01. No letter is present if no significant difference was observed