Figure 4: Attenuation of influenza-mediated lung injury requires AMs during S. aureus priming.

(a) Surface expression of TLR2 on AMs from WT mice at day 3 after S. aureus priming. (b) The number of AMs from WT mice at the indicated time points after S. aureus priming. (c) Two days after CL₂MDP-lip treatment, mice were primed with S. aureus and then analysed for AMs in BALF 3 days later. (d) Three days after priming with control saline or S. aureus, control PBS-lip-treated and CL₂MDP-lip-treated WT mice were infected with 0.5 HA of PR8 and analysed for survival. (e) Two days after CL₂MDP-lip treatment, mice were primed with control saline or S. aureus, and then AMs from control or S. aureus-primed WT mice were adoptively transferred i.n. into these mice 3 days later. Survival of recipient mice was measured after infecting with 0.5 HA of PR8 immediately after adoptive transfer. (f) Two days after CL₂MDP-lip treatment, mice were primed with control saline or S. aureus, and then AMs from S. aureus-primed WT mice or S. aureus-primed Tlr2^−/− mice were adoptively transferred i.n. into these mice 3 days later. Survival of recipient mice was measured after infecting with 0.5 HA of PR8 immediately after adoptive transfer. Two-tailed Student’s t-tests were used in (a,b), Gehan–Breslow–Wilcoxon tests were used in (e,f); NS, not significant; *P<0.05, **P<0.01, ***P<0.001. Data are expressed as mean±s.e.m. Data represent three independent experiments with at least five mice per group in (a–d), or represent two independent experiments with at least five mice per group in (e,f).