Figure 3. Enhanced levels of cytokines after A. baumannii infection in aged mice. Young and aged mice were infected intratracheally with 5×106 CFU of LAC-4. At 0 h and 24 hpi, serum and BALF were collected and mRNA was isolated from lungs. TNFα, IL-6, and IL-1β levels in serum (A) and BALF (B) were detected by ELISA. (C) TNFα, IL-6, and IL-1β mRNA expression in lungs were detected by real-time PCR. Data are presented as mean ± SEM of five mice per condition and represent one of 2 independent experiments. Statistical analyses were performed by Student’s t test. *, P < 0.05, **, P < 0.01.