Fig. 3.

Pulmonary immune cell profiles in neonatal and juvenile mice challenged with E. coli. Flow cytometry was used to measure the changes in the dynamics of (A) neutrophils, (B) Ly6C⁺ monocytes, (c) alveolar macrophages, and (D) γδT cells in wildtype C57BL/6NJ neonates (N) and juvenile (J) mice after aspiration challenge with 2.0 × 10⁶ CFUs of E. coli (NE, JE) or PBS (NP, JP). For all panels, statistics are displayed for each time point comparing E. coli challenged neonates or juveniles with their respective PBS challenged controls (Student’s t test). Neonate: *p < 0.05, **p < 0.01, ***p < 0.001 and juvenile: ^†p < 0.05, ^††p < 0.01, ^†††p < 0.001. A. Neutrophils in the lungs of E. coli challenged neonates and juvenile mice were significantly increased at 24, 48 and 72 h. B. Ly6C⁺ monocytes in the lungs of E. coli challenged neonates and juveniles were significantly increased at 24, 48 and 72 h. C. Alveolar macrophages in the lungs of E. coli challenged neonates and juveniles were significantly increased at 48 and 72 h. D. γδT cells in the lungs of E. coli challenged neonates and juveniles were significantly increased at 48 and 72 h. N = 4–7 animals for each time point.