Figure 2

Lung Cell Infiltration. Isolated lung cells were evaluated for viability by trypan blue exclusion (A). The number of cells was adjusted for the weight of the lungs and reported as cells per gram of tissue. Aged mice (white squares) showed a delay in the kinetics of lung cell. The graph shows cumulative data of three sets of experiments, a total of 9 mice were assayed at each time point, except for days 15 and 19, which contain 8 animals each. (B) Gating strategy used to analyze innate cells in the lungs. Initially cells were gated in the non-lymphocyte area (R1), this was followed by selection in the live gate (R2). Two APC populations (R3 and R4 gates) were selected based on CD11b and CD11c expression. R3 gate corresponds to cDCs (CD11c^high/CD11b^high). Cells in R4 gate were further divided based on the diffential expression of Gr-1 (neutrophils (CD11b^high/CD11c^low/Gr1^high) and lung macrophages (CD11b^high/CD11c^low/Gr1^med). MHC class II and CD40 expression was analyzed in R3 and R6 gates. An average of 500,000 events was collected for the analysis of these populations. Stars indicate statistical difference between aged and naïve animals.*P < 0.05. **P < 0.01. ***P < 0.001.