Figure 4

Innate Cells Activation. The expression of CD40 and MHC class II was assayed in lung macrophages and cDCs (R6 and R3 in Fig 2B, respectively). Example of expression of CD40 by these cells is shown in adult (first column) and aged (second column) animals at different time points (A and D). An overlay of the histograms is shown to compare differences in up-regulation (third column) of the marker. Panels B and C show upergulation of CD40 and MHC class II respectively. Panels B and C display the average of two different experiments, on which of 3 mice were assayed at each time point (a total of 6 animals per time point), bars represent SEM. Aged animals are represented in white squares and adult animals in black circles. Expression of CD40 on lung macrophages and cDCs was similar in adult and aged animals at day 0. Up-regulation of this marker was slower in aged animals and statistically significant differences were detected as early as day 3 (B and E). On the other hand, MHC class II expression at day 0 and up-regulation was similar between adult and aged animals in both lung macrophages and cDCs (C and F). For expression of activation markers an average of 500,000 events were collected. *P < 0.05. **P < 0.01. ***P < 0.001.