Figure 7

Lymphocytic cells. Several innate and adaptive lymphocytic cells were analyzed in the lungs of aged and adult mice. CD4⁺ and CD8⁺ T-cells were more abundant in adult mice (black bars) at day 0 (A). Adult mice (black circles) had a significantly higher infiltration of NK (DX5) cells in the lungs (B). The kinetics of B-cell lung infiltration, on adult (black circles) and aged (white squares) mice were similar (C). Expression of the early activation marker CD69 by NK and B-cells was detected earlier and at a higher percentage in adult mice in (black circles) (E and F), which suggested that despite similar infiltration kinetics, adult B-cells started to produce antibodies earlier. This was confirmed later when HAI were performed (Fig. 8). The graphs represent cumulative results of two different experiments. The arithmetic means (± SEM) of the number of cells (C and D) or percentages (A, D and E) at each time point (4-6 mice per time point) were plotted. Stars indicate statistical difference between aged and naïve animals. *P < 0.05. **P < 0.01. ***P < 0.001.