Figure 2.

Apoptosis of alveolar macrophages induced by Mycobacterium bovis at day 3 and day 7 post-infection. BALB/c mice were intratracheally infected with low dose (1 × 10⁵) and high dose (1 × 10⁷) of attenuated (bacillus Calmette–Guérin) and virulent (ATCC19274) M. bovis strains. Lung cells obtained by enzymatic digestion were stained with annexin V and propidium iodide for analysis by flow cytometry. Annexin V/PI dot plots of these macrophage populations were generated and the percentage of apoptotic macrophages (Annexin V⁺/PI⁻) was determined. (a) Each bar represents the arithmetic mean ± SEM of six mice. Results are representative of two different experiments. *P< 0·05 versus non-infected control; ^#P< 0·05 versus infected with attenuated strain. (b) Dot plots of representative samples are shown.