Figure 2

IL-1-induced pro-IL-1β production in alveolar macrophages. (a) Intracellular levels of pro-IL-1β in structural cells (CD45^- cells), T (CD5⁺ cells) and B (B220⁺ cells) lymphocytes, dendritic cells (F4/80^- CD11c⁺ cells) and alveolar macrophages (F4/80⁺) purified from lungs 3 hours after silica instillation (crystalline DQ12, 2.5 mg). n = 2 to 6. (b) Intracellular levels of pro-IL-1β in primary cultured alveolar macrophages exposed overnight to LPS (0.1 μg/ml) or silica (DQ12). n = 4. Intracellular levels of pro-IL-1β in primary cultured lung macrophages exposed overnight to LPS (0.1 μg/ml) or recombinant IL-1α, IL-33 or IL-1β in different experiments ((c), (e) and (g) respectively) or in the same experiment (10 ng/ml) (h). n = 3 to 5. Western blot analysis of intracellular pro-IL-1β and β-actin in primary cultured alveolar macrophages exposed during 18 hours to LPS (0.1 μg/ml), (d) recombinant IL-1α or (f) IL-33. Values are means ± SEM. **p < 0.01 and ***p < 0.001 denotes significant difference between cells in DMEM and cells exposed to LPS, silica, recombinant IL-1α, recombinant IL-33 or recombinant IL-1β; ns, denotes no significant difference. P-values are estimated by t-test.