Anti–IL-1β and anti–TNF-α mAbs prevent endothelial cell activation by blast cell supernatants.

(Ai-ii) Endothelial cells were incubated with medium containing 10 U/mL IL-1β in the absence (i) or the presence (ii) of 5 μg/mL mAb anti-IL-1β. (Aiii-iv) Endothelial cells were incubated for 4 hours at 37°C with culture medium of M2 AML myeloblasts (patient 1) in the absence (iii) or the presence (iv) of 5 μg/mL mAb anti-IL-1β. Endothelial cells were analyzed for E-selectin expression by flow cytometry. (B) Partial inhibition of endothelial cell activation by anti–IL-1β and anti–TNF-α antibodies. (Bi-ii) Endothelial cells were incubated for 4 hours at 37°C with medium supplemented with 10 U/mL IL-1β (i) or with supernatant from M4 AML myeloblasts (ii). (Biii) Endothelial cells were incubated with the culture medium of M4 AML myeloblasts (patient 3) treated with anti–IL-1β (5 μg/mL). (Biv) endothelial cells were incubated with supernatant from M4 AML myeloblasts treated with anti–IL-1β (5 μg/mL) and anti–TNF-α (10 μg/mL). E-selectin expression by endothelial cells was evaluated by flow cytometry. Background staining by an unreactive isotype-matched mAb is indicated by the dotted line. Dashed lines show the expression of ICAM-1 by unactivated endothelium.