FIG. 3.

Induction of the release of proinflammatory cytokines from human whole blood cells by various pyrogens. Freshly drawn heparinized human peripheral blood (225 μl) was incubated for 4 h at 37°C with 25 μl of saline containing various concentrations of pyrogens. After incubation, the blood samples were diluted with 750 μl of saline and centrifuged for 5 min at 15,000 × g. The release of IL-6, TNF-α, or IL-1 in the supernatants was evaluated by an ELISA. The amounts of cytokines released from human whole blood cells cultured in blood containing 0 μg of pyrogen/ml were as follows: IL-6, 1.0 ± 0.5 pg/ml; TNF-α, 1.8 ± 0.2 pg/ml; and IL-1, 2.1 ± 1.3 pg/ml. Data are expressed as the mean and SEM for three donors.