Fig. 4.

Effect of CD14 blockade on cytokine production. IFN-γ pre-activated THP-1 cells were pre-incubated for 1 h at 37°C with anti-human CD14 MoAb MY4 (10 μg/ml), MoAb IOM2 (20 μg/ml) or MoAb Leu-M3 (5 μg/ml), before adding the bacterial stimulus (heat-killed 31533 strain at 10⁹ cfu/ml) or the LPS (1 μg/ml, used as a reference to evaluate the effect of anti-CD14 MoAbs). TNF-α, at 3 h of incubation, and IL-1, IL-6, IL-8 and MCP-1 at 24 h of incubation, were measured by ELISA titration of stimulated cell supernatant fluids. Data were transformed to percentage of inhibition with respect to values for bacteria or LPS without treatment (100% of production), and expressed as mean ± s.d. from four separate blockade experiments. (▪) LPS MY4; () LPS IOM2; () LPS Leu-M3; (□) Streptococcus suis MY4; () S. suis IOM2; () S. suis Leu-M3. * P < 0·01 (versus the corresponding stimulus without treatment).