Figure 1.
Dose-dependent effect of haptoglobin on LPS-induced cytokine release by PBMC. (a) PBMC (1 × 106/ml) were incubated in serum-free culture medium. LPS (1 μg) was added at the beginning of the culture, Hp was added simultaneously resulting in final concentrations of 0, 50, 250, 500, or 1000 μg/ml. Cytokine production was assessed by ELISA after 72 hr of culture. Results are reported as mean ± SEM of four (TNF-α and IL-10) and three (IL-12p70) independent experiments. (b) Results for IL-1ra, IL-6 and IL-8 are reported as mean ± SEM from six experiments. (c) PBMC (1 × 106/ml) were cultured in X-Vivo15 medium in the presence of 1 μg LPS, 250 U rIFN-γ, and increasing Hp concentrations. TNF-α and IL-12p70 concentration was assessed after 3 days of culture using ELISA. Results are reported as mean ± SEM of four independent experiments. *P < 0·05, **P < 0·01 vs. control.