Differential Secretion of IL-1β, TNF and IL-6 in response to opsonized vs unopsonized CS2 IE. MDM from eight independent donor monocytes were cultured for seven days without 48 hr priming with 100 ng/ml IFN-γ (panels A, D, G) or with IFN-γ priming (panels B, E, H). MDM were exposed to human erythrocytes (E), CS2 IE or CS2 IE opsonized with PPS (IE-PPS) for 24 hr after which time the culture medium was analysed for IL-1β, TNF and IL-6 concentration as described in Methods. IFNγ-primed MDM from nine additional donors were exposed to CS2 IE or CS2 IE opsonized with PPS (IE-PPS) (panels C, F, I) for 24 hr and analysed as above. IL-6 concentrations are plotted on a log scale, whereas TNF and IL-1β are presented on linear scale. Differences were assessed for significance using Wilcoxon matched-pairs signed rank test.