FIGURE 1.

C3b opsonization of acLDL occurred already at very low concentrations of normal human serum (NHS), but concentrations of at least 2.5% were necessary to establish C3b opsonization of LDL (A). C3b opsonization occurred on both LDL and acLDL upon incubation with 10% NHS. Mannan served as a positive control, whereas human serum albumin (HSA) served as a negative control. The addition of EDTA to NHS prevented complement activation and C3b opsonization of LDL and acLDL completely (B). Every figure represents the mean ± S.E. of at least three experiments.