Fig. 6. Lipoprotein displacement of Oregon-HDL₃ cell-association with J774-A1 cells. J774-A1 cells were cholesterol loaded with AcLDL (50 µg apo B/ml) as described in Materials and Methods. After an 18 hour equilibration period, the cells were incubated in duplicate with 25 µg apo A-I/ml of native (A) or tyrosylated (B) Oregon-HDL₃ for 3 hours at 37°C, in the presence or absence (control) of 5, 10 or 15-fold excess concentration of the unlabeled competitors: native HDL₃ (•), tyrosylated HDL₃ (), AcLDL () and oxLDL (). The non-specific binding was determined in the presence of 50-fold excess of the corresponding unlabeled HDL₃. After extensive cell washing, cell association of control and tyrosylated Oregon-HDL₃ was determined by flow cytometry. Depicted values represent the percentages of specific binding. Data shown are the means±s.e.m. of four independent experiments.