Fig. 4.

HDL binding to GAS cells. (a) HDL binding to GAS cells by ELISA. GAS cells were immobilized onto microplate wells and incubated with HDL. Wells were washed with buffer containing or lacking Tween 20. Bound HDL was detected with anti-HDL-specific antibody followed by HRP-conjugated secondary antibody and the HRP-substrate reaction was measured spectrophotometrically at 450 nm. Average absorbance value±SD from triplicate wells were obtained after subtracting the OD values of the control wells without HDL. (b) HDL binding to GAS cells in suspension. GAS cells were incubated with 1% BSA for 1.5 h. After washing cells were mixed with human plasma. Cells with adsorbed proteins were washed with TBS or TBST. Surface-bound proteins were then dissociated from the cells with glycine-HCl buffer (pH 2.0) and TCA-precipitated. Detections of ApoAI and ApoB100 were carried out by immunoblotting using goat anti-ApoAI antibody and goat anti-LDL antibody, respectively.