Immunodepletion of protein S. (A) AcLDL uptake in THP-1 macrophages. Protein S was immunodepleted by rabbit anti–protein S antibody for 2 hours at 4°C. The immune complexes and antibody were removed using protein G Sepharose for 1 hour at 4°C. The resultant supernatant fluid was used for the AcLDL uptake assay in THP-1 macrophages, and the degree of protein S depletion was monitored by immunoblotting using the same anti–protein S antibody. Normal rabbit IgG was used as a negative control. (B) AcLDL uptake in THP-1 macrophages. Protein S was immunodepleted by monoclonal mouse anti–protein S antibody and protein G sepharose. Normal mouse IgG was used as a negative control. Representative results were from 3 experiments. Columns and bars denote the mean and SD. *P < .05 versus untreated controls.