A new method for detecting circulating IgG immune complexes (IC) using guinea pig peritoneal exudate cells (PEC) has been established. Binding of (125)I BSA-anti BSA IgG IC to PEC was inhibited by serum containing IC in a dose dependent fashion. A 100μl aliquot of PEC suspension (2.5X10(6) cells/ml) was preincubated with diluted five fold serum for 60 minutes at 4℃. After washing pretreated PEC 3 times, 100μl of (125)I labelled 3 times antigen excess-IC was added and incubated for 90 minutes at 4℃. At the end of incubation, the suspension was centrifuged at 10,000G for 1 minute, and the radioactivity of the pellet was measured. This method mainly utilizes the reaction between Fc receptors on PEC and the Fc portion of the complexed IgG.
guinea pig peritoneal exudate cell