Macrophage stimulation by precipitating and soluble immune complexes at different antigen or antibody excess

ABSTRACT

Precipitating immune complexes were prepared, in vitro, by using different concentrations of antigen excess or a fixed concentration of antibody excess or equivalent antigen-antibody concentrations. Maximal macrophages' stimulation were noted at an antigen-antibody concentration of 1/16 to 1 when challenged with different total immune complexes. This was measured by determination of complement c[2] culture levels. However, soluble immune complexes at different antigen-antibody excess preparations obtained by centrifugation of total immune complexes did not show a stimulatory effect on macrophages in the culture media