Suppressive effect of IgE soluble immune complex on neutrophil chemotaxis

The effect of IgE soluble immune complex (SIC) and IgG SIC on neutrophil chemotaxis was investigated. Eight types of SIC were prepared from kappa type IgE myeloma protein and IgG myeloma protein: IgE-anti-kappa SIC in IgE excess and in anti-kappa excess, IgE-anti-epsilon SIC in IgE excess and in anti-epsilon excess, IgG-anti-kappa SIC in IgG excess and in anti-kappa excess, IgG-anti-gamma SIC in IgG excess and in anti-gamma excess. Four types of IgE SIC markedly suppressed neutrophil and chemotaxis, but free IgE, free anti-kappa chain antibody, free anti-epsilon chain antibody and IgG SIC had no inhibitory activity. This inhibitory activity of IgE SIC on neutrophil chemotaxis was cell directed and concentration-dependent. IgE immune complex also inhibited neutrophil chemotaxis when immune complex was formed in the neutrophil chemotaxis.