Activation of human neutrophils and monocytes induced by immune complexes prepared with cationized antibodies or antigens.

We have recently showed that soluble immune complexes (IC) prepared with cationic antibodies (catIC) induce high levels of neutrophil-mediated cytotoxicity against nonsensitized target cells. In the present work we extended our previous findings by studying the ability of catIC to induce different responses mediated by monocytes and/or neutrophils: monocyte cytotoxicity against nonsensitized target cells, chemiluminescence emission by monocytes and neutrophils, and elastase release from neutrophils. Our results showed that, in all cases, cell responses induced by catIC were markedly higher than those induced by control IC, indicating that cationized antibodies enhance IC ability to trigger phagocytic cell activation. A second aim of the present study was to analyze the effect of antigen cationization on IC properties. Interestingly, we found that all the phagocytic cell responses induced by IC prepared with cationized ovalbumin (OA) were significantly higher than those induced by IC prepared with untreated OA. Our results suggest that the charge of antibody and/or antigen constitutes a critical property that conditions the biological activity of IC. Furthermore, these findings support an important role of cationic antibodies and antigens in the development of inflammatory events associated with certain IC-induced diseases.