DETECTION OF NUCLEOSOME-IGG IMMUNE-COMPLEXES IN ASCITES FROM MICE TRANSPLANTED WITH ANTI-DNA ANTIBODY-SECRETING HYBRIDOMAS AND IN PLASMAS FROM MRL-LPR LPR MICE/

Autoantibodies directed against chromatin components characterize lupu s diseases. Immune complexes made of these autoantibodies bound to nuc leosomes released from dead cells could play some pathogenic role. The aims of this study were to investigate if nucleosome-IgG complexes co uld contaminate IgG anti-DNA MoAb preparations, and if such complexes circulate in lupus diseases. A new method was set up using preformed n ucleosome-IgG complexes. Complexes were adsorbed onto microplate throu gh Fc binding and nucleosomal DNA was detected by internal incorporati on of labelled nucleotide. Using this method, high amounts of complexe s were found in ascites from mice transplanted with anti-DNA antibody- secreting hybridomas. In some ascites, nucleosome was found to be stro ngly associated with the MoAb, confirming that nucleosome-IgG complexe s could contaminate monoclonal autoantibody preparations. In MRL-lpi/l pr mice, nucleosome-IgG complexes were detected at 16-24 weeks of age at a time when kidney lesions are rapidly worsening, raising the quest ion of their pathogenic significance.