Monoclonal anti-DNA antibodies: an approach to studying SLE nephritis

Several data suggest that the glomerular deposits of DNA and anti-DNA antibodies observed in SLE result from complex formation in situ. The aim of this study was to investigate this hypothesis in normal C57BL/6 mice by using monoclonal anti-DNA antibodies (mAb). Renal localization of intravenously introduced ds DNA was demonstrated in mice injected intraperitoneally with LPS 48 h before. Then, a single IgG2b or a mixture of IgG2a and IgG2b anti-ds DNA mAb were given with the aim of forming DNA: anti-DNA complexes at the glomerular level. No immunoglobulin deposits were observed regardless of the antibody dose used. The mAb used may possess some of the qualitative properties suspected to be nephritogenic. Thus, the limiting factors in the induction of a passive nephritis could be either the absence of glomerular DNA deposits or the inability by using a single antigen-antibody system, to recreate the pathophysiological conditions seen in SLE, where a high number of antigen-antibody systems is implicated in the genesis, of glomerular lesions.