Murine monoclonal antibodies to DNA. A comparison of MRL/lpr NZB/W and chronically graft-versus-host-diseased mice.

Hybridomas producing monoclonal antibodies to DNA were prepared from NZB/W F1 (n = 20), MRL/lpr (n = 13), mice with a chronical graft versus-host-disease (GVHD) (n = 8) and polyclonally stimulated mice (n = 9). Screening was performed by means of an anti-DNA ELISA. Reaction patterns in four different anti-DNA assays (anti-DNA ELISA, indirect immunofluorescence on Crithidia luciliae, PEG assay and Farr assay) as well as avidity and cross-reactivity of these monoclonals were studied in relation to anti-DNA (sub)class and murine origin of the clones. It was found that monoclonal anti-DNA derived from mice with chronic GVHD did not differ from monoclonal anti-DNA derived from NZB/W F1 or MRL/lpr mice, with respect to isotype distribution, avidity towards DNA, cross-reactivity and assay behaviour in the anti-DNA assays mentioned before. In contrast, monoclonal anti-DNA obtained from polyclonally stimulated mice were all of the IgM isotype and displayed a stronger cross-reactive behaviour than the other three models. Altogether, these results exclude the possibility that anti-DNA in the GVHD mice originates from the non-specific pool of natural autoantibodies and further emphasize the relevance of chronic GVHD as a murine model of systemic lupus erythematosus.