Monoclonal autoantibody directed toward histone and capable of inducing LE cell formation

LE cell formation is one feature of systemic lupus erythematosus exhibited by virtually all mice of the NZB/NZW strain and is the result of accumulation of antibodies directed against components of cell nuclei. A hybrid cell line which produces antibodies capable of inducing LE cell formation in vitro has been isolated in a hybridoma fusion using the splenocytes of unimmunized NZB/NZW mice. These monoclonal autoantibodies provide an intense staining of the chromatin in cells of a number of divergent species and tissues. They bind strongly to the histone rich (2 M NaCl) fraction of extracted, isolated nuclei. Further analyses using the antibodies in immune precipitations and in antibody labeling of capillary blots on nitrocellulose sheets of calf thymus histone demonstrate that the antibodies are directed against histones and are capable of reacting with H1, H2a, H2b, H3, and H4 histones individually. In contrast to human autoantibodies with histone specificity, no cross-reactivity of this monoclonal autoantibody with the lymphocyte surface could be detected by either immunofluorescence or immunoelectron microscopy.