2 DUAL-SPECIFIC (ANTI-IGG AND ANTI-DSDNA) MONOCLONAL AUTOANTIBODIES DERIVED FROM THE NZB NZW F1 RECOGNIZE AN EPITOPE IN THE HINGE REGION/

The anti-IgG properties of two dual-specific (anti-dsDNA and anti-IgG) monoclonal NZB/NZW F1-derived autoantibodies, BV 17-45 and BV 16-13, were studied to resolve the location and possible commonality of the I gG epitope. To determine if BV 17-45 and BV 16-13 recognized the same IgG epitope, the relative temperature sensitivity of the conformationa l IgG epitopes were evaluated using the conformational sensitive immun oassay. Comparison of the temperature sensitivity of the conformationa l immunoglobulin epitopes over a temperature range of 25-100 degrees C suggested that the epitope recognized by BV 17-45 was the same as the IgG epitope recognized by BV 16-13. Further studies with papain- and pepsin-generated F(ab')(2), Fab, and Fc fragments of BV 17-45 and BV 1 6-13 revealed that the dual-specific autoantibodies BV 17-45 and BV 16 -13 both bound an epitope in the hinge region of the IgG molecule. The potential correlation between these studies and the pathogenic nature of dual-specific autoantibodies is discussed.