Dual specificity and the formation of stable autoimmune complexes.
Since dual specificity at the antibody active-site level involves new principles relative to monospecific antigen-antibody interactions and may be a general property of autoantibodies, it was important to further characterize such antibodies. Four lupus derived autoantibodies were studied to understand parameters and mechanisms involved in the participation of dual-specific antibody molecules in the formation of highly stable immune complexes. Because the dual-specific binding properties of selected lupus-related murine autoantibodies had been previously described using a solid-phase polystyrene-based ELISA, a conformational sensitive membrane based assay (CSI) was used on a comparative basis to further characterize NZB/NZW F1 murine monoclonal anti-DNA autoantibodies BV 04-01 (anti-ssDNA), BV 16-19 (anti-ssDNA), BV 17-45 (anti-dsDNA), and BV 16-13 (anti-dsDNA). All four monoclonal autoantibodies exhibited anti-IgG binding in the solid-phase ELISA. However in the CSI assay, only anti-dsDNA monoclonal autoantibodies BV 17-45 and BV 16-13 demonstrated anti-IgG binding, while anti-ssDNA autoantibodies BV 04-01 and BV 16-19 did not. Upon subjection to time-dependent thermal denaturation, with and without thiol reduction at 100 degrees C in the CSI, the self-binding activities of BV 17-45 and BV 16-13 were abrogated demonstrating that the recognized IgG autoepitope(s) possessed conformational or discontinuous three-dimensional properties. The immunological implications of dual specificity are discussed on a structure-function basis and its correlation with formation of pathogenic immune complexes.
Workman
C J
CJ
Department of Microbiology, University of Illinois, Urbana 61801-3704, USA.
Pfund
W P
WP
Voss
E W
EW
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D000918:Antibody Specificity / Q000276:immunology*; D000936:Antigen-Antibody Complex / Q000276:immunology*; D001323:Autoantibodies / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay; D000939:Epitopes / Q000276:immunology; D005260:Female; D006801:Humans; D007118:Immunoassay; D008180:Lupus Erythematosus, Systemic / Q000276:immunology*; D051379:Mice; D008807:Mice, Inbred BALB C; D011489:Protein Denaturation
D000911:Antibodies, Monoclonal; D000936:Antigen-Antibody Complex; D001323:Autoantibodies; D000939:Epitopes