Lupus-derived autoantibodies with dual autoactivity: anti-DNA and anti-Fc. II. Fine specificity of anti-self autoreactivity.
The anti-immunoglobulin reactivity of two monoclonal, dual specific, autoantibodies, BV 17-45 and BV 04-01 was examined. The current study further defined the anti-immunoglobulin autoreactivity of these MoAbs to be Fc-specific. Both BV 17-45 and BV 04-01 bound their own Fc domains in addition to Fc regions of other MoAbs of similar isotype with varying levels of activity. The different anti-Fc reactivity patterns of BV 17-45 and BV 04-01 suggested that these MoAbs recognized distinct epitopes. Neither BV 17-45 nor BV 04-01 bound Fab fragments or single-chain antibody derivatives, which confirmed that the anti-immunoglobulin reactivity of these autoantibodies was Fc-specific. In addition, abrogation of anti-Fc reactivity was observed when affinity-labelled MoAbs were used as coating antigens in solid-phase ELISAs. These results implied that active-site ligand binding induced conformational changes which altered the Fc epitope(s) recognized by BV 17-45 and BV 04-01.
Rumbley
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CA
Department of Cell and Structural Biology, University of Illinois, Urbana 61801, USA.
Voss
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D000818:Animals; D000888:Antibodies, Anti-Idiotypic / Q000276:immunology*; D000974:Antibodies, Antinuclear / Q000276:immunology*; D000911:Antibodies, Monoclonal / Q000276:immunology; D000918:Antibody Specificity; D000936:Antigen-Antibody Complex / Q000737:chemistry; D001666:Binding Sites, Antibody / Q000276:immunology; D007141:Immunoglobulin Fc Fragments / Q000276:immunology*; D008024:Ligands; D051379:Mice; D008814:Mice, Inbred NZB; D011487:Protein Conformation
D000888:Antibodies, Anti-Idiotypic; D000974:Antibodies, Antinuclear; D000911:Antibodies, Monoclonal; D000936:Antigen-Antibody Complex; D007141:Immunoglobulin Fc Fragments; D008024:Ligands