Peroxynitrite-modified DNA: a better antigen for systemic lupus erythematosus anti-DNA autoantibodies.
Native human DNA was modified by ONOO- (peroxynitrite), generated by the synergistic action of sodium nitroprusside [Na2Fe(CN)5NO], an NO donor, and pyrogallol, a superoxide donor. The modifications were analysed by UV absorption characteristics, fluorescence emission transitions, nuclease S1 digestibility and melting-temperature studies. Modified DNA was found to be highly immunogenic, inducing high-titre immunogen-specific antibodies in experimental animals. A maximum of 85% inhibition of the antibody binding was observed in competition ELISA with immunogen as inhibitor. SLE (systemic lupus erythematosus) anti-DNA autoantibodies recognized modified DNA as a better antigen than the native analogue. Modification of native DNA by ONOO-, forming neo-epitopes on the molecule, may be one of the factors for the induction of the autoimmune response seen in SLE.
Habib
Safia
S
Department of Biochemistry, Jawaharlal Nehru Medical College, Aligarh Muslim University, Aligarh, Uttar Pradesh 202002, India.
Moinuddin
Ali
Rashid
R
D000818:Animals; D000974:Antibodies, Antinuclear / Q000276:immunology*; D001667:Binding, Competitive; D004247:DNA / Q000737:chemistry* / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D008180:Lupus Erythematosus, Systemic / Q000276:immunology*; D020030:Nitric Oxide Donors / Q000737:chemistry; D009599:Nitroprusside / Q000737:chemistry; D030421:Peroxynitrous Acid / Q000737:chemistry*; D011748:Pyrogallol / Q000737:chemistry; D013050:Spectrometry, Fluorescence; D013056:Spectrophotometry, Ultraviolet
D000974:Antibodies, Antinuclear; D020030:Nitric Oxide Donors; D011748:Pyrogallol; D030421:Peroxynitrous Acid; D009599:Nitroprusside; D004247:DNA