Immunogenicity of superoxide radical modified-DNA: studies on induced antibodies and SLE anti-DNA autoantibodies.
Superoxide anion radical (SAR) is formed in almost all aerobic cells and it is the most abundant species generated by several enzymatic and non-enzymatic pathways in mammalian tissues, leading to unfavorable alteration of biomolecules including DNA. The SAR-modified macromolecules have been implicated in several disease states including disorders of inflammation. The SAR-induced damage to DNA showed hyperchromicity, single strand breaks, decrease in melting temperature, and modification of bases. Superoxide modified-DNA in rabbits elicited high titer antibodies and showed diverse antigens binding characteristics. The induced antibodies recognized native DNA and other nucleic acid polymers. Anti-DNA IgG from SLE sera, purified on Protein-A-Sepharose matrix, exhibited increased recognition of superoxide anion radical modified-DNA than native DNA in competitive immunoassay. The visual formation of immune complex between induced antibodies and native DNA, and between SLE anti-DNA IgG and superoxide modified-DNA, is a clear indication of property sharing between SLE autoantibodies and experimentally induced antibodies against superoxide modified-DNA.
Waris
Gulam
G
Department of Biochemistry, Faculty of Medicine, A.M.U., Aligarh 202 002, India.
Alam
Khurshid
K
D000818:Animals; D000974:Antibodies, Antinuclear / Q000276:immunology*; D004247:DNA / Q000276:immunology* / Q000378:metabolism; D004249:DNA Damage; D007074:Immunoglobulin G / Q000276:immunology; D008180:Lupus Erythematosus, Systemic; D011817:Rabbits; D013481:Superoxides / Q000378:metabolism*
D000974:Antibodies, Antinuclear; D007074:Immunoglobulin G; D013481:Superoxides; D004247:DNA