Pisetsky D S, Reich C F
Medical Research Service, Durham Veterans Administration Hospital, North Carolina.
Clin Immunol Immunopathol. 1994 Sep;72(3):350-6. doi: 10.1006/clin.1994.1152.
To elucidate the interaction of anti-DNA antibodies with DNA, the reactivity of lupus sera with single-stranded fragments from calf thymus, Escherichia coli, and salmon testes DNA was investigated. These fragments were generated by digestion with the restriction enzyme HinfI and ranged in size from approximately 100-4000 bases. By ELISA using polystyrene microtiter plates, fragments from all three species were weakly antigenic compared to intact DNA. These fragments, however, were all antigenic when tested as inhibitors in competition-binding assays. The weak antigenicity of fragments could not be explained by poor adherence to the plates since fragments and intact DNA showed similar levels of binding as assessed using biotinylated preparations. Together, these results demonstrate that the antigenicity of DNA fragments is dramatically altered by solid-phase binding and suggest that constraints on topological or conformational rearrangements of DNA in the solid phase limit antibody interaction.
为阐明抗DNA抗体与DNA的相互作用，研究了狼疮血清与来自小牛胸腺、大肠杆菌和鲑鱼睾丸DNA的单链片段的反应性。这些片段是用限制性内切酶HinfI消化产生的，大小范围约为100 - 4000个碱基。通过使用聚苯乙烯微量滴定板的ELISA法，与完整DNA相比，来自所有三个物种的片段抗原性较弱。然而，当在竞争结合试验中作为抑制剂进行测试时，这些片段都具有抗原性。片段的弱抗原性不能用与板的结合不佳来解释，因为使用生物素化制剂评估时，片段和完整DNA显示出相似的结合水平。总之，这些结果表明，DNA片段的抗原性因固相结合而发生显著改变，并表明固相中DNA拓扑或构象重排的限制限制了抗体相互作用。
