DNA ANTI-DNA IMMUNE-COMPLEXES - ANTIBODY PROTECTION OF A DISCRETE DNA FRAGMENT FROM DNASE DIGESTION INVITRO
DNA ANTI-DNA IMMUNE-COMPLEXES - ANTIBODY PROTECTION OF A DISCRETE DNA FRAGMENT FROM DNASE DIGESTION INVITRO
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DOI：
10.1172/jci111400
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发表时间：
1984-01-01
影响因子：
15.9
通讯作者：
BURDICK, G
中科院分区：
文献类型：
--
作者：
EMLEN, W;ANSARI, R;BURDICK, G
检测了DNA酶I消化DNA-抗DNA免疫复合物中所含DNA的能力。从20例系统性红斑狼疮（SLE）患者血清中分离出抗DNA抗体的IgG，与双链DNA共同孵育形成免疫复合物。加入过量的DNA酶，通过DNA转化为TCA[三氯乙酸]可溶性产物来监测DNA的消化。来自20名SLE患者中的8名的IgG保护DNA免受DNA酶的降解，与在Farr结合测定中测量的结合至IgG的DNA的量成正比。使用来自这些血清的IgG，显示出被保护免于降解的DNA在消化期间保持与IgG结合，并且大小为35-45个碱基对。该片段的大小与已经提出的IgG与DNA的单配二价结合所需的最小大小相同。比较了F（ab“）2和Fab”保护DNA免受DNA酶消化的能力，证明了二价F（ab“）2片段具有保护性，而单价Fab”片段则没有。一些通过单配二价结合与DNA结合的DNA抗体可能可以保护35-45个碱基对的DNA片段免受DNA酶消化。这一发现的影响进行了讨论，在体内的行为和潜在的致病性的小DNA-抗DNA免疫复合物。
The ability of DNase I to digest DNA that was contained with DNA-anti-DNA immune complexes was examined. IgG isolated from the sera of 20 patients with systemic lupus erythematosus (SLE) and containing antibodies to DNA was incubated with double-stranded DNA to form immune complexes. Excess DNase was added, and digestion of DNA was monitored by the conversion of DNA to TCA[trichloroacetic acid]-soluble products. IgG from 8 of the 20 SLE patients protected DNA from degradation by DNase in direct proportion to the amount of DNA bound to IgG as measured in the Farr binding assay. Using IgG from these sera, it was shown that the DNA protected from degradation remained bound to IgG during digestion and was 35-45 base pairs in size. The size of this fragment is the same as that which has been proposed to be the minimal size necessary for monogamous bivalent binding of IgG to DNA. The ability of F(ab'')2 and Fab'' to protect DNA from DNase digestion was compared and it was demonstrated that the bivalent F(ab'')2 fragments were protective, but that the univalent Fab'' fragments were not. Some antibodies to DNA that bind to DNA via monogamous bivalent binding can probably protect a 35-45-base pair DNA fragment from DNase digestion. The implications of this finding are discussed with regard to the in vivo behavior and potential pathogenicity of small DNA-anti-DNA immune complexes.