HUMAN AUTOANTIBODY RECOGNITION OF DNA
HUMAN AUTOANTIBODY RECOGNITION OF DNA
复制标题
DOI：
10.1073/pnas.92.7.2529
复制
发表时间：
1995-03-28
影响因子：
11.1
通讯作者：
BURTON, DR
中科院分区：
文献类型：
--
作者：
BARBAS, SM;DITZEL, HJ;BURTON, DR
从系统性红斑狼疮（SLE）供体和健康供体制备的组合IgG Fab噬菌体展示文库对人胎盘DNA进行亲和力筛选。从这两个文库中均分离到DNA特异性的人单克隆抗体Fab片段，但仅从狼疮文库中分离到亲和力最高的Fab片段。一般来说，fab对人胎盘DNA、纯化双链DNA和变性DNA的表观亲和力大致相当。表面等离子体共振显示，双链寡脱氧核苷酸的Fab结合常数为0.2-1.3 x 10(8) M（-1）。根据与人胎盘DNA或寡核苷酸探针的结合程度，高亲和力Fab在通常用于SLE诊断的透明Crithidia luciliae检测中检测为阳性，有趣的是，编码这些抗体重链可变区域的基因显示出只有极少的体细胞高突变。SLE fab的重链的特点是互补决定区3 （CDR3）的N端具有优势的碱性残基。重链CDR3 （HCDR3）在高亲和力DNA识别中的关键作用，是通过从SLE抗体中移植HCDR3在不相关抗体中产生DNA结合而提出的。我们提出，由于不适当的HCDR3s的表达，高亲和力的dna结合抗体可以在SLE中产生，而不会在可变区基因中产生广泛的体细胞超突变。
Combinatorial IgG Fab phage display libraries prepared from a systemic lupus erythematosus (SLE) donor and a healthy donor were affinity selected against human placental DNA. Human monoclonal antibody Fab fragments specific for DNA were isolated from both libraries, although Fabs of the highest affinity were isolated only from the lupus library. Generally, apparent affinities of the Fabs for human placental DNA, purified double-stranded DNA, and denatured DNA were approximately equivalent. Surface plasmon resonance indicated Fab binding constants for a double-stranded oligodeoxynucleotide of 0.2-1.3 x 10(8) M(-1) The higher-affinity Fabs, as ranked by binding to human placental DNA or to the oligonucleotide probe, tested positive in the Crithidia luciliae assay commonly used in the diagnosis of SLE, and interestingly the genes encoding the heavy-chain variable regions of these antibodies displayed evidence of only minimal somatic hypermutation. The heavy chains of the SLE Fabs were characterized by a predominance of basic residues toward the N terminus of complementarity-determining region 3 (CDR3). The crucial role of heavy-chain CDR3 (HCDR3) in high-affinity DNA recognition was suggested by the creation of DNA binding in an unrelated antibody by HCDR3 transplantation from SLE antibodies. We propose that high-affinity DNA-binding antibodies can arise in SLE without extensive somatic hypermutation in the variable-region genes because of the expression of inappropriate HCDR3s.