系统性红斑狼疮模拟自身抗原肽分子的筛选及其诊断价值的初步研究

Screening and diagnostic value of mimic peptides of autoantigen of systemic lupus erythematosus

目的从噬菌体随机12肽库中筛选系统性红斑狼疮(SLE)自身抗原模拟肽分子并初步研究其诊断价值。方法首先用自健康人血清提取的IgG作为固相配基吸除非特异性噬菌体,再以自SLE患者血清提取的IgG包被,按吸附-洗脱-扩增的淘洗过程对上述处理过的噬菌体液进行3轮筛选,随机挑取噬菌体克隆,用ELISA检测其特异性。用混合阳性克隆包被的ELISA法检测SLE、类风湿关节炎(RA)、骨关节炎(OA)患者及健康对照血清与混合阳性克隆的结合力。结果经过3轮筛选,回收率从4.4×10-5增加到1.4×10-2,得到良好的富集效果。第3轮洗脱物中挑选出的22个克隆中,19个克隆与SLE患者血清IgG具有较强的结合力。用第3轮的混合噬菌体克隆检测SLE、RA、OA患者及健康对照的血清,阳性率分别为80.0%、15.0%、0和0。结论成功利用噬菌体12肽库对SLE患者血清进行了模拟肽筛选,得到的模拟肽分子用于ELISA,对SLE具有一定的诊断价值。

Objective To screen the mimic peptide of systemic lupus erythematosus（SLE） from the phage peptide library and to evaluate its diagnostic value.Methods Phage random peptide library of 12 amino acids was immunoscreened with purified IgG from sera of healthy individuals,followed by three rounds of screening with IgG purified from sera of SLE patients.Positive clones were detected by ELISA.The binding of mixed positive clones with the sera from patients with SLE,rheumatoid arthritis（RA）,and osteoarthritis（OA）,and from healthy individuals was detected using phage-ELISA.Results After 3 rounds screening,the input-output ratio increased from 4.4×10-5 to 1.4×10-2.Twenty-two clones were selected for test with antibodies from patients′ sera.Nineteen of them were proved to specifically react with the patients′ sera.When mixed phages were coated to react with the sera from patients with SLE,RA,and OA,and from the healthy controls,the positive rates were 80.0%,15.0%,0 and 0,respectively（χ2= 17.878,P0.01）.Conclusion The data demonstrate that the antigen-mimic peptide has been successfully screened from 12 random phage peptide library and the peptides may be diagnostically valuable for SLE.