中国结核分枝杆菌MPT64蛋白多态性及对MPT64抗原检测试剂盒的敏感性影响

发布时间：2018-06-13 09:10

本文选题：结核分枝杆菌 + MPT　；参考：《实用预防医学》2015年04期

【摘要】：目的探讨中国结核分枝杆菌MPT64抗原的多态性及对其T/B细胞抗原表位的影响;应用MPT64抗原检测试剂盒对MPT64基因突变菌株和野生菌株进行检测,以进一步分析MPT64抗原多态性对结核感染检测的影响。方法从中国疾病预防控制中心传染病预防控制所结核室保存的2 346株国内结核分枝杆菌复合群临床分离株中挑选180株,对其MPT64基因扩增后进行序列比对,比较其T/B细胞抗原表位与非表位的多态性,对突变的菌株与野生菌株进行BACTEC MGIT 960系统与液体培养管进行培养,报阳后,用胶体金标记抗MPT64单克隆抗体采用免疫层析色谱法进行MPT64蛋白检测。结果 180株临床分离株中有15株(包括2株BCG菌株)表现有MPT64蛋白的多态性,占菌株数的8.33%,8株菌有63bp的缺失,4株菌有单位点的非同义突变,1株是单位点插入。MPT64基因的突变造成13个T细胞抗原表位(56.52%)和4个B细胞抗原表位(占80%)的改变,T/B细胞抗原表位区的dN/dS值均高于对应的非表位区。8株有63bp缺失的菌株胶体金检测阴性,对应的野生株检测阳性;5株单位点突变的菌株与对应的野生菌株胶体金检测均阳性。结论中国结核分枝杆菌MPT64蛋白存在多态性,这是产生抗原改变的原因之一,这会影响抗原相关功能的改变并引起免疫逃逸。63bp缺失会造成MPT64抗原检测试剂盒的假阴性,而某些单位点突变对检测效率无影响。
[Abstract]:Objective to investigate the polymorphism of MPT64 antigen of Mycobacterium tuberculosis in China and its effect on T / B cell epitope, and to detect the mutant and wild strains of MPT64 gene by using MPT64 antigen detection kit. To further analyze the influence of MPT 64 antigen polymorphism on tuberculosis infection detection. Methods 180 strains of Mycobacterium tuberculosis were selected from the clinical isolates of 2 346 strains of Mycobacterium tuberculosis in the laboratory of the Infectious Disease Control and Prevention Center of China Center for Disease Control and Prevention. The MPT64 gene was amplified and sequenced. The polymorphism of T / B cell epitope and non-epitope was compared. The mutant strain and wild strain were cultured in BACTEC MGIT960 system and liquid culture tube. MPT 64 protein was detected by immunochromatography with colloidal gold labeled anti-MPT 64 monoclonal antibody. Results Fifteen of 180 clinical isolates (including 2 BCG strains) showed MPT64 protein polymorphism. 8 strains with 63bp missing 4 strains with non-synonymous mutation with unit point insertion of .MPT64 gene mutation resulting in 13 T cell epitopes 56.52% and 4 B cell antigen epitopes (80%) The values of DN / DS in the epitope of cell antigen were higher than those in the corresponding non-epitope. 8 strains with 63bp deletion were negative for colloidal gold. 5 strains with unit point mutation and the corresponding wild strains were tested positive for colloidal gold. Conclusion there is polymorphism in MPT64 protein of Mycobacterium tuberculosis in China, which is one of the causes of antigen change. It will affect the change of antigen-related function and cause the deletion of immune escape. 63 BP will result in false negative of MPT64 antigen detection kit. However, some unit point mutations had no effect on detection efficiency.
【作者单位】：中国疾病预防控制中心传染病预防控制所传染病预防控制国家重点实验室感染性疾病诊治协同创新中心;
【基金】：国家自然科学基金项目(编号:81401647)
【分类号】：R378.911

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