内源性逆转录病毒长末端重复序列在嗜酸性粒细胞增多症的基因表达及核苷酸序列分析

The Expression and Sequencing of Human Endogenous Retrovirus Long Terminal Repeats in Eosinophilia Cells

探索人内源性逆转录病毒长末端重复序列(LTR)基因及表达与嗜酸性粒细胞增多症发生的关系。PCR法检测嗜酸性粒细胞增多症患者外周血中内源性逆转录病毒长末端重复序列基因,RT-PCR法检测内源性逆转录病毒基因表达。变性高效液相分析和序列测定LTR片段核苷酸序列,对不同株基因序列作同源性的比较分析。PCR结果显示:20例嗜酸性粒细胞增多症患者细胞中均获得内源性逆转录病毒长末端重复序列扩增产物,嗜酸性粒细胞增多症组中长末端重复序列基因有高的表达,而正常人表达为阴性。与HERV-K家族LTR基因相应区域核苷酸序列比较;嗜酸性粒细胞增多组长末端重复序列U3、R、U5区同源性分析有核苷酸的改变,与淋巴瘤对照比较没有大片段的缺失。人类基因组中普遍存在逆转录病毒长末端重复序列。正常人和嗜酸性粒细胞增多症患者中长末端重复序列有不同程度核苷酸碱基的变异,但是,二者比较,这种改变与嗜酸性粒细胞的增多没有明显的相关性。在嗜酸性粒细胞增多症患者中有高的基因表达而正常人中没有可检出的病毒基因的表达,嗜酸粒细胞的增多可能与逆转录病毒基因表达水平有关,其诱导嗜酸粒细胞增多的机制需进一步的研究。

To explore the relationship between gene expression of endogenous retrovirus long terminal repeat and eosinphilia, PCR was used to amplify the peripheral blood granulocyte DNA fragments in 20 cases of eosinophilia, 1 case of malignant lymphoma and 10 healthy persons as control. The expression of long terminal repeat （LTR） gene was detected by RT-PCR. Denatured high performance liquid chromatography （DHPLC） was used to array the long terminal repeat DNA fragments, and then the nucleotide sequence of LTR was analyzed by automatic sequence meter. The PCR results indicated that the LTR gene fragments were found in eosinophilia patients, RT-PCR revealed that LTR gene was higher expressed in 20 cases of eosinophilia patient while no expression was detected in healthy persons. To contrast the homogeneity of nucleotide sequence of eosinophilia on locus of U3、R、U5 to that of HERV-K strain, there showed nucleotide changes. These results demonstrated that human beings carry human endogenous retrovirus sequences as an integral part of their genomes. There may be a relationship between gene expression of human endogenous retrovirus and eosinophilia developing. The mechanism abode in inducing eosinophilia needs further investigation.