免疫接种后HBV感染者PreS2基因变异的情况  

Hepatitis B virus Pre S2 gene mutations in patients after hepatitis B vaccine immunization

作　　者：龙云[1] 杨莉[1] 曹向红[2] 李晓进[3] 

机构地区：[1]昆明医科大学附属延安医院老年病科,云南省昆明市650051 [2]昆明医科大学附属延安医院检验科,云南省昆明市650051 [3]昆明医科大学附属四院血液科,云南省昆明市650051

出　　处：《世界华人消化杂志》2015年第4期547-555,共9页World Chinese Journal of Digestology

基　　金：云南省科技厅应用基础研究自筹经费基金资助项目;No.2010ZC196~~

摘　　要：目的:本课题应用PCR和基因测序等技术,观察免疫接种后慢性乙型肝炎病毒(hepatitis Bvirus,H B V)感染者的PreS2基因变异情况,进而初步探讨乙型肝炎疫苗免疫失败与P r e S2基因变异之间的相互关系;为进一步探索新的HBV抗病毒基因治疗靶点提供理论基础.方法:收集昆明市延安医院和昆明市第三人民医院免疫接种后慢性HBV感染者的血液标本共47例,从血清标本中提取HBV DNA;用PCR法扩增Pre S2基因片段;扩增后的基因片段进行DNA序列分析.扩增出PCR产物的有35例,上海生工测序最终完成测序的有32例,其中男18例,女14例,年龄19-56岁,平均年龄32.75岁±10.22岁.32份样本的HBV Pre S2基因片段测序后,以Gen Bank数据库中登录号为NC_003977.1的HBV DNA全基因序列为参照,用Chromas软件分析测序图及BLASTN对测序结果进行比对分析后,采用SPSS11.5统计软件进行统计分析.结果:32例标本中Pre S2基因全部出现点突变(100%),其中2例出现缺失突变(6.3%),提示可能存在Ile、Tyr、Phe、Gly、Arg等氨基酸的缺失,32例标本均未发现Pre S2起始密码子ATG的变异,点突变共发生517次,Pre S2基因碱基突变有11种类型:G-A、A-G、T-C、A-T、G-T、C-T、G-C、A-C、C-G、C-A、T-A.11种不同类型的点突变在突变例数率及突变次数率方面均不全相同,其中A-T的突变例数较多,G-A的突变次数较多,差异有统计学意义(P<0.05).Pre S2基因不同部位点突变比较结果显示Pre S2基因前端、中段、末端点突变率不全相同,其中中段(nt45-99),即Pre S2基因的56-110位点突变率较高,前端突变率较低,差异有统计学意义(P<0.05).结论:Pre S2基因变异与免疫失败可能存在相关关系,这将为今后深入研究乙型肝炎疫苗免疫失败的发生机制并用于指导临床实践提供理论基础.同时,进一步确定Pre S2基因变异位点,并针对这些靶点设计相应的基因治疗方法,也可能成为今后乙型肝炎疫苗免疫研究�AIM： To observe hepatitis B virus（HBV） Pre S2 gene mutations in patients after hepatitis B vaccine immunization, and to discuss the relationship between hepatitis B vaccine immunization failure and Pre S2 gene mutations.METHODS： Forty-seven blood samples were collected from patients with chronic HBV infection after hepatitis B vaccine immunization who were treated at the Kunming Yan’an Hospital and the Third People’s Hospital. HBV DNA was extracted from serum samples, and Pre S2 gene fragments were amplified by PCR. The amplified gene fragments were analyzed by DNA sequencing. PCR products were obtained in 35 cases, and DNA sequencing was performed in 32 cases. There were 18 males and 14 females, and their age ranged from 19 to 56 years, with a mean value of 32.75 ± 10.22. The sequences of the amplifed Pre S2 gene fragment sequences were analyzed with Chromas software and compared with sequenced deposited in Genbank with BLASTN. The results were analyzed using SPSS11.5 software.RESULTS： The rate of Pre S2 point mutations was 100% in the 32 specimens, including two（6.3%） cases of deletion mutations（6.3%）, indicating that there maybe deletion of amino acids such as Ile, Tyr, Phe, Gly, and Arg. Variation in the pre S2 start codon（ATG） was not found in the 32 cases. There were a total of 517 point mutations, and pre S2 base mutations had 11 types, namely, G-A, A-G, T-C, A-T, G-T, C-T, G-C, A-C, C-G, C-A, and T-A. The rate of different types of point mutations and the number of cases withdifferent types of point mutations varied, with the rate of G-A mutation being highest and the greatest number of cases having the A-T mutation（P 〈 0.05）. The rate of point mutations in different regions of the Pre S2 gene also varied, with the middle region（nt 45-99） having a higher mutation rate and the upstream region having a lower mutation rate（P 〈 0.05）.CONCLUSION： There may be a correlation between Pre S2 gene mutations and immunization failure, which will provide a theoretical basis

关 键 词：乙型肝炎疫苗 免疫接种 乙型肝炎病毒感染 Pre S2基因变异 

分 类 号：R512.62[医药卫生—内科学]