摘要
目的分析乙型肝炎患者体内ＨＢＶＳ基因的变异情况及对乙型肝炎的免疫预防的现实意义。方法采用巢式聚合酶链反应（ＰＣＲ）、Ｍ１３噬菌体克隆和核苷酸序列分析方法对一例乙型肝炎免疫失败儿童患者体内ＨＢＶＳ基因序列进行分析。结果发现该患儿所感染ＨＢＶ的Ｓ基因上有一个重要的点突变，即第５５１位碱基由野生型的Ａ变为Ｇ。该突变使乙型肝炎表面抗原（ＨＢｓＡｇ）１３３位氨基酸由甲硫（ＡＴＧ）变为缬（ＧＴＧ）。这一氨基酸替换恰恰发生在ＨＢｓＡｇ中和性α抗原决定簇区段（ａａ１２４～ａａ１４７）内。结论鉴于该患者接种乙型肝炎疫苗，其血清呈抗－ＨＢｓ阳性和ＨＢｓＡｇ阴性。
Objective Hepatitis B surface antigen (HBsAg) mutant of hepatitis B virus (HBV) is one of the most important factors that result in immune escape and cause failure of immunization. To study the mutations occurring in the S gene of HBV in patients and to provide theoretical data for prevention of hepatitis B infection in China. Methods A methodology combined with polymerase chain reaction (PCR) amplifying, M13 bacteriophage cloning and nucleotide sequencing was used to analyse the sera of the pediatric patient who was hepatitis B immune failure. Results It was found that there was an important point mutation at nt 551 of the HBV genome. The usual A was substituted with a G. The mutation would change the HBsAg at amino acid position of aa133, leading to a substitution of methionine to valine. The amino acid site was within the region constructing the α determinant of HBsAg. Conclusions According to the fact that the patient had been immunized with hepatitis B vaccine and that the serum was anti HBs positive and HBsAg negative, the HBV is considered to be a new vaccine induced immune escape mutant different from the known ones.
出处
《中华微生物学和免疫学杂志》
CAS
CSCD
北大核心
1999年第4期326-329,共4页
Chinese Journal of Microbiology and Immunology
基金
江苏省自然科学基金
关键词
乙型肝炎病毒
变异株
免疫逃避株
基因序列
Hepatitis B virus Hepatitis B surface antigen Mutant Immune escape Gene,viral Nacleotide sequences
