Wang G T, Tian G S, Zhang G Q
Department of Infectious Diseases, First Teaching Hospital, Beijing Medical University.
Zhonghua Yi Xue Za Zhi. 1994 Jun;74(6):355-7, 391.
We amplificated a HBV DNA fragment coding the major HBsAg from a chronic HBsAg carrier's serum with high titer of HBsAg and anti-HBs using polymerase chain reaction (PCR). The direct sequencing of PCR products revealed a single mutation from adnosine to guanosine at the nucleotide position 532 of HBV DNA of the escape mutant. This mutation might result in an amino acid substitution from threonine to alanime at the amino acid position 126 of HBsAg. Since this amino acid is located in the first loop of the "a" determinant of HBsAg, the mutation might result in an alteration of the structural antigenicity of the "a" determinant and induce escape mutant of HBV.
我们使用聚合酶链反应（PCR）从一名慢性乙肝表面抗原（HBsAg）携带者的血清中扩增出编码主要HBsAg的乙肝病毒（HBV）DNA片段，该携带者血清中HBsAg和抗-HBs滴度较高。对PCR产物进行直接测序显示，逃逸突变体的HBV DNA在核苷酸位置532处发生了从腺苷到鸟苷的单突变。这种突变可能导致HBsAg氨基酸位置126处的苏氨酸被丙氨酸取代。由于该氨基酸位于HBsAg“a”决定簇的第一个环中，该突变可能导致“a”决定簇的结构抗原性改变，并诱导HBV逃逸突变体产生。
