苏南地区乙型肝炎病毒S基因序列的多态性研究

目的:探讨乙型肝炎病毒(HBV)S基因序列的多态性,为研究HBV-S基因变异提供参照指导。方法:采用聚合酶链反应技术对81例乙型肝炎表面抗原阳性的HBV感染者的S基因进行扩增,再对扩增产物进行DNA测序,将结果与标准序列进行比较分析。结果:81价标本中,测得adr型38例,adw型43例,未发现有ayr及ayw型。38例adr型中氨基酸第121～125位点(AA121～125)、AA127～130、AA132、AA135～160高度保守,而AA126为异亮氨酸(Ile),也可为苏氨酸(Thr)或丝氨酸(Ser);AA131多为Thr,少数为天冬酰胺(Asn),1例为脯氨酸(Pro),AA133多为蛋氨酸,少数为Thr;AA134为苯丙氨酸,仅1例为精氨酸。43例adw型中,AA131均为Thr,而非Asn;AA126为Thr,也可为丙氨酸(Ala),少数为Ser;AA127多为Pro,少数为Thr;AA123为Thr,少数为Ala或Ile;AA141多为赖氨酸,少数为谷氨酸;AA133、AA140分别为Thr、Ile各1例。其他位点则高度保守。结论:HBV亚型分布具有地域性,苏南地区多以adw和adr型为主。HBV-S基因(“a”决定簇)序列存在多态性,其中adw亚型略为明显。

Surface Gene Variability of Hepatitis B Virus in Sunan Area

Objective: To understand the surface (S) gene variability of hepatitis B virus (HBV) in Sunan area. Methods: The S genes from 81 HBsAg-positive patients in Sunan area were amplified and sequenced directly for its molecular characterization. Then these sepuences were compared with the consensus sequences. Results: In all 81 patients, 38 patients belong to subtype adr and 43 patients to subtype adw. In 38 patients for subtype adr, amino acid residues were found to be highly conservative nothing , except at four positions . These were at positions 126 (Ile or Thr or Ser) , 131 (Thr or Asn or Pro) , 133 (Met or Thr), 134 (Phe or Arg). In 43 patients for subtype ad-w, amino acid residues at the positions 121, 124, 125, 128-130, 132, 134-139 and 142-160 were highly conservative. But amino acid residues at the position 131 were all Thr, not Asn. Amino acid residues at the positions 123, 126, 133, 140 and 141 were also substituted by other amino acid. Conclusion: The different HBV subtypes have different patterns of geographic distribution. Subtypes ad-w and adr are the major types in Sunan area. S gene sepuence of HBV has its variability, especially in subtype adw.