Durante Mangoni Emanuele, Forton Daniel M, Ruggiero Giuseppe, Karayiannis Peter
Department of Medicine A, Faculty of Medicine, Imperial College of Science, Technology and Medicine, St Mary's Campus-QEQMW, London, United Kingdom.
J Med Virol. 2003 May;70(1):62-73. doi: 10.1002/jmv.10351.
To determine the pattern and significance of the HCV genetic heterogeneity before and during treatment with recombinant-2b or lymphoblastoid alpha-interferon, hypervariable region 1 (HVR-1) and NS5A quasispecies were characterised by cloning and sequencing in 12 HCV-1b-infected subjects. Patients were either responder-relapsers or non-responders to treatment. Extensive amino acid sequence analysis was applied to reveal the significance of HCV variation at key sites within HVR-1 and NS5A regions. Genetic complexity, genetic diversity, and the non-synonymous to synonymous substitution ratios of HVR-1 quasispecies decreased during treatment in responder-relapser patients only, and more markedly so following lymphoblastoid alpha-interferon. In non-responders, the HVR-1 quasispecies broadened. Amino acids G406 and Q409, which represent a major viral epitope, were highly conserved throughout treatment. Responder-relapser patients had a higher mutation frequency in NS5A than non-responders. Lymphoblastoid alpha-interferon promoted the selection of intermediate Interferon Sensitivity Determining Region (ISDR) sequences, whereas recombinant-2b alpha-interferon favoured maintenance or selection of conserved ISDR sequences. Variability upstream of the ISDR was associated with treatment response, but the amino acid substitutions conferring higher replicative ability to in vitro HCV replicons were absent in in vivo isolates. In conclusion, the pattern of HVR-1 quasispecies evolution correlates with the clinical response, and the conservation of specific amino acids may be useful for immune targeting in vivo. In responder-relapser patients, the initial HVR-1 evolution resembles that found in sustained responders. Variability within the entire NS5A, as opposed to a single region (ISDR), may have a role in influencing alpha-interferon treatment outcome. A differential effect of different alpha-interferon preparations on HCV quasispecies kinetics may exist.
为确定重组-2b或淋巴母细胞样α干扰素治疗前及治疗期间丙型肝炎病毒（HCV）基因异质性的模式及意义，对12例HCV-1b感染患者的高变区1（HVR-1）和NS5A准种进行了克隆和测序分析。患者分为应答-复发者或无应答者。应用广泛的氨基酸序列分析来揭示HVR-1和NS5A区域关键位点HCV变异的意义。仅在应答-复发患者治疗期间，HVR-1准种的基因复杂性、基因多样性及非同义与同义替换率降低，且在接受淋巴母细胞样α干扰素治疗后更明显。在无应答者中，HVR-1准种谱变宽。代表主要病毒表位的氨基酸G406和Q409在整个治疗过程中高度保守。应答-复发患者NS5A的突变频率高于无应答者。淋巴母细胞样α干扰素促进了中间干扰素敏感性决定区（ISDR）序列的选择，而重组-2bα干扰素则有利于保守ISDR序列的维持或选择。ISDR上游的变异性与治疗反应相关，但体内分离株中不存在赋予体外HCV复制子更高复制能力的氨基酸替换。总之，HVR-1准种进化模式与临床反应相关，特定氨基酸的保守性可能有助于体内免疫靶向。在应答-复发患者中，初始HVR-1进化类似于持续应答者。与单个区域（ISDR）不同，整个NS5A内的变异性可能在影响α干扰素治疗结果中起作用。不同α干扰素制剂对HCV准种动力学可能存在差异效应。
