Zampino R, Pickering J, Iqbal M, Gaud U, Thomas H C, Karayiannis P
Department of Medicine A, Imperial College of Science, Technology and Medicine, London, UK.
J Viral Hepat. 1999 May;6(3):209-18. doi: 10.1046/j.1365-2893.1999.00162.x.
Persistent infection with hepatitis G virus (HGV) or GB virus-C (GBV-C) is common and may last for years. In addition, the principal site of virus replication remains undefined. Sequencing studies of E2 in four patients showed that a hypervariable region equivalent to that of hepatitis C virus (HCV) was absent and that viral quasispecies were less frequent than in HCV infection, particularly with respect to amino acid variation. Recurrence of viraemia following interferon treatment did not result in the emergence of new quasispecies. Virus persistence therefore does not appear to be related to immune escape by strains bearing a hypervariable E2 region. We also investigated whether virus replication occurred in peripheral blood mononuclear cells. The positive-RNA strand of the virus, but no negative strand, was detected in both serum and lymphocytes. The lymphocytes harbouring the virus were CD4 and CD19 positive. Direct sequencing and cloning of amplicons from the region of the non-structural 3 (NS3) protein showed that the nucleotide sequences in lymphocytes were different from those in serum and did not represent any of the minor serum quasispecies. Although evidence of replication in lymphocytes has not been forthcoming, the differences in sequences between serum and lymphocytes suggest that circulating virus originates from a non-hepatic site, other than lymphocytes.
庚型肝炎病毒（HGV）或GB病毒C型（GBV-C）的持续感染很常见，可能会持续数年。此外，病毒复制的主要部位仍不明确。对4例患者的E2进行测序研究表明，不存在与丙型肝炎病毒（HCV）等效的高变区，并且病毒准种比HCV感染时少见，尤其是在氨基酸变异方面。干扰素治疗后病毒血症复发并未导致新的准种出现。因此，病毒持续存在似乎与带有高变E2区的毒株的免疫逃逸无关。我们还研究了病毒是否在外周血单核细胞中复制。在血清和淋巴细胞中均检测到病毒的正链RNA，但未检测到负链。携带病毒的淋巴细胞CD4和CD19呈阳性。对非结构3（NS3）蛋白区域的扩增子进行直接测序和克隆表明，淋巴细胞中的核苷酸序列与血清中的不同，并不代表任何次要的血清准种。尽管尚未有淋巴细胞中复制的证据，但血清和淋巴细胞之间序列的差异表明，循环病毒起源于淋巴细胞以外的非肝脏部位。
