Department of Gastroenterology, Hepatology and Endocrinology, Medical School Hannover, Germany; German Centre for Infection Research (DZIF), Partner Site Hannover-Braunschweig, Germany.
Department of Gastroenterology, Hepatology and Endocrinology, Medical School Hannover, Germany; German Centre for Infection Research (DZIF), Partner Site Hannover-Braunschweig, Germany; Institute for Molecular Biology, Medical School Hannover, Hannover, Germany.
Antiviral Res. 2014 Jan;101:37-44. doi: 10.1016/j.antiviral.2013.10.018. Epub 2013 Nov 7.
End stage liver disease caused by chronic infection with the hepatitis C virus (HCV) is a leading indication for liver transplantation, yet outcomes are poor since the liver graft is rapidly re-infected by HCV. Antibodies against the essential HCV receptor CD81 have been shown to inhibit HCV cell entry in vitro and in vivo and may represent an attractive treatment option. However, several CD81 variants exist at low levels in human populations. We aimed to investigate to what extent these variants function as HCV receptors and would be amenable to therapeutic interventions with CD81 antibodies. We used lentiviral expression to introduce wildtype or variant CD81 in the CD81(low) Lunet N4 cell line. HCV replication cycle steps and neutralization by CD81 antibodies were then investigated using full length HCV reporter viruses (HCVcc) as well as HCV pseudoparticles (HCVpp). We found that all tested CD81 variants support cell entry by HCVpp and HCVcc with an efficiency similar to wildtype CD81. Other replication cycle steps, namely intracellular RNA replication and release of new particles, were also unaffected by the presence of CD81 variants. Importantly, four neutralizing antibodies directed against the CD81 LEL (5A6, JS81, 1D6 and 1.3.3.22) retained their ability to inhibit HCV infection when wildtype CD81 on target cells was replaced with any of the CD81 variants. These data indicate that CD81 variants that exist in the human population are fully functional as HCV receptors and their presence would not diminish the efficacy of therapeutic regimens that include CD81-antibodies.
慢性丙型肝炎病毒(HCV)感染导致的终末期肝病是肝移植的主要指征,但由于肝移植物迅速被 HCV 再次感染,其预后仍较差。已证明针对 HCV 必需受体 CD81 的抗体可在体外和体内抑制 HCV 细胞进入,这可能是一种有吸引力的治疗选择。然而,人类群体中低水平存在几种 CD81 变体。我们旨在研究这些变体在多大程度上作为 HCV 受体发挥作用,并可通过 CD81 抗体进行治疗干预。我们使用慢病毒表达在 CD81(low) Lunet N4 细胞系中引入野生型或变体 CD81。然后使用全长 HCV 报告病毒 (HCVcc) 和 HCV 假病毒 (HCVpp) 研究 HCV 复制周期步骤和 CD81 抗体的中和作用。我们发现所有测试的 CD81 变体都能以类似于野生型 CD81 的效率支持 HCVpp 和 HCVcc 的细胞进入。其他复制周期步骤,即细胞内 RNA 复制和新颗粒的释放,也不受 CD81 变体的影响。重要的是,针对 CD81 LEL(5A6、JS81、1D6 和 1.3.3.22)的四种中和抗体在靶细胞上的野生型 CD81 被任何一种 CD81 变体取代时,仍保留抑制 HCV 感染的能力。这些数据表明,人类群体中存在的 CD81 变体作为 HCV 受体完全有效,其存在不会降低包括 CD81 抗体在内的治疗方案的疗效。